SYSTEMIC LUPUS-ERYTHEMATOSUS, THROMBOCYTOPENIA, MICROANGIOPATHIC HEMOLYTIC-ANEMIA AND ANTI-CD36 ANTIBODIES

Thrombocytopenia in patients with acute systemic lupus erythematosus ( SLE) frequently presents the clinician with considerable diagnostic an d therapeutic difficulties. In this Grand Round, we present a 48-yr-ol d woman with a 7 yr history of lupus, who presented with acute prolife rative glomerulonephritis and nephrotic syndrome, pneumonia, profound hypocomplementaemia and a severe microangiopathic haemolytic anaemia w ith associated thrombocytopenia. Her thrombocytopenia proved initially refractory to conventional immunosuppressive therapy, and corticoster oids, and resolved only with plasma exchange and repeated fresh frozen plasma infusions. Serological testing revealed high-titre antinuclear antibodies (ANA) and markedly raised antibodies to double-stranded (d s) DNA, but no significant elevation in anticardiolipin antibodies. Pl atelet-associated Ige and IgM and antibodies to the CD36 glycoprotein antigen, expressed on platelets and endothelium, were detected in the serum. We address some of the difficult diagnostic and management issu es raised by this complex patient and the possible immunopathological links between antibodies to CD36, immune-mediated red cell destruction , thrombocytopenia and thrombotic microangiopathic haemolytic anaemia.