Measurement of macrophage marker in hyperhaemolytic transfusion reaction: a case report.

BACKGROUND: Hyperhaemolytic transfusion reaction (HHTR) has been well described in patients with sickle cell disease (SCD). It is characterised by a decrease in haemoglobin concentration to levels below those before transfusion and a fall in the absolute reticulocyte count. As red blood cells (RBC) alloantibodies are typically not detected in post-transfusion samples in acute forms of HHTR, we have previously proposed that both the transfused and autologous RBCs cells (HbSS/reticulocytes) are destroyed by activated macrophages. CASE REPORTS: We report a patient with SCD who presented with vaso-occlusive sickle cell crisis and developed a severe HHTR attributable to anti-Fy3. In addition to the usual supportive measures, the patient was treated with intravenous immunoglobulin (IVIG) and steroids. Serum ferritin levels were measured as an aspecific marker of macrophage activation. RESULTS: Steroids and IVIG were effective in managing HHTR. Ferritin levels were high at the time of haemolysis, (>10000 µg L(-1)) whereas recovery and cessation of haemolysis correlated with a decrease in ferritin levels. CONCLUSION: Serum ferritin values >10,000 µg L(-1) are considered pathognomic for conditions characterised by abnormal macrophage activation. In our case, serum ferritin levels correlate well with the disease activity and clinical response. This further supports our previous proposal that the activated macrophages play an important role in HHTR. Serum ferritin is a nonspecific marker of inflammation. A rapid specific bio-marker to measure the activity of macrophages in SCD in HHTR is desirable, and this area warrants further investigation.

Management of pregnancy complicated by anti-hrB/anti-HrB.

Anti-hrB and anti-HrB are rare alloantibodies found predominantly in people of Black African descent. It has been assumed that strongly reacting examples of anti-hrB may cause hemolytic transfusion reactions, but precise information is limited. Anti-HrB is a clinically significant antibody and may cause hemolytic transfusion reactions and HDN. Selection of blood for transfusion support for patients with these alloantibodies, and especially with anti-HrB, imposes a special challenge in the United Kingdom. We report two antenatal patients (both patients were of the partial D phenotype DIII), one with anti-hrB, anti-Ce, and anti-D; the other,with anti-hrB and anti-D, who later formed anti-HrB. Transfusion support and the outcome of the pregnancies are discussed. A literature search confirms that,apart from some publications in abstract form,there is not much detailed clinical information available for either anti-hrB or anti-HrB. Further information and publications are warranted to gain more knowledge of these rare antibodies.

Use of red cells preserved in extended storage media for exchange transfusion in anti-k haemolytic disease of the newborn.

Anti-k is a Kell-related antibody. There is little correlation between the maternal antibody titre and the severity of haemolytic disease of the foetus and newborn, and anaemia is usually associated with low bilirubin levels. Severe erythroblastosis has been reported with a low titre anti-k (IAT 8-16). We report a case of severe haemolytic disease of the newborn (HDN) due to anti-k. HDN was associated with a normal bilirubin level and reticulocytopenia. The foetus was monitored by ultrasound, and delivery by elective caesarean section (CS) was planned. The mother was admitted 1 week before the expected date of delivery, and the infant was delivered by urgent CS. The infant required exchange transfusion. As suitable plasma-reduced (k antigen(-)) red cell units were not readily available, k- SAGM red cell units (preserved in extended storage media: SAGM sodium chloride, adenine, glucose and mannitol) were provided. The post-transfusion Hb remained stable, and the infant did not require further transfusion support. Our findings (reticulocytopenia and normal bilirubin levels) support the hypothesis that the pathogenesis of anaemia and haemolysis in anti-k HDN may be similar to that in anti-K (suppression of erythropoesis and immune destruction of K+ erythroid progenitor cells by macrophages in the foetal liver). The ideal product for exchange transfusion is plasma-reduced RBC, less than 5-days old. We provided a 4-day-old SAGM red cell unit for exchange transfusion in a term infant, and this was uneventful. Caution should be taken, however, and renal function and electrolyte levels should be monitored closely. More information is required regarding the safety of SAGM units for exchange transfusion.

ABH and Lewis antigen and antibody expression after bone marrow transplantation.

We have tested 10 bone marrow transplant donors and recipients for ABH and Lewis antigens and ABH antibodies. Two group A2 recipients stably engrafted with group O marrow produced anti-A1. Small quantities of recipient-type ABH substance were found on the posttransplant erythrocytes in cases where the recipient was a secretor but not in a single nonsecretor recipient. Lewis antigens were always of recipient type. The incidence of graft-versus-host disease and graft rejection were similar in 41 patients who received ABO-mismatched and 61 patients who received ABO-matched grafts.