Adequate dialysis with special attention to proper nutrition aimed to achieve the high end of normal BMI may help to reduce the high mortality and morbidity in hemodialysis patients.

Delayed haemolytic transfusion reactions (DHTRs) are seen more frequently in patients with sickle cell disease (SCD) than in other groups of patients, and are characterised by a positive direct antiglobulin test and the appearance of previously undetected red blood cell (RBC) alloantibodies in the patient's serum. Recently a syndrome of post-transfusion hyperhaemolysis has been described in children with SCD, characterised by destruction of both autologous and transfused RBCs with negative serological findings: continuation of RBC transfusion exacerbated haemolysis further. We describe a case of life-threatening post-transfusion hyperhaemolysis in an adult patient with SCD in whom severe anaemia necessitated further RBC transfusion, which was successfully performed in conjunction with intravenous immunoglobulin. This approach may be useful in the management of post-transfusion hyperhaemolysis in SCD as well as in the management of severe DHTRs.

Summary. The refusal of Jehovah's Witnesses with leukaemia to accept transfusion provides a major clinical challenge because of the myelosuppressive effects of chemotherapy. Experience in treating five such patients is described. Two patients with acute lymphoblastic leukaemia (ALL) achieved remission following chemotherapy, the first without transfusion support, the second, a minor, receiving transfusion under a court order; the first patient remains in remission 5 years later, whereas the second subsequently relapsed and died. Of three patients with acute myeloid leukaemia (AML), two received chemotherapy: one died of anaemia during induction chemotherapy whereas the second eventually consented to transfusion but died of refractory leukaemia.The third patient died of anaemia despite erythropoietin. We feel Jehovah's Witnesses should not be denied antileukaemic therapy if they fully understand the risks involved. Minimizing phlebotomy, use of antifibrinolytic agents and growth factors may make chemotherapy feasible, especially in ALL where remission may be induced with less myelosuppressive agents. The outlook for those with AML treated with conventional chemotherapy appears poor; alternative approaches to treatment should be considered in these patients.

Forty adult subjects were studied with the aim of establishing positive diagnostic criteria in primary proliferative polycythaemia (polycythaemia vera, PPP). These comprised 14 patients with PPP, eight secondary polycythaemia (SP), five idiopathic erythrocytosis, and 13 normal subjects, classified under standard criteria following comprehensive investigation for causes of SP. Erythroid colony formation from peripheral blood in a serum-free system was assayed with the addition of recombinant human erythropoietin (Epo), interleukin 3 (IL3), or alpha-interferon (alpha-IFN). The differential sensitivity of primitive and mature progenitors (BFU-E) was assessed by counting the number of clusters ('sub-colonies') comprising each erythroid burst. 'Endogenous' erythroid colonies were found in both PPP (56%) and controls (17%). In Epo containing cultures, the mean number of clusters per burst was lower in PPP than controls, and the percentage of small (less than or equal to 8 clusters) bursts was higher. In PPP primitive BFU-E demonstrated greater dependence on IL3 than controls, and mature BFU-E greater inhibition by alpha-IFN. These findings suggest an abnormal response to several growth factors, rather than dysfunction of a single growth factor receptor. Regression analysis of these data defined a discriminant of high diagnostic sensitivity and specificity. This discriminant accurately predicted diagnosis in a further nine polycythaemic patients.