Antisynthetase syndrome: Difference between revisions

Jump to navigation Jump to search
(→‎Physical Examination: Added content)
 
(42 intermediate revisions by the same user not shown)
Line 7: Line 7:
==Overview==
==Overview==


Antisynthetase syndrome, an uncommon autoimmune disorder, is characterized by antibodies against '''aminoacyl-transfer ribonucleic acid synthetases''', with various combinations of three cardinal manifestations of '''interstitial lung disease (ILD)''', '''polymyositis''', and '''arthritis'''.  Other features of antisynthetase syndrome may include pyrexia of unknown origin, mechanic's hand (hyperkeratotic skin changes along the lateral surfaces of the digits) and Raynaud's phenomenon. <ref name="pmid26933302">{{cite journal| author=Maturu VN, Lakshman A, Bal A, Dhir V, Sharma A, Garg M | display-authors=etal| title=Antisynthetase syndrome: An under-recognized cause of interstitial lung disease. | journal=Lung India | year= 2016 | volume= 33 | issue= 1 | pages= 20-6 | pmid=26933302 | doi=10.4103/0970-2113.173055 | pmc=4748659 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=26933302  }} </ref> <ref name="pmid32675964">{{cite journal| author=Robinson D, Scholz B| title=The antisynthetase syndrome. | journal=Proc (Bayl Univ Med Cent) | year= 2020 | volume= 33 | issue= 3 | pages= 401-403 | pmid=32675964 | doi=10.1080/08998280.2020.1764818 | pmc=7340408 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=32675964  }} </ref>
Antisynthetase syndrome, an uncommon autoimmune disorder, is characterized by antibodies against '''aminoacyl-transfer ribonucleic acid synthetases''', with various combinations of three cardinal manifestations of '''[[interstitial lung disease]] (ILD)''', '''[[Polymyositis and dermatomyositis|polymyositis]]''', and '''[[arthritis]]'''.  Other features of antisynthetase syndrome may include [[Fever of unknown origin|pyrexia of unknown origin]], mechanic's hand (hyperkeratotic skin changes along the lateral surfaces of the digits) and [[Raynaud's phenomenon]].<ref name="pmid26933302">{{cite journal| author=Maturu VN, Lakshman A, Bal A, Dhir V, Sharma A, Garg M | display-authors=etal| title=Antisynthetase syndrome: An under-recognized cause of interstitial lung disease. | journal=Lung India | year= 2016 | volume= 33 | issue= 1 | pages= 20-6 | pmid=26933302 | doi=10.4103/0970-2113.173055 | pmc=4748659 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=26933302  }} </ref><ref name="pmid32675964">{{cite journal| author=Robinson D, Scholz B| title=The antisynthetase syndrome. | journal=Proc (Bayl Univ Med Cent) | year= 2020 | volume= 33 | issue= 3 | pages= 401-403 | pmid=32675964 | doi=10.1080/08998280.2020.1764818 | pmc=7340408 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=32675964  }} </ref>


Till date, nine different anti-aminoacyl t-RNA synthetase (ARS) antibodies have been identified to play a role in the development of antisynthetase syndrome. <ref name="pmid26933302">{{cite journal| author=Maturu VN, Lakshman A, Bal A, Dhir V, Sharma A, Garg M | display-authors=etal| title=Antisynthetase syndrome: An under-recognized cause of interstitial lung disease. | journal=Lung India | year= 2016 | volume= 33 | issue= 1 | pages= 20-6 | pmid=26933302 | doi=10.4103/0970-2113.173055 | pmc=4748659 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=26933302  }} </ref>
So far, nine different anti-aminoacyl t-RNA synthetase (ARS) antibodies have been identified to play a role in the development of antisynthetase syndrome.<ref name="pmid26933302">{{cite journal| author=Maturu VN, Lakshman A, Bal A, Dhir V, Sharma A, Garg M | display-authors=etal| title=Antisynthetase syndrome: An under-recognized cause of interstitial lung disease. | journal=Lung India | year= 2016 | volume= 33 | issue= 1 | pages= 20-6 | pmid=26933302 | doi=10.4103/0970-2113.173055 | pmc=4748659 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=26933302  }} </ref>
==Historical Perspective==
==Historical Perspective==


In 1990, '''Marguerie et al''' and coworkers first described antisynthetase syndrome as a triad of polymyositis, interstitial lung disease (ILD), and the presence of myositis-specific autoantibodies to aminoacyl-transfer ribonucleic acid synthetases. <ref name="pmid27134916">{{cite journal| author=Devi HG, Pasha MM, Padmaja MS, Halappa S| title=Antisynthetase Syndrome: A Rare Cause for ILD. | journal=J Clin Diagn Res | year= 2016 | volume= 10 | issue= 3 | pages= OD08-9 | pmid=27134916 | doi=10.7860/JCDR/2016/16872.7361 | pmc=4843302 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27134916  }} </ref>
In 1990, '''Marguerie et al''' and coworkers first described antisynthetase syndrome as a triad of [[Polymyositis and dermatomyositis|polymyositis]], [[interstitial lung disease]] (ILD), and the presence of myositis-specific autoantibodies to aminoacyl-transfer ribonucleic acid synthetases.<ref name="pmid27134916">{{cite journal| author=Devi HG, Pasha MM, Padmaja MS, Halappa S| title=Antisynthetase Syndrome: A Rare Cause for ILD. | journal=J Clin Diagn Res | year= 2016 | volume= 10 | issue= 3 | pages= OD08-9 | pmid=27134916 | doi=10.7860/JCDR/2016/16872.7361 | pmc=4843302 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27134916  }} </ref>
==Classification==
==Classification==


