-
The Journal of Infectious Diseases Jul 2019Glucan is the major cell wall component of Pneumocystis cysts. In the current study, we have characterized Pneumocystis Bgl2 (EC 3.2.1.58), an enzyme with...
Glucan is the major cell wall component of Pneumocystis cysts. In the current study, we have characterized Pneumocystis Bgl2 (EC 3.2.1.58), an enzyme with glucanosyltransferase and β-1,3 endoglucanase activity in other fungi. Pneumocystis murina, Pneumocystis carinii, and Pneumocystis jirovecii bgl2 complementary DNA sequences encode proteins of 437, 447, and 408 amino acids, respectively. Recombinant P. murina Bgl2 expressed in COS-1 cells demonstrated β-glucanase activity, as shown by degradation of the cell wall of Pneumocystis cysts. It also cleaved reduced laminaripentaose and transferred oligosaccharides, resulting in polymers of 6 and 7 glucan residues, demonstrating glucanosyltransferase activity. Surprisingly, confocal immunofluorescence analysis of P. murina-infected mouse lung sections using an antibody against recombinant Bgl2 showed that the native protein is localized primarily to the trophic form of Pneumocystis in both untreated mice and mice treated with caspofungin, an antifungal drug that inhibits β-1,3-glucan synthase. Thus, like other fungi, Bgl2 of Pneumocystis has both endoglucanase and glucanosyltransferase activities. Given that it is expressed primarily in trophic forms, further studies are needed to better understand its role in the biology of Pneumocystis.
Topics: Amino Acid Sequence; Animals; Antifungal Agents; CD40 Ligand; COS Cells; Caspofungin; Cell Wall; Chlorocebus aethiops; Glucan Endo-1,3-beta-D-Glucosidase; Glucans; Lung; Mice; Mice, Inbred C57BL; Mice, Knockout; Pneumocystis; Pneumonia, Pneumocystis; Recombinant Proteins; Sequence Alignment
PubMed: 31100118
DOI: 10.1093/infdis/jiz172 -
Chest Jun 2024Pneumocystis jirovecii pneumonia (PcP) remains associated with high rates of mortality, and the impact of immunocompromising underlying disease on the clinical... (Observational Study)
Observational Study
BACKGROUND
Pneumocystis jirovecii pneumonia (PcP) remains associated with high rates of mortality, and the impact of immunocompromising underlying disease on the clinical presentation, severity, and mortality of PcP has not been adequately evaluated.
RESEARCH QUESTION
Does the underlying disease and immunosuppression causing PcP impact the outcome and clinical presentation of the disease?
STUDY DESIGN AND METHODS
In this multicenter retrospective observational study, conducted from January 2011 to December 2021, all consecutive patients admitted with a proven or probable diagnosis of PcP according to the European Organisation for Research and Treatment of Cancer consensus definitions were included to assess the epidemiology and impact of underlying immunosuppressive diseases on overall and 90-day mortality.
RESULTS
Overall, 481 patients were included in the study; 180 (37.4%) were defined as proven PcP and 301 (62.6%) were defined as probable PcP. Patients with immune-mediated inflammatory diseases (IMIDs) or solid tumors had a statistically poorer prognosis than other patients with PcP at day 90. In multivariate analysis, among the HIV-negative population, solid tumor underlying disease (OR, 5.47; 95% CI, 2.16-14.1; P < .001), IMIDs (OR, 2.19; 95% CI, 1.05-4.60; P = .037), long-term corticosteroid exposure (OR, 2.07; 95% CI, 1.03-4.31; P = .045), cysts in sputum/BAL smears (OR, 1.92; 95% CI, 1.02-3.62; P = .043), and SOFA score at admission (OR, 1.58; 95% CI, 1.39-1.82; P < .001) were independently associated with 90-day mortality. Prior corticotherapy was the only immunosuppressant associated with 90-day mortality (OR, 1.67; 95% CI, 1.03-2.71; P = .035), especially for a prednisone daily dose ≥ 10 mg (OR, 1.80; 95% CI, 1.14-2.85; P = .010).
