Preliminary Evaluation of Tacrolimus Impact on Glycemic Control, Renal Function, and Hematological Inflammatory Markers in Kidney Transplant Recipients

Background: Tacrolimus, a widely used calcineurin inhibitor in kidney transplantation, has a narrow therapeutic window and is associated with metabolic, renal, and hematological effects. Objective: To evaluate the relationship between tacrolimus blood concentrations, glycemic status, kidney function tests, and hematological inflammatory indices in kidney transplant recipients. Methods: This pilot study included 28 kidney allograft recipients, divided into two groups according to tacrolimus trough level (<7.5 ng/mL and >7.5 ng/mL). Fasting blood glucose, serum creatinine, blood urea nitrogen (BUN), and hematological indices, including neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), and platelet-to-lymphocyte ratio (PLR), were measured at baseline and three months post-transplant. Results: After three months, tacrolimus administration was associated with significant reductions in fasting blood glucose, serum creatinine, and BUN, particularly in female patients. Tacrolimus trough levels declined significantly in both sexes, with a more marked decrease in males. No significant changes were observed in NLR, MLR, PLR, or other hematological indices, and no significant associations were found between tacrolimus concentration groups and the studied parameters. Conclusions: Tacrolimus use over three months post-transplant was linked to improvements in glycemic control and renal function parameters without significant alterations in hematological inflammatory indices. Larger, long-term studies are warranted to confirm these findings and explore potential sex-related differences in tacrolimus pharmacokinetics and clinical effects.