   
Antisynthetase syndrome may be classified in accordance with the type of antibodies that are present. Some of the identified antibodies include Anti-Jo-1, Anti PL-12, Anti-Pl-7, Anti-OJ, Anti-KS, Anti-EJ, Anti-Ha, and Anti-Zo.<ref name="pmid27594777">{{cite journal| author=Witt LJ, Curran JJ, Strek ME| title=The Diagnosis and Treatment of Antisynthetase Syndrome. | journal=Clin Pulm Med | year= 2016 | volume= 23 | issue= 5 | pages= 218-226 | pmid=27594777 | doi=10.1097/CPM.0000000000000171 | pmc=5006392 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27594777  }} </ref>
 
==Pathophysiology==
==Pathophysiology==


   
Antisynthetase syndrome is characterized by the presence of myositis-specific anti-synthetase antibodies.<ref name="pmid28461832">{{cite journal| author=Cojocaru M, Cojocaru IM, Chicos B| title=New Insights into Antisynthetase Syndrome. | journal=Maedica (Bucur) | year= 2016 | volume= 11 | issue= 2 | pages= 130-135 | pmid=28461832 | doi= | pmc=5394574 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=28461832 }} </ref>
{| class="wikitable"
|+
!Anti-ARS antibodies
!Antigen
!Clinical features
|-
|Anti-Jo-1
|Histidyl-tRNA synthetase
|
*Antisynthetase syndrome
**Arthritis
**Interstitial lung disease
**Fever
**Mechanic's hands
**Raynaud's phenomenon
*Flare up in spring
*Moderate response to treatment
*Poor prognosis
*Associated with epstein-Barr virus (EBV), adenovirus, and influenza infection
|-
|Anti PL-12
|Alanyl-tRNA synthetase, Alanyl-tRNA
|
*Fever, Raynaud's phenomenon, high frequency of ILD
*Epstein-Barr virus (EBV), adenovirus, and influenza infection
|-
|Anti-PL-7
|Glycyl-tRNA synthetase
|
*Myositis, mechanic's hands, [[Dermatomyositis|Gottron's papules]], arthritis
|-
|Anti-OJ
|Isoleucyl-tRNA synthetase
|
|-
|Anti-KS
|Asparaginyl-tRNA synthetase
|
|-
|Anti-EJ
|Glycyl-tRNA synthetase
|
*
|-
|Anti-Ha
|Tyrosyl-tRNA synthetase
|
|-
|Anti-Zo
|Phenylalanyl-tRNA synthetase
|
|}
 
==Causes==
==Causes==


The exact cause of antisynthetase syndrome is '''not fully understood.'''
==Differentiating Antisynthetase syndrome from other Diseases==
==Differentiating Antisynthetase syndrome from other Diseases==
Antisynthetase syndrome may be misdiagnosed as idiopathic interstitial lung disease (ILD) or inflammatory myopathy, as a result of rarity, lack of awareness of the disease, as well as due to the lack of available testing for anti-ARS antibodies. <ref name="pmid26933302">{{cite journal| author=Maturu VN, Lakshman A, Bal A, Dhir V, Sharma A, Garg M | display-authors=etal| title=Antisynthetase syndrome: An under-recognized cause of interstitial lung disease. | journal=Lung India | year= 2016 | volume= 33 | issue= 1 | pages= 20-6 | pmid=26933302 | doi=10.4103/0970-2113.173055 | pmc=4748659 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=26933302  }} </ref>
Antisynthetase syndrome may be misdiagnosed as idiopathic interstitial lung disease (ILD) or inflammatory myopathy, as a result of rarity, lack of awareness of the disease, as well as due to the lack of available testing for anti-ARS antibodies.<ref name="pmid26933302">{{cite journal| author=Maturu VN, Lakshman A, Bal A, Dhir V, Sharma A, Garg M | display-authors=etal| title=Antisynthetase syndrome: An under-recognized cause of interstitial lung disease. | journal=Lung India | year= 2016 | volume= 33 | issue= 1 | pages= 20-6 | pmid=26933302 | doi=10.4103/0970-2113.173055 | pmc=4748659 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=26933302  }} </ref>


==Epidemiology and Demographics==
==Epidemiology and Demographics==
   
   
===Age===
===Age===


   
The mean age at onset of antisynthetase syndrome in adults varies from 43 to 60 years.<ref name="pmid28461832">{{cite journal| author=Cojocaru M, Cojocaru IM, Chicos B| title=New Insights into Antisynthetase Syndrome. | journal=Maedica (Bucur) | year= 2016 | volume= 11 | issue= 2 | pages= 130-135 | pmid=28461832 | doi= | pmc=5394574 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=28461832 }} </ref>
 
===Gender===
===Gender===


   
Antisynthetase syndrome is 2–3 times more common in women than in men.<ref name="pmid28461832">{{cite journal| author=Cojocaru M, Cojocaru IM, Chicos B| title=New Insights into Antisynthetase Syndrome. | journal=Maedica (Bucur) | year= 2016 | volume= 11 | issue= 2 | pages= 130-135 | pmid=28461832 | doi= | pmc=5394574 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=28461832 }} </ref>
 
