Blood Group Lewis Alloantibodies Cause Antibody-Mediated Rejection in Renal Transplant Recipients

The Role of the Duffy Blood Group Antigens in Renal Transplantation and Rejection. A Mini Review

Finding a compatible donor for kidney transplant candidates requires overcoming immunological barriers such as human leukocyte antigens (HLA) compatibility and ABO compatibility. Emerging data suggest a role for red blood cell antigens (RCA) in renal transplant outcomes. The incidence of RCA alloimmunization is high in chronically transfused individuals, such as end stage renal disease patients, but whether antibodies to RCA can mediate renal graft rejection remains debatable. The Duffy blood group antigens (Fy) has been shown to be expressed in the kidney, among other tissues. There are some data to suggest that donor-recipient Fy mismatches may increase the risk for chronic allograft damage and that anti-Fy antibodies may be involved in renal graft rejection, however, while it is routine to screen renal transplant candidates for ABO antigens, detailed RCA phenotyping of the donor kidney is not routinely tested. In this paper, we review the current data on the role of Fy in renal transplantation and discuss the potential mechanisms of its biological function.

Serological characteristics of Lewis antibodies and their clinical significance - A case series

INTRODUCTION

Lewis antibodies have been thought to play a small role in clinical transfusion practice, but recent reports suggest that they have gained more importance in the context of transfusion and transplantation. Data regarding the prevalence of Lewis antibodies and their clinical significance in the Indian context is very limited. Hence, this study was aimed at analyzing the serological characteristics and clinical significance of Lewis antibodies encountered in our patient and donor populations.

METHODS

The retrospective data analyzed the records of red cell antibody screening results and the additional serological evaluation performed on the donor and patient samples included in the study.

RESULTS

A total of 26 study subjects were noted to have Lewis antibodies (including 6 healthy donors and 20 patients). Of them, 13 individuals had anti-Le^b, 10 had anti-Le^a and the remaining three had an anti-Le^a/Le^b mixture. IgG Lewis antibodies were detected in 7 individuals. All cases of IgM Lewis antibodies detected were reacting at 37°C. Two patients were suspected of having hemolytic transfusion reactions due to Lewis antibodies. Antigen-negative cross-match compatible units were provided for transfusion in the recipients.

CONCLUSION

Lewis antibodies of the IgM class reacting at 37°C should be regarded as clinically important. The present study findings urge that the lab personnel look for the thermal amplitude of Lewis antibodies, irrespective of the fact that the antibody class and antigen-negative crossmatch compatible units should be provided to avoid hemolytic transfusion reactions.

The potential role of antibodies against minor blood group antigens in renal transplantation

Blood group antigens are red blood cell (RBC) surface markers comprising specific carbohydrate moieties attached to the glycolipids and glycoproteins within the membrane. In addition to the major ABO blood group antigens, at least 35 minor blood group antigens have been defined to date. These antigens have immunogenic potential and may cause a transfusion reaction. There is evidence for renal expression of antigens from the Kidd, MNS, Duffy and Lewis groups and therefore the potential for antibodies directed against these antigens to cross-react in a transplanted kidney. In individuals lacking a specific RBC antigen, antibodies may develop after de novo exposure to that antigen, in addition to the potential presence of pre-existing innate antibodies. Relatively little attention has been paid to non-ABO system antibodies, with most reports in the literature focusing on transfusion reactions rather than on any putative role in allograft rejection. Here, we review each of these antigens in the context of renal transplantation and what limited evidence there is on how such immunological risk may be assessed and managed.

