[Significance of blood groups in surgical practice]

Based on their personal experience and analysis of literature data the authors elucidate the significance of achievements of the present-day immunohematology in surgical practice: in blood transfusion, allotransplantation, the connection of surgical diseases with group antigens of blood.

A double buffy coat method for red cell removal from ABO-incompatible marrow

Hemolytic reactions caused by transfusion of ABO-incompatible marrow can be ameliorated by either reduction of isohemagglutinins in the recipient or depletion of incompatible red cells from the harvested marrow. This article describes a rapid and reliable method for removal of incompatible marrow red cells on a blood cell processor using a double buffy coat technique. In five allogeneic bone marrow transplants, the maximum value of transfused incompatible red cells was 8.8 ml. There was no evidence of a hemolytic transfusion reaction in any patient. The median cell recovery for nucleated marrow cells and progenitor cells was 77 and 104 percent, respectively. Engraftment occurred at a median of 13 days (range, 11-21 days) after transplantation. The double buffy coat method of red cell depletion is an acceptable method for processing ABO-incompatible marrow.

ABO-incompatible living related donor kidney transplantation: report of two cases

The courses of two recipients of ABO-incompatible HLA-identical living related donor kidney transplants are described, the first an A into O and the second a B into A. Both patients were prepared by a month of preoperative azathioprine and a week of plasmapheresis to reduce isohemagglutinin titers in one to 1:2 and in the other to 0 at the time of transplant. Both had early mild steroid-reversible rejections, and the first patient has had an uneventful subsequent course 20 months postgrafting on low-dose cyclosporine and prednisone. The second patient developed a further immunologic event at 1 month that may have been isohemagglutinin mediated or may have been rejection but subsided with OKT3 therapy and plasmapheresis. She lost her graft at 5 months despite normal function during attempts to repair a ureteric fibrosis. Neither patient had donor-specific transfusion or splenectomy. This approach is feasible and should be considered for those patients having related but ABO-incompatible donors.

[Delayed hemolytic transfusion reaction caused by an anti-U]

Delayed hemolytic transfusion reactions due to anti-U are rare, only two (2) cases having been reported in the literature. We now report a third case: a multiparous black woman without any transfusion history was admitted to hospital for severe microlytic anemia (31 g/l). The patient was group AB negative, the direct antiglobulin test was negative and an anti P1 cold allo-antibody was present in her serum. Five A, Rh negative, P2 packed red cells were cross-marched with the sample obtained at admission on January 8, 1988. She was transfused on January 8, 9, 10, 11 and 12. On the 12th of January her hemoglobin level reached 125 g/l. On January 13, the patient presented clinical signs of hemolysis and her hemoglobin fell to 60 g/l within 24 hours. On January 15, the direct antiglobulin test was positive and an antibody found in her serum was reactive with all the red cells of the commercial panel. The sample was referred to our red cell serology reference laboratory. The phenotype of the pre-transfusion sample was found to be Fy(a-b-) M, N, S-s-U-. An anti-U was detected in the eluate and the serum. The patient was transfused with two (2) units of O-P2, U-red cells obtained from the American Red Cross, Syracuse, and her hemoglobin reached 90 g/l within 48 hours. This is the third reported case of a delayed hemolytic transfusion reaction due to anti-U. This case illustrates the need to perform cross-matches with samples obtained within 48 hours of the scheduled transfusion for patients who have been transfused with blood in the preceding 3 months. Also, this case emphasises the need to recruit U negative blood donors for the Canadian rare donor file.

Risk of alloimmunization and delayed hemolytic transfusion reactions in patients with sickle cell disease

Blood transfusion is an integral part of the supportive care of patients with sickle cell diseases. The hazards of red blood cell alloimmunization and delayed hemolytic transfusion reactions (DHTRs) complicate the treatment of patients with sickle cell diseases, particularly since such reactions may be misinterpreted as a pain crisis, and, as a result, specific transfusion serologic studies may not be performed. The frequency of alloimmunization in this population has been the subject of several reports; however, the frequency of DHTRs is unknown. To determine the frequency of this event, we retrospectively reviewed the medical and transfusion service records of all adult patients with sickle cell diseases transfused during the six-year period from January 1980 to December 1985. Seventy-three adult patients with sickle cell diseases received transfusions. The prevalence of recognized DHTR was three (4%) of 73. Red blood cell alloimmunization was seen in 22 (30%) of 73 of the patients. The calculated risk of alloimmunization was 3.1% per unit of blood. These observations suggest that alloimmunization and clinically apparent DHTRs occur more frequently in patients with sickle cell diseases and support pretransfusion testing for at least Rh and Kell red blood cell antigens in patients who are at high risk of such events (patients who have formed an alloantibody or who are being enrolled in a transfusion program).

Loss of red cell alloantibodies over time

The loss of red cell alloantibodies over time was analyzed in 160 patients with 209 antibodies retested 1 to 60 months after initial identification. The mean follow-up consisted of 3.6 specimens taken over 18 months. Twenty-nine percent of clinically significant and 72 percent of clinically insignificant antibodies were not detected on at least one follow-up screening. Anti-Jka and anti-C were lost in 59 and 45 percent of cases, respectively. No significant differences in overall antibody loss were found according to sex, diagnosis, or the presence of multiple antibodies. Patients under 20 years of age may be more likely to lose significant antibodies. Pretransfusion review of previous records is vital for the prevention of delayed hemolytic transfusion reactions, because of the high number of clinically significant antibodies that are undetected in subsequent routine screening.