===Race===
===Race===
Antisynthetase syndrome usually affects individuals of the black American ethnicity race.<ref name="pmid26933302">{{cite journal| author=Maturu VN, Lakshman A, Bal A, Dhir V, Sharma A, Garg M | display-authors=etal| title=Antisynthetase syndrome: An under-recognized cause of interstitial lung disease. | journal=Lung India | year= 2016 | volume= 33 | issue= 1 | pages= 20-6 | pmid=26933302 | doi=10.4103/0970-2113.173055 | pmc=4748659 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=26933302  }} </ref>


==Risk Factors==
==Risk Factors==


   
There are several environmental exposures associated with antisynthetase syndrome. These include ultraviolet radiation, stress, muscle overexertion, collage implants, infections such as retroviruses and streptococci bacteria, and certain drugs and chemicals.<ref name=“NIH”>{{cite web|url= https://www.niehs.nih.gov/research/clinical/bethesda/participants/studies/erftas/index.cfm}} </ref>
 
==Natural History, Complications and Prognosis==
==Natural History, Complications and Prognosis==


   
 
Main causes of death in antisynthetase syndrome is '''anti-Jo-1'''-positive patients included '''interstitial lung disease''', '''neoplasm''', '''infectious diseases including pneumonia''', '''severe myositis''' and '''cardiovascular disorders.
 
The cumulative ten-year survival rate in patients with antisynthetase syndrome was estimated as 76.8%.<ref name=“Elsevier”>{{cite web|url= https://www.sciencedirect.com/science/article/abs/pii/S0049017220303085}} </ref>
{| class="wikitable"
|+
!Poor prognostic factors associated with Antisynthetase syndrome <ref name="pmid26933302">{{cite journal| author=Maturu VN, Lakshman A, Bal A, Dhir V, Sharma A, Garg M | display-authors=etal| title=Antisynthetase syndrome: An under-recognized cause of interstitial lung disease. | journal=Lung India | year= 2016 | volume= 33 | issue= 1 | pages= 20-6 | pmid=26933302 | doi=10.4103/0970-2113.173055 | pmc=4748659 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=26933302 }} </ref>
|-
|1) Anti-Ro 52
|-
|2) Rapidly progressive interstitial lung disease
|-
|3) Pulmonary hypertension
|-
|4) Malignancy
|-
|5) Male sex
|-
|6) Reduced diffusing capacity of lung for carbon monoxide
|-
|7) Elevated serum ferritin
|-
|8) Black American ethnicity
|}
 
==Diagnosis==
==Diagnosis==
===Diagnostic Criteria===
===Diagnostic Criteria===
In 2010, '''Connors ''et al''''' proposed a formal criteria for the diagnosis of antisynthetase syndrome.  This criteria proposed that all patients must have a presence of an anti-aminoacyl tRNA synthetase antibody in addition to one or more of the following clinical features: mechanic’s hands, Raynaud’s phenomenon, myositis, ILD, arthritis, and/or unexplained fever.     
In 2010, '''Connors ''et al''''' proposed a formal criteria for the diagnosis of antisynthetase syndrome.  This criteria proposed that all patients must have a presence of an anti-aminoacyl tRNA synthetase antibody in addition to one or more of the following clinical features: mechanic’s hands, [[Raynaud’s phenomenon]], [[myositis]], [[interstitial lung disease]] (ILD), [[arthritis]], and/or unexplained fever.     


In 2011, '''Solomon ''et al''''' proposed alternative criteria, which is more strict.  This criteria requires the presence of anti-aminoacyl tRNA synthetase antibody plus '''two major or one major and two minor criteria.'''   
In 2011, '''Solomon ''et al''''' proposed alternative criteria, which is more strict.  This criteria requires the presence of anti-aminoacyl tRNA synthetase antibody plus '''two major or one major and two minor criteria.'''   


'''<u>Major criteria includes</u>:''' Interstitial Lung Disease (not attributable to another cause), and Polymyositis or dermatomyositis.
'''<u>Major criteria includes</u>:''' Interstitial Lung Disease (not attributable to another cause), and [[Polymyositis]] or [[dermatomyositis]].


'''<u>Minor criteria includes</u>:''' arthritis, Raynaud’s phenomenon, and mechanic’s hands. <ref name="pmid27594777">{{cite journal| author=Witt LJ, Curran JJ, Strek ME| title=The Diagnosis and Treatment of Antisynthetase Syndrome. | journal=Clin Pulm Med | year= 2016 | volume= 23 | issue= 5 | pages= 218-226 | pmid=27594777 | doi=10.1097/CPM.0000000000000171 | pmc=5006392 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27594777  }} </ref>
'''<u>Minor criteria includes</u>:''' arthritis, Raynaud’s phenomenon, and mechanic’s hands.<ref name="pmid27594777">{{cite journal| author=Witt LJ, Curran JJ, Strek ME| title=The Diagnosis and Treatment of Antisynthetase Syndrome. | journal=Clin Pulm Med | year= 2016 | volume= 23 | issue= 5 | pages= 218-226 | pmid=27594777 | doi=10.1097/CPM.0000000000000171 | pmc=5006392 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27594777  }} </ref>


{| class="wikitable"
{| class="wikitable"
Line 95: Line 176:


