Red blood cell and leukocyte alloimmunization in patients awaiting kidney transplantation

Recent trends in perioperative blood transfusion during elective kidney transplantation

Background

Accurately predicting the demand for blood transfusions is crucial for blood banks. Given the potential for emergency situations, it is imperative that blood banks maintain a sufficient inventory of blood products. In this study, we examined the use of perioperative transfusions in patients undergoing elective kidney transplants.

Methods

Data on all complement-dependent cytotoxicity-crossmatched assays between 2013 and 2022 were collected. We excluded repeated assays and patients who did not undergo kidney transplantation. Transfusion records and transfusion adverse reactions were reviewed retrospectively.

Results

In total, 30 patients underwent elective kidney transplantation from 2013 to 2022. The mean age of the patients was 48.1±9.7 years. The male-to-female ratio was 1.5:1. Four patients received transfusions intraoperatively, whereas eight patients were transfused postoperatively. The postoperative hemoglobin level of the transfusion group (n=9, 8.9±1.3) was significantly lower than that of the nontransfusion group (n=21, 10.4±1.2). The most commonly transfused blood product intraoperatively was leuko-reduced filtered red blood cells, followed by fresh frozen plasma. When the study period was divided into two halves based on the time of operation, the first half showed a higher number of significant transfusions.

Conclusions

In most elective kidney transplant cases, surgery was conducted without the need for blood transfusion. The timing of transfusion, when necessary, shifted from during the operation to after the operation. The implementation of patient blood management, coupled with advancements in surgical techniques, appears to have impacted the pattern of perioperative transfusion.

Red blood cell alloimmunization in multi-transfused patients with chronic kidney disease in Port Harcourt, South-South Nigeria

BACKGROUND

Serological safety is an integral part of overall safety for blood banks.

OBJECTIVES

The aim of the study was to determine the prevalence and specificities of red blood cell alloimmunization in multi-transfused patients with chronic kidney disease (CKD).

METHODS

A cross-sectional case-control study carried out at the University of Port Harcourt Teaching Hospital in which 186 patients with CKD were enrolled consecutively, 124 had received multiple transfusions (more than one unit of blood in one month, or at least 10 units within 3 months), while 62 had never been transfused. Antibody screen test was performed by the gel agglutination technique. RBC antibody identification was performed on the sera of those that tested positive to antibody screening test.

RESULTS

Out of the 124 multi-transfused patients (total of 789 transfusions), 4 (3.2%) were alloimmunised. The alloimmunised patients received a higher mean number of 17.5 ± 12 blood units, compared to 6 ± 6 units by the non-alloimmunised multi-transfused patient (p= <0.001). Six clinically significant alloantibodies were identified with all of the alloimmunised patients forming more than one antibody. Anti-E was detected in all alloimmunised patients.

CONCLUSION

The prevalence of RBC alloimmunisation in multi-transfused CKD patients was 3.2% with anti-E being the most frequently identified antibody.

Effect of Single Sensitization Event on Human Leukocyte Antigen Alloimmunization in Kidney Transplant Candidates: A Single-Center Experience

OBJECTIVES

Human leukocyte antigen alloimmunization is caused by exposure to HLA antigens through transfusion, pregnancy, or transplant. Our study objective was to present the rate of positivity of anti-HLA antibody considering the effects of a single sensitization event in kidney transplant candidates at our center.

MATERIALS AND METHODS

Our study reviewed 606 kidney transplant candidates. Patient sera were analyzed using Luminex xMAP technology. Panel reactive antibody positivity rates and antibody strengths in patients were analyzed according to a single sensitization event.

RESULTS

Our findings showed 246 patients (40.6%) with a panel reactive antibody > 0, of which 97 (39.4%) were sensitized from a single event, 119 (48.4%) were sensitized by multiple events, and 30 (12.2%) had no known sensitizing event. Considering patients sensitized by a single event with a panel reactive antibody > 0, we found that 25.8% had received transplant only, 49.5% had previous pregnancy only, and 24.7% had received transfusion only. The strength of antibodies was significantly higher in patients with previous transplant procedures than in those with transfusion for HLA-A (P < .01), HLA-B (P < .05), HLA-C (P < .05), HLA-DR (P < .001), HLA-DQ (P < .05), and HLA-DP (P < .05). Similarly, we observed significantly higher median fluorescence intensity values for HLA-A, -DR, -DQ, and -DP loci in patients with a previous transplant procedure versus pregnancy. The strength of antibodies against HLA-DR was significantly higher in patients with a previous pregnancy compared with those with transfusion (P < .01).

CONCLUSIONS

This study documents the profile of HLA alloimmunization in kidney transplant candidates. In particular, transplant procedures appear to have a greater immunologic impact, followed by pregnancy and transfusion. Our data confirm and are in accordance with those of several studies in which the sensitization events were associated with higher prevalence of anti-HLA antibodies.

Evaluation of the humoral immune response to human leukocyte antigens in Brazilian renal transplant candidates

Pre-transplant sensitization to human leukocyte antigens (HLA) is a risk factor for graft failure. Studies of the immunological profile related to anti-HLA antibodies in Brazilian renal transplant candidates are few. In this study, we evaluated the humoral immune response to HLA antigens in 269 renal transplant candidates, in Paraná State, Brazil. The HLA typing was performed by the polymerase chain reaction sequence-specific oligonucleotide method (PCR-SSO) combined with Luminex technology, using an SSO-LABType commercial kit (One Lambda, Inc., Canoga Park, CA, USA). The percentages of panel-reactive antibodies (PRA) and the specificity of anti-HLA antibodies were determined using the LS1PRA and LS2PRA commercial kits (One Lambda, Inc.). The PRA-positive group consisted of 182 (67.7%) patients, and the PRA-negative group of 87 (32.3%) patients. The two groups differed significantly only with respect to gender. Females were the most sensitized. Among the 182 patients with PRA- positive, 62 (34.1%) were positive for class I and negative for class II, 39 (21.4%) were negative for class I and positive for class II, and 81 (44.5%) were positive for both classes I and II. The HLA-A*02, A*24, A*01, B*44, B*35, B*15, DRB1*11, DRB1*04 and DRB1*03 allele groups were the most frequent. The specificities of anti-HLA antibodies were more frequent: A34, B57, Cw15, Cw16, DR51, DQ8 and DP14. This study documented the profile of anti-HLA antibodies in patients with chronic renal failure who were on waiting lists for an organ in Paraná, and found high sensitization to HLA antigens in the samples.