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Annals of Clinical Microbiology and... Jan 2024Pneumocystis jirovecii (P. jirovecii) is an opportunistic fungus responsible for Pneumocystis pneumonia (PCP) in deeply immunocompromised patients and for pulmonary...
BACKGROUND
Pneumocystis jirovecii (P. jirovecii) is an opportunistic fungus responsible for Pneumocystis pneumonia (PCP) in deeply immunocompromised patients and for pulmonary colonization in individuals with mild immunosuppression or impaired respiratory function. PCP and Cytomegalovirus (CMV) co-infections have been widely described whereas those involving other Herpesviruses (HVs) such as Epstein-Barr virus (EBV), Herpes simplex virus type 1 and type 2 (HSV-1 and -2), and Varicella zoster virus (VZV) remain scarce. To date, no data are available concerning HVs co-infections in P. jirovecii colonization.
METHODS
Our main objective was to evaluate the frequency of HVs in bronchoalveolar lavage fluid (BALF) samples from patients with PCP or with pulmonary colonization. The secondary objective was to assess the relationship between HVs and the mortality rate in PCP patients. A retrospective single-center study over a seven-year period was conducted. All patients with P. jirovecii detected using PCR in a BALF sample and for whom a PCR assay for HVs detection was performed were included in the study.
RESULTS
One hundred and twenty-five patients were included, corresponding to 77 patients with PCP and 48 colonized patients. At least one HV was detected in 54/77 (70.1%) PCP patients and in 28/48 (58.3%) colonized patients. EBV was the most frequent in both groups. Furthermore, the 30-day survival rate in PCP patients was significantly lower with [EBV + CMV] co-infection than that with EBV co-infection, [EBV + HSV-1] co-infection and without HV co-infection.
CONCLUSION
Our results show that the frequency of HV, alone or in combination is similar in PCP and colonization. They also suggest that [EBV + CMV] detection in BALF samples from PCP patients is associated with an increased mortality rate, underlying the significance to detect HVs in the course of PCP.
Topics: Humans; Pneumocystis carinii; Retrospective Studies; Pneumonia, Pneumocystis; Coinfection; Epstein-Barr Virus Infections; Herpesvirus 4, Human; Herpesviridae; Cytomegalovirus Infections
PubMed: 38245721
DOI: 10.1186/s12941-023-00663-2 -
Microbiology Spectrum Feb 2024spp. are host obligate fungal pathogens that can cause severe pneumonia in mammals and rely heavily on their host for essential nutrients. The lack of a sustainable...
spp. are host obligate fungal pathogens that can cause severe pneumonia in mammals and rely heavily on their host for essential nutrients. The lack of a sustainable culture system poses challenges in understanding their metabolism, and the acquisition of essential nutrients from host lungs remains unexplored. Transmission electron micrographs show that extracellular vesicles (EVs) are found near spp. within the lung. We hypothesized that EVs transport essential nutrients to the fungi during infection. To investigate this, EVs from - and -infected rodents were biochemically and functionally characterized. These EVs contained host proteins involved in cellular, metabolic, and immune processes as well as proteins with homologs found in other fungal EV proteomes, indicating that may release EVs. Notably, EV uptake by indicated their potential involvement in nutrient acquisition and a possibility for using engineered EVs for efficient therapeutic delivery. However, EVs added to did not show increased growth or viability, implying that additional nutrients or factors are necessary to support their metabolic requirements. Exposure of macrophages to EVs increased proinflammatory cytokine levels but did not affect macrophages' ability to kill or phagocytose . These findings provide vital insights into and host EV interactions, yet the mechanisms underlying 's survival in the lung remain uncertain. These studies are the first to isolate, characterize, and functionally assess EVs from -infected rodents, promising to enhance our understanding of host-pathogen dynamics and therapeutic potential.IMPORTANCE spp. are fungal pathogens that can cause severe pneumonia in mammals, relying heavily on the host for essential nutrients. The absence of an culture system poses challenges in understanding their metabolism, and the acquisition of vital nutrients from host lungs remains unexplored. Extracellular vesicles (EVs) are found near spp., and it is hypothesized that these vesicles transport nutrients to the pathogenic fungi. proteins within the EVs showed homology to other fungal EV proteomes, suggesting that spp. release EVs. While EVs did not significantly enhance growth , displayed active uptake of these vesicles. Moreover, EVs induced proinflammatory cytokine production in macrophages without compromising their ability to combat . These findings provide valuable insights into EV dynamics during host-pathogen interactions in pneumonia. However, the precise underlying mechanisms remain uncertain. This research also raises the potential for engineered EVs in therapeutic applications.
Topics: Rats; Animals; Pneumocystis carinii; Proteome; Pneumonia, Pneumocystis; Pneumocystis; Macrophages; Mammals; Cytokines; Extracellular Vesicles
PubMed: 38236033
DOI: 10.1128/spectrum.03653-23 -
Clinical Microbiology Reviews Mar 2024is a ubiquitous opportunistic fungus that can cause life-threatening pneumonia. People with HIV (PWH) who have low CD4 counts are one of the populations at the greatest... (Review)
Review
is a ubiquitous opportunistic fungus that can cause life-threatening pneumonia. People with HIV (PWH) who have low CD4 counts are one of the populations at the greatest risk of pneumonia (PCP). While guidelines have approached the diagnosis, prophylaxis, and management of PCP, the numerous studies of PCP in PWH are dominated by the 1980s and 1990s. As such, most studies have included younger male populations, despite PCP affecting both sexes and a broad age range. Many studies have been small and observational in nature, with an overall lack of randomized controlled trials. In many jurisdictions, and especially in low- and middle-income countries, the diagnosis can be challenging due to lack of access to advanced and/or invasive diagnostics. Worldwide, most patients will be treated with 21 days of high-dose trimethoprim sulfamethoxazole, although both the dose and the duration are primarily based on historical practice. Whether treatment with a lower dose is as effective and less toxic is gaining interest based on observational studies. Similarly, a 21-day tapering regimen of prednisone is used for patients with more severe disease, yet other doses, other steroids, or shorter durations of treatment with corticosteroids have not been evaluated. Now with the widespread availability of antiretroviral therapy, improved and less invasive PCP diagnostic techniques, and interest in novel treatment strategies, this review consolidates the scientific body of literature on the diagnosis and management of PCP in PWH, as well as identifies areas in need of more study and thoughtfully designed clinical trials.