===Symptoms===
===Symptoms===
Symptoms seen at the diagnosis of antisynthetase syndrome include the following:<ref name="pmid26933302">{{cite journal| author=Maturu VN, Lakshman A, Bal A, Dhir V, Sharma A, Garg M | display-authors=etal| title=Antisynthetase syndrome: An under-recognized cause of interstitial lung disease. | journal=Lung India | year= 2016 | volume= 33 | issue= 1 | pages= 20-6 | pmid=26933302 | doi=10.4103/0970-2113.173055 | pmc=4748659 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=26933302  }} </ref>
{| class="wikitable"
|+
!Symptoms of antisynthetase syndrome
|-
|1) Fever
|-
|2) Weight loss
|-
|3) Anorexia
|-
|4) Dyspnea
|-
|5) Dry cough
|-
|6) Arthralgia
|-
|7) Joint swelling
|-
|8) Proximal muscle weakness
|-
|9) Myalgia
|-
|10) Raynaud's phenomenon
|}


===Physical Examination===
===Physical Examination===


Physical exam findings play an important role in diagnosis of antisynthetase syndrome as they may be classified into major and minor criteria.  Clinical findings on examination includes:
Physical exam findings play an important role in diagnosis of antisynthetase syndrome as the findings may be classified into major and minor criteria.  Clinical findings on examination includes:<ref name="pmid26933302">{{cite journal| author=Maturu VN, Lakshman A, Bal A, Dhir V, Sharma A, Garg M | display-authors=etal| title=Antisynthetase syndrome: An under-recognized cause of interstitial lung disease. | journal=Lung India | year= 2016 | volume= 33 | issue= 1 | pages= 20-6 | pmid=26933302 | doi=10.4103/0970-2113.173055 | pmc=4748659 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=26933302  }} </ref>
{| class="wikitable"
|+
!Clinical findings
|-
|1) [[Polyarthritis]]
|-
|2) Mechanics hands (hyperkeratotic lesions on the radial and palmar aspects of the hands and fingers with fissuring and scaling of the skin)
|-
|3) [[Calcinosis cutis]]
|-
|4) [[Malar rash]]
|-
|5) Cutaneous ulcers
|-
|6) Crackles on chest auscultation
|}


#  Polyarthritis
===Laboratory Findings===
#  Mechanics hands
#  Calcinosis cutis
#  Malar rash - presence of characteristic hyperkeratotic lesions on the radial and palmar aspects of the hands and fingers with fissuring and scaling of the skin.
#  Cutaneous ulcers
#  Crackles on chest auscultation  <br />


===Laboratory Findings===
Suggested lab findings based on the systems are as follows:<ref name="pmid35382516">{{cite journal| author=Huang K, Aggarwal R| title=Antisynthetase syndrome: A distinct disease spectrum. | journal=J Scleroderma Relat Disord | year= 2020 | volume= 5 | issue= 3 | pages= 178-191 | pmid=35382516 | doi=10.1177/2397198320902667 | pmc=8922626 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=35382516  }} </ref>
{| class="wikitable"
|+
!Domains
!Suggested investigations
|-
|Bloodwork
|CBC, creatinine, CK, LDH, aldolase, AST, ALT, ANA, ENA, RF, ACPA, MSAs and MAAs
|-
|Muscle
|MMT8 and consider: MRI pelvic/thighs and shoulder girdle muscles, EMG, and Muscle biopsy
|-
|Joint
|TJC, SJC
|-
|Lung
|CXR, HRCT, PFT, 6MWT, echocardiogram for PAH if isolated decrease in DLCO,
Referral to respirology for co-management if ILD
|-
|Skin
|General assessment and consider documentation with CDASI
Referral to dermatologists
|-
|Raynaud’s phenomenon
|Conservative and pharmacological management review
|-
|Overall disease activity and damage assessment
|Consider MDAAT, MDI
|-
| colspan="2" |TJC: tender joint count; SJC: swollen joint count; PAH: pulmonary artery hypertension; MMT8: manual muscle testing 8
MRI: magnetic resonance imaging; EMG: electromyography; CXR: chest X-ray; HRCT: high-resolution computed tomography; PFT: pulmonary function test; 6MWT: 6-minute walk test;
 
DLCO: diffusing capacity of lung for carbon monoxide; ILD: interstitial lung disease; CDASI: cutaneous dermatomyositis disease area and severity index; CBC: complete blood count;
 
CK: creatine kinase; LDH: lactate dehydrogenase; AST: aspartate aminotransferase; ALT: alanine transaminase; ANA: antinuclear antibody; ENA: extractable nuclear antigens;
 
RF: rheumatoid factor; ACPA: anti-citrullinated protein antibody; MSA: myositis-specific antibody; MAA: myositis-associated antibody; MDAAT: Myositis Disease Activity Assessment Tool; MDI: myositis damage index
|}