INTERPRETATION
Among patients who were HIV-negative, long-term corticosteroid prior to PcP diagnosis was independently associated with increased 90-day mortality, specifically in patients with IMIDs. These results highlight both the needs for PcP prophylaxis in patients with IMIDs and to early consider PcP curative treatment in severe pneumonia among patients with IMIDs.
Topics: Humans; Pneumonia, Pneumocystis; Male; Female; Retrospective Studies; Middle Aged; Prognosis; Aged; Pneumocystis carinii; Immunocompromised Host; Risk Factors
PubMed: 38215935
DOI: 10.1016/j.chest.2024.01.015 -
PloS One 2015Pneumocystis jiroveci pneumonia (PCP) is frequently reported in lymphoma patients treated with rituximab-contained regimens. There is a trend toward a difference in PCP... (Meta-Analysis)
Meta-Analysis Review
Pneumocystis jiroveci pneumonia (PCP) is frequently reported in lymphoma patients treated with rituximab-contained regimens. There is a trend toward a difference in PCP risk between bi- and tri-weekly regimens. The aims of this systemic review and meta-analysis were to estimate the risk for PCP in these patients, compare the impact of different regimens on the risk, and evaluate the efficacy of prophylaxis. The cohort studies with incept up to January 2014 were retrieved from the Cochrane Library, Medline, Embase, and Web of Science databases. Studies that compared the incidence of PCP in patients with and without rituximab treatment were conducted. Studies that reported the results of prophylaxis were concentrated to evaluate the efficacy of prophylaxis. Fixed effect Mantel-Haenszel model was chosen as the main analysis method. Funnel plots were examined to estimate the potential selection bias. Egger's test and Begg's test were used for the determination of possible small study bias. Eleven cohort studies that met the inclusion criteria were finally included. Results indicated that rituximab was associated with a significantly increased risk for PCP (28/942 vs 5/977; risk ratio: 3.65; 95% confidence interval 1.65 to 8.07; P=0.001), and no heterogeneity existed between different studies (I2=0%). Little significant difference in PCP risk was found between bi-weekly and tri-weekly regimens (risk ratio: 3.11; 95% confidence interval 0.92 to 10.52, P=0.068). PCP risk was inversely associated with prophylaxis in patients treated with rituximab (0/222 vs 26/986; risk ratio: 0.28; 95% confidence interval 0.09 to 0.94; P=0.039). In conclusion, PCP risk was increased significantly in lymphoma patients subjected to rituximab-contained chemotherapies. Difference in PCP risk between bi-weekly and tri-weekly regimens was not significant. Additionally, prophylaxis was dramatically effective in preventing PCP in rituximab-received lymphoma patients, suggesting that rituximab should be recommended for these patients.
Topics: Anti-Bacterial Agents; Antibiotic Prophylaxis; Humans; Incidence; Lymphoma; Odds Ratio; Pneumocystis carinii; Pneumonia, Pneumocystis; Publication Bias; Rituximab; Treatment Outcome; Trimethoprim, Sulfamethoxazole Drug Combination
PubMed: 25909634
DOI: 10.1371/journal.pone.0122171 -
Swiss Medical Weekly 2016Every year, Candida, Aspergillus, Cryptococcus and Pneumocystis infect an estimated two million individuals worldwide. Most are immunocompromised or critically ill.... (Review)
Review
Every year, Candida, Aspergillus, Cryptococcus and Pneumocystis infect an estimated two million individuals worldwide. Most are immunocompromised or critically ill. Candida is the most common fungal pathogen of the critically ill and of recipients of transplanted abdominal organs. In high-risk haemato-oncological patients, in contrast, the introduction of antifungal prophylaxis with fluconazole and later with mould-active posaconazole has led to a remarkable reduction of invasive candidiasis and is likely to have a similar effect on invasive aspergillosis. Invasive aspergillosis remains the dominant