['New-onset posttransplant diabetes mellitus (PTDM) is a frequent complication of kidney transplantation. The goal of this study was to identify if the tendency to develop PTDM was associated to the HLA, as is seen in the general population.', 'A retrospective study was made of 525 patients who underwent renal transplantation between 1997 and 2004. They were divided into three categories depending on the diabetic status before and after kidney transplantation. The HLA profile of each patient was identified for class 1 and class 2 antigens including HLA-A, HLA-B, and DR-R. Antigen frequencies were calculated and gene frequencies derived. These were compared among the three groups and with the published data for the Puerto Rico population. Other variables studied included weight, age, gender, and family history.', 'Seventy-two of 526 (13.7%) were diabetic before transplantation; 92/453 (20.3%) developed PTDM after kidney transplantation. Pretransplant diabetics showed a higher incidence of A3 (0.1102 vs 0.0869 vs 0.0361), DR4 (0.3334 vs 0.1932 vs 0.2124), and DR-13 (0.1835 vs 0.1115 vs 0.1175) than nondiabetics and the normal Puerto Rican population. Posttransplant diabetics showed a higher A3 (0.1154) and a higher DR3 (0.0675 vs 0.0295 vs 0.0022) than nondiabetics and normal population.'] Is hLA predictive of posttransplant diabetes mellitus?