===Imaging Findings===
===Imaging Findings===


As antisynthetase syndrome is associated with interstitial lung disease, and therefore, high resolution computed tomography (HRCT) plays an important role in its work up, as well as to monitor the disease activity.  Radiographic features seen on HRCT at the ''initial diagnosis'' include '''traction bronchiectasis''', '''ground glass opacities''' and '''reticulation'''. <ref name="pmid27594777">{{cite journal| author=Witt LJ, Curran JJ, Strek ME| title=The Diagnosis and Treatment of Antisynthetase Syndrome. | journal=Clin Pulm Med | year= 2016 | volume= 23 | issue= 5 | pages= 218-226 | pmid=27594777 | doi=10.1097/CPM.0000000000000171 | pmc=5006392 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27594777  }} </ref>
As antisynthetase syndrome is associated with interstitial lung disease, and therefore, high resolution computed tomography (HRCT) plays an important role in its work up, as well as to monitor the disease activity.  Radiographic features seen on HRCT at the ''initial diagnosis'' include '''traction bronchiectasis''', '''ground glass opacities''' and '''reticulation'''.<ref name="pmid27594777">{{cite journal| author=Witt LJ, Curran JJ, Strek ME| title=The Diagnosis and Treatment of Antisynthetase Syndrome. | journal=Clin Pulm Med | year= 2016 | volume= 23 | issue= 5 | pages= 218-226 | pmid=27594777 | doi=10.1097/CPM.0000000000000171 | pmc=5006392 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27594777  }} </ref>
[[File:Usual-interstitial-pneumonia-uip-2.jpg|none|thumb|[https://radiopaedia.org/articles/interstitial-lung-disease?lang=us Case courtesy of Dr David Cuete]]]
[[File:Usual-interstitial-pneumonia-uip-2.jpg|none|thumb|[https://radiopaedia.org/articles/interstitial-lung-disease?lang=us Case courtesy of Dr David Cuete]]]


===Other Diagnostic Studies===
===Other Diagnostic Studies===


Pertinent diagnostic studies can be found under the laboratory findings.
==Treatment==
==Treatment==
===Medical Therapy===
===Medical Therapy===
Various immunosuppressive agents, such as '''azathioprine''', '''mycophenolate mofetil''', and/or '''tacrolimus''', are used in the treatment of antisynthetase syndrome.  Additionally, '''corticosteroids''' may be added for management of the myositis and pulmonary manifestations of anti-synthetase syndrome.  The choice of immunosuppressive agent is dependent on the practitioner and is based on the potential risks of therapy as no agent is superior to the other.   
Various immunosuppressive agents, such as '''[[azathioprine]]''', '''mycophenolate mofetil''', and/or '''[[tacrolimus]]''', are used in the treatment of antisynthetase syndrome.  Additionally, '''[[Corticosteroid|corticosteroids]]''' may be added for management of the myositis and pulmonary manifestations of anti-synthetase syndrome.  The choice of immunosuppressive agent is dependent on the practitioner and is based on the potential risks of therapy as no agent is superior to the other.   


Prednisone and azathioprine or mycophenolate mofetil may be used in patients with '''anti-synthetase syndrome related ILD'''.  In addition to that, tacrolimus may be added for rapid disease control in more '''severe cases of ILD'''.   
Prednisone and azathioprine or mycophenolate mofetil may be used in patients with '''anti-synthetase syndrome related interstitial lung disease (ILD)'''.  In addition to that, tacrolimus may be added for rapid disease control in more '''severe cases of ILD'''.   


In patients with severe progressive or refractory ILD, '''rituximab''' may be added; while '''cyclophosphamide''' is reserved for those with acute respiratory distress syndrome.
In patients with severe progressive or refractory ILD, '''[[rituximab]]''' may be added; while '''[[cyclophosphamide]]''' is reserved for those with acute respiratory distress syndrome.
 
The physician must also been on the lookout for other co-morbid conditions associated with antisynthetase syndrome i.e. '''[[pulmonary hypertension]]''' and '''screening for malignancies'''.<ref name="pmid27594777">{{cite journal| author=Witt LJ, Curran JJ, Strek ME| title=The Diagnosis and Treatment of Antisynthetase Syndrome. | journal=Clin Pulm Med | year= 2016 | volume= 23 | issue= 5 | pages= 218-226 | pmid=27594777 | doi=10.1097/CPM.0000000000000171 | pmc=5006392 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27594777  }} </ref>
{| class="wikitable"
|+
! colspan="5" |Therapies for Anti-synthetase Syndrome-ILD
|-
! colspan="1" rowspan="1" |Drug
|'''Clinical Use'''
|'''Monitoring'''
|'''Adverse effects*'''
|'''Suggested Starting Dose'''
|-
|Corticosteroids
|First-line therapy
|Glucose, weight, blood pressure
|Hypertension, weight gain, hyperglycemia
|1 mg/kg/day
|-
|Azathioprine
|Most common second-line agent
|CBC, renal/liver function
|Leukopenia, hepatic injury, pancreatitis
|1 mg/kg/day
|-
|Mycophenolate mofetil
|Second-line agent in addition to corticosteroids
|CBC
| colspan="1" rowspan="1" |Diarrhea, cytopenias
|500 mg twice daily
|-
|Rituximab
|Rescue therapy, added to standard immunosuppression
|CBC
| colspan="1" rowspan="1" |Infection, neutropenia, infusion reaction
|**
|-
|Cyclophosphamide
|Rescue therapy (e.g. ARDS)
|CBC, urinalysis, renal function
|Malignancy, cytopenias, hemorrhagic cystitis, sterility
|1–2 mg/kg/day by mouth or 500–1000 mg IV every 4 weeks**
|-
|Tacrolimus
|Add-on therapy
|Renal function, blood pressure, electrolytes, CBC, drug level
|Renal failure, hypertension, hyperglycemia
|1 mg twice daily
|-
|IVIG
|Add-on therapy
|Immunoglobulin G levels
|Infusion reaction, infection from donor
|**
|-
| colspan="5" |ILD = Interstitial lung disease; ARDS = acute respiratory distress syndrome; IVIG = intravenous immunoglobulin G; mg = milligram; kg = kilogram
<nowiki>*</nowiki>all except IVIG increase the risk of opportunistic infection


