Potential Utility of Neutrophil-to-Lymphocyte, Platelet-to-Lymphocyte, and Neutrophil, Lymphocyte, and Platelet Ratios in Differential Diagnosis of Kidney Transplant Acute Rejection: A Retrospective, Propensity Score Matched Analysis

Background: Acute kidney transplant rejection can negatively affect long-term graft function. The neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio have been proposed as non-invasive predictors of acute rejection in stable kidney transplant recipients. The aim of this study was to validate the predictive value of these ratios, as well as neutrophil, lymphocyte, and platelet ratios in the diagnosis of acute rejection during the early post-transplant period. Material/Methods: After propensity score matching, we compared 71 kidney recipients with biopsy-proven acute rejection with 71 patients without rejection and also subjects with different histologic types of rejection. All 3 types of blood cell count-derived ratios were calculated 6 and 3 days prior to biopsy and on the day of biopsy. Results: There were 15 patients with T cell-mediated rejection, 33 with vascular rejection, and 23 with antibody-mediated rejection. The values of all examined ratios did not differ between subgroups with and without rejection. However, at all post-transplant study time-points, patients with antibody-mediated rejection had significantly higher values of all analyzed ratios than subjects with other types of rejection. In multivariate regression models, higher values of blood cell count-derived ratios were independently associated with the occurrence of antibody-mediated rejection. Conclusions: In the early post-transplant period, the values of neutrophil-to-lymphocyte, platelet-to-lymphocyte, and neutrophil, lymphocyte, and platelet ratios were similar in patients with and without an acute rejection episode, but significantly higher values were found in subjects with antibody-mediated rejection as compared with other types of rejection and those without rejection. High values of analyzed ratios in patients with satisfactory early kidney graft function may be helpful in selecting subjects with increased risk of subclinical antibody-mediated rejection.