diagnosed in the presence of evidence of multiple organ system involvement, so no laboratory study is pathognomonic TABLE 101.2 IMMUNOMODULATORY AGENTS FOR THE TREATMENT OF SLE IN CHILDREN Biologic effects Principal toxicities Hydroxychloroquine Blocks Retinopathy, nausea, rash, lysosome agranulocytosis processing of autoantigens Azathioprine Precursor of 6- Bone marrow suppression, MP; blocks infection (especially purine zoster), nausea, hepatitis, synthesis rash Mycophenolate Blocks purine Bone marrow suppression, mofetil synthesis infections, nausea, diarrhea Cyclophosphamide Alkylates Bone marrow suppression, DNA opportunistic infections, leading to nausea, alopecia, bladder cytotoxicity toxicity, infertility, cardiotoxicity Rituximab Chimeric anti- Tumor lysis syndrome, CD20 anaphylaxis, monoclonal hypogammaglobulinemia, antibody opportunistic infections that depletes B-cells Belimumab Monoclonal Opportunistic infections, antibody infusion reactions, directed headache, nausea, fatigue, against depression including BLyS suicidal ideation Monitor Ophthalmology evaluation every mo, CBC, LFTs every 3–6 mo CBC, lymphocyte count, LFTs CBC, lymphocyte count WBC, UA, BUN/Cr IgG level, lymphocyte count Monitor for worsening depression SLE, systemic lupus erythematosus; CBC, complete blood cell count; LFT, liver function test; 6-MP, 6mercaptopurine; DNA, deoxyribonucleic acid; WBC, white blood cells; UA, urinalysis; BUN/Cr, blood urea nitrogen/creatinine; CD20, B lymphocyte surface marker; IgG, immunoglobulin G; BLyS, B lymphocyte stimulator