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Medical Mycology Nov 2020Pneumocystis jirovecii can cause life-threatening pneumonia in immunocompromised patients. Traditional diagnostic testing has relied on staining and direct visualization... (Review)
Review
Pneumocystis jirovecii can cause life-threatening pneumonia in immunocompromised patients. Traditional diagnostic testing has relied on staining and direct visualization of the life-forms in bronchoalveolar lavage fluid. This method has proven insensitive, and invasive procedures may be needed to obtain adequate samples. Molecular methods of detection such as polymerase chain reaction (PCR), loop-mediated isothermal amplification (LAMP), and antibody-antigen assays have been developed in an effort to solve these problems. These techniques are very sensitive and have the potential to detect Pneumocystis life-forms in noninvasive samples such as sputum, oral washes, nasopharyngeal aspirates, and serum. This review evaluates 100 studies that compare use of various diagnostic tests for Pneumocystis jirovecii pneumonia (PCP) in patient samples. Novel diagnostic methods have been widely used in the research setting but have faced barriers to clinical implementation including: interpretation of low fungal burdens, standardization of techniques, integration into resource-poor settings, poor understanding of the impact of host factors, geographic variations in the organism, heterogeneity of studies, and limited clinician recognition of PCP. Addressing these barriers will require identification of phenotypes that progress to PCP and diagnostic cut-offs for colonization, generation of life-form specific markers, comparison of commercial PCR assays, investigation of cost-effective point of care options, evaluation of host factors such as HIV status that may impact diagnosis, and identification of markers of genetic diversity that may be useful in diagnostic panels. Performing high-quality studies and educating physicians will be crucial to improve the rates of diagnosis of PCP and ultimately to improve patient outcomes.
Topics: Humans; Immunoassay; Immunocompromised Host; Microbiological Techniques; Pneumocystis carinii; Pneumonia, Pneumocystis; Polymerase Chain Reaction; Sensitivity and Specificity; Specimen Handling; Staining and Labeling
PubMed: 32400869
DOI: 10.1093/mmy/myaa024 -
Respiration; International Review of... 2018The substantial decline in the Pneumocystis jirovecii pneumonia (PCP) incidence in HIV-infected patients after the introduction of antiretroviral therapy (ART) in... (Review)
Review
The substantial decline in the Pneumocystis jirovecii pneumonia (PCP) incidence in HIV-infected patients after the introduction of antiretroviral therapy (ART) in resource-rich settings and the growing number of non-HIV-infected immunocompromised patients at risk leads to considerable epidemiologic changes with clinical, diagnostic, and treatment consequences for physicians. HIV-infected patients usually develop a subacute course of disease, while non-HIV-infected immunocompromised patients are characterized by a rapid disease progression with higher risk of respiratory failure and higher mortality. The main symptoms usually include exertional dyspnea, dry cough, and subfebrile temperature or fever. Lactate dehydrogenase may be elevated. Typical findings on computed tomography scans of the chest are bilateral ground-glass opacities with or without cystic lesions, which are usually associated with the presence of AIDS. Empiric treatment should be initiated as soon as PCP is suspected. Bronchoalveolar lavage has a higher diagnostic yield compared to induced sputum. Immunofluorescence is superior to conventional staining. A combination of different diagnostic tests such as microscopy, polymerase chain reaction, and (1,3)-β-D-glucan is recommended. Trimeth-oprim/sulfamethoxazole for 21 days is the treatment of choice in adults and children. Alternative treatment regimens include dapsone with trimethoprim, clindamycin with primaquine, atovaquone, or pentamidine. Patients with moderate to severe disease should receive adjunctive corticosteroids. In newly diagnosed HIV-infected patients with PCP, ART should be initiated as soon as possible. In non-HIV-infected immunocompromised patients, improvement of the immune status should be discussed (e.g., temporary reduction of immunosuppressive agents). PCP prophylaxis is effective and depends on the immune status of the patient and the underlying immunocompromising disease.
