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Parasite (Paris, France) Feb 2011Pneumocystis pneumonia (PcP) remains a significant cause of morbidity and mortality in immunocompromised persons, especially those with human immunodeficiency virus... (Review)
Review
Pneumocystis pneumonia (PcP) remains a significant cause of morbidity and mortality in immunocompromised persons, especially those with human immunodeficiency virus (HIV) infection. Pneumocystis colonization is described increasingly in a wide range of immunocompromised and immunocompetent populations and associations between Pneumocystis colonization and significant pulmonary diseases such as chronic obstructive pulmonary disease (COPD) have emerged. This mini-review summarizes recent advances in our clinical understanding of Pneumocystis and PcP, describes ongoing areas of clinical and translational research, and offers recommendations for future clinical research from researchers participating in the "First centenary of the Pneumocystis discovery".
Topics: AIDS-Related Opportunistic Infections; Biomedical Research; Drug Resistance, Fungal; Humans; Pneumocystis; Pneumonia, Pneumocystis; Translational Research, Biomedical
PubMed: 21395200
DOI: 10.1051/parasite/2011181003 -
Parasitology Research Oct 2015Pneumocystis pneumonia is an opportunistic disease caused by invasion of unicellular fungus Pneumocystis jirovecii. Initially, it was responsible for majority of... (Review)
Review
Pneumocystis pneumonia is an opportunistic disease caused by invasion of unicellular fungus Pneumocystis jirovecii. Initially, it was responsible for majority of morbidity and mortality cases among HIV-infected patients, which later have been reduced due to the introduction of anti-retroviral therapy, as well as anti-Pneumocystis prophylaxis among these patients. Pneumocystis pneumonia, however, is still a significant cause of mortality among HIV-negative patients being under immunosuppression caused by different factors, such as transplant recipients as well as oncologically treated ones. The issue of pneumocystosis among these people is particularly emphasized in the article, since rapid onset and fast progression of severe symptoms result in high mortality rate among these patients, who thereby represent the group of highest risk of developing Pneumocystis pneumonia. In contrast, fungal invasion in immunocompetent people usually leads to asymptomatic colonization, which frequent incidence among healthy infants has even suggested the possibility of its association with sudden unexpected infant death syndrome. In the face of emerging strains with different epidemiological profiles resulting from genetic diversity, including drug-resistant genotypes, the colonization phenomenon desires particular attention, discussed in this article. We also summarize specific and sensitive methods, required for detection of Pneumocystis invasion and for distinguish colonization from the disease.
Topics: AIDS-Related Opportunistic Infections; Genotype; Humans; Immunocompromised Host; Pneumocystis carinii; Pneumonia, Pneumocystis
PubMed: 26281787
DOI: 10.1007/s00436-015-4678-6 -
Medical Mycology Journal 2016Pneumocystis jirovecii is a prototypical opportunistic pathogen, causing an asymptomatic or mild infection in normal hosts and fulminating pneumonia (Pneumocystis... (Review)
Review
Pneumocystis jirovecii is a prototypical opportunistic pathogen, causing an asymptomatic or mild infection in normal hosts and fulminating pneumonia (Pneumocystis pneumonia, PCP) in immunocompromised hosts. PCP is a leading cause of morbidity and mortality in immunocompromised patients such as AIDS patients. Microscopic detection of cysts and trophic forms of P. jirovecii in respiratory secretions is simple and useful but may underestimate the P. jirovecii infection. Conventional polymerase chain reaction (PCR) and nested PCR increase the sensitivity and specificity to identify PCP and provide an approach to discriminate PCP from pulmonary P. jirovecii colonization, but the targeted genes and cut-off value from quantitative real-time PCR remain to be determined. Serum (1-3)-β-D-glucan level and the specific serum antibody titer are ancillary indicators for PCP diagnosis. The successful cultivation of P. jirovecii in vitro is an important progress for PCP research. The diagnosis of PCP relies on the combination of these laboratory examinations as well as the clinical presentations.
