Pneumocystis jirovecii pneumonia (PCP) PCR-negative conversion predicts prognosis of HIV-negative patients with PCP and acute respiratory failure.

Abstract

Pneumocystis jirovecii pneumonia (PCP) is often fatal in human immunodeficiency (HIV)-negative patients and typically presents with respiratory insufficiency. Predicting treatment failure is challenging. This study aimed to identify prognostic factors and examine PCP polymerase chain reaction (PCR)-negative conversion in non-HIV PCP patients with respiratory failure. We retrospectively enrolled 81 non-HIV patients diagnosed with and treated for PCP with respiratory failure in the intensive care unit at a tertiary hospital over a 3-year period. PCP was diagnosed via nested PCR-mediated detection of Pneumocystis jirovecii in induced sputum samples, endotracheal aspirates, and bronchoalveolar lavage fluids. PCP PCR was performed weekly to check for negative conversion. The overall survival rate was 35.8%. Seventy-four patients (91.3%) required mechanical ventilation, and 6 (7.4%) required high-flow nasal oxygen treatment. The PCP PCR-negative conversion rate was 70.5% (survivors, 97%; non-survivors, 63.5%); the median time to conversion was 10 (7.0-14.0) days. On univariate analysis, the APACHE II score (p < 0.001), renal failure requiring renal replacement therapy (p = 0.04), PCP PCR-negative conversion (p = 0.003), and the PaO2/FiO2 ratio (first 24 hours) (p < 0.001) significantly correlated with mortality. On multivariate analysis, PCP PCR-negative conversion (hazard ratio, 0.433; 95% confidence interval, 0.203-0.928; p = 0.031) and the PaO2/FiO2 ratio (first 24 hours) (hazard ratio, 0.988; 95% confidence interval, 0.983-0.993; p < 0.001) independently predicted prognosis. Determination of PCP PCR-negative conversion and PaO2/FiO2 ratios may help physicians predict treatment failure and mortality in non-HIV PCP patients with respiratory failure.