The physician must also been on the lookout for other co-morbid conditions associated with antisynthetase syndrome i.e. '''pulmonary hypertension''' and '''screening for malignancies'''. <ref name="pmid27594777">{{cite journal| author=Witt LJ, Curran JJ, Strek ME| title=The Diagnosis and Treatment of Antisynthetase Syndrome. | journal=Clin Pulm Med | year= 2016 | volume= 23 | issue= 5 | pages= 218-226 | pmid=27594777 | doi=10.1097/CPM.0000000000000171 | pmc=5006392 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27594777  }} </ref>
<nowiki>**</nowiki>rheumatology consult strongly advised
|}


===Surgery===
===Surgery===
Surgical intervention is not recommended for the management of antisynthetase syndrome.


===Prevention===
===Prevention===
There are no primary preventive measures available for antisynthetase syndrome.


==References==
==References==

Latest revision as of 18:43, 11 August 2022

WikiDoc Resources for Antisynthetase syndrome

Articles

Most recent articles on Antisynthetase syndrome

Most cited articles on Antisynthetase syndrome

Review articles on Antisynthetase syndrome

Articles on Antisynthetase syndrome in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on Antisynthetase syndrome

Images of Antisynthetase syndrome

Photos of Antisynthetase syndrome

Podcasts & MP3s on Antisynthetase syndrome

Videos on Antisynthetase syndrome

Evidence Based Medicine

Cochrane Collaboration on Antisynthetase syndrome

Bandolier on Antisynthetase syndrome

TRIP on Antisynthetase syndrome

Clinical Trials

Ongoing Trials on Antisynthetase syndrome at Clinical Trials.gov

Trial results on Antisynthetase syndrome

Clinical Trials on Antisynthetase syndrome at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Antisynthetase syndrome

NICE Guidance on Antisynthetase syndrome

NHS PRODIGY Guidance

FDA on Antisynthetase syndrome

CDC on Antisynthetase syndrome

Books

Books on Antisynthetase syndrome

News

Antisynthetase syndrome in the news

Be alerted to news on Antisynthetase syndrome

News trends on Antisynthetase syndrome

Commentary

Blogs on Antisynthetase syndrome

Definitions

Definitions of Antisynthetase syndrome

Patient Resources / Community

Patient resources on Antisynthetase syndrome

Discussion groups on Antisynthetase syndrome

Patient Handouts on Antisynthetase syndrome

Directions to Hospitals Treating Antisynthetase syndrome

Risk calculators and risk factors for Antisynthetase syndrome

Healthcare Provider Resources

Symptoms of Antisynthetase syndrome

Causes & Risk Factors for Antisynthetase syndrome

Diagnostic studies for Antisynthetase syndrome

Treatment of Antisynthetase syndrome

Continuing Medical Education (CME)

CME Programs on Antisynthetase syndrome

International

Antisynthetase syndrome en Espanol

Antisynthetase syndrome en Francais

Business

Antisynthetase syndrome in the Marketplace

Patents on Antisynthetase syndrome

Experimental / Informatics

List of terms related to Antisynthetase syndrome

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-In-Chief: M. Hassan, M.B.B.S

Synonyms and keywords:

Overview

Antisynthetase syndrome, an uncommon autoimmune disorder, is characterized by antibodies against aminoacyl-transfer ribonucleic acid synthetases, with various combinations of three cardinal manifestations of interstitial lung disease (ILD), polymyositis, and arthritis. Other features of antisynthetase syndrome may include pyrexia of unknown origin, mechanic's hand (hyperkeratotic skin changes along the lateral surfaces of the digits) and Raynaud's phenomenon.[1][2]

So far, nine different anti-aminoacyl t-RNA synthetase (ARS) antibodies have been identified to play a role in the development of antisynthetase syndrome.[1]

Historical Perspective

In 1990, Marguerie et al and coworkers first described antisynthetase syndrome as a triad of polymyositis, interstitial lung disease (ILD), and the presence of myositis-specific autoantibodies to aminoacyl-transfer ribonucleic acid synthetases.[3]

Classification

Antisynthetase syndrome may be classified in accordance with the type of antibodies that are present. Some of the identified antibodies include Anti-Jo-1, Anti PL-12, Anti-Pl-7, Anti-OJ, Anti-KS, Anti-EJ, Anti-Ha, and Anti-Zo.[4]

Pathophysiology

Antisynthetase syndrome is characterized by the presence of myositis-specific anti-synthetase antibodies.[5]

Anti-ARS antibodies Antigen Clinical features
Anti-Jo-1 Histidyl-tRNA synthetase
  • Antisynthetase syndrome
    • Arthritis
    • Interstitial lung disease
    • Fever
    • Mechanic's hands
    • Raynaud's phenomenon
  • Flare up in spring
  • Moderate response to treatment
  • Poor prognosis
  • Associated with epstein-Barr virus (EBV), adenovirus, and influenza infection
Anti PL-12 Alanyl-tRNA synthetase, Alanyl-tRNA
  • Fever, Raynaud's phenomenon, high frequency of ILD
  • Epstein-Barr virus (EBV), adenovirus, and influenza infection
Anti-PL-7 Glycyl-tRNA synthetase
Anti-OJ Isoleucyl-tRNA synthetase
Anti-KS Asparaginyl-tRNA synthetase
Anti-EJ Glycyl-tRNA synthetase
Anti-Ha Tyrosyl-tRNA synthetase
Anti-Zo Phenylalanyl-tRNA synthetase

Causes

The exact cause of antisynthetase syndrome is not fully understood.