Topics: Adult; Bronchoalveolar Lavage; Child; Drug Therapy, Combination; Fluorescent Antibody Technique; HIV Infections; HIV Seronegativity; Humans; Immunocompromised Host; Lung; Male; Middle Aged; Pneumocystis carinii; Pneumonia, Pneumocystis; Radiography, Thoracic; Trimethoprim, Sulfamethoxazole Drug Combination
PubMed: 29635251
DOI: 10.1159/000487713 -
Current Opinion in Infectious Diseases Aug 2019Pneumocystis pneumonia (PCP) is a frequent opportunistic infection associated with a high mortality rate. PCP is of increasing importance in non-HIV immunocompromised... (Review)
Review
PURPOSE OF REVIEW
Pneumocystis pneumonia (PCP) is a frequent opportunistic infection associated with a high mortality rate. PCP is of increasing importance in non-HIV immunocompromised patients, who present with severe respiratory distress with low fungal loads. Molecular detection of Pneumocystis in broncho-alveolar lavage (BAL) has become an important diagnostic tool, but quantitative PCR (qPCR) needs standardization.
RECENT FINDINGS
Despite a high negative predictive value, the positive predictive value of qPCR is moderate, as it also detects colonized patients. Attempts are made to set a cut-off value of qPCR to discriminate between PCP and colonization, or to use noninvasive samples or combined strategies to increase specificity.
SUMMARY
It is easy to set a qPCR cut-off for HIV-infected patients. In non-HIV IC patients, a gain in specificity could be obtained by combining strategies, that is, qPCR on BAL and a noninvasive sample, or qPCR and serum beta-1,3-D-glucan dosage.
Topics: Bronchoalveolar Lavage Fluid; Coinfection; Disease Management; HIV Infections; Humans; Immunocompromised Host; Molecular Diagnostic Techniques; Opportunistic Infections; Pneumocystis carinii; Pneumonia, Pneumocystis; Real-Time Polymerase Chain Reaction; Reproducibility of Results; Sensitivity and Specificity
PubMed: 31107250
DOI: 10.1097/QCO.0000000000000559 -
Expert Review of Anti-infective Therapy Oct 2019: pneumonia (PcP) has classically been described as a serious complication in patients infected with the human immunodeficiency virus (HIV). However, the emerging... (Review)
Review
: pneumonia (PcP) has classically been described as a serious complication in patients infected with the human immunodeficiency virus (HIV). However, the emerging number of conditions associated with immunosuppression has led to its appearance in other patient populations. : This article reviews the most recent publications on PcP in the HIV-infected and HIV-uninfected population, focusing on epidemiology, diagnostic, therapy and prevention. The data discussed here were mainly obtained from a non-systematic review using Medline and references from relevant articles including randomized clinical trials, meta-analyses, observational studies and clinical reviews. : The growing incidence of infection in the HIV-uninfected population suggests the need for new global epidemiological studies in order to identify the true scale of the disease in this population. These data would allow us to improve diagnosis, therapeutic strategies, and clinical management. It is very important that both patients and physicians realize that HIV-uninfected patients are at risk of PcP and that rapid diagnosis and early initiation of treatment are associated with better prognosis. Currently, in-hospital mortality rates are very high: 15% for HIV-infected patients and 50% in some HIV-uninfected patients. Therefore, adequate preventive measures should be implemented to avoid the high mortality rates seen in recent decades.
Topics: AIDS-Related Opportunistic Infections; Animals; HIV Infections; Humans; Immunocompromised Host; Pneumonia, Pneumocystis; Randomized Controlled Trials as Topic
PubMed: 31550942
DOI: 10.1080/14787210.2019.1671823 -
Clinical Microbiology and Infection :... Jan 2022Pneumocystis jirovecii pneumonia (PCP) is an opportunistic infection commonly affecting immunocompromised people. Diagnosis usually requires invasive techniques to... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Pneumocystis jirovecii pneumonia (PCP) is an opportunistic infection commonly affecting immunocompromised people. Diagnosis usually requires invasive techniques to obtain respiratory specimens. Minimally invasive detection tests have been proposed, but their operating characteristics are poorly described.
