Hemolytic transfusion reactions causing acute renal failure. Serologic and clinical considerations

Analytic Reviews : Hemolytic Transfusion Reactions: A Review of Mechanisms, Sequelae, and Management

The transfusion of blood and blood products is an im portant therapeutic procedure, but it is associated with several potentially serious adverse effects. Among these complications are hemalytic reactions, which in most cases result from the interaction between donor red cell antigens and recipient plasma antibodies. Clinical mani festations and sequelae are largely determined by the physical and immunological characteristics of the anti gens and antibodies. Early recognition may be difficult in the anesthetized or intensively monitored patient. Acute hemolytic reactions are responsible for significant morbidity and mortality and may lead to life-threatening shock, disseminated intravascular coagulation, and renal failure. Fortunately, fatal hemolytic transfusion reactions are rare; they usually result from clerical errors. Proper diagnosis and management requires sound clinical judg ment, thorough laboratory investigation, and timely therapeutic intervention.

Current concepts and issues in blood management

Blood management in orthopedic surgery is no longer an option; it is a requirement. The combination of patient desire to avoid transfusion, increasing evidence of multiple risks, decreasing blood supplies, and increasing costs mandate attention. This article addresses the balance of risk versus benefit in blood transfusion and presents a perioperative plan of blood management for patients undergoing orthopedic surgery.

Transfusion to blood group A and O patients of group B RBCs that have been enzymatically converted to group O

BACKGROUND

The transfusion of ABO-incompatible RBCs is the leading cause of fatal transfusion reactions. Group O RBCs, lacking terminal immunodominant A and B sugars to which humans are immunized, are safe for transfusion to persons of any ABO blood group. With the use of a recombinant alpha-galactosidase to remove terminal galactose from group B RBCs, the safety and efficacy of enzyme-converted group-B-to-group-O (ECO) RBC components were studied in transfusion-dependent patients.

STUDY DESIGN AND METHODS

Twenty-four patients (blood groups A and O) were randomly assigned to receive transfusion(s) of either ECO or control group O RBCs. If a second transfusion was given, the other blood component was administered.

RESULTS

Twenty-one patients were given ECO RBCs; 18 also underwent control transfusions. One patient received only a small aliquot for RBC survival studies, instead of a full-unit transfusion, because his serum was incompatible with ECO RBCs. No adverse events occurred. Both ECO and control transfusions resulted in appropriate Hb increments and comparable (51)Cr-labeled RBC survival studies. One patient developed a transient, weak-positive DAT, without hemolysis. Two weeks after transfusion, 5 of 19 evaluable ECO RBC recipients had increases in anti-B titers.

CONCLUSION

ECO RBCs were comparable to group O cells for safety and efficacy in this study. The clinical significance of the increase in anti-B and of occasional serologic incompatibilities with ECO RBCs is unclear. If strategies can be developed to remove A epitopes, enzymatic conversion could be used to create a universal (group O) donor blood supply.

[Immuno-hemolytic transfusion reactions. IV. Analysis, risks and prevention]

The immunological risk of red blood cell transfusions now seems higher than the viral risk. According to studies, severe accidents due to blood incompatibility occur with a frequency estimated at 1/6000 to 1/29000; despite technical progress, the risk does not significantly diminish. The majority of accidents do not originate from laboratory or production stages but from defects in the application of clinical procedures. Preventive measures are based on (i) the elaboration of clinical guidelines, (ii) the compliance to strict rules in carrying out bedside ABO check, and (iii) the realization and interpretation of antibody screening tests. The implementation of quality assurance systems and of the epidemiological surveillance system, which define the basis of a prevention policy, leads to the expectation of an improvement of transfusion safety.

A prospective study of the incidence of delayed haemolytic transfusion reactions following peri-operative blood transfusion

Delayed haemolytic transfusion reactions (DHTRs) are a recognized sequel of blood transfusion. The true incidence and importance of this complication have been difficult to estimate due to the lack of any prospective studies. We have carried out such a study by testing 530 patients who were transfused during cardiac surgery. 2% of the patients had new red cell alloantibodies detectable 1 week following transfusion. Despite this finding, and the fact that at the time the study was performed pre-transfusion antibody screening of recipients was not routine practice, no DHTRs were diagnosed on clinical or laboratory criteria. These results indicate that the reported incidences, based on retrospective recognition of DHTRs, are not a serious underestimate of the frequency of the complication.