CD4<sup>+</sup> T cell lymphopenia predicts mortality from <i>Pneumocystis</i> pneumonia in kidney transplant patients
Tilo Freiwald, Stefan Büttner, Nardos T. Cheru, Despina Avaniadi, Simon S. Martin, Christoph Stephan, Rainer U. Pliquett, Aida Asbe‐Vollkopf, Gundolf Schüttfort, Volkmar Jacobi, Eva Herrmann, Helmut Geiger, Ingeborg A. Hauser
Abstract
Abstract Background Pneumocystis jirovecii pneumonia (PcP) remains a life‐threatening opportunistic infection after solid organ transplantation, even in the era of Pneumocystis prophylaxis. The association between risk of developing PcP and low CD4 + T cell counts has been well established. However, it is unknown whether lymphopenia in the context of post‐renal transplant PcP increases the risk of mortality. Methods We carried out a retrospective analysis of a cohort of kidney transplant patients with PcP (n = 49) to determine the risk factors for mortality associated with PcP. We correlated clinical and demographic data with the outcome of the disease. For CD4 + T cell counts, we used the Wilcoxon rank sum test for in‐hospital mortality and a Cox proportional‐hazards regression model for 60‐day mortality. Results In univariate analyses, high CRP, high neutrophils, CD4 + T cell lymphopenia, mechanical ventilation, and high acute kidney injury network stage were associated with in‐hospital mortality following presentation with PcP. In a receiver‐operator characteristic (ROC) analysis, an optimum cutoff of ≤200 CD4 + T cells/µL predicted in‐hospital mortality, CD4 + T cell lymphopenia remained a risk factor in a Cox regression model. Conclusions Low CD4 + T cell count in kidney transplant recipients is a biomarker for disease severity and a risk factor for in‐hospital mortality following presentation with PcP.