OBJECTIVES
To systematically review and meta-analyse the performance of minimally invasive PCP detection tests to inform diagnostic algorithms.
DATA SOURCES
Medline, Embase, Cochrane Library (inception to 15 October 2020).
STUDY ELIGIBILITY CRITERIA
Studies of minimally invasive PCP detection tests were included if they contained a minimum of ten PCP cases.
PARTICIPANTS
Adults at risk of PCP.
TESTS
Non-invasive PCP detection tests.
REFERENCE STANDARD
Diagnosis using the combination of clinical and radiographical features with invasive sampling.
ASSESSMENT OF RISK BIAS
Using the QUADAS-2 tool.
METHODS
We used bivariate and, when necessary, univariate analysis models to estimate diagnostic test sensitivity and specificity.
RESULTS
Fifty-two studies were included; most studies (40) comprised exclusively human immunodeficiency virus (HIV) -infected individuals; nine were mixed (HIV and non-HIV), two were non-HIV and one study did not report HIV status. Sampling sites included induced sputum, nasopharyngeal aspirate, oral wash and blood. The four testing modalities evaluated were cytological staining, fluorescent antibody, PCR and lactate dehydrogenase. Induced sputum had the most data available; this modality was both highly sensitive at 99% (95% CI 51%-100%) and specific at 96% (95% CI 88%-99%). Induced sputum cytological staining had moderate sensitivity at 50% (95% CI 39%-61%) and high specificity at 100% (95% CI 100%-100%), as did fluorescent antibody testing with sensitivity 74% (95% CI 62%-87%) and specificity 100% (95% CI 91%-100%).
CONCLUSION
There are several promising minimally invasive PCP diagnostic tests available, some of which may reduce the need for invasive respiratory sampling. Understanding the operating characteristics of these tests can augment current diagnostic strategies and help establish a more confident clinical diagnosis of PCP. Further studies in non-HIV infected populations are needed.
Topics: Adult; HIV Infections; Humans; Immunocompromised Host; Pneumocystis carinii; Pneumonia, Pneumocystis; Sensitivity and Specificity; Sputum
PubMed: 34464734
DOI: 10.1016/j.cmi.2021.08.017 -
Cold Spring Harbor Perspectives in... Nov 2014Since its initial misidentification as a trypanosome some 100 years ago, Pneumocystis has remained recalcitrant to study. Although we have learned much, we still do not... (Review)
Review
Since its initial misidentification as a trypanosome some 100 years ago, Pneumocystis has remained recalcitrant to study. Although we have learned much, we still do not have definitive answers to such basic questions as, where is the reservoir of infection, how does Pneumocystis reproduce, what is the mechanism of infection, and are there true species of Pneumocystis? The goal of this review is to provide the reader the most up to date information available about the biology of Pneumocystis and the disease it produces.
Topics: Humans; Pneumocystis; Pneumocystis Infections; Pneumonia, Pneumocystis; Virulence Factors
PubMed: 25367973
DOI: 10.1101/cshperspect.a019828 -
Annals of Hematology Jun 2021Hematologic and oncologic patients with chemo- or immunotherapy-related immunosuppression are at substantial risk for bacterial infections and Pneumocystis jirovecii...
Primary prophylaxis of bacterial infections and Pneumocystis jirovecii pneumonia in patients with hematologic malignancies and solid tumors: 2020 updated guidelines of the Infectious Diseases Working Party of the German Society of Hematology and Medical Oncology (AGIHO/DGHO).