Topics: Antibodies, Fungal; Biomarkers; DNA, Fungal; Humans; Immunocompromised Host; Pneumocystis carinii; Pneumonia, Pneumocystis; Polymerase Chain Reaction; Proteoglycans; Sensitivity and Specificity; beta-Glucans
PubMed: 27904052
DOI: 10.3314/mmj.16-00019 -
Clinics in Chest Medicine Jun 2013Pneumocystis pneumonia (PCP) is caused by the yeastlike fungus Pneumocystis. Despite the widespread availability of specific anti-Pneumocystis prophylaxis and of... (Review)
Review
Pneumocystis pneumonia (PCP) is caused by the yeastlike fungus Pneumocystis. Despite the widespread availability of specific anti-Pneumocystis prophylaxis and of combination antiretroviral therapy (ART), PCP remains a common AIDS-defining presentation. PCP is increasingly recognized among persons living in Africa. Pneumocystis cannot be cultured and bronchoalveolar lavage is the gold standard diagnostic test to diagnose PCP. Use of adjunctive biomarkers for diagnosis requires further evaluation. Trimethoprim-sulfamethoxazole remains the preferred first-line treatment regimen. In the era of ART, mortality from PCP is approximately 10% to 12%. The optimal time to start ART in a patient with PCP remains uncertain.
Topics: AIDS-Related Opportunistic Infections; Africa; Anti-Retroviral Agents; Antifungal Agents; Biomarkers; Bronchoalveolar Lavage; HIV Infections; Humans; Pneumocystis; Pneumonia, Pneumocystis
PubMed: 23702173
DOI: 10.1016/j.ccm.2013.02.001 -
International Journal of Environmental... Mar 2022Pneumocystis is an atypical fungus that resides in the pulmonary parenchyma of many mammals, including humans and dogs. Immunocompetent human hosts are usually...
Pneumocystis is an atypical fungus that resides in the pulmonary parenchyma of many mammals, including humans and dogs. Immunocompetent human hosts are usually asymptomatically colonised or show subtle clinical signs, but some immunocompromised people can develop florid life-threatening Pneumocystis pneumonia (PCP). Since much less is known concerning Pneumocystis in dogs, we posit the question: can Pneumocystis colonization be present in dogs with inflammatory airway or lung disease caused by other pathogens or disease processes? In this study, Pneumocystis DNA was detected in bronchoalveolar lavage fluid (BALF) of 22/255 dogs (9%) with respiratory distress and/or chronic cough. Although young dogs (<1 year-of-age) and pedigree breeds were more often Pneumocystis-qPCR positive than older dogs and crossbreds, adult dogs with other infectious conditions and/or a history of therapy-resistant pulmonary disease could also be qPCR-positive, including two patients with suppression of the immune system. Absence of pathognomonic clinical or radiographic signs render it impossible to convincingly discriminate between overt PCP versus other lung/airway disease processes colonised by P. canis. It is possible that colonisation with P. canis might play a certain role as a co-pathogen in some canine patients with lower respiratory disease.
Topics: Animals; Bronchoalveolar Lavage Fluid; Dogs; Humans; Lung; Mammals; Plant Breeding; Pneumocystis; Pneumonia, Pneumocystis
PubMed: 35328882
DOI: 10.3390/ijerph19063192 -
MSphere Sep 2019pneumonia is the most common serious opportunistic infection in patients with HIV/AIDS. Furthermore, pneumonia is a feared complication of the immunosuppressive drug...
pneumonia is the most common serious opportunistic infection in patients with HIV/AIDS. Furthermore, pneumonia is a feared complication of the immunosuppressive drug regimens used to treat autoimmunity, malignancy, and posttransplantation rejection. With an increasing at-risk population, there is a strong need for novel approaches to discover diagnostic and vaccine targets. There are multiple challenges to finding these targets, however. First, has a largely unannotated genome. To address this, we evaluated each protein encoded within the genome by comparisons to proteins encoded within the genomes of other fungi using NCBI BLAST. Second, relies on a multiphasic life cycle, as both the transmissible form (the ascus) and the replicative form (the trophozoite [troph]) reside within the alveolar space of the host. To that end, we purified asci and trophs from and utilized transcriptomics to identify differentially regulated genes. Two such genes, and , are differentially regulated in the ascus and the troph, respectively, and can be utilized to characterize the state of the life cycle , encoding a β-1,3-glucan synthase with a large extracellular domain previously identified using surface proteomics, was more highly expressed on the ascus form of GSC-1 ectodomain immunization generated a strong antibody response that demonstrated the ability to recognize the surface of the asci. GSC-1 ectodomain immunization was also capable of reducing ascus burden following primary challenge with Finally, mice immunized with the GSC-1 ectodomain had limited fungal burden following natural transmission of using a cohousing model. The current report enhances our understanding of biology in a number of ways. First, the current study provided a preliminary annotation of the genome, addressing a long-standing issue in the field. Second, this study validated two novel transcripts enriched in the two predominant life forms of These findings allow better characterization of the life cycle and could be valuable diagnostic tools. Furthermore, this study outlined a novel pipeline of -omics techniques capable of revealing novel antigens (e.g., GSC-1) for the development of vaccines against .
Topics: Animals; Antigens, Fungal; Female; Fungal Proteins; Gene Expression Profiling; Gene Expression Regulation, Fungal; Genome, Fungal; Lung; Mice; Mice, Inbred C57BL; Pneumocystis; Pneumonia, Pneumocystis; Proteomics; Transcriptome
PubMed: 31484742
DOI: 10.1128/mSphere.00488-19 -
Frontiers in Immunology 2023β-glucan is the most abundant polysaccharide in the cell wall of , which has attracted extensive attention because of its unique immunobiological characteristics.... (Review)
Review
β-glucan is the most abundant polysaccharide in the cell wall of , which has attracted extensive attention because of its unique immunobiological characteristics. β-glucan binds to various cell surface receptors, which produces an inflammatory response and accounts for its immune effects. A deeper comprehension of the processes by β-glucan recognizes its receptors, activates related signaling pathways, and regulates immunity as required. Such understanding will provide a basis for developing new therapies against . Herein, we briefly review the structural composition of β-glucans as a vital component of the cell wall, the host immunity mediated by β-glucans after their recognition, and discuss opportunities for the development of new strategies to combat .
Topics: Pneumocystis; beta-Glucans; Glucans; Pneumonia, Pneumocystis; Cell Wall
PubMed: 36845149
DOI: 10.3389/fimmu.2023.1094464 -
American Journal of Respiratory Cell... Jun 2020
Topics: Humans; Macrophage Activation; Pneumocystis; Pneumonia, Pneumocystis; Programmed Cell Death 1 Receptor; Th1 Cells
PubMed: 32109143
DOI: 10.1165/rcmb.2020-0051ED -
PloS One 2013Pneumocystis jirovecii pneumonia (PCP), the commonest opportunistic infection in HIV-infected patients in the developed world, is less commonly described in tropical and... (Review)
Review
OBJECTIVE
Pneumocystis jirovecii pneumonia (PCP), the commonest opportunistic infection in HIV-infected patients in the developed world, is less commonly described in tropical and low and middle income countries (LMIC). We sought to investigate predictors of PCP in these settings.
DESIGN
Systematic review and meta-regression.
METHODS
Meta-regression of predictors of PCP diagnosis (33 studies). Qualitative and quantitative assessment of recorded CD4 counts, receipt of prophylaxis and antiretrovirals, sensitivity and specificity of clinical signs and symptoms for PCP, co-infection with other pathogens, and case fatality (117 studies).
RESULTS
The most significant predictor of PCP was per capita Gross Domestic Product, which showed strong linear association with odds of PCP diagnosis (p<0.0001). This was not explained by study design or diagnostic quality. Geographical area, population age, study setting and year of study also contributed to risk of PCP. Co-infection was common (444 episodes/1425 PCP cases), frequently with virulent organisms. The predictive value of symptoms, signs or simple tests in LMIC settings for diagnosis of PCP was poor. Case fatality was >30%; treatment was largely appropriate. Prophylaxis appeared to reduce the risk for development of PCP, however 24% of children with PCP were receiving prophylaxis. CD4 counts at presentation with PCP were usually <200×10(3/)ml.
CONCLUSIONS
There is a positive relationship between GDP and risk of PCP diagnosis. Although failure to diagnose infection in poorer countries may contribute to this, we also hypothesise that poverty exposes at-risk patients to a wide range of infections and that the relatively non-pathogenic P. jirovecii is therefore under-represented. As LMIC develop economically they eliminate the conditions underlying transmission of virulent infection: P. jirovecii, ubiquitous in all settings, then becomes a greater relative threat.
Topics: Developing Countries; Humans; Meta-Analysis as Topic; Pneumocystis carinii; Pneumonia, Pneumocystis
PubMed: 23936365
DOI: 10.1371/journal.pone.0069969 -
FEMS Immunology and Medical Microbiology Sep 1998
Topics: Humans; Pneumocystis; Pneumonia, Pneumocystis
PubMed: 9792055
DOI: 10.1111/j.1574-695X.1998.tb01181.x