invasive fungal disease (IFD) of haemato-oncological patients and solid-organ transplant recipients and is increasingly found in individuals with exacerbated chronic obstructive pulmonary disease on corticosteroids. In the developed world, owing to antiretroviral therapy Pneumocystis pneumonia and cryptococcosis have become rare in patients with human immunodeficiency virus (HIV) and are mainly found in solid-organ transplant recipients or immunocompromised patients. In the developing world, cryptococcosis remains a common and highly lethal disease of HIV positive individuals. With invasive candidiasis and invasive aspergillosis, timely diagnosis is the principal challenge. The clinical presentation is nonspecific and current diagnostic tests lack sensitivity and specificity. The combination of several tests improves sensitivity, but not specificity. Standardised polymerase chain-reaction-based assays may be promising tools for more rapid and specific diagnosis of candidiasis and invasive aspergillosis. Nevertheless, initiation of treatment is often based solely on clinical suspicion. Empirical therapy, however, may lead to over-treatment of patients without IFD or it may miss its target in the case of resistance. Despite the success of antifungal prophylaxis in reducing the incidence of IFDs in haemato-oncological patients, there are a considerable number of breakthrough infections demonstrating not only fungal resistance but also the emergence of rare and often lethal fungal pathogens. Knowledge of the local epidemiology and antifungal resistance is therefore pivotal. Current trial-based guidelines leave major gaps in identifying those most at risk, who may benefit from prophylaxis. Ongoing searches for disease-associated genetic polymorphisms may contribute to the establishment of individual risk profiles and targeted prophylaxis.
Topics: Antifungal Agents; Aspergillosis; Candidiasis, Invasive; Cryptococcosis; HIV Infections; Humans; Immunocompromised Host; Pneumonia, Pneumocystis; Switzerland
PubMed: 26901377
DOI: 10.4414/smw.2016.14281 -
The Korean Journal of Parasitology Oct 2022This study determined the recent status and trend of Pneumocystis jirovecii pneumonia (PcP) in the non-human immunodeficiency virus (HIV) (non-HIV-PcP) and HIV (HIV-PcP)...
This study determined the recent status and trend of Pneumocystis jirovecii pneumonia (PcP) in the non-human immunodeficiency virus (HIV) (non-HIV-PcP) and HIV (HIV-PcP) infected populations using data from the Health Insurance Review & Assessment Service (HIRA) and the Korea Disease Control and Prevention Agency (KDCA). SaTScan and Joinpoint were used for statistical analyses. Non-HIV-PcP cases showed an upward trend during the study period from 2010 to 2021, with the largest number in 2021 (551 cases). The upward trend was similar until 2020 after adjusting for the population. Seoul had the highest number of cases (1,597) in the non-HIV-PcP group, which was the same after adjusting for the population (162 cases/1,000,000). It was followed by Jeju-do (89 cases/1,000,000). The most likely cluster (MLC) for the non-HIV-PCP group was Seoul (Relative Risk (RR)=4.59, Log Likelihood Ratio (LLR)=825.531), followed by Jeju-do (RR=1.59, LLR=5.431). An upward trend was observed among the non-HIV-PcP group in the Jeju-do/Jeollanam-do/Jeollabuk-do/Gyeongsangnam-do/Busan/Daejeon/Daegu/Ulsan joint cluster (29.02%, LLR=11.638, P<0.001) located in the southern part of Korea. Both women and men in the non-HIV groups showed an overall upward trend of PcP during the study period. Men in the 60-69 age group had the highest annual percentage change (APC 41.8) during 2014-2019. In contrast, the HIV groups showed a falling trend of PcP recently. Men in the 60-69 age group had the most decrease (APC -17.6) during 2018-2021. This study provides an analytic basis for health measures and a nationwide epidemiological surveillance system for the management of PcP.
