Clinical and biological factors predisposing to hyperkalemic renal tubular acidosis in solid organ transplant recipients : a retrospective monocentric study

Abstract

Background The occurrence of hyperkalemic renal tubular acidosis in the post-transplantation period is likely underestimate, and its identification remains important to offer adequate medical management. Transplanted recipients frequently present clinical and biological characteristics which are associated in the literature with the occurrence of this complication. Post-transplant exposure to drugs that cause hyperkalemic renal tubular acidosis may therefore appear risky. We conducted a single-center retrospective comparative study in which we compared patients with hyperkalemic renal tubular acidosis and a control group to identify clinical and biological factors significantly associated with this complication.Methods The Fisher’s exact test was applied to test whether there is a significant association between hyperkalemic renal tubular acidosis and qualitative variable. The Mann-Whitney test was applied for the quantitative variables. We performed a multivariate logistic regression excluding some variables and then selected the variables using a stepwise procedure. The best logistic model according to the Akaike Information Criterion was the final model.Results Kidney and heart transplant recipients appear to be at greater risk of developing this complication than lung transplant recipients (p = 0.016). No other qualitative variable showed a significant association with the occurrence of hyperkalemic RTA. We also found a significant difference in kalemia (p < 0.01), chloremia (p < 0.01), and bicarbonatemia (p < 0.01).Neither the residual serum tacrolimus level (p = 0.19) nor the creatinine level of renal transplant patients (p = 0.17) was significantly associated with hyperkalemic renal tubular acidosis. In multivariate logistic regression, the analysis of the final model confirms the significant impact of kalemia (p < 0.01), chloremia (p < 0.01), and bicarbonatemia (p = 0.013) in the occurrence of this complication.Conclusion In our study, the type of transplanted organ, kalemia, chloremia, and bicarbonatemia seem to be significantly associated with the occurrence of hyperkalemic renal tubular acidosis. It is essential to identify this complication and to treat hyperkalemia first before proposing additional treatments. Larger studies are needed to more accurately define transplanted patients at risk for hyperkalemic renal tubular acidosis.