The CYP3A5 and ABCB1 Gene Polymorphisms in Kidney Transplant Patients and Establishment of Initial Daily Tacrolimus Dosing Formula.

Background: Tacrolimus is an immunosuppressive drug used to prevent organ rejections. Many factors could influence blood concentration of tacrolimus.

Objective: To detect genotypes of cytochrome () and in kidney transplant patients and establish initial daily tacrolimus dosing formula based on genotypes of and and patients' clinical parameters.

Methods: Sequence specific primer polymerase chain reaction (PCR) and PCR restriction fragment length polymorphism were used to detect genotypes of and . The blood cell, procalcitonin, C-reactive protein, height, weight, age, gender and other clinical parameters were recorded. Multiple linear regression analysis and Pearson correlation analysis were used to conduct date analysis.

Results: 102 cases were enrolled in cohort 1, and there were 10 cases of *1/*1 (9.8%), 28 cases of *1/*3 (27.5%), and 64 cases of *3/*3 (62.7%). The distributions of genotype were 36 (35.3%), 52 (51.0%), and 14 (13.7%). The distributions of genotype were 39 (38.2%), 40 (39.2%), and 23 (22.5%). The formula was 7.499 + (0.053 × Weight) - (0.029 × Hemoglobin concentration) - (1.045 × genotype) ( genotype: *1/*1 type inputs 0, *1/*3 type inputs 1, *3/*3 type inputs 2). The predicted doses from the established formula had a significant correlation ( = 0.605) with actual clinical doses ( < 0.05).

Conclusion And Relevance: Hemoglobin concentration, weight, and genotype should be considered using tacrolimus. The initial daily tacrolimus dosing formula established can make a good prediction.