Differentiating Antisynthetase syndrome from other Diseases

Antisynthetase syndrome may be misdiagnosed as idiopathic interstitial lung disease (ILD) or inflammatory myopathy, as a result of rarity, lack of awareness of the disease, as well as due to the lack of available testing for anti-ARS antibodies.[1]

Epidemiology and Demographics

Age

The mean age at onset of antisynthetase syndrome in adults varies from 43 to 60 years.[5]

Gender

Antisynthetase syndrome is 2–3 times more common in women than in men.[5]

Race

Antisynthetase syndrome usually affects individuals of the black American ethnicity race.[1]

Risk Factors

There are several environmental exposures associated with antisynthetase syndrome. These include ultraviolet radiation, stress, muscle overexertion, collage implants, infections such as retroviruses and streptococci bacteria, and certain drugs and chemicals.[6]

Natural History, Complications and Prognosis

Main causes of death in antisynthetase syndrome is anti-Jo-1-positive patients included interstitial lung disease, neoplasm, infectious diseases including pneumonia, severe myositis and cardiovascular disorders.

The cumulative ten-year survival rate in patients with antisynthetase syndrome was estimated as 76.8%.[7]

Poor prognostic factors associated with Antisynthetase syndrome [1]
1) Anti-Ro 52
2) Rapidly progressive interstitial lung disease
3) Pulmonary hypertension
4) Malignancy
5) Male sex
6) Reduced diffusing capacity of lung for carbon monoxide
7) Elevated serum ferritin
8) Black American ethnicity

Diagnosis

Diagnostic Criteria

In 2010, Connors et al proposed a formal criteria for the diagnosis of antisynthetase syndrome. This criteria proposed that all patients must have a presence of an anti-aminoacyl tRNA synthetase antibody in addition to one or more of the following clinical features: mechanic’s hands, Raynaud’s phenomenon, myositis, interstitial lung disease (ILD), arthritis, and/or unexplained fever.

In 2011, Solomon et al proposed alternative criteria, which is more strict. This criteria requires the presence of anti-aminoacyl tRNA synthetase antibody plus two major or one major and two minor criteria.

Major criteria includes: Interstitial Lung Disease (not attributable to another cause), and Polymyositis or dermatomyositis.

Minor criteria includes: arthritis, Raynaud’s phenomenon, and mechanic’s hands.[4]

Connors et al (2010) criteria
Required: Presence of an anti-aminoacyl tRNA synthetase antibody
PLUS one or more of the following clinical features:

1) Raynaud’s phenomenon

2) Arthritis

3) Interstitial lung disease

4) Fever (not attributable to another cause)

5) Mechanic’s hands (thickened and cracked skin on hands, particularly at fingertips)

Solomon et al (2011) criteria
Required: Presence of anti-aminoacyl tRNA synthetase antibody
PLUS two major or one major and two minor criteria:


Major:

1) Interstitial Lung Disease (not attributable to another cause)

2) Polymyositis or dermatomyositis


Minor:

1) Arthritis

2) Raynaud’s phenomenon

3) Mechanic’s hands

Symptoms

Symptoms seen at the diagnosis of antisynthetase syndrome include the following:[1]

Symptoms of antisynthetase syndrome
1) Fever
2) Weight loss
3) Anorexia
4) Dyspnea
5) Dry cough
6) Arthralgia
7) Joint swelling
8) Proximal muscle weakness
9) Myalgia
10) Raynaud's phenomenon

Physical Examination

Physical exam findings play an important role in diagnosis of antisynthetase syndrome as the findings may be classified into major and minor criteria. Clinical findings on examination includes:[1]

Clinical findings
1) Polyarthritis
2) Mechanics hands (hyperkeratotic lesions on the radial and palmar aspects of the hands and fingers with fissuring and scaling of the skin)
3) Calcinosis cutis
4) Malar rash
5) Cutaneous ulcers
6) Crackles on chest auscultation

Laboratory Findings

Suggested lab findings based on the systems are as follows:[8]

Domains Suggested investigations
Bloodwork CBC, creatinine, CK, LDH, aldolase, AST, ALT, ANA, ENA, RF, ACPA, MSAs and MAAs
Muscle MMT8 and consider: MRI pelvic/thighs and shoulder girdle muscles, EMG, and Muscle biopsy
Joint TJC, SJC
Lung CXR, HRCT, PFT, 6MWT, echocardiogram for PAH if isolated decrease in DLCO,

Referral to respirology for co-management if ILD

Skin General assessment and consider documentation with CDASI

Referral to dermatologists

Raynaud’s phenomenon Conservative and pharmacological management review
Overall disease activity and damage assessment Consider MDAAT, MDI
TJC: tender joint count; SJC: swollen joint count; PAH: pulmonary artery hypertension; MMT8: manual muscle testing 8

MRI: magnetic resonance imaging; EMG: electromyography; CXR: chest X-ray; HRCT: high-resolution computed tomography; PFT: pulmonary function test; 6MWT: 6-minute walk test;

DLCO: diffusing capacity of lung for carbon monoxide; ILD: interstitial lung disease; CDASI: cutaneous dermatomyositis disease area and severity index; CBC: complete blood count;

