Fibromuscular dysplasia pathophysiology: Difference between revisions
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==Genetics== | ==Genetics== | ||
*Genetic predisposition may | *[[Genetic predisposition]] may play a role in the [[development]] of fibromuscular dysplasia. Owing to, FMD is more common among the first-degree relatives of patients with this condition. | ||
* Some studies showed an autosomal dominant transmission pattern for fibromuscular dysplasia | *Some studies showed an [[autosomal dominant transmission]] pattern for fibromuscular dysplasia; However, as of yet, | ||
no etiologic genes have been identified for this disease. Applying molecular genetics investigations will reveal information about FMD pathogenesis, and family-based studies, evaluating genome of candidates, and wide genome studies can help to recognize pathophysiology of FMD. | no [[etiologic genes]] have been identified for this disease. Applying [[molecular genetics]] investigations will reveal information about FMD [[pathogenesis]], and family-based studies, evaluating [[genome]] of candidates, and wide [[genome]] studies can help to recognize [[pathophysiology]] of FMD. | ||
In the US Registry, | *In the US Registry, about eight percent of patients report a confirmed diagnosis of FMD in one or more in first- or second-degree family members. However, the high prevalence of aneurysms, sudden death , and stroke among first- and second-degree family members in the US Registry shows that FMD may be associated with systemic arteriopathy with a great diversity of clinical [[phenotype traits]]. It is hypothesized that FMD may have common features with vascular connective tissue diseases, such as Loeys-Dietz syndrome or the vascular type of Ehlers-Danlos syndrome. | ||
*Increased level of [[TGF]]-b1 and 2 secreted by [[fibroblasts]] in patients with FMD in comparison to matched | |||
FMD patients also had elevated plasma levels of circulating TGF-b1 and TGF-b2 relative to matched controls. | FMD patients also had elevated plasma levels of circulating TGF-b1 and TGF-b2 relative to matched controls. The potential involvement of TGF-b pathways in the [[pathogenesis]] of FMD is an area for future investigation, especially as this pathway could provide a potential target for disease-modifying medical therapies. | ||
*[[Polymorphisms]] of angiotensin-converting–enzyme allele ACE-I among patients with multifocal renal arterial fibromuscular | |||
dysplasia has been investigated.<ref>{{Cite journal | |||
| author = [[A. Bofinger]], [[C. Hawley]], [[P. Fisher]], [[N. Daunt]], [[M. Stowasser]] & [[R. Gordon]] | |||
| title = Polymorphisms of the renin-angiotensin system in patients with multifocal renal arterial fibromuscular dysplasia | |||
| journal = [[Journal of human hypertension]] | |||
| volume = 15 | |||
| issue = 3 | |||
| pages = 185–190 | |||
| year = 2001 | |||
| month = March | |||
| doi = 10.1038/sj.jhh.1001144 | |||
| pmid = 11317203 | |||
}}</ref> | |||
In case reports, FMD | *In some case reports, the association of FMD with neurofibromatosis, Alport syndrome, and pheochromocytoma have been considered; Ans [[mutations]] in [[collagen]], and with [[alpha1-antitrypsin deficiency]] have also been suggested. | ||
==Associated Conditions== | ==Associated Conditions== | ||
Revision as of 17:03, 14 June 2018
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Fibromuscular dysplasia Microchapters |
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Diagnosis |
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Treatment |
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ASA/ACCF/AHA Guideline Recommendations |
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Management of Patients With Fibromuscular Dysplasia of the Extracranial Carotid Arteries |
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Case Studies |
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Fibromuscular dysplasia pathophysiology On the Web |
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American Roentgen Ray Society Images of Fibromuscular dysplasia pathophysiology |
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Risk calculators and risk factors for Fibromuscular dysplasia pathophysiology |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Mohsen Basiri M.D.
Overview
Pathophysiology
In Fibromuscular dysplasia, the proliferation of vascular smooth muscle of one or more small or medium-sized arteries undergo dysplasia and cause stenosis. this abnormal cellular development is characterized by fibrous thickening of the intima, media, or adventitia of the involved arteries; which ultimately lead to arterial narrowing.
Pathogenesis
- Despite numerous genetic, hormonal and mechanical factors have been proposed, the etiology fibromuscular dysplasia remains unknown. A variety of factors have been implicated. These include:
1.Cigarette smoking and a history of hypertension[1]
2.Genetic factors with a reported autosomal mode of inheritance in some families.[2]
- Some studies suggest fibromuscular dysplasia is a systemic disease with altered TGF-βexpression and connective tissue features
3.Hormonal influence, The increased incidence of FMD in women as compared with men suggests a possible hormonal given the predominance in women of childbearing age No association has been found between fibromuscular dysplasia and previous use of oral contraceptives or abnormalities of endogenous sex hormones.[3] 4.Some authors have proposed the sex difference to be related to immune system functioning, but overt inflammation, as is observed in most classic autoimmune diseases, is histologically lacking.
