Lab Workup for Raynaud Disease with SLE
For a patient with both Raynaud disease and SLE, obtain a comprehensive baseline autoantibody panel including ANA, anti-dsDNA, anti-Ro, anti-La, anti-RNP, anti-Sm, anti-phospholipid antibodies, C3, and C4, along with routine monitoring labs every 6-12 months. 1
Baseline Autoantibody and Complement Testing
The European League Against Rheumatism (EULAR) provides clear guidance for laboratory monitoring in SLE patients, which is directly applicable to those with concurrent Raynaud phenomenon:
Initial Comprehensive Panel
- ANA (antinuclear antibodies) 1
- Anti-dsDNA antibodies 1
- Anti-Ro (SSA) antibodies 1
- Anti-La (SSB) antibodies 1
- Anti-RNP antibodies 1
- Anti-Sm antibodies 1
- Anti-phospholipid antibodies (lupus anticoagulant, anticardiolipin, anti-β2-glycoprotein I) 1
- C3 and C4 complement levels 1
The anti-RNP antibodies are particularly relevant in this clinical scenario, as they are associated with Raynaud phenomenon in connective tissue diseases and may suggest overlap syndromes or mixed connective tissue disease 2, 3.
Routine Monitoring Labs (Every 6-12 Months for Inactive Disease)
For patients with stable, inactive SLE, the following should be monitored at 6-12 month intervals: 1
- Complete blood count (to detect cytopenias) 1
- Erythrocyte sedimentation rate (ESR) 1
- C-reactive protein (CRP) 1
- Serum albumin 1
- Serum creatinine or estimated glomerular filtration rate (eGFR) 1
- Urinalysis and urine protein/creatinine ratio 1
Selective Re-evaluation of Autoantibodies
Not all autoantibodies require routine serial monitoring. Re-test previously negative patients for: 1
Anti-phospholipid Antibodies
Re-check before:
- Pregnancy 1
- Surgery 1
- Transplantation 1
- Use of estrogen-containing treatments 1
- New neurological or vascular events 1
This is particularly important in Raynaud patients, as anti-phospholipid antibodies can cause thrombotic complications that may mimic or worsen vascular symptoms 4.
Anti-Ro and Anti-La Antibodies
Anti-dsDNA and Complement (C3/C4)
- May be repeated to support evidence of disease activity or remission 1
Additional Considerations for Raynaud Phenomenon
While the EULAR guidelines focus on SLE monitoring, patients with Raynaud phenomenon warrant additional baseline evaluation:
- Nailfold capillaroscopy should be performed to distinguish primary from secondary Raynaud and to detect early systemic sclerosis 5
- Thyroid function tests to exclude thyroid disease as a contributor 5
- Protein electrophoresis if cryoglobulinemia is suspected 5
Important Caveats
The anti-dsDNA testing method matters: The Farr assay and Crithidia luciliae immunofluorescence test (CLIFT) offer the highest clinical specificity for SLE. If alternative methods are used and yield positive results, confirmation with CLIFT or Farr assay is recommended 1. Always use the same method for serial monitoring of disease activity 1.
ANA testing should use indirect immunofluorescence assay (IIFA) on HEp-2 cells as the gold standard. If clinical suspicion is high and an alternative method is negative, IIFA must be performed 1. Report both the pattern and the highest dilution demonstrating reactivity 1.
Drug monitoring is mandatory: If the patient is on specific drug treatments (antimalarials, immunosuppressives, glucocorticoids), additional monitoring for drug toxicity is required beyond the standard SLE panel 1.