From the Guidelines
Initial laboratory tests for evaluating autoimmune or endocrine disorders should include a comprehensive metabolic panel (CMP), complete blood count (CBC), thyroid function tests (TSH, free T4, free T3), and specific autoantibody panels based on suspected conditions, as recommended by the most recent guidelines 1. When checking a patient for autoimmune or endocrine disorders, it is essential to consider the patient's clinical presentation and tailor the testing accordingly.
Initial Lab Tests
The following initial lab tests are recommended:
- Comprehensive metabolic panel (CMP)
- Complete blood count (CBC)
- Thyroid function tests (TSH, free T4, free T3)
- Specific autoantibody panels based on suspected conditions
Autoimmune Evaluation
For autoimmune evaluation, the following tests are recommended:
- Antinuclear antibody (ANA)
- Erythrocyte sedimentation rate (ESR)
- C-reactive protein (CRP)
- Rheumatoid factor (RF)
Endocrine Assessment
Endocrine assessment should include:
- Fasting glucose
- HbA1c
- Cortisol levels (morning)
- Hormone-specific tests like FSH, LH, estradiol, testosterone, or prolactin depending on symptoms
Additional Targeted Tests
Additional targeted tests may include:
- Anti-thyroid antibodies (TPO, TgAb) for suspected autoimmune thyroid disease, as recommended by recent studies 1
- 25-hydroxyvitamin D levels
- Organ-specific autoantibodies for conditions like celiac disease or type 1 diabetes These tests provide a baseline assessment of organ function, inflammatory markers, and specific autoimmune indicators.
Interpretation of Results
The pattern of abnormalities helps distinguish between different autoimmune and endocrine conditions, guiding further specialized testing. Results should be interpreted in the clinical context, as some autoantibodies may be present in healthy individuals or may precede clinical disease by years 1. It is crucial to prioritize the patient's clinical presentation and tailor the testing accordingly, as symptoms of these disorders often overlap and can be nonspecific 1.
From the Research
Initial Lab Tests for Autoimmune or Endocrine Disorders
When evaluating a patient for autoimmune or endocrine disorders, the following initial lab tests are recommended:
- Complete blood count (CBC) with differential to assess the total numbers and characteristics of cell components in the blood 2
- Comprehensive metabolic panel to evaluate the patient's metabolic status 3
- Measurement of inflammatory markers to assess disease activity and severity 3
- Autoantibody tests to confirm a diagnosis and estimate disease severity 3
- Flow cytometry to evaluate immune cell function and detect any abnormalities 3
Labs to Order for a Specialist
For a specialist, the following labs may be ordered to further evaluate a patient with a suspected autoimmune or endocrine disorder:
- Organ-specific immunologic tests to assess disease activity and severity in specific organs 3
- Additional autoantibody tests to confirm a diagnosis and estimate disease severity 3
- Hormone level tests to evaluate endocrine function and detect any abnormalities
- Imaging studies, such as ultrasound or MRI, to evaluate organ structure and function
Rationale for Lab Tests
The laboratory tests ordered for a patient with a suspected autoimmune or endocrine disorder are useful for: