Shu-Li Yang1, Ying-Hao Wen2, Yu-Shan Wu2, Mei-Chia Wang1, Pi-Yueh Chang3, Shuan Yang2, Jang-Jih Lu4. 1. Department of Laboratory Medicine, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan; Department of Medical Biotechnology and Laboratory Science, Chang Gung University, Taoyuan, Taiwan. 2. Department of Laboratory Medicine, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan. 3. Department of Laboratory Medicine, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan; Department of Medical Biotechnology and Laboratory Science, Chang Gung University, Taoyuan, Taiwan; Graduate Institute of Biomedical Sciences, Chang Gung University, Taoyuan, Taiwan. 4. Department of Laboratory Medicine, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan; Department of Medical Biotechnology and Laboratory Science, Chang Gung University, Taoyuan, Taiwan; Department of Medicine, College of Medicine, Chang Gung University, Taoyuan, Taiwan. Electronic address: janglu45@gmail.com.
Abstract
BACKGROUND: Pneumocystis pneumonia (PCP) is a disease caused by the opportunistic infection of the fungus Pneumocystis jirovecii. Several PCR methods have been developed to aid in the diagnosis of PCP. In this study, we evaluated the performance of a real-time PCR in the diagnosis of PCP, in patients with various underlying diseases. METHODS: Ninety-seven BAL samples and 94 sputum samples from 191 patients were used in the study. Patients were classified as PCP (121 patients) or non-PCP (70 patients) based on their clinical and radiological presentations. RESULTS: Real time PCR amplified the P. jirovecii mitochondrial large-subunit rRNA gene with a detection limit of 68 copies of DNA per reaction. Non-PCP pathogens including 32 different fungi and bacteria were also evaluated. Overall, 71.9% of the samples from PCP patients and 14.5% of those from non-PCP patients were positive for the PCR test with a CT value of the real-time PCR below 45. The main underlying diseases of the patients were hematological or solid malignancies (47.1%) and HIV infection (8.9%). The CT values of the test were significantly lower in BAL samples from PCP patients than those from non-PCP patients (p = 0.024). No non-PCP patient had a CT value below 30, whereas samples from 24.8% of PCP patients with underlying diseases had a CT value below 30. CONCLUSION: Since false positive PCR results were obtained, perhaps due to colonization, we suggest that the diagnosis of PCP should be based on a combination of clinical symptoms, underlying diseases, and PCR results.
BACKGROUND:Pneumocystis pneumonia (PCP) is a disease caused by the opportunistic infection of the fungus Pneumocystis jirovecii. Several PCR methods have been developed to aid in the diagnosis of PCP. In this study, we evaluated the performance of a real-time PCR in the diagnosis of PCP, in patients with various underlying diseases. METHODS: Ninety-seven BAL samples and 94 sputum samples from 191 patients were used in the study. Patients were classified as PCP (121 patients) or non-PCP (70 patients) based on their clinical and radiological presentations. RESULTS: Real time PCR amplified the P. jirovecii mitochondrial large-subunit rRNA gene with a detection limit of 68 copies of DNA per reaction. Non-PCP pathogens including 32 different fungi and bacteria were also evaluated. Overall, 71.9% of the samples from PCPpatients and 14.5% of those from non-PCPpatients were positive for the PCR test with a CT value of the real-time PCR below 45. The main underlying diseases of the patients were hematological or solid malignancies (47.1%) and HIV infection (8.9%). The CT values of the test were significantly lower in BAL samples from PCPpatients than those from non-PCPpatients (p = 0.024). No non-PCPpatient had a CT value below 30, whereas samples from 24.8% of PCPpatients with underlying diseases had a CT value below 30. CONCLUSION: Since false positive PCR results were obtained, perhaps due to colonization, we suggest that the diagnosis of PCP should be based on a combination of clinical symptoms, underlying diseases, and PCR results.
Authors: Luis Pla; Anna Aviñó; Ramón Eritja; Alba Ruiz-Gaitán; Javier Pemán; Vicente Friaza; Enrique J Calderón; Elena Aznar; Ramón Martínez-Máñez; Sara Santiago-Felipe Journal: J Fungi (Basel) Date: 2020-11-17
Authors: Patrizia Danesi; Matteo Petini; Christian Falcaro; Michela Bertola; Elisa Mazzotta; Tommaso Furlanello; Mark Krockenberger; Richard Malik Journal: Int J Environ Res Public Health Date: 2022-03-08 Impact factor: 3.390