CK: creatine kinase; LDH: lactate dehydrogenase; AST: aspartate aminotransferase; ALT: alanine transaminase; ANA: antinuclear antibody; ENA: extractable nuclear antigens;

RF: rheumatoid factor; ACPA: anti-citrullinated protein antibody; MSA: myositis-specific antibody; MAA: myositis-associated antibody; MDAAT: Myositis Disease Activity Assessment Tool; MDI: myositis damage index

Imaging Findings

As antisynthetase syndrome is associated with interstitial lung disease, and therefore, high resolution computed tomography (HRCT) plays an important role in its work up, as well as to monitor the disease activity. Radiographic features seen on HRCT at the initial diagnosis include traction bronchiectasis, ground glass opacities and reticulation.[4]

Case courtesy of Dr David Cuete

Other Diagnostic Studies

Pertinent diagnostic studies can be found under the laboratory findings.

Treatment

Medical Therapy

Various immunosuppressive agents, such as azathioprine, mycophenolate mofetil, and/or tacrolimus, are used in the treatment of antisynthetase syndrome. Additionally, corticosteroids may be added for management of the myositis and pulmonary manifestations of anti-synthetase syndrome. The choice of immunosuppressive agent is dependent on the practitioner and is based on the potential risks of therapy as no agent is superior to the other.

Prednisone and azathioprine or mycophenolate mofetil may be used in patients with anti-synthetase syndrome related interstitial lung disease (ILD). In addition to that, tacrolimus may be added for rapid disease control in more severe cases of ILD.

In patients with severe progressive or refractory ILD, rituximab may be added; while cyclophosphamide is reserved for those with acute respiratory distress syndrome.

The physician must also been on the lookout for other co-morbid conditions associated with antisynthetase syndrome i.e. pulmonary hypertension and screening for malignancies.[4]

Therapies for Anti-synthetase Syndrome-ILD
Drug Clinical Use Monitoring Adverse effects* Suggested Starting Dose
Corticosteroids First-line therapy Glucose, weight, blood pressure Hypertension, weight gain, hyperglycemia 1 mg/kg/day
Azathioprine Most common second-line agent CBC, renal/liver function Leukopenia, hepatic injury, pancreatitis 1 mg/kg/day
Mycophenolate mofetil Second-line agent in addition to corticosteroids CBC Diarrhea, cytopenias 500 mg twice daily
Rituximab Rescue therapy, added to standard immunosuppression CBC Infection, neutropenia, infusion reaction **
Cyclophosphamide Rescue therapy (e.g. ARDS) CBC, urinalysis, renal function Malignancy, cytopenias, hemorrhagic cystitis, sterility 1–2 mg/kg/day by mouth or 500–1000 mg IV every 4 weeks**
Tacrolimus Add-on therapy Renal function, blood pressure, electrolytes, CBC, drug level Renal failure, hypertension, hyperglycemia 1 mg twice daily
IVIG Add-on therapy Immunoglobulin G levels Infusion reaction, infection from donor **
ILD = Interstitial lung disease; ARDS = acute respiratory distress syndrome; IVIG = intravenous immunoglobulin G; mg = milligram; kg = kilogram

*all except IVIG increase the risk of opportunistic infection

**rheumatology consult strongly advised

Surgery

Surgical intervention is not recommended for the management of antisynthetase syndrome.

Prevention

There are no primary preventive measures available for antisynthetase syndrome.

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Maturu VN, Lakshman A, Bal A, Dhir V, Sharma A, Garg M; et al. (2016). "Antisynthetase syndrome: An under-recognized cause of interstitial lung disease". Lung India. 33 (1): 20–6. doi:10.4103/0970-2113.173055. PMC 4748659. PMID 26933302.
  2. Robinson D, Scholz B (2020). "The antisynthetase syndrome". Proc (Bayl Univ Med Cent). 33 (3): 401–403. doi:10.1080/08998280.2020.1764818. PMC 7340408 Check |pmc= value (help). PMID 32675964 Check |pmid= value (help).
  3. Devi HG, Pasha MM, Padmaja MS, Halappa S (2016). "Antisynthetase Syndrome: A Rare Cause for ILD". J Clin Diagn Res. 10 (3): OD08–9. doi:10.7860/JCDR/2016/16872.7361. PMC 4843302. PMID 27134916.
  4. 4.0 4.1 4.2 4.3 Witt LJ, Curran JJ, Strek ME (2016). "The Diagnosis and Treatment of Antisynthetase Syndrome". Clin Pulm Med. 23 (5): 218–226. doi:10.1097/CPM.0000000000000171. PMC 5006392. PMID 27594777.
  5. 5.0 5.1 5.2 Cojocaru M, Cojocaru IM, Chicos B (2016). "New Insights into Antisynthetase Syndrome". Maedica (Bucur). 11 (2): 130–135. PMC 5394574. PMID 28461832.
  6. https://www.niehs.nih.gov/research/clinical/bethesda/participants/studies/erftas/index.cfm. Missing or empty |title= (help)
  7. https://www.sciencedirect.com/science/article/abs/pii/S0049017220303085. Missing or empty |title= (help)
  8. Huang K, Aggarwal R (2020). "Antisynthetase syndrome: A distinct disease spectrum". J Scleroderma Relat Disord. 5 (3): 178–191. doi:10.1177/2397198320902667. PMC 8922626 Check |pmc= value (help). PMID 35382516 Check |pmid= value (help).