5.Mechanical factors due to stretching of smooth muscle cells and microtrauma to the vessel wall
6.Ischemia due to fibrotic occlusion of the vasa Vasorum
Genetics
- Genetic predisposition may play a role in the development of fibromuscular dysplasia. Owing to, FMD is more common among the first-degree relatives of patients with this condition.
- Some studies showed an autosomal dominant transmission pattern for fibromuscular dysplasia; However, as of yet,
no etiologic genes have been identified for this disease. Applying molecular genetics investigations will reveal information about FMD pathogenesis, and family-based studies, evaluating genome of candidates, and wide genome studies can help to recognize pathophysiology of FMD.
- In the US Registry, about eight percent of patients report a confirmed diagnosis of FMD in one or more in first- or second-degree family members. However, the high prevalence of aneurysms, sudden death , and stroke among first- and second-degree family members in the US Registry shows that FMD may be associated with systemic arteriopathy with a great diversity of clinical phenotype traits. It is hypothesized that FMD may have common features with vascular connective tissue diseases, such as Loeys-Dietz syndrome or the vascular type of Ehlers-Danlos syndrome.
- Increased level of TGF-b1 and 2 secreted by fibroblasts in patients with FMD in comparison to matched
FMD patients also had elevated plasma levels of circulating TGF-b1 and TGF-b2 relative to matched controls. The potential involvement of TGF-b pathways in the pathogenesis of FMD is an area for future investigation, especially as this pathway could provide a potential target for disease-modifying medical therapies.
- Polymorphisms of angiotensin-converting–enzyme allele ACE-I among patients with multifocal renal arterial fibromuscular
dysplasia has been investigated.[4]
- In some case reports, the association of FMD with neurofibromatosis, Alport syndrome, and pheochromocytoma have been considered; Ans mutations in collagen, and with alpha1-antitrypsin deficiency have also been suggested.
Associated Conditions
Associated vascular pathologies In 1982, Mettinger and Ericson [14] scrutinized 4000 consecutively performed cerebral angiographies and found 37 that were consistent with FMD. Of these, 19 patients had aneurysms. In 1988, Cloft et al performed a meta-analysis including 498 FMD patients as well as examined 117 of their own patients and found a combined prevalence of aneurysms to be 7.3%. [15] In 1975, Stanley et al found that 8 of their 17 cerebrovascular FMD cases had intracranial aneurysms, and they proposed a classification system that includes a "medial fibroplasias with aneurysms" subtype. [11] The beadlike dilatations observed within FMD lesions share gross and histologic characteristics of aneurysms. The casual link between FMD and aneurysms is less clear but is possibly related to an underlying connective tissue problem that results in loss of arterial wall strength. This wall weakness may allow for vessel dilation (aneurysm formation and beading in FMD) as well as injury, which then causes compensatory fibroplasia. Besides aneurysms, many case series and reports have identified FMD in patients presenting with arterial dissection. [16, 17]
FMD lesions likely predispose the artery to dissection through weakening of the arterial wall. FMD is a predisposing factor in 15% of spontaneous cervical carotid dissections. Dissections in FMD are more commonly multiple than in patients without an identified underlying arteriopathy.
Gross Pathology
- On gross pathology, [feature1], [feature2], and [feature3] are characteristic findings of [disease name].
Microscopic Pathology
- On microscopic histopathological analysis, [feature1], [feature2], and [feature3] are characteristic findings of [disease name].
References
- ↑ C. N. Sang, P. K. Whelton, U. M. Hamper, M. Connolly, S. Kadir, R. I. White, R. Sanders, K. Y. Liang & W. Bias (1989). "Etiologic factors in renovascular fibromuscular dysplasia. A case-control study". Hypertension (Dallas, Tex. : 1979). 14 (5): 472–479. PMID 2680961. Unknown parameter
|month=ignored (help) - ↑ J. Perdu, P. Boutouyrie, C. Bourgain, N. Stern, B. Laloux, E. Bozec, M. Azizi, C. Bonaiti-Pellie, P.-F. Plouin, S. Laurent, A.-P. Gimenez-Roqueplo & X. Jeunemaitre (2007). "Inheritance of arterial lesions in renal fibromuscular dysplasia". Journal of human hypertension. 21 (5): 393–400. doi:10.1038/sj.jhh.1002156. PMID 17330059. Unknown parameter
|month=ignored (help) - ↑ C. N. Sang, P. K. Whelton, U. M. Hamper, M. Connolly, S. Kadir, R. I. White, R. Sanders, K. Y. Liang & W. Bias (1989). "Etiologic factors in renovascular fibromuscular dysplasia. A case-control study". Hypertension (Dallas, Tex. : 1979). 14 (5): 472–479. PMID 2680961. Unknown parameter
|month=ignored (help) - ↑ A. Bofinger, C. Hawley, P. Fisher, N. Daunt, M. Stowasser & R. Gordon (2001). "Polymorphisms of the renin-angiotensin system in patients with multifocal renal arterial fibromuscular dysplasia". Journal of human hypertension. 15 (3): 185–190. doi:10.1038/sj.jhh.1001144. PMID 11317203. Unknown parameter
|month=ignored (help)