Class I HLA molecules on human erythrocytes. Quantitation and transfusion effects

HLA class I molecules were quantitated on erythrocytes from individuals expressing either high or low levels of such antigens. Quantitative determinations were accomplished using 125I-labeled Fab fragments of the anti-HLA monoclonal antibody W6/32 in a competitive binding assay. The experimental conditions of the test system were established using red cells from an individual found to express high levels of red cell HLA when examined by flow cytometry. The competitive binding assay met the requirements of ligand specificity and specific binding saturability. Scatchard analysis revealed that there were 1684 +/- 39 (mean +/- SD) HLA molecules/red cell. In two other donors in whom erythrocyte HLA was undetectable by flow cytometry specific binding of the 125I-W6/32 Fab fragments was clearly demonstrated, indicating the presence of HLA on red cells of these donors as well. The number of HLA molecules/red cell was estimated to be between 100 and 200 for these individuals. Thus, in a blood transfusion unit, the number of HLA molecules contributed by the red cells is comparable to that of the leukocytes. Blood highly depleted of leukocytes and platelets and selected from donors with low amounts of red cell HLA was not beneficial (when transfused to selected patients) in that their sensitizing effects were not significantly different from regular blood transfusions. These results show that the amount of HLA antigens on red cells, while low if compared with other cell types, is significant in terms of the absolute antigenic content of blood transfusions. They also show that transfusion of blood units containing HLA antigens in concentrations as low as can be achieved with current technology were not useful in preventing HLA sensitization in patients at risk.

[Transfusion reaction following blood warmed with a microwave blood warmer]

A transfusion reaction was observed with blood warmed by a microwave blood warmer. Analysis of the blood remaining in the bag excluded the possibility of incompatibility but revealed hemolysis and clot formation which was attributed to overheating by the blood warmer.

Prediction of crossmatch outcome in highly sensitized dialysis patients based on the identification of serum HLA antibodies

High levels of allosensitization (greater than 50%), which often occur in dialysis patients awaiting renal transplant, make donor selection difficult. Such patients may be included in elaborate protocols in which they are crossmatched with all available ABO compatible donors, or crossmatching may be deferred until a very-well-matched donor becomes available. The former approach of random crossmatching is costly and inefficient, while the latter approach may overlook crossmatch-compatible donors. We believe that the identification of antibodies present in highly reactive sera and the use of this information in donor selection would increase the frequency of crossmatch-negative donors for these patients. In this study eleven sera, reactive with 70% to 100% of a random cell panel, were obtained from multiply transfused dialysis patients. Sera were analyzed by standard (CDC) and antiglobulin augmented (AHG-CDC) lymphocytotoxicity, and by differential absorption with HLA-typed platelets. All sera contained only one or two antibodies directed against the high frequency public HLA epitopes, accounting for 85% to 100% of each serum's total reactivity. These characterized sera were crossmatched with 114 random normal donors. The frequency of negative crossmatches was 20.5%. However, if the serum antibody data had been used to preselect donors for crossmatch--that is, to exclude donors that were likely to be positive--the negative crossmatch frequency would have increased to 86.4%. The use of the serum analysis data in donor selection would have reduced the total number of required crossmatches by 78%. Serum analysis correctly predicted the outcome of 95.6% of crossmatches performed with an average of 3% false positives and 1.3% false negatives. This approach to donor selection reduces unnecessary crossmatching and increases the likelihood of finding crossmatch-compatible donors for highly reactive patients.

Interdonor incompatibility due to anti-Kell antibody undetectable by automated antibody screening

A unit of whole donor blood, the plasma of which contained anti-Kell antibody, was transfused into a Kell-negative patient who had received a unit of Kell-positive blood 4 weeks previously. A haemolytic transfusion reaction ensued. The antibody had gone undetected in routine automated screening of the donor blood. Automated antibody detection techniques do not offer reliable detection of anti-Kell antibodies.

HLA-B35 is associated with red cell alloimmunization in sickle cell disease

HLA-A, -B, -C, and DR antigens were determined in 33 patients with sickle cell disease (SCD), who had received red blood cell (RBC) transfusions. Twenty-one patients formed red cell alloantibodies after transfusions (responders) while 12 multitransfused SCD patients did not form any RBC antibodies (non-responders). We found that 67% of the SCD responder participants had HLA-B35 versus 25% of the non-responders (chi 2 = 5.3079, P = 0.0212). The frequency of B35 in non-responder SCD patients was similar to that of a normal healthy Black population consisting of 139 individuals. Calculation of the relative risk showed that sickle cell patients with B35 are six times more likely to form RBC alloantibodies after transfusion than those lacking that HLA antigen. We found no significant increase or association between any HLA-DR antigens and sickle cell disease.

Kell alloimmunization, hemolytic disease of the newborn, and perinatal management

The relative frequency of Kell (K:1) antibodies in pregnant women and a series of cases of Kell hemolytic disease of newborns were evaluated to review the strategy of managing potential disease. Among reproductive-aged women, Kell antibodies are about 60% as frequent as Rho (D) antibodies, but Kell disease is only 3% as common as Rho hemolytic disease. The reason is related to frequent transfusion-alloimmunization by Kell antigen and the low frequency of the K:1 gene among fathers. Kell hemolysis is severe in about half of cases. Amniocentesis is indicated in only a few circumstances: previous child with erythroblastosis fetalis, significant increase in maternal Coombs titer, presence of Kell antigen in the father, and after comparison of the relative risks of hemolytic disease and amniocentesis in each patient. Screening for Kell antigen before transfusing premenopausal women would be a means of avoiding erythroblastosis, but the rarity of severe disease does not justify this approach.