# Immunological consequences of past transfusions in kidney transplant candidates: A focus on anti-HLA antibody formation

## TL;DR

This study examines how blood transfusions affect immune responses in kidney transplant candidates, focusing on the formation of anti-HLA antibodies.

## Contribution

The study identifies that blood components containing white blood cells and packed red blood cells are associated with higher sensitization rates.

## Key findings

- Leukodepleted blood components and those containing white blood cells are linked to increased anti-HLA antibody formation.
- Sensitization was detected more frequently over 12 months after transfusion.
- Packed red blood cells showed a significantly higher sensitization rate compared to other transfusion types.

## Abstract

Blood transfusions are crucial for saving lives but can affect the recipient's immune system. A significant concern is the development of anti-human leukocyte antigen (HLA) antibodies, which can influence organ transplantation outcomes. The presence of these antibodies increases the risk of transplant rejection. The aim of this study was to evaluate how blood component characteristics (leukodepletion, type, number, volume) and timing from the last transfusion to anti-HLA antibody detection affect sensitization in kidney transplant candidates.

This retrospective study analyzed 115 candidates on the cadaveric kidney transplant list from South Bačka and Novi Sad, Serbia. Among them, 69 received blood transfusions, classified as either leukodepleted or containing leukocytes (WBCs), for sensitization control. Anti-HLA antibodies were detected using Complement-Dependent Cytotoxicity, Enzyme-Linked Immunosorbent Assay, and Luminex technology. This study evaluated demographic data, transfusion history, and sensitization. Statistical analysis focused on the relationship between sensitization and blood component variables.

In this study, 53.7 % were sensitized. The number of blood components received (p-value = 0.437), blood unit (p-value = 0.6809), and blood volume (p-value = 0.5857) were not significantly associated with sensitization rates. The use of leukodepleted blood components (p-value = 0.0057), as well as blood components containing WBCs (p-value = 0.030) is associated with a higher sensitization. Sensitization was detected in 67.57 % of cases more than 12 months after transfusion (p-value = 0.046). A significant difference in sensitization was shown when packed red blood cells were used (89.19 % versus 68.75 %; p-value = 0.006).

Sensitization was higher with blood components containing WBCs and packed RBCs. The longer time after transfusion, the more often sensitization is detected.