Use of nasopharyngeal aspirate for diagnosis of pneumocystis pneumonia.
Ontology highlight
ABSTRACT:
SUBMITTER: To KK
PROVIDER: S-EPMC3647954 | biostudies-literature | 2013 May
REPOSITORIES: biostudies-literature
Publications
Use of nasopharyngeal aspirate for diagnosis of pneumocystis pneumonia.
To Kelvin K W KK Wong Sally C Y SC Xu Ting T Poon Rosana W S RW Mok Ka-Yi KY Chan Jasper F W JF Cheng Vincent C C VC Chan Kwok-Hung KH Hung Ivan F N IF Yuen Kwok-Yung KY
Journal of clinical microbiology 20130213 5
Quantitative PCR on nasopharyngeal aspirate (NPA) can achieve high sensitivity and specificity in diagnosing Pneumocystis pneumonia (PCP) compared to microscopic examination of bronchoscopic specimens in a population with low HIV prevalence. Since NPA is a minimally invasive procedure, it is ideal as a screening test for PCP. ...[more]
Similar Datasets
Project description:Objectives: Pneumocystis jirovecii pneumonia (PCP) is an AIDS-defining illness. In patients with HIV, the benefit of PCP prophylaxis is well-defined when the CD4 T-cell count decreases below 200 cells/?L. In other immunocompromised patients, the value of PCP prophylaxis is not always as well-established. This study aimed to describe the epidemiology of PCP in recent years and assess how many patients with PCP did or did not receive prophylaxis in the month preceding the infection. Material and Methods: A multicenter retrospective study was performed in 3 tertiary care hospital. A list of patients that underwent broncho-alveolar lavage sampling and Pneumocystis jirovecii (PJ) PCR testing was retrieved from the microbiology laboratories. An in-house PJ quantitative PCR (qPCR) was used in each center. A cycle threshold (Ct) value of ? 28.5-30 was considered a probable PCP. For patients with a positive PJ qPCR but above this threshold, a predefined case definition of possible PCP was defined as a qPCR Ct value ? 34-35 and both of the following criteria: 1. Clinical and radiological features compatible with PCP and 2. The patient died or received PCP therapy and survived. Patient files from those with a qPCR Ct value ? 35 were reviewed to determine whether the patient fulfilled the case definition and if PCP prophylaxis had been used in the weeks preceding the PCP. Disease-specific guidelines, as well as hospital-wide guidelines, were used to evaluate if prophylaxis could be considered indicated. Results: From 2012 to 2018, 482 BAL samples were tested. Two hundred and four had a qPCR Ct value ? 35 and were further evaluated: 90 fulfilled the definition of probable and 63 of possible PCP while the remaining 51 were considered colonized. Seventy-four percentages of the patients with PCP were HIV-negative. Only 11 (7%) of the 153 patients had received prophylaxis, despite that in 133 (87%) cases prophylaxis was indicated according to guidelines. Conclusion: In regions where HIV testing and treatment is available without restrictions, PCP is mainly diagnosed in non-HIV immunocompromised patients. More than four out of five patients with PCP had not received prophylaxis. Strategies to improve awareness of antimicrobial prophylaxis guidelines in immunocompromised patients are urgently needed.
| S-EPMC7243458 | biostudies-literature
Project description:According to the immunodepression status, the diagnosis of Pneumocystis jirovecii pneumonia (PjP) may be difficult. Molecular methods appear very sensitive, but they lack specificity because Pj DNA can be detected in Pneumocystis-colonized patients. The aim of this study was to evaluate the value of a serum ß-d-Glucan (BDG) assay for the diagnosis of PjP in a large cohort of HIV-negative and HIV-positive patients, either as a first-line diagnostic test for PjP or as a tool to distinguish between colonization and PjP in cases of low fungal load. Data of Pj qPCR performed on bronchopulmonary specimens over a 3-year period were retrieved retrospectively. For each result, we searched for a BDG serum assay performed within ±5 days. Among the 69 episodes that occurred in HIV-positive patients and the 609 episodes that occurred in immunocompromised HIV-negative patients, we find an equivalent sensitivity of BDG assays compared with molecular methods to diagnose probable/proven PjP, in a first-line strategy. Furthermore, BDG assay can be used confidently to distinguish between infected and colonized patients using a 80 pg/mL cut-off. Finally, it is necessary to search for causes of false positivity to increase BDG assay performance. BDG assay represents a valuable adjunctive tool to distinguish between colonization and infection.
