Systemic lupus erythematosus after acute lymphoblastic leukaemia.

Systemic lupus erythematosus after acute lymphoblastic leukaemia SIR, Systemic lupus erythematosus (SLE) is associated with an increased risk of neoplasia of the lympho-reticular system, particularly lymphoma [1, 2]. While non-Hodgkin's and Hodgkin's lymphomas are the commonest associated malignancies [3, 4], cases of myeloma [5, 6] and leukaemia [7] have also been documented and there have been reports of SLE occurring after thymectomy or thymomectomy [8] or after chemotherapy and radiotherapy for malignant thymoma [9]. Usually, SLE precedes the onset of lymphoprolifera-tive disease [10–13], but the neoplasia can occur earlier [10] or simultaneously [14]. Single cases have been described of SLE preceding acute lymphoblastic leukaemia (ALL) [15] and of SLE appearing 5 yr after complete remission of ALL induced by mercaptopurine [16]. This report describes the appearance of SLE in a young woman 10 yr after she completed successful treatment for ALL. The patient presented in 1976 at the age of 2 yr with pancytopenia, lymphadenopathy and hepatospleno-megaly. ALL was diagnosed on a bone marrow biopsy and she was commenced on UKALL V chemotherapy, comprising cycles of prednisolone, vincristine, metho-trexate and mercaptopurine. At the onset of treatment she also received cranial irradiation. She completed her last UKALL V cycle in 1979 and subsequently remained in full haematological remission. In 1989, when the patient was 15 yr old, she developed an intermittent rash and limb pains with a slightly elevated erythrocyte sedimentation rate (ESR) of 22 mmuh. Further investigation for joint pains in 1993 revealed a mild lymphopenia of 1.0 3 10 9 ul and an ESR of 36 mmuh. Antinuclear antibodies (ANA) were detected to a titre of >1 : 320 and rheumatoid factor to a titre of 1 : 80, whereas DNA binding activity was within the normal reference range. In 1994 she was referred to the rheumatology clinic with widespread pains and Raynaud's phenomenon. There was no overt synovitis but she had a mild flexion contracture of her right elbow. Her total white blood cell count was 2.7 3 10 9 ul with a differential of 1.0 lymphocytes and 1.5 neutrophils, and an extractable nuclear antigen screen revealed anti-Sm antibodies. Her platelet count, serum creatinine concentration, urine chemistry and microscopy, liver function tests and serum creatine phosphokinase were normal. She was diagnosed as having mild SLE. Various mechanisms have been postulated to explain the association between SLE and malignancies of the lymphoreticular system. Hypotheses include a common stimulus, such …