Introduction: Transplantation is the most clinically accepted therapy for the treatment of ESRD. Rejection diagnosis is complicated due to multiple factors involved in this process and in transplant failure; therefore, the main aim of our study was to identify immunological and non-immunological factors associated with rejection and kidney allograft loss in a cohort of 991 transplanted patients in Medellín, Colombia, between 2005 and 2015.
Methods: In this retrospective observational cohort study, the descriptive component was carried out by frequencies, and bivariate analysis by the Kaplan Meier method, in the Cox proportional hazards model was applied the Hosmer Lemeshow Criterion and the Cox Regression Method.
Results: In this cohort, the half of the follow-up time where 50% of the rejection occurred was 24 months. The overall incidence of rejection was 17.5% and 13.5% of kidney allograft loss. According to rejection by the Banff classification, the most frequent was T cell-mediated rejection (TCMR) with a frequency of 26%. Of the 173 patients diagnosed with rejection, 107 lost the graft. Statistically significant associations were found in the categories of the following variables: Age, <30 years HR7.398 (IC95%, 2.024-27.034) p=0.002, 31-40 years HR4.433 (IC95%, 1.111-17.072) p=0.03, 41-50 years 4.22 (IC95%, 1,102-16,165) p=0.036. Gender, female HR3,509 (IC95%, 1,431-8,606) P=0,006; Within these, women with more than 4 pregnancies HR4.11 (IC95% 1,535-11,056) p=0.005. Sensitization, HLA class I antibodies Class-I HR2.932 (IC95%, 1.352-6.359) p=0.006, with the persistent risk of allograft rejection during the entire time of the study. Finally, transplanted recipients from donors younger than 20 and from 21 to 30 years old, have a protective factor in order not to lose the kidney allograft (HR 0.33 (95% CI, 0.123-0.889) p=0.028 and HR 0.35 (IC95%, 0.13-0.952) p=0.04) respectively.
Discussion and Conclusions: This study becomes an important scientific evidence for the transplant centres in the city of Medellín and in all de country. The overall incidence of rejection of the study is higher than that previously reported in a cohort of receptors in the city, the type of rejection mediated by T cells is the most frequent throughout the follow-up, as well as during the first 36 months post-transplant, the interaction of patients under the age of 51 years, female and HLA class I antibodies are associated with an increased risk of allograft rejection. The understanding and the importance of these variables, during the different moments of the transplant in our population, become useful and important tools to increase the survival rates and decrease the incidence of rejection and loss of the renal allograft.