Função tardia do enxerto em transplante renal: análise de rins pareado

Abstract

Delayed graft function (DGF) is the most frequent post-transplantation (Tx) complication in renal recipients of deceased donors, with multifactorial causes and a negative impact on the transplantation outcome. Factors related to the donor can influence the initial function of the graft and therefore, an analysis concerning two kidney transplant recipients from the same donor (paired kidneys) can minimize the bias related to these factors. Objective: To evaluate risk factors and DGF influences on paired renal transplant recipients (RTx). Methods: The 53 pairs of RTx were grouped according to the presence (+) or absence (-) of DGF: DGF (+/+), DGF (-/-) and DGF (+/-). In a second analysis, due to the importance of the cold ischemia time (CIT) as a risk factor for DGF, Rtx were also assessed comparing the first and second receptors to be transplanted and also according to: CIT ≤ 20 hours, CIT > 20 hours, and mixed pairs where one CIT receptor ≤ 20 hours and the other CIT > 20 hours. Results: The 53 donors were predominantly male (58%), with mean age of 42 ± 15 years, 70% were standard criteria donors (SCD) with mean Kidney Donor Profile Index (KDPI) of 61.5% ± 28. Of the 106 RTx, 82% presented DGF, with a mean duration of 12 ± 7 days. Comparing the pairs according to DGF occurrence, CIT was significantly shorter in pairs without DGF (DGF (-/-) 22 ± 7 hours vs. DGF (+/+) 26 ± 5 hours; p = 0.003) and pairs who underwent DGF were significantly older (DGF (+/+) 50 ± 11 years vs. DGF (-/-) 40 ± 9 years; p = 0.008). The KDPI was higher in pairs with DGF (DGF (+/+) 67% vs. DGF (-/-) 48%; p = 0.01) and the number of extended criteria donors (ECD) was significantly higher in pairs who underwent DGF (+/+), while the DGF (-/-) did not present any ECD (33% vs. 0%; p = 0.03). No statistical difference between the three groups regarding Tx outcomes (renal function, acute rejection, and patient and graft survival) at 1 year follow-up were observed. A logistic regression analysis indicated that older recipient (OR = 6.3; CI = 1.5-25.8; p = 0.009) and higher CIT (OR = 4.6; CI = 1.2-17.7; p = 0.002) were significant risk factors for DGF. In a second CIT related analysis comparing the first with the second graft from the same donor to be transplanted, no statistical difference in Tx outcomes were observed. Considering pairs grouped according to CIT: > 20 hours, ≤ 20 hours and mixed pairs, the mean CIT was different among the three groups (p = 0.0001) and the DGF rate was higher in the CIT group > 20 hours (CIT > 20h: 87.5% vs. CIT ≤ 20h: 58%; p = 0.002). No statistical difference between the three groups concerning Tx outcomes at 1 year follow-up regarding renal function, acute rejection, and patient and graft survival were observed. The logistic regression analysis indicated that CIT > 20h is a risk factor for DGF (OR = 5.02; CI = 1.65-15.22, p = 0.004). Conclusions: Pairs that underwent DGF were associated to ECD donors and a higher KDPI. Older recipients (> 50 years old) and CIT > 20 hours were the main risk factors for DGF in the present study. Measures to decrease CIT may decrease DGF rates, mainly in ECD donors, with higher KDPI, and recipients > 50 years old.