Clinical characteristics and outcomes of tuberculosis infection in kidney transplant recipients

Abstract

Purpose: The aim of this study was to assess demographic, clinical characteristics and outcomes of tuberculosis (TB) infection after kidney transplantation (KT). Methods: Retrospective cohort study, including KT recipients in a single transplant center located in the Northeast region of Brazil. It was included those patients whose diagnosis was performed between 2004 and 2018 (n=33). Results: Cohort was predominantly composed by male (54.5%), young adults (39.8 12.3 years-old), with median of 29.7 months after KT. Nine received treatment for latent tuberculosis infection (LTBI) due to tuberculin test≥5mm (100%). The main immunosuppressive regimen was the induction therapy with Thymoglobulin (48.4%), and combination of tacrolimus and mycophenolate (72.7%). The main initial symptoms were fever (63.6%), weight loss (21.2%) and cough (21.2%). Twenty-four patients presented localized TB infection, 5 had disseminated infections forms, and 4 were empirically treated without defined site localization (unknown fever origin). All patients received rifampicin/isoniazid and pyrazinamide treatment, with or without ethambutol. The mean treatment time was 8.4 3.8 months. Seven patients had hepatotoxicity and 2 presented peripheral neuropathy as treatment side-effects. The pre-treatment serum tacrolimus concentration was 5.4 1.9 ng/mL, decreasing to 1.6 0.6ng/mL post treatment (lowest concentration), and a 75.5% increase in the tacrolimus dose was required. In 12 patients, immunosuppressive regimen was partial or completely withdrawn along the TB treatment. 79% patients evolved with acute kidney injury (AKI), according to KDIGO staging, 15 patients were KDIGO 1, 8 were KDIGO 2 e 3 were KDIGO 3, and pre-renal AKI was the main etiology. Three patients died during the course of the disease or along the period of the treatment. Conclusions: TB took place late after KT, and fever was the main initial symptom. There was a high percentage of extrapulmonary TB infections. Empirical treatment is a reality in our context. Treatment was associated to significant decrease of the calcineurin inhibitor blood concentration, probably due to the pharmacokinetic interaction with rifampicin. The percentage of renal allograft acute dysfunction was significant.