Renal transplantation in Mapuche people

Previous studies have demonstrated higher concentrations of some histocompatibility antigens in Mapuche people compared with non-Mapuche Chileans in the renal transplantation program. With the aim of evaluating whether those antigenic differences might induce differences in the outcomes of renal transplantation among patients belonging to that ethnic group, we reviewed HLA studies and at least 6 months follow-up of all patients with a first kidney transplant between 1980 and 2006. The 248 patients had a mean age of 37.6 years, 40% were females, and 48% had living related donors. The mean kidney follow-up was 90 months and patient follow-up was 106 months. Thirty-nine patients (16%) were classified as Mapuche, according to their surnames, including 16 women with overall mean age of 34.5 years, and 14 had been transplanted from a living related donor. Mapuche patients received organs with better HLA matching expressed as number of identities (3.4 +/- 0.1 versus 2.8 +/- 0.1 among non-Mapuche; P < .05), and the proportion receiving organs with > or = 3 compatibilities was significantly higher (Mapuche 38% versus non-Mapuche 22%; P < .05). Kaplan-Meier survival curves showed nonsignificant differences in kidney survival: 86% at 5 years and 68% at 10 years in Mapuche; and 83% and 65%, respectively, for non-Mapuche. Patient survival rates were 97% at 5 years and 86% at 10 years in the Mapuche group versus 91% and 79%, respectively, in the non-Mapuche group; both results were not significantly different. Our results showed similar outcomes of kidney and patient survivals among Mapuche people even when they received organs with better HLA matches.