Hematologic and oncologic patients with chemo- or immunotherapy-related immunosuppression are at substantial risk for bacterial infections and Pneumocystis jirovecii pneumonia (PcP). As bacterial resistances are increasing worldwide and new research reshapes our understanding of the interactions between the human host and bacterial commensals, administration of antibacterial prophylaxis has become a matter of discussion. This guideline constitutes an update of the 2013 published guideline of the Infectious Diseases Working Party (AGIHO) of the German Society for Hematology and Medical Oncology (DGHO). It gives an overview about current strategies for antibacterial prophylaxis in cancer patients while taking into account the impact of antibacterial prophylaxis on the human microbiome and resistance development. Current literature published from January 2012 to August 2020 was searched and evidence-based recommendations were developed by an expert panel. All recommendations were discussed and approved in a consensus conference of the AGIHO prior to publication. As a result, we present a comprehensive update and extension of our guideline for antibacterial and PcP prophylaxis in cancer patients.
Topics: Anti-Bacterial Agents; Antineoplastic Agents; Drug Resistance, Bacterial; Fluoroquinolones; Germany; Hematologic Neoplasms; Hematology; Humans; Medical Oncology; Microbiota; Pneumocystis carinii; Pneumonia, Pneumocystis; Societies, Medical
PubMed: 33846857
DOI: 10.1007/s00277-021-04452-9 -
Clinical Microbiology and Infection :... Sep 2020Pneumocystis jirovecii pneumonia (PJP) can be a life-threatening opportunistic infection in immunocompromised hosts. The diagnosis can be challenging, often requiring... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Pneumocystis jirovecii pneumonia (PJP) can be a life-threatening opportunistic infection in immunocompromised hosts. The diagnosis can be challenging, often requiring semi-invasive respiratory sampling. The serum 1,3-β-D-glucan (BDG) assay has been proposed as a minimally invasive test for the presumptive diagnosis of PJP.
METHOD
We carried out a systematic review and meta-analysis using articles in the English language published between January 1960 and September 2019. We estimated the pooled sensitivity and specificity of BDG testing using a bivariate random effects approach and compared test performance in human immunodeficiency virus (HIV) and non-HIV subgroups with meta-regression. Data from the pooled sensitivity and specificity were transformed to generate pre- and post-test probability curves.
RESULTS
Twenty-three studies were included. The pooled sensitivity and specificity of serum BDG testing for PJP were 91% (95%CI 87-94%) and 79% (95%CI 72-84%) respectively. The sensitivity in patients with HIV was better than in patients without (94%, 95%CI 91-96%) versus 86% (95%CI 78-91%) (p 0.02), with comparable specificity (83%, 95%CI 69-92% versus 83%, 95%CI 72-90%) (p 0.10). A negative BDG was only associated with a low post-test probability of PJP (≤5%) when the pre-test probability was low to intermediate (≤20% in non-HIV and ≤50% in HIV).
CONCLUSIONS
Among patients with a higher likelihood of PJP, the pooled sensitivity of BDG is insufficient to exclude infection. Similarly, for most cases, the pooled specificity is inadequate to diagnose PJP. Understanding the performance of BDG in the population being investigated is therefore essential to optimal clinical decision-making.
Topics: Humans; Pneumocystis carinii; Pneumonia, Pneumocystis; Sensitivity and Specificity; Serologic Tests; beta-Glucans
PubMed: 32479781
DOI: 10.1016/j.cmi.2020.05.024 -
Annals of the Rheumatic Diseases May 2018To investigate the efficacy and safety of trimethoprim/sulfamethoxazole (TMP-SMX) as primary prophylaxis for pneumocystis pneumonia (PCP) in patients with rheumatic...
OBJECTIVES
To investigate the efficacy and safety of trimethoprim/sulfamethoxazole (TMP-SMX) as primary prophylaxis for pneumocystis pneumonia (PCP) in patients with rheumatic diseases receiving high-dose steroids.
METHODS
The study included 1522 treatment episodes with prolonged (≥4 weeks) high-dose (≥30 mg/day prednisone) steroids in 1092 patients over a 12-year period. Of these, 262 treatment episodes involved TMP-SMX (prophylaxis group) while other episodes involved no prophylaxis (control group). Differences in 1-year PCP incidence and its mortality between the two groups were estimated using Cox regression. To minimise baseline imbalance, propensity score matching was performed and efficacy outcome was mainly assessed in the postmatched population (n=235 in both groups).
