Thrombotic thrombocytopenic purpura (T.T.P.) and systemic lupus erythematosus (S.L.E.)

Abstract

T.T.P. and S.L.E. are both multisystem diseases and the latter may manifest a wide range of haemopoietic abnormalities that may mimic T.T.P. This has led to diagnostic confusion and reports of the two diseases occurring in the one patient. We describe an illustrative case of a 15-yr-old girl who presented at the age of 12 with purpura, fever, headaches and changes in conscious state. She had thrombocytopenia, microangiopathic haemolytic anaemia, and despite the absence of renal disease T.T.P. was diagnosed. ANA and LE cells were negative then, and when repeated 1 yr later. In 1979 she presented again with the nephrotic syndrome with a positive ANA (1:100) and elevated DNA antibodies (79 U/ml, N < 25). Platelet count was 270,000, PTTK 61 sec (N 25-40) and a circulating anticoagulant was present. Renal biopsy confirmed the presence of lupus nephritis. Up to 20% of cases of T.T.P. have features of S.L.E. This case is presented to illustrate this overlap between the two entities, both of which are associated with immune complexes, and the possible diagnostic difficulties. T.T.P. and S.L.E. are both multisystem diseases and the latter may manifest a wide range of haemopoietic abnormalities that may mimic T.T.P. This has led to diagnostic confusion and reports of the two diseases occurring in the one patient. We describe an illustrative case of a 15-yr-old girl who presented at the age of 12 with purpura, fever, headaches and changes in conscious state. She had thrombocytopenia, microangiopathic haemolytic anaemia, and despite the absence of renal disease T.T.P. was diagnosed. ANA and LE cells were negative then, and when repeated 1 yr later. In 1979 she presented again with the nephrotic syndrome with a positive ANA (1:100) and elevated DNA antibodies (79 U/ml, N < 25). Platelet count was 270,000, PTTK 61 sec (N 25-40) and a circulating anticoagulant was present. Renal biopsy confirmed the presence of lupus nephritis. Up to 20% of cases of T.T.P. have features of S.L.E. This case is presented to illustrate this overlap between the two entities, both of which are associated with immune complexes, and the possible diagnostic difficulties.