LAUSR

BACKGROUND Allograft rejection remains a significant challenge in managing post-transplant recipients despite the improvement in immunologic risk assessment and immunosuppressive therapy. Published literature including animal studies has demonstrated that the cells responsible for rejection are beyond the innate T and B cells, and other studies revealed evidence supporting natural killer (NK) cells' role in kidney allograft injury. This study aims to find the association between the peripheral blood lymphocyte subset counts, primarily NK cells, and the kidney allograft biopsy findings. METHODS This is a prospective cross-sectional study among a total of 100 kidney allograft biopsies in 61 kidney transplant recipients. The peripheral blood for the lymphocyte subset was sent just before the allograft biopsy. The patients' immunosuppression and other laboratory investigations were managed as per clinical practices by the attending nephrologist. RESULTS Overall, the mean age of our patients was 43.72 ± 10.68 years old, and 55.7% of recipients were male. Higher counts of T cells (CD4+; 658.8 ± 441.4 cells/µL; P = .043) and NK cells (CD3-CD16+CD56+; 188 [interquartile range = 133.0-363.0 cells/µL]; P = .002) were associated with higher risk of allograft rejection in the initial analysis. Patients with an allograft age <12 months had significantly higher total T cells, CD4+ T cells, and NK cells in the rejection groups. However, after assessing factors associated with rejection in the multivariate analysis, we only found that being ABO-incompatible and having >497 CD4+ cells/µL had a higher odds of allograft rejection. CONCLUSIONS Higher CD4± counts were associated with a higher risk of allograft rejection. However, there was no significant increase in CD8±, CD19±, and NK cells count in our cohort with allograft rejection.