Topics: Female; Humans; Pneumocystis carinii; Pneumonia, Pneumocystis; HIV Infections; Risk; Republic of Korea
PubMed: 36320109
DOI: 10.3347/kjp.2022.60.5.327 -
Clinics in Chest Medicine Sep 2017Many fungi cause pulmonary disease in patients with human immunodeficiency virus (HIV) infection. Pathogens include Pneumocystis jirovecii, Cryptococcus neoformans,... (Review)
Review
Many fungi cause pulmonary disease in patients with human immunodeficiency virus (HIV) infection. Pathogens include Pneumocystis jirovecii, Cryptococcus neoformans, Aspergillus spp, Histoplasma capsulatum, Coccidioides spp, Blastomyces dermatitidis, Paracoccidioides brasiliensis, Talaromyces marneffei, and Emmonsia spp. Because symptoms are frequently nonspecific, a high index of suspicion for fungal infection is required for diagnosis. Clinical manifestations of fungal infection in HIV-infected patients frequently depend on the degree of immunosuppression and the CD4 helper T cell count. Establishing definitive diagnosis is important because treatments differ. Primary and secondary prophylaxes depend on CD4 helper T cell counts, geographic location, and local prevalence of disease.
Topics: HIV Infections; Humans; Mycoses; Pneumocystis; Pneumonia, Pneumocystis
PubMed: 28797489
DOI: 10.1016/j.ccm.2017.04.008 -
Journal of Medical Case Reports Feb 2024Pneumocystis jirovecii (PJP) pneumonia is a serious life-threatening condition in immunocompromised individuals and is often associated with human immunodeficiency virus...
INTRODUCTION AND IMPORTANCE
Pneumocystis jirovecii (PJP) pneumonia is a serious life-threatening condition in immunocompromised individuals and is often associated with human immunodeficiency virus (HIV) + patients. We describe a case of PJP pneumonia which provided a diagnostic challenge in a patient who presented with no known risk factors leading to a delay in initiation of appropriate antibiotic therapy.
CASE PRESENTATION
A 71-year-old previously healthy white/Caucasian male presented with subacute hypoxic respiratory failure due to multifocal pneumonia with diffuse bilateral ground glass opacities with consolidations despite prior treatment with antibiotics and steroids. He was admitted and started on intravenous broad-spectrum antibiotics but continued to deteriorate, eventually requiring intubation and transfer to the ICU. Bronchoscopy revealed PJP and treatment was initiated, but the patient developed refractory shock and multiorgan failure, and ultimately died. It was later discovered that he was HIV-1 positive.
CLINICAL DISCUSSION
PJP, as a potential cause of his presentation, was not considered given that our patient lacked any overt risk factors for PJP pneumonia. He continued to worsen despite broad spectrum antibiotic therapy and hence bronchoscopy was pursued. His clinical profile, in hindsight, was suspicious for PJP pneumonia and early PJP-directed antibiotic therapy may have prevented a fatal outcome, as in this case. There was an element of cognitive bias across multiple providers which may have contributed to the delay in treatment despite his rapid clinical decline while on conventional pneumonia treatment protocol. His diagnosis was later evident when his BAL-DFA grew PJP in addition to his low levels of CD4 and CD8 cells. He was found to be HIV-1 positive five days after his death; there was a delay in this diagnosis since all positive HIV tests from the hospital are reported as 'pending' until the presumptive positive sample goes to the Connecticut Department of Public Health State laboratory for the confirmatory test. PJP-targeted therapies were initiated later in our patient's hospital course when the infection had progressed to refractory septic shock with multiorgan failure and eventual death.
CONCLUSION
PJP pneumonia is a fatal disease if not recognized early in the course of illness, and the patient usually undergoes multiple antibiotic regimens before they are diagnosed and receive appropriate clinical care. The gold standard of diagnostic testing for PJP is by obtaining bronchial washings through a flexible bronchoscopy and the turnaround time for such results may take a few days to result. A significant proportion of patients may not have any overt risk factors of immunosuppression and early empiric treatment for PJP may be clinically appropriate as the delay in diagnosis may be associated with significant morbidity and mortality risk.
Topics: Humans; Male; Aged; Pneumonia, Pneumocystis; Pneumocystis carinii; Risk Factors; Anti-Bacterial Agents; HIV Infections
PubMed: 38342895
DOI: 10.1186/s13256-024-04350-4 -
The Malaysian Journal of Pathology Dec 2020Report of a 3-month old girl child who died due to multi-systemic infection of cytomegalovirus (CMV) involving the lungs, liver and kidneys along with pneumocystis...