| S-EPMC9318034 | biostudies-literature
Project description:Pneumonia due to Pneumocystis jirovecii (PCP) is a frequent infection among HIV-positive or other immunocompromised patients. In the past several years, PCR on pulmonary samples has become an essential element for the laboratory diagnosis of PCP. Nevertheless, very few comparative studies of available PCR assays have been published. In this work, we evaluated the concordance between four real-time PCR assays, including three commercial kits, AmpliSens, MycAssay, and Bio-Evolution PCR, and an in-house PCR (J. Fillaux et al. 2008, J Microbiol Methods 75:258-261, doi:http://dx.doi.org/10.1016/j.mimet.2008.06.009), on 148 pulmonary samples. The results showed concordance rates ranging from 81.6% to 96.6% (kappa, 0.64 to 0.93). Concordance was excellent between three assays: the in-house assay, AmpliSens, and the MycAssay PCR (kappa, >0.8). The performances of these PCR assays were also evaluated according to the classification of the probability of PCP (proven, probable, possible, or no final diagnosis of PCP) based on clinical and radiological signs as well as on the direct examination of bronchoalveolar lavage samples. In the proven PCP category, Pneumocystis jirovecii DNA was detected with all four assays. In the probable PCP category, the in-house PCR, AmpliSens, and the MycAssay PCR were positive for all samples, while the Bio-Evolution PCR failed to detect Pneumocystis jirovecii DNA in two samples. In the possible PCP category, the percentage of positive samples according to PCR varied from 54.5% to 86.4%. Detection of colonized patients is discussed. Finally, among the four evaluated PCR assays, one was not suitable for colonization detection but showed good performance in the proven and probable PCP groups. For the three other assays, performances were excellent and allowed detection of a very low fungal burden.
| S-EPMC4767985 | biostudies-literature
Project description:Pneumocystis carinii pneumonia (PCP) is one of the most predominant opportunistic infectious diseases in patients with AIDS. Nested PCR has been described as a sensitive and specific tool for detecting P. carinii DNA in clinical specimens. Little is known about the correlation of positive PCR results and clinical evidence of PCP in patients with different forms of immunosuppression. One hundred and thirty-six sputum samples, 26 tracheal-bronchial aspirate samples, 35 bronchoalveolar lavage samples, and 11 lung biopsy samples from (i) human immunodeficiency virus (HIV)-infected patients with AIDS, (ii) immunocompromised patients with leukemia or lymphoma, and (iii) immunocompetent control patients were investigated by a nested PCR amplifying DNA from the mitochondrial large subunit of P. carinii. All patients suffered from acute episodes of respiratory disease. The resulting data were correlated with clinical evidence of PCP. A high degree of association of positive P. carinii PCR results and clinical evidence of PCP in HIV-infected patients with AIDS was found. When calculated for bronchoalveolar lavage and lung biopsy samples, the positive and the negative predictive values of P. carinii PCR for PCP diagnosis in HIV-infected patients with AIDS were 1 and the specificity and the sensitivity were 100%. In contrast, in the group of patients with leukemia or lymphoma, the positive predictive value of the nested PCR for these materials was found to be as low as 0.09, the negative predictive value was 0.73, the specificity was 44.4%, and the sensitivity was 25.0%. No P. carinii DNA could be detected in specimens from immunocompetent patients. In summary, in contrast to patients with leukemia and lymphoma, nested PCR seems to be a sensitive and specific tool for PCP diagnosis in HIV-infected patients with AIDS.
