Tuberculosis after kidney transplantation is associated with significantly impaired allograft function.

Background: This study aimed to evaluate renal function before, during, and after the course of tuberculosis (TB) disease in kidney transplant recipients, and assess the risk factors for non-recovery of baseline renal function.

Methods: We performed a retrospective, single-center cohort study, including all patients with confirmed or presumed TB diagnosis after kidney transplant (n=34, 2.1%). Renal function was assessed by serum creatinine (Cr) and glomerular filtration rate (GFR) adjusted for deaths and graft losses.

Results: A significant increase was seen in serum Cr during TB disease and treatment: 1.5 mg/dL at baseline (Cr ), 1.7 mg/dL at diagnosis (P<.001 vs. Cr ), and 2.4 mg/dL during the peak (P<.001 vs. Cr ). According to acute kidney injury (AKI) Kidney Disease: Improving Global Outcomes (KDIGO) classification, 29 (85%) patients had AKI: 16 stage 1, 2 stage 2, and 11 stage 3. Three months after the end of the TB treatment, five patients (14.7%) had lost their graft and two others (5.9%) had died. The GFR was lower than the baseline (42.4 mL/min vs 51.6 mL/min, P=.007). In the univariate analysis, peak Cr (odds ratio [OR] 1.276, 95% confidence interval [CI] 0.955-1.705, P=.100), AKI KDIGO stages 2 or 3 (OR 4.958, 95% CI 1.062-23.157, P=.042), severe disease (OR 5.700, 95% CI 1.147-28.330, P=.033), and acute rejection (AR) episodes after TB diagnosis (OR 3.937, 95% CI 0.551-28.116, P=.172) were associated with non-recovery of baseline renal function. No variable was identified in the multivariable model.

Conclusion: Post-transplantation TB was associated with a high incidence of AKI, and complete recovery of baseline renal function was not achieved after treatment. The severity of TB disease, AKI, and AR episodes that occurred after TB diagnosis are potential causes for this outcome.