Report of a 3-month old girl child who died due to multi-systemic infection of cytomegalovirus (CMV) involving the lungs, liver and kidneys along with pneumocystis jiroveci pneumonia (PJP). The mother of the child tested positive for CMV IgG and HIV with a very low CD4 count (160/ μl). Co-infection of cytomegalovirus and pneumocystis jiroveci always occurs in the setting of immunocompromise. Congenital CMV infection is transmitted through the placenta, especially during the first trimester and causes severe multi-systemic disease whereas perinatal infection is acquired during childbirth/ breastfeeding where the babies have maternal protective antibodies leading to much milder or asymptomatic infection. PJP is more common in infancy and presents as hypoxic pneumonia. CMV causes cyto-nucleomegaly and classic "owl's eye" inclusions on histology while PJP presents with characteristic fluffy "cotton ball" alveolar exudates.
Topics: Coinfection; Cytomegalovirus Infections; Female; Humans; Immunocompromised Host; Infant; Infectious Disease Transmission, Vertical; Pneumocystis carinii; Pneumonia, Pneumocystis
PubMed: 33361734
DOI: No ID Found -
Antimicrobial Agents and Chemotherapy Aug 2022A3IS (Mycosinate) is a synthetic product which only contains ingredients found naturally within honey. A3IS is a broad-spectrum antimicrobial product which produces a...
A3IS (Mycosinate) is a synthetic product which only contains ingredients found naturally within honey. A3IS is a broad-spectrum antimicrobial product which produces a sustained release of hydrogen peroxide at low but therapeutic levels. The product elicits this release through an enzymatic reaction between glucose oxidase and the substrate glucose once the product is hydrated. As medical uses for different honeys are being re-evaluated, the purpose of this study was to evaluate the effects of A3IS against a comprehensive panel of human pathogens, including Pneumocystis species, providing a unique assessment against a panel of eukaryotic pathogens. Without exception, A3IS exhibited significant efficacy at 50% and 100% inhibitory concentrations against a broad spectrum of human pathogens including yeasts, molds (both hyaline and dematiaceous), and dimorphic fungi. Notably, A3IS was effective against fungal strains with a high level of resistance to fluconazole or voriconazole. The 50% inhibitory concentrations for Pneumocystis carinii and P. murina (surrogates for ) were considered "Marked" and "Moderate" on an established rank scale, and would be considered for studies, based on an established pipeline. These results indicate that A3IS is a novel anti-fungal agent against an extensive range of human fungal pathogens.
Topics: Antifungal Agents; Fluconazole; Fungi; Humans; Microbial Sensitivity Tests; Pneumocystis; Pneumonia, Pneumocystis; Voriconazole
PubMed: 35852368
DOI: 10.1128/aac.00521-22 -
The Journal of Infectious Diseases Feb 2022Pneumocystis species interaction with myeloid cells is well known, especially in macrophages; however, how the organism binds to lung epithelial cells is incompletely...
Pneumocystis species interaction with myeloid cells is well known, especially in macrophages; however, how the organism binds to lung epithelial cells is incompletely understood. Ephrin type-A receptor 2 (EphA2) has been previously identified as a lung epithelial pattern recognition receptor that binds to fungal β-glucans. Herein, we also report that EphA2 can also bind Pneumocystis β-glucans, both in isolated forms and also on exposed surfaces of the organism. Furthermore, binding of Pneumocystis β-glucans resulted in phosphorylation of the EphA2 receptor, which has been shown to be important for downstream proinflammatory response. Indeed, we also show that interleukin 6 cytokine is significantly increased when lung epithelial cells are exposed to Pneumocystis β-glucans, and that this response could be blocked by preincubation with a specific antibody to EphA2. Our study presents another Pneumocystis lung epithelial cell receptor with implications for initial colonization and possible therapeutic intervention.
Topics: Carrier Proteins; Epithelial Cells; Humans; Lung; Pneumocystis; Pneumonia, Pneumocystis; Receptor, EphA2; beta-Glucans
PubMed: 34289046
DOI: 10.1093/infdis/jiab384