Risk Factors for Mortality among Kidney Transplant Recipients with Pneumocystis Jirovecii Infection

Abstract

Infection by P. jirovecii (PCP) has been described with increased incidence among kidney transplant recipients (KTR) in the recent years and a high mortality rate was associated with these infections. The aim of this study was to analyze risk factor for mortality due to PCP infection in a cohort of KTR. We analyzed all KTR that developed PCP in a single center from January 2004 to December 2016. Case of PCP was defined based on a combination of clinical assessment, plus radiologic changes, and one confirmatory test (positive PCR or direct fluorescent-antibody test of respiratory specimens or histological exam of lung). We excluded combined transplant. Independent variables analyzed were related to donors’ aspects, receptor aspects, induction therapy, cold ischemia time, immunosuppression at time of PCP, previous CMV disease, acute cellular rejection and laboratory tests and clinical presentation of PCP at diagnosis. The outcome was death related to PCP, defined as persistence of signs and symptoms of PCP infection at the time of death, or death occurring within 30 days after the diagnosis of the infection with no other cause identified. All patients were followed for 60 days. Statistical analysis was performed through Cox regression, we included in initial model of multivariate analysis all variable with P <0.2 in univariate analysis. A total of 60 cases were identified during study period, the most common radiological features were ground-glass pattern in 48 (80%) cases, consolidation in 6 (10%) and small nodules and tree-in-bud opacities in 6 (10%), median lactate dehydrogenase dosage at diagnosis was 527.5 U/L, 46(76.7%) patients needed ICU stay, and 34 (56.6%) needed mechanical ventilation, five (8.3%) patients were under PCP prophylaxis, one patient died before received specific PCP treatment. Only 2 patients received another drug than Sulfamethoxazole -Trimethoprim due to toxicity. The death related mortality rate was 26.6%. Risk factor associated to increased mortality rate were KTR age at PCP diagnosis(p 0.05 HR 1.05 95%CI 1.01-1.10), previous hospital stays in the last 3 months (p0.05 HR 2.74 95%CI 1.20-7.49) and HLA-B mismatch (p0.04 HR2.40 95%CI1.06-5.46). In conclusion, any radiological or laboratory aspects at PCP diagnosis was associated to a worse outcome of PCP infection. Features that increased mortality were associated to KTR aspects and comorbidities.