A case report: a pediatric patient with acute lupus hemophagocytic syndrome; differences from reactive hemophagocytosis caused by hypercytokinemia

Abstract We report the youngest known girl with acute lupus hemophagocytic syndrome (ALHS) at the onset of her illness. We investigated the pathogenesis of ALHS by assessment of factors thought to influence the onset, such as cytokines, Th1/Th2 balance, immune complexes, and autoantibodies. A girl 8 years and 10 months old with systemic lupus erythematosus (SLE) had high fever, pancytopenia, and hemophagocytosis in the bone marrow. We diagnosed SLE complicated by ALHS. Treatment with predonisolone (2 mg/kg/day) was started, and her clinical features improved. Th2 dominance of the Th1/Th2 balance, hypocomplementemia, and high levels of anti-ds-DNA antibody, PAIgG, and immune complexes were seen, but no hypercytokinenemia, hyperferritinemia, or hypertriglyceridemia. ALHS at the onset of SLE, excluding that caused by infections, could be a form of reactive hemophagocytosis caused by excessive production of autoantibodies and immune complexes. High-dose steroid therapy is effective without need for immunosuppressive drugs. Our patient showed hypocomplementemia along with high levels of anti-dsDNA antibody, anticardiolipin antibody, platelet-associated IgG (PAIgG), and immune complexes. The autoimmune-associated hemophagocytic syndrome (AAHS) is thought to involve an autoantibody-mediated mechanism or an immune complex-mediated mechanism. On the basis of our data, ALHS could simultaneously involve both these mechanisms. We demonstrated that there was no hypercytokinemia and no hyperferritinemia in ALHS associated with Th2 dominance. Autoantibodies and immune complexes may cause histiocytic hemophagocytosis in ALHS. High-dose steroids and high-dose immunoglobulin are effective but immunosuppressive drugs are not needed.