Report on anti-Dib encountered in two Hong Kong Chinese.

Two cases of anti-Dib, a rarely encountered antibody, were identified in serum samples referred by hospital blood banks during the past 13 months. Case 1 is a 41-year-old female who required blood for elective surgery. Case 2 is a premature infant suffering from mild neonatal jaundice on day 2 after birth. The anti-Dib in both cases exhibited marked dosage effect. The titer/score against Di(a+b+) and Di(a-b+) red blood cells (RBCs) in case 1 was 8/10 and 32/32, respectively, and in case 2, 4/18 and 32/46. The monocyte monolayer assay (MMA) also gave a similar pattern of results, being l5 percent and 100 percent reactive when tested with Di(a+b+) and Di(a-b+) RBCs in case 1, and 0.4 percent (within normal range) and l4.4 percent in case 2. The patient in case 1 underwent her operation without blood transfusion. The infant in case 2 was treated by phototherapy and subsequently recovered without the need for exchange transfusion.

Do monocyte ADCC assays accurately predict the severity of hemolytic disease of the newborn caused by antibodies to high-frequency antigens?

Monocyte ADCC assays are helpful indicators of the severity of hemolytic disease of the newborn (HDN) due to anti-D. It would be particularly useful if the assays also accurately predicted the ability of antibodies to high-frequency antigens (HFA) to cause HDN. To investigate this possibility, 14 antenatal sera containing antibodies to HFA were tested and the results correlated with the severity of HDN. Antibody titers were determined using an indirect antiglobulin test (IAT). Eight sera (anti-Hy, -Dib, -Jra, -Sc1, -Inb, -Wrb, and -U [n = 2]) had low ADCC activity (< 28%) and did not cause HDN. The IAT titers ranged from 4 to 128. Two antibodies (anti-Ena and anti-Rh29) had high ADCC activity (>/= 72%) and high IAT titers (>/= 1,024), and both caused severe HDN. The remaining four antibodies (anti-Cra, -Inb, and -U [n = 2]) had ADCC activity >/= 40 percent and titers >/= 128, but they did not cause HDN. The inability of anti-Cra and anti-Inb to cause HDN is presumed to be related to fetal antigen expression and tissue distribution. The anti-Inb was further investigated using monocyte binding and inhibition studies. The absence of HDN in the presence of potent anti-U remains unexplained. In general, antibodies with low ADCC activity do not cause HDN, but high ADCC activity does not always indicate severe HDN.

Hemolytic transfusion reactions due to anti-e+f detectable only by nonstandard serologic techniques.

A patient was transfused with a total of 14 units of red blood cells (RBCs) over 33 days (January 14 to February 15) at two hospitals. Febrile transfusion reactions were noted on three occasions, and hemoglobinuria was seen twice. Alloantibodies were not detected in a sample dated February 14, following a transfusion reaction, and this sample was referred to the North London Blond Transfusion Centre. Further samples were also obtained from before and after all transfusions at both hospitals. The patient's RBCs typed as A, D+, probable Rh phenotype (cDE/cDE). The direct antiglobulin test was negative, and serum samples following the second transfusion were red/brown in color. Serologic investigations were inconclusive on all samples taken until February 13 (after the fourth transfusion). At this time, a weak anti-e reacting by manual polybrene technique and an anti-e+f reacting by two-stage papain technique were detected. The serum also contained potent HLA antibodies. The patient subsequently received leukocyte-depleted group A, cDE/cDE RBCs with out any untoward effect. This case demonstrates the importance of a complete transfusion history and emphasizes that alloantibodies detectable only by nonstandard techniques can be clinically significant.

An example of anti-LWa in a 10-month-old infant.

Blood samples from a 10-month-old male infant requiring transfusion were found to contain an allomtibody reacting at 37 degrees C in saline, by indirect antiglobulin test (IAT), and with a manual polybrene technique. Preliminary results suggested anti-D and another weaker reacting antibody, but the patient had been previously transfused with only D- blood. His serum reacted more weakly by IAT against red cells treated with 0.2M dithiothreitol (DTT), and one D+, LW(a-) sample was nonreactive. The patient's red blood cells (RBCs) typed as B, D-, LW(a-), K-, Fy(a-). Due to the age and clinical status of the child, 51Cr survival studies were not performed. One pediatric unit of D-, K-, Fy(a-) blood was transfused uneventfully; the expected increment of hemoglobin was achieved. Repeat testing 3 months later showed a weakly positive DAT, the patient's RBCs typed as LW(a+), and anti-LWa was detected only by a two-stage papain technique. These results suggest that the patient had a transient depression of LWa with a concurrent anti-LWa.

