Systemic lupus erythematosus, thrombocytopenia, microangiopathic haemolytic anaemia and anti-CD36 antibodies [clinical conference]

Thrombocytopenia in patients with acute systemic lupus erythematosus (SLE)frequently presents the clinician with considerable diagnostic andtherapeutic difficulties. In this Grand Round, we present a 48-yr- oldwoman with a 7 yr history of lupus, who presented with acute proliferativeglomerulonephritis and nephrotic syndrome, pneumonia, profoundhypocomplementaemia and a severe microangiopathic haemolytic anaemia withassociated thrombocytopenia. Her thrombocytopenia proved initiallyrefractory to conventional immunosuppressive therapy, and corticosteroids,and resolved only with plasma exchange and repeated fresh frozen plasmainfusions. Serological testing revealed high-titre antinuclear antibodies(ANA) and markedly raised antibodies to double- stranded (ds) DNA, but nosignificant elevation in anticardiolipin antibodies. Platelet-associatedIgG and IgM and antibodies to the CD36 glycoprotein antigen, expressed onplatelets and endothelium, were detected in the serum. We address some ofthe difficult diagnostic and management issues raised by this complexpatient and the possible immunopathological links between antibodies toCD36, immune-mediated red cell destruction, thrombocytopenia and thromboticmicroangiopathic haemolytic anaemia.