| S-EPMC229764 | biostudies-other
Project description:Pneumocystis carinii pneumonia Diagnosis via Metagenomic Next-Generation Sequencing
| PRJEB43652 | ENA
Project description:Pneumocystis jirovecii pneumonia (PJP) is an important cause of pneumonia in the HIV-negative immunocompromised population, for whom the fungal load is low, the differential diagnosis is difficult, and a bronchoalveolar lavage (BAL) sample is often not readily available. Molecular techniques have improved the microbiological diagnosis in this scenario. The usefulness of two real-time PCR techniques targeting nuclear single-copy and mitochondrial multicopy genes, respectively, applied to oral wash specimens (OW) for PJP diagnosis was assessed, and its accuracy was compared to a BAL fluid-based diagnosis. Immunocompromised patients having PJP in the differential diagnosis of an acute respiratory episode, and from whom OW and BAL or lung biopsy specimens were obtained ?48?h apart, were retrospectively included. PCRs targeting the dihydropteroate synthase gene (DHPS) and the mitochondrial small-subunit (mtSSU) rRNA gene were performed in paired OW-BAL specimens. Thirty-six patients were included (88.6% HIV negative). Fifteen patients (41.7%) were classified as PJP, and a further 8 were considered P. jirovecii colonized. Quantification of DHPS and mtSSU in BAL fluid showed an accuracy of 96.9% and 93.0%, respectively, for PJP diagnosis, whereas a qualitative approach performed better when applied to OW (accuracy, 91.7%) irrespective of the PCR target studied (kappa?=?1). Qualitative molecular diagnosis applied to OW showed an excellent performance for PJP diagnosis regardless of the target studied, being easier to interpret than the quantitative approach needed for BAL fluid.
| S-EPMC6879283 | biostudies-literature
Project description:The opportunistic pathogen Pneumocystis jirovecii is a significant cause of disease in HIV-infected patients and others with immunosuppressive conditions. Pneumocystis can also cause complications in treatment following antiretroviral therapy or reversal of immunosuppressive therapy, as the newly reconstituted immune system can develop a pathological inflammatory response to remaining antigens or a previously undetected infection. To target ?-(1,3)-glucan, a structural component of the Pneumocystis cell wall with immune-stimulating properties, we have developed immunoadhesins consisting of the carbohydrate binding domain of Dectin-1 fused to the Fc regions of the 4 subtypes of murine IgG (mIgG). These immunoadhesins bind ?-glucan with high affinity, and precoating the surface of zymosan with Dectin-1:Fc can reduce cytokine production by macrophages in an in vitro stimulation assay. All Dectin-1:Fc variants showed specificity of binding to the asci of Pneumocystis murina, but effector activity of the fusion molecules varied depending on Fc subtype. Dectin-1:mIgG2a Fc was able to reduce the viability of P. murina in culture through a complement-dependent mechanism, whereas previous studies have shown the mIgG1 Fc fusion to increase macrophage-dependent killing. In an in vivo challenge model, systemic expression of Dectin-1:mIgG1 Fc significantly reduced ascus burden in the lung. When administered postinfection in a model of immune reconstitution inflammatory syndrome (IRIS), both Dectin-1:mIgG1 and Dectin-1:mIgG2a Fc reduced hypoxemia despite minimal effects on fungal burden in the lung. Taken together, these data indicate that molecules targeting ?-glucan may provide a mechanism for treatment of fungal infection and for modulation of the inflammatory response to Pneumocystis and other pathogens.