Demonstration by the monoclonal antibody-specific immobilization of erythrocyte antigens assay that a new red cell antigen belongs to the Kell blood group system.

BACKGROUND: The Kell blood group system comprises 21 antigens residing on a red cell membrane glycoprotein of apparent M(r) 93,000. STUDY DESIGN AND METHODS: Serologic techniques were used to identify a new red cell antigen. The monoclonal antibody-specific immobilization of erythrocyte antigens (MAIEA) assay was used to identify the red cell membrane component carrying that antigen. RESULTS: A new high-frequency red cell antigen was identified and provisionally named RAZ. RAZ is absent from K.o red cells and from red cells treated with 2-amino-ethylisothiouronium bromide and is expressed weakly on McLeod phenotype cells. It differs from all other Kell system antigens, and no depression of other Kell system antigens on RAZ+ red cells was noticed. The RAZ antigen was shown by the MAIEA assay to be located on the Kell glycoprotein. CONCLUSION: RAZ is a new high-frequency antigen located on the Kell glycoprotein. The MAIEA assay is a very effective method of demonstrating the membrane structure carrying a red cell antigen.

The application of enhanced chemiluminescence to membrane-based nucleic acid detection.

The ECL gene detection system is a novel, sensitive, non-radioactive system for the detection of nucleic acid hybridized on both nylon and nitrocellulose membranes. It is characterized by direct labeling of probe sequences with horseradish peroxidase combined with an enhanced chemiluminescent (ECL) detection reaction; the light output is captured on blue-light sensitive film. The application of the system to a range of standard molecular biology hybridization techniques is described.

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.

Induction of red blood cell destruction by graft-derived antibodies after minor ABO-mismatched heart and lung transplantation.

Heart-lung transplantation (HLT) unlike other solid-organ transplants involves transplantation of a large amount of lymphoid tissue; hence there is considerable potential for graft-versus-host reaction if there is an antigen mismatch between donor and recipient. Due to the shortage of suitable donors, minor ABO-mismatched HLT (group O organs given to A, B, or AB recipients) are performed. Of 84 consecutive HLT at Harefield Hospital, nine fully ABO-matched and nine ABO-mismatched HLT were studied. Six minor ABO-mismatched HLT patients had evidence of immune destruction of recipient's red cells. Haemolysis started from days 4-12 and lasted for a mean of 13 days; in four cases transfusion support was necessary. ABO antibodies incompatible with the recipient ABO antigens, but compatible with the donor, were found in the serum and red cell eluates of these patients. In two cases, these antibodies were detected for over one year after transplantation. These changes were not seen in the fully ABO-matched controls. Our findings suggest that donor-derived lymphocytes from group O organs continue to produce anti-A and/or anti-B after transplantation, and if the recipient is group A, B, or AB, mount a secondary immune response following antigenic stimulation by the recipient's differing ABO antigens. The specific transfusion management of these patients is discussed.

Delayed haemolytic transfusion reaction due to simultaneous appearance of anti-Fya and Anti-Fy5.

We report here the development of anti-Fy5 in a young Negro female with sickle cell disease. The antibody was responsible for a delayed hemolytic transfusion reaction. We believe this is the first report of such an antibody in Europe.

Serologic characteristics of a further example of anti-Xga and the frequency of Xga in North London blood donors.

An example of an IgG anti-Xga of subclasses IgG1 and IgG2 that fixed complement was detected in a 92-year-old man. The serum was used to test 4000 routine British blood donors. The incidence of Xga was 0.677 in men and 0.895 in women.

Red cell alloimmunization in sickle cell disease.

Alloimmunization to red cell antigens contributes to morbidity in transfused patients. It has been recommended that blood for sickle cell patients need not be matched for antigens other than ABO and Rh(D), as there is no greater incidence of antibody production than in other multitransfused patient populations. Post transfusion alloimmunization was studied in a group of 34 sickle cell disease patients attending a U.K. haemoglobinopathy clinic. Red cell antibodies were formed in 17.6% of the transfused patients and Rhesus and Kell antibodies accounted for 66% of this total. In order to reduce alloimmunization, a policy of performing extended red cell phenotyping on the patients, and providing blood matched for Kell, and in certain circumstances the Rhesus antigens other than Rh(D), is recommended.

Eosinophilic ulcer of the tongue.

A case of an eosinophilic ulcer of the tongue is described and the literature reviewed. Eighteen other cases have been reported in the English literature.