Diagnosis Of Pneumocystis Jirovecii Pneumonia In Patients Research Articles

Development and Validation of a Diagnostic Nomogram for Pneumocystis jirovecii Pneumonia in Non-HIV-Infected Pneumonia Patients Undergoing Oral Glucocorticoid Treatment.

Pneumocystis jirovecii pneumonia (PJP) is an opportunistic but potentially fatal infection with increasing prevalence in HIV-free patients. Glucocorticoid therapy is one of the most important risk factors for PJP. The delay in diagnosis contributes to poor outcomes. Hence, the aim of this study was to develop and validate a nomogram for the diagnosis of PJP in patients with non-HIV-infected pneumonia who are undergoing oral glucocorticoid treatment. This study was a retrospective, cross-sectional research. The development group included 434 patients who were admitted with pneumonia from 6 hospitals. Demographics, symptomatic features, laboratory and computed tomography data were analyzed using the least absolute shrinkage and selection operator (LASSO) to select potential diagnostic indicators. Binary logistic regression was used to develop a diagnostic nomogram. Another 119 patients with pneumonia admitted at Sichuan Provincial People's Hospital was used as the validation group. The diagnostic performance of the nomogram was measured by area under the receiver-operating-characteristics curve (AUC), calibration curves, and the net benefit by decision curve. PJP prevalence was 25.3% in the development group. LASSO regression revealed that age, lymphocyte count, fever, dry cough, respiratory failure, ground-glass opacity in lungs, glucocorticoid therapy duration, and immunosuppressive therapy were indicators of PJP. The nomogram showed robust discrimination, with an AUC of 0.82 (95% CI 0.77-0.86) in the development group and an AUC of 0.87 (95% CI 0.80-0.94) in the validation group, both showing acceptable calibration. In the decision curve analysis, our model consistently achieved a greater net benefit across almost all ranges of clinical thresholds. We developed a nomogram with good diagnostic power for PJP diagnosis in pneumonia patients receiving oral glucocorticoids. This nomogram may help promote timely treatment of PJP and thus reduce the mortality rate in these patients.

Effectiveness of a real-time PCR for diagnosis of Pneumocystis pneumonia in immunocompromised patients – Experience from a tertiary care center, India

Pneumocystis jirovecii pneumonia (PCP) is a life-threatening fungal infection in immunocompromised patients. Traditionally, the laboratory diagnosis of PCP relied on the visualization of organisms by microscopy as Pneumocystis cannot be readily cultured in the laboratory. The polymerase chain reaction (PCR) method is preferred over the conventional microscopic methods as PCR is rapid and found to have higher sensitivity. This retrospective study aimed to analyze the diagnostic value of a real-time PCR (qPCR) for routine diagnosis of PCP in immunocompromised patients with various underlying conditions. The qPCR targets a 121 bp fragment of P.jirovecii mitochondrial large subunit rRNA gene. The study was conducted in a 2600-bed tertiary care hospital between January and December 2019. All patients whose respiratory samples were tested for PCP by qPCR were included. The clinical diagnosis was made for each patient and categorized into PCP and non-PCP based on multi-component clinical criteria by a multi-disciplinary team. The performance characteristics of qPCR were analyzed using clinical diagnosis as the reference. A total of 339 respiratory samples from 289 patients were tested for PCP by qPCR during the study period. The overall sensitivity and specificity of qPCR were 84.75% (95% CI, 73.01% to 92.78%) and 96.1% (95% CI, 92.7 to 98.2), respectively. The sensitivity was slightly higher among HIV-infected patients (91%) than the non- HIV group (81%). The PCR exhibited higher sensitivity in bronchoalveolar lavage (BAL) (94%) than in sputum samples (81%). The colonization can be ruled out with the cycle threshold (CT) value of below 34 with a sensitivity and specificity of 100% and 78%, respectively.The real-time PCR showed good sensitivity and specificity for routine diagnosis of PCP in patients with various underlying conditions. In addition, a cut-off CT value (≤ 34) was determined to exclude colonization from active pneumonia.

Clinical Utility of Serum .BETA.-D-Glucan and KL-6 Levels in Pneumocystis jirovecii Pneumonia

New serum markers (1-->3) beta-D-glucan (beta-D-glucan) and KL-6 are reported to be useful for the clinical diagnosis of Pneumocystis jirovecii pneumonia (PCP). However, the utility of these markers in PCP with HIV infection (HIV PCP) and without HIV (non-HIV PCP) is unknown. This study was aimed to evaluate the utility of beta-D-glucan and KL-6 for the diagnosis of PCP in patients with HIV infection (HIV PCP) and non-HIV PCP. Retrospective study. We reviewed the medical records of consecutive 35 patients. The serum levels of beta-D-glucan and KL-6 in HIV PCP and non-HIV PCP were comparatively evaluated. We evaluated these markers in survivors and non survivors. The detection rates of serum beta-D-glucan and KL-6 levels in non-HIV PCP were lower than those in HIV PCP (88% vs. 100%, 66% vs. 88%, respectively). The false positive rates of these markers in both groups were similar (12%, 37%, respectively). Oxygenation index, serum albumin, and mechanical ventilation were the variables which were significantly associated with poor outcome in the univariate analysis. In conclusion, beta-D-glucan was a reliable diagnostic marker for PCP. However, the detection rate of beta-D-glucan and KL-6 in non-HIV PCP was lower than in HIV PCP. Neither beta-D-glucan nor KL-6 was associated with the outcome of PCP.