Polymyositis and dermatomyositis laboratory findings

Polymyositis and dermatomyositis Microchapters
Home
Patient Information
Overview
Historical Perspective
Classification
Pathophysiology
Causes
Differentiating Polymyositis and dermatomyositis from other Diseases
Epidemiology and Demographics
Risk Factors
Screening
Natural History, Complications and Prognosis
Diagnosis
Diagnostic Study of Choice
History and Symptoms
Physical Examination
Laboratory Findings
Electrocardiogram
X-ray
Echocardiography and Ultrasound
CT scan
MRI
Other Imaging Findings
Other Diagnostic Studies
Treatment
Medical Therapy
Surgery
Primary Prevention
Secondary Prevention
Cost-Effectiveness of Therapy
Future or Investigational Therapies
Case Studies
Case #1
Polymyositis and dermatomyositis laboratory findings On the Web
Most recent articles
Most cited articles
Review articles
CME Programs
Powerpoint slides
Images
American Roentgen Ray Society Images of Polymyositis and dermatomyositis laboratory findings All Images X-rays Echo & Ultrasound CT Images MRI
Ongoing Trials at Clinical Trials.gov
US National Guidelines Clearinghouse
NICE Guidance
FDA on Polymyositis and dermatomyositis laboratory findings
CDC on Polymyositis and dermatomyositis laboratory findings
Polymyositis and dermatomyositis laboratory findings in the news
Blogs on Polymyositis and dermatomyositis laboratory findings
Directions to Hospitals Treating Psoriasis
Risk calculators and risk factors for Polymyositis and dermatomyositis laboratory findings

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Sadaf Sharfaei M.D.[2]

Overview

An elevated/reduced concentration of serum/blood/urinary/CSF/other [lab test] is diagnostic of [disease name].

OR

Laboratory findings consistent with the diagnosis of [disease name] include [abnormal test 1], [abnormal test 2], and [abnormal test 3].

OR

[Test] is usually normal for patients with [disease name].

OR

Some patients with [disease name] may have elevated/reduced concentration of [test], which is usually suggestive of [progression/complication].

OR

There are no diagnostic laboratory findings associated with [disease name].

Laboratory Findings

• Different laboratory tests may be used to diagnose polymyositis and dermatomyositis and exclude other myopathies which include:
  • Sarcoplasmic enzymes
  • Myositis-specific autoantibodies

Sarcoplasmic enzymes

• Sarcoplasmic enzymes consistent with the diagnosis of polymyositis and dermatomyositis include:

• • Creatine phosphokinase
  • Aldolase
  • Transaminases
  • Lactic dehydrogenase

Myositis-specific autoantibodies

Autoantibody	Antigen	Association	Percentage
Anti-Jo-1	Histidyl-tRNA synthetase	Antisynthetase syndrome Flare up in spring Epstein-Barr virus (EBV), adenovirus, and influenza infection
Anti Mi-2)	Chromodomain helicase DNA binding protein 4	Severe dermatomyositis rash without significant lung involvement
Anti-SRP	Signal recognition particle	Flare up in fall
Anti PL-12	Alanyl-tRNA synthetase	Epstein-Barr virus (EBV), adenovirus, and influenza infection
Anti TIF-1γ antibody	Transcriptional intermediary factor 1-gamma	Cancer-associated myositis Juvenile dermatomyositis
Anti NXP-2 antibody	Nuclear matrix protein	Cancer-associated myositis Juvenile dermatomyositis
Anti-SAE antibody	Anti-small ubiquitin-like modifier activating enzyme	Cancer-associated myositis
Anti HMGCR antibody	3-hydroxy-3-methylglutaryl-coenzyme A reductase	Statin-associated necrotizing autoimmune myopathy (SANAM)	6%