From the Guidelines
When approaching an autoimmune workup, start with a thorough history and physical examination focusing on specific symptoms, family history, and organ systems involved, as recommended by the most recent guidelines 1. This initial step is crucial in identifying potential autoimmune diseases and guiding further testing.
- Initial laboratory testing should include complete blood count, comprehensive metabolic panel, erythrocyte sedimentation rate, and C-reactive protein to assess for inflammation.
- Order antinuclear antibody (ANA) testing as a screening tool, and if positive, proceed with more specific antibody tests based on clinical suspicion, such as anti-dsDNA for lupus, anti-CCP for rheumatoid arthritis, or anti-SSA/SSB for Sjögren's syndrome, as suggested by 1.
- Include complement levels (C3, C4) to evaluate immune complex diseases. Depending on presenting symptoms, consider organ-specific testing like thyroid function tests, urinalysis for kidney involvement, or pulmonary function tests for lung manifestations, as outlined in 1. Imaging studies such as X-rays, CT scans, or MRIs may be necessary to evaluate affected organs. In some cases, tissue biopsy from affected organs provides definitive diagnosis. This systematic approach is essential because autoimmune diseases often present with overlapping symptoms, and targeted testing based on clinical presentation improves diagnostic accuracy while avoiding unnecessary tests 1. Remember that autoimmune conditions may evolve over time, so periodic reassessment may be necessary if initial testing is inconclusive but clinical suspicion remains high. It is also important to consider referral to a specialist, such as a dermatologist or neurologist, if an autoimmune skin disease or neurological disorder is suspected, as recommended by 1. By following this approach, clinicians can ensure that patients receive accurate diagnoses and appropriate treatment, ultimately improving morbidity, mortality, and quality of life outcomes.
From the Research
Approach to Autoimmune Workup
When approaching an autoimmune workup, several key components should be considered:
- A thorough clinical evaluation is essential in conjunction with laboratory testing to understand a patient's immunologic disease 2
- Laboratory testing can confirm a diagnosis, estimate disease severity, aid in assessing prognosis, and follow disease activity 2
- Components of the laboratory examination may include:
- Complete blood count with differential
- Comprehensive metabolic panel
- Measurement of inflammatory markers and autoantibodies
- Flow cytometry 2
Laboratory Evaluation
A comprehensive laboratory evaluation is crucial in the workup of suspected autoimmune diseases:
- General laboratory and autoantibody screening should be performed in children with suspected autoimmune disease 3
- A thorough history and physical examination, as well as laboratory evaluation, are recommended to elucidate the cause of positive test results 3
- Autoantibody testing should only be performed in the context of the clinical workup of patients who have a reasonable likelihood of having the disease for which the testing is relevant 4
Autoantibody Testing
Autoantibody testing plays a significant role in the diagnosis and classification of autoimmune diseases:
- Measurement of autoantibodies, such as rheumatoid factor and anti-citrullinated protein/peptide antibodies, is essential in the diagnosis of rheumatoid arthritis 5
- Autoantibody tests should be aligned to a common diagnostic specificity to provide more accurate results 5
- Clinicians should be aware of the methodology used for autoantibody testing and develop a relationship with the laboratory pathologist to investigate inconsistent or surprising results 4