What blood work and treatment are recommended for a patient with suspected or confirmed lupus?

Lupus Blood Work and Treatment Recommendations

Initial Diagnostic Testing

For suspected lupus, begin with ANA testing by indirect immunofluorescence on HEp-2 cells, which has nearly 100% sensitivity for SLE, and if positive, proceed immediately to a comprehensive autoantibody panel including anti-dsDNA, anti-Sm, anti-Ro/SSA, anti-La/SSB, anti-RNP, antiphospholipid antibodies, and complement levels (C3, C4). 1, 2

Core Autoantibody Panel

• ANA (Antinuclear Antibodies): Use indirect immunofluorescence assay (IIFA) on HEp-2 cells as the gold standard method 1, 3
• Anti-dsDNA antibodies: Highly specific for SLE (present in 40-80% of patients); use Farr assay or Crithidia luciliae immunofluorescence test (CLIFT) for highest clinical specificity 1, 2, 3
• Anti-Sm antibodies: Highly specific for SLE diagnosis 1, 2, 4
• Anti-Ro/SSA and anti-La/SSB antibodies: Essential for identifying risk of congenital heart block and neonatal lupus 1, 2
• Anti-RNP antibodies: Part of comprehensive ENA panel 1, 2
• Antiphospholipid antibodies: Include lupus anticoagulant, anticardiolipin, and anti-β2-glycoprotein I to identify antiphospholipid syndrome risk 1, 2, 3
• Complement levels (C3 and C4): Low levels indicate active disease and consumption 1, 2

Additional Baseline Laboratory Tests

• Complete blood count (CBC): To detect cytopenias (anemia, leukopenia, thrombocytopenia) 1, 2
• Inflammatory markers: ESR and CRP 1, 2
• Renal function: Serum creatinine or eGFR, urinalysis, and urine protein/creatinine ratio 1, 2
• Serum albumin: Part of baseline assessment 1, 2

Important caveat: Do not rely solely on ANA without further specific antibody testing, as this leads to misdiagnosis given ANA's low specificity 2, 5

Routine Monitoring for Stable Disease

For patients with stable, inactive SLE, perform monitoring labs every 6-12 months including CBC, ESR, CRP, serum albumin, serum creatinine or eGFR, urinalysis, and urine protein/creatinine ratio. 1, 2

Standard Monitoring Panel (Every 6-12 Months)

• Complete blood count 1, 2
• Erythrocyte sedimentation rate (ESR) 1, 2
• C-reactive protein (CRP) 1, 2
• Serum albumin 1, 2
• Serum creatinine or estimated glomerular filtration rate (eGFR) 1, 2
• Urinalysis and urine protein/creatinine ratio 1, 2

Selective Re-testing of Autoantibodies

Re-test antiphospholipid antibodies before pregnancy, surgery, transplantation, use of estrogen-containing treatments, or new neurological/vascular events in previously negative patients. 1, 2

• Anti-Ro and anti-La antibodies: Re-test before pregnancy due to risk of congenital heart block and neonatal lupus 1, 2
• Anti-dsDNA and complement (C3/C4): May be repeated to support evidence of disease activity or remission 1

Enhanced Monitoring for Active Disease

Patients with established nephropathy require monitoring every 3 months for the first 2-3 years, including proteinuria, immunological tests (C3, C4, anti-dsDNA), urine microscopy, and blood pressure. 2

Disease Activity Assessment

Evaluate disease activity using a validated index at each visit, such as SLEDAI or BILAG, and assess organ damage annually using the SLICC Damage Index. 2

• Disease activity indices (SLEDAI or BILAG) should be performed at each visit 2
• Organ damage assessment (SLICC Damage Index) should be performed annually 2
• Quality of life evaluation by patient history or 0-10 visual analog scale at each visit 2

Treatment Approach

First-Line Therapy

Hydroxychloroquine is the cornerstone of treatment for all lupus patients because it reduces disease flares and constitutional symptoms. 6

• All patients should receive hydroxychloroquine unless contraindicated 6
• Baseline ophthalmologic examination is required before starting antimalarials 2
• Drug toxicity monitoring is mandatory for patients on antimalarials 1

Glucocorticoid Therapy

Low-dose glucocorticoids can treat most manifestations of lupus, but calcium and vitamin D supplementation must be provided to all patients on long-term glucocorticoid therapy to prevent osteoporosis. 2, 6

• Calcium and vitamin D supplementation is standard adjunctive therapy for patients on glucocorticoids 2
• Monitor bone health in postmenopausal women and those on medications that reduce bone mineral density 2

Immunosuppressive Therapy

The use of immunosuppressive and cytotoxic agents depends on the specific organ systems affected, with mycophenolate or cyclophosphamide used for lupus nephritis induction therapy. 7, 6

• For active proliferative and/or membranous lupus nephritis: corticosteroids plus either mycophenolate (for induction and maintenance) or cyclophosphamide (for induction) followed by azathioprine (for maintenance) 7

Biologic Therapy

Belimumab (BENLYSTA) 10 mg/kg IV is indicated for lupus nephritis when added to standard therapy, achieving 43% primary efficacy renal response at Week 104 versus 32% with placebo. 7

• Belimumab significantly improves complete renal response (30% vs 20% placebo) and reduces time to renal-related events or death 7
• Administered intravenously on Days 0,14,28, and then every 28 days 7

Comorbidity Screening

Cardiovascular Risk Assessment

Screen all lupus patients for cardiovascular risk factors including smoking status, history of vascular events, physical activity level, use of oral contraceptives/hormonal therapies, family history of cardiovascular disease, blood cholesterol and glucose, and blood pressure. 8, 2

• SLE patients have accelerated atherosclerosis requiring enhanced cardiovascular screening 8, 2

Infection Risk Screening

Perform infection screening for HIV, HCV, HBV, and tuberculosis according to local guidelines, as infections are a major cause of morbidity and mortality in SLE patients. 8, 2

Osteoporosis Assessment

Assess calcium and vitamin D intake, exercise habits, and smoking status at baseline and every 6-12 months; follow osteoporosis screening guidelines for postmenopausal women and patients on steroids. 2

Cancer Screening

Perform cancer screening according to general population guidelines, including cervical smear tests. 2

Clinical Monitoring Priorities

Renal Symptoms

Specifically ask about edema, foamy urine, hematuria, changes in urinary frequency or volume, and hypertension symptoms (headaches, vision changes). 8

Neuropsychiatric Symptoms

Screen for seizures, headaches, cognitive dysfunction (multitasking problems, difficulty with household tasks, memory problems, attention/concentration difficulties, word-finding difficulties), mood disorders, peripheral neuropathy, and stroke symptoms. 8

Thrombosis History

Document any history of arterial thrombosis (stroke, TIA, myocardial infarction at young age) and venous thrombosis (DVT, PE), as antiphospholipid syndrome significantly increases morbidity and mortality. 8

Obstetric History

Ask about pregnancy complications including recurrent miscarriages, preeclampsia, intrauterine growth restriction, and stillbirths. 8