| S-EPMC3754224 | biostudies-literature
Project description:Pneumocystis pneumonia (PCP) has historically been one of the leading causes of disease among persons with AIDS. The introduction of highly active antiretroviral therapy in industrialized nations has brought about dramatic declines in the incidence of AIDS-associated complications, including PCP. In the adult population, the incidence of PCP has significantly decreased, but it remains among the most common AIDS-defining infections. Similar declines have been documented in the pediatric population. In much of the developing world, PCP remains a significant health problem, although its incidence among adults in sub-Saharan Africa has been debated. This review discusses the epidemiology of PCP during the current era of the AIDS epidemic. Although fewer cases of PCP occur in industrialized countries, increasing drug-resistant HIV infections, possible drug-resistant PCP, and the tremendous number of AIDS cases in developing countries make this disease of continued public health importance.
| S-EPMC3323247 | biostudies-literature
Project description:Pneumocystis pneumonia remains an important complication of immune suppression. The cell wall of Pneumocystis has been demonstrated to potently stimulate host inflammatory responses, with most studies focusing on β-glucan components of the Pneumocystis cell wall. In the current study, we have elaborated the potential role of chitins and chitinases in Pneumocystis pneumonia. We demonstrated differential host mammalian chitinase expression during Pneumocystis pneumonia. We further characterized a chitin synthase gene in Pneumocystis carinii termed Pcchs5, a gene with considerable homolog to the fungal chitin biosynthesis protein Chs5. We also observed the impact of chitinase digestion on Pneumocystis-induced host inflammatory responses by measuring TNFα release and mammalian chitinase expression by cultured lung epithelial and macrophage cells stimulated with Pneumocystis cell wall isolates in the presence and absence of exogenous chitinase digestion. These findings provide evidence supporting a chitin biosynthetic pathway in Pneumocystis organisms and that chitinases modulate inflammatory responses in lung cells. We further demonstrate lung expression of chitinase molecules during Pneumocystis pneumonia.
| S-EPMC3913163 | biostudies-literature
Project description:BACKGROUND:Thoracic ultrasound is helpful to evaluate lung pathology in patients with acute dyspnea. Several studies have demonstrated the efficacy of point-of-care ultrasound in patients with extrapulmonary TB and HIV co-infection. This retrospective, open-label case-control study explores the role of lung ultrasound in the diagnosis of Pneumocystis jirovecii pneumonia (PJP) in HIV-positive patients. In particular, it highlights the potential role of specific sonographic features that may be unique to this population. METHODS:The record of all HIV-positive patients admitted from 1.1.2013 to 31.6.2017 to the Department of Infectious Diseases and Tropical Medicine of san Bortolo Hospital, Vicenza, Italy, with a discharge diagnosis of acute lung injury (ALI) and who received point-of-care ultrasound of the chest for clinical purposes was included in the analysis. The patients were scanned according with the evidence-based recommendation. RESULTS:Of 273 HIV-positive patients whose records were reviewed, 81 (29.6%) were diagnosed with ALI. Complete documentation was available for 24 patients, of which 14 (58.3%) had microbiologically confirmed PJP (PJP+) and 10 (41.7%) had other conditions (PJP-). B-lines, subpleural consolidations, and cystic changes were significantly more frequent in patients with PJP (14/14 vs. 6/10, p = 0.0198; 14/14 vs. 4/10, p = 0.0016; 8/14 vs. 0/10, p = 0.0019, respectively). In particular, B-lines and subpleural consolidations were present in all PJP+ patients in our cohort giving a sensitivity of 100%, but their specificity was low (45 and 60%, respectively). On the contrary, the presence of consolidations with cystic changes had a very high specificity for PJP (100%), but low sensitivity (57%). Pleural effusions and consolidations with linear air bronchograms were not observed in PJP+ patients. CONCLUSIONS:B-lines, subpleural consolidations, and cystic changes are suggestive of PJP. Lung consolidation with air bronchograms and pleural effusion should prompt suspicion of other etiologies. These findings have the potential to be useful in the daily management of HIV-positive patients in resource-limited settings where other diagnostic tools are rarely available.
| S-EPMC5904093 | biostudies-literature