RESULTS
During a total of 1474.4 person-years, 30 PCP cases occurred with a mortality rate of 36.7%. One non-fatal case occurred in the prophylaxis group. TMP-SMX significantly reduced the 1-year PCP incidence (adjusted HR=0.07(95% CI 0.01 to 0.53)) and related mortality (adjusted HR=0.08 (95% CI 0.0006 to 0.71)) in the postmatched population. The result of the same analysis performed in the whole population was consistent with that of the primary analysis. Incidence rate of adverse drug reactions (ADR) related to TMP-SMX was 21.2 (14.8-29.3)/100 person-years. Only two serious ADRs (including one Stevens-Johnson syndrome case) occurred. The number needed to treat for preventing one PCP (52 (33-124)) was lower than the number needed to harm for serious ADR (131 (55-∞)).
CONCLUSION
TMP-SMX prophylaxis significantly reduces the PCP incidence with a favourable safety profile in patients with rheumatic disease receiving prolonged, high-dose steroids.
Topics: Adult; Antifungal Agents; Female; Glucocorticoids; Humans; Incidence; Male; Middle Aged; Pneumonia, Pneumocystis; Propensity Score; Retrospective Studies; Rheumatic Diseases; Time Factors; Trimethoprim, Sulfamethoxazole Drug Combination
PubMed: 29092853
DOI: 10.1136/annrheumdis-2017-211796 -
MBio Feb 2023Pneumocystis jirovecii kills hundreds of thousands of immunocompromised patients each year. Yet many aspects of the biology of this obligate pathogen remain obscure...
Pneumocystis jirovecii kills hundreds of thousands of immunocompromised patients each year. Yet many aspects of the biology of this obligate pathogen remain obscure because it is not possible to culture the fungus independently of its host. Consequently, our understanding of Pneumocystis pathobiology is heavily reliant upon bioinformatic inferences. We have exploited a powerful combination of genomic and phylogenetic approaches to examine the evolution of transcription factors in Pneumocystis species. We selected protein families (Pfam families) that correspond to transcriptional regulators and used bioinformatic approaches to compare these families in the seven Pneumocystis species that have been sequenced to date with those from other yeasts, other human and plant pathogens, and other obligate parasites. Some Pfam families of transcription factors have undergone significant reduction during their evolution in the Pneumocystis genus, and other Pfam families have been lost or appear to be in the process of being lost. Meanwhile, other transcription factor families have been retained in Pneumocystis species, and some even appear to have undergone expansion. On this basis, Pneumocystis species seem to have retained transcriptional regulators that control chromosome maintenance, ribosomal gene regulation, RNA processing and modification, and respiration. Meanwhile, regulators that promote the assimilation of alternative carbon sources, amino acid, lipid, and sterol biosynthesis, and iron sensing and homeostasis appear to have been lost. Our analyses of transcription factor retention, loss, and gain provide important insights into the biology and lifestyle of Pneumocystis. Pneumocystis jirovecii is a major fungal pathogen of humans that infects healthy individuals, colonizing the lungs of infants. In immunocompromised and transplant patients, this fungus causes life-threatening pneumonia, and these Pneumocystis infections remain among the most common and serious infections in HIV/AIDS patients. Yet we remain remarkably ignorant about the biology and epidemiology of Pneumocystis due to the inability to culture this fungus . Our analyses of transcription factor retentions, losses, and gains in sequenced Pneumocystis species provide valuable new views of their specialized biology, suggesting the retention of many metabolic and stress regulators and the loss of others that are essential in free-living fungi. Given the lack of culture methods for Pneumocystis, this powerful bioinformatic approach has advanced our understanding of the lifestyle of and the nature of its dependence on the host for survival.
Topics: Humans; Pneumocystis; Phylogeny; Transcription Factors; Pneumonia, Pneumocystis; Pneumocystis carinii; Genomics; Life Style
PubMed: 36651897
DOI: 10.1128/mbio.02711-22