From the Guidelines
A full autoimmune workup should include a complete history and examination, autoimmune myositis and neurologic panel, EMG, MRI of affected proximal limbs as needed, and consideration of muscle biopsy if diagnosis is uncertain, as recommended by the American Society of Clinical Oncology clinical practice guideline 1. When evaluating a patient for autoimmune disorders, it is essential to start with basic screening tests, including complete blood count (CBC), comprehensive metabolic panel (CMP), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) to assess for inflammation.
- Specific autoantibody tests should include:
- Antinuclear antibody (ANA)
- Rheumatoid factor (RF)
- Anti-cyclic citrullinated peptide (anti-CCP) antibodies
- Complement levels (C3, C4)
- Anti-double stranded DNA (anti-dsDNA)
- Anti-Smith
- Anti-Ro/SSA
- Anti-La/SSB
- Anti-RNP
- Anti-Jo-1
- Anti-Scl-70 antibodies
- Additional testing may be warranted based on clinical suspicion, such as:
- Anti-neutrophil cytoplasmic antibodies (ANCA) for suspected vasculitis
- Thyroid function tests and thyroid antibodies (anti-TPO, anti-thyroglobulin) for autoimmune thyroid disease
- Tissue transglutaminase antibodies (tTG-IgA) and total IgA for celiac disease It is crucial to interpret test results in the context of clinical symptoms, as positive results do not always indicate disease, and negative results do not completely rule out autoimmune disorders, as highlighted in the international recommendations for the assessment of autoantibodies to cellular antigens referred to as anti-nuclear antibodies 1. The workup should be tailored to the patient's specific symptoms rather than ordering all tests indiscriminately. Early referral to a rheumatologist or neurologist is also recommended for further evaluation and management 1.
From the Research
Full Autoimmune Workup
A full autoimmune workup is a comprehensive diagnostic evaluation used to identify autoimmune diseases. The workup typically includes a combination of clinical assessments, laboratory tests, and imaging studies.
- The clinical assessment involves a detailed medical history and physical examination to identify symptoms and signs suggestive of an autoimmune disease 2.
- Laboratory tests may include:
- Complete blood count with differential
- Comprehensive metabolic panel
- Measurement of inflammatory markers and autoantibodies
- Flow cytometry 3
- Autoantibody testing, such as antinuclear antibodies (ANA), is commonly used to help diagnose autoimmune diseases, but may also be positive in non-autoimmune inflammatory diseases, including infections 4.
- A thorough evaluation of a suspected autoimmune illness, including laboratory testing and clinical assessment, provides a better understanding of a patient's immunologic disease 3.
Common Autoimmune Diseases
Some common autoimmune diseases that may be evaluated in a full autoimmune workup include:
- Systemic lupus erythematosus (SLE)
- Rheumatoid arthritis (RA)
- Autoimmune thyroid disease (AITD)
- These diseases may present with a range of symptoms, including fever, fatigue, joint pain, rash, and muscle weakness 2.
Diagnostic Approach
A diagnostic approach to autoimmune disorders involves a combination of clinical evaluation, laboratory testing, and imaging studies. The evaluation should consider the patient's medical history, physical examination, and laboratory results to guide the diagnosis and management of the disease 2, 5.
Laboratory Evaluation
Laboratory evaluation is a crucial component of a full autoimmune workup. The results can confirm a diagnosis, estimate disease severity, aid in assessing prognosis, and are useful for following disease activity 3.
Clinical Manifestations
Autoimmune disorders may present with a range of clinical manifestations, including symptoms that involve multiple organ systems. A detailed history and careful physical examination play an important role in guiding laboratory evaluation for these disorders 2.