A positive complement dependent cytotoxicity immunoglobulin G crossmatch due to auto-antibodies with a negative luminex bead assays in a renal transplant recipient: A Diagnostic dilemma

Transplant recipients are always at a risk of developing anti-human leukocyte antigen (HLA) antibodies due to prior sensitizing events such as blood transfusions, multiple pregnancies, or transplantation. Unexpected positive outcomes can be seen in complement dependent cytotoxicity (CDC) based assays due to underlying autoimmune disorders or pharmacological treatment (rituximab/intravenous immunoglobulin/anti-thymocyte globulin administration), therefore, limiting its value. CDC based assay results strongly depend on the vitality of the donor lymphocytes, highlighting another major limitation of this assay. Thus, as an alternative approach, solid phase based crossmatch assays were introduced which function independently of the cell quality and have higher sensitivity and specificity in detecting anti-HLA antibodies. We describe a case where the patient awaiting renal transplantation from living related donor was evaluated by pretransplant histocompatibility testing for the detection of anti-HLA antibodies. The histocompatibility testing revealed positive CDC anti-human globulin and flow crossmatch along with negative Luminex based assays (HLA antibody screen, luminex crossmatch, and luminex single bead assay). Detailed histocompatibility workup revealed immunoglobulin G autoantibodies which were complement activating and lympocytoxic in nature.

Long-term follow-up of non-HLA and anti-HLA antibodies: incidence and importance in renal transplantation

BACKGROUND

Detection of antibody-mediated injury is becoming increasingly important in post-transplant patient care. The role of donor-specific anti-human leukocyte antigen (HLA) antibodies in kidney transplant damage is known, whereas the significance of non-HLA antibodies remains an unresolved concern. The aim of the study was to determine the presence and influence on renal function of non-HLA and anti-HLA antibodies in stable patients at 5 years after kidney transplantation.

METHODS

We evaluated the antibodies in 35 consecutive patients with stable renal function at 5 years after transplantation.

RESULTS

Pretransplant screening for donor-specific antibodies by CDC cross-matches was negative in all patients. Anti-endothelial cell antibodies (AECA), anti-angiotensin II type 1 receptor antibodies (anti-AT1R), and anti-endothelin receptor antibodies (anti-ETAR) were assayed as non-HLA antibodies. Non-HLA antibodies were observed in 12 (34%) patients, including AECA (n = 5; 14%), anti- AT1R (n = 6; 17%), anti-ETAR (n = 4; 11%), and both anti-AT1R and anti-ETAR (n = 3). Among 13 (37%) patients with anti-HLA antibodies, 7 also had both non-HLA antibodies: AECA (n = 1), anti-AT1R (n = 3), and anti-ETAR (n = 3). The antibody-negative group (n = 13) showed significantly better renal function than the antibody-positive group (non-HLA and/or anti-HLA; n = 22). Biopsy-proven acute rejection had occurred in 2 of 13 (15%) antibody-negative versus 8 of 22 (36%) antibody-positive patients. These preliminary data revealed an high prevalence of autoantibody and alloantibody production among stable patients at 5 years after kidney transplantation.

CONCLUSION

Simultaneous production of these antibodies and their association with reduced renal function suggests that active humoral immune responses are poorly controlled by immunosuppression.

Non-ABO blood group systems phenotyping in non-human primates for blood banking laboratory and xenotransplantation

Some biomedical research procedures, such as organ xenotransplantation, usually require intensive hemotherapy. Knowledge of the whole phenotype of blood donor and graft could be useful in the field of xenotransplantation. Human and simian-type categories of blood groups have been established and they can be tested by standard methods used for human blood grouping. The aim of this work was to study the incidence of non-ABO blood group systems in different species of non-human primates, which are employed in biomedical research. The phenotype of Rh, Lewis, Kidd, Kell, MNSs, Lutheran, P and Duffy antigens was investigated in olive baboon (n = 48), chacma baboon (n = 9), Guinea baboon (n = 14), Rhesus macaque (n = 38) and squirrel monkey (n = 30) by using commercial microtyping cards. Kell, Lutheran, Kidd and Duffy antigens have been detected in all species, Rh in squirrel monkey, MNSs in rhesus macaque and squirrel monkey, and Lewis in baboon and rhesus macaque. There were differences in frequency and haemagglutination scores between species regardless of their gender and age. The main differences were found in squirrel monkey when compared with baboons and macaques. This typing system provides a tool to assess the presence of antigens in animals used for experimental procedures, such as xenotransplantation and xenotransfusion.