Topics: Female; Humans; Male; Pneumonia, Pneumocystis; Pneumocystis carinii; HIV Infections; Trimethoprim, Sulfamethoxazole Drug Combination
PubMed: 38235979
DOI: 10.1128/cmr.00101-22 -
Current Opinion in Infectious Diseases Apr 2024This review highlights the epidemiology of Pneumocystis jirovecii pneumonia in solid organ transplant recipients, advancements in the diagnostic landscape, and updates... (Review)
Review
PURPOSE OF REVIEW
This review highlights the epidemiology of Pneumocystis jirovecii pneumonia in solid organ transplant recipients, advancements in the diagnostic landscape, and updates in treatment and prevention.
RECENT FINDINGS
The increasing use of immune-depleting agents in the context of solid organ transplantation has given rise to P. jirovecii pneumonia in this population. The use of prophylaxis has dramatically reduced risk of infection; however, late-onset infections occur after cessation of prophylaxis and in the setting of lymphopenia, advancing patient age, acute allograft rejection, and cytomegalovirus infection. Diagnosis requires respiratory specimens, with PCR detection of Pneumocystis replacing traditional staining methods. Quantitative PCR may be a useful adjunct to differentiate between infection and colonization. Metagenomic next-generation sequencing is gaining attention as a noninvasive diagnostic tool. Trimethoprim-sulfamethoxazole remains the drug of choice for treatment and prevention of Pneumocystis pneumonia. Novel antifungal agents are under investigation.
SUMMARY
P. jirovecii is a fungal opportunistic pathogen that remains a cause of significant morbidity and mortality in solid organ transplant recipients. Early detection and timely treatment remain the pillars of management.
Topics: Humans; Pneumocystis carinii; Pneumonia, Pneumocystis; Trimethoprim, Sulfamethoxazole Drug Combination; Organ Transplantation; Transplantation, Homologous; Transplant Recipients
PubMed: 38230604
DOI: 10.1097/QCO.0000000000001002 -
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 -
Mycoses Jan 2024Pneumocystis jirovecii pneumonia (PJP) is a common and troublesome complication of kidney transplantation. In the era of prophylaxis, the peak incidence of PJP after...
BACKGROUND
Pneumocystis jirovecii pneumonia (PJP) is a common and troublesome complication of kidney transplantation. In the era of prophylaxis, the peak incidence of PJP after kidney transplantation and specific characteristics of late-onset PJP have always been debated.
METHODS
We performed a retrospective study by analysing the data of post-transplantation pneumonia in adult kidney transplantation recipients between March 2014 and December 2021 in The Affiliated First Hospital of University of Science and Technology of China (USTC). A total of 361 patients were included and divided into early-onset PJP, late-onset PJP and non-PJP groups. The characteristics of each group and related risk factors for the late-onset patients were investigated.
RESULTS
Some patients developed PJP 9 months later with a second higher occurrence between month 10 and 15 after transplantation. Compared with non-PJP, ABO-incompatible and cytomegalovirus (CMV) viremia were significantly associated with late onset of PJP in multivariate analysis. The use of tacrolimus, CMV viremia, elevated CD8(+) T cell percent and hypoalbuminemia were risk factors for late PJP. Receiver operating characteristic curve analysis demonstrated that a combination of those factors could increase the sensitivity of prediction remarkably, with an area under the curve of 0.82, a sensitivity of 80% and a specificity of 83%.
CONCLUSIONS
PJP could occur months after kidney transplantation. ABO-incompatible transplant recipients are at high risk of PJP. In the later stages of transplantation, CMV viremia, T lymphocyte subsets percentage and serum albumin levels should be monitored in patients using tacrolimus.
Topics: Adult; Humans; Pneumonia, Pneumocystis; Kidney Transplantation; Retrospective Studies; Transplant Recipients; Tacrolimus; Viremia; Pneumocystis carinii; Risk Factors; Cytomegalovirus Infections
PubMed: 38214337
DOI: 10.1111/myc.13688 -
Antimicrobial Agents and Chemotherapy Feb 2024the fungus that causes pneumonia (PJP), is a leading cause of morbidity and mortality in immunocompromised individuals. We have previously shown that lung epithelial...
the fungus that causes pneumonia (PJP), is a leading cause of morbidity and mortality in immunocompromised individuals. We have previously shown that lung epithelial cells can bind spp. β-glucans via the EphA2 receptor, resulting in activation and release of proinflammatory cytokines. Herein, we show that spp. β-glucans activation of the inflammatory signaling cascade in macrophages can be pharmacodynamically inhibited with the EphA2 receptor small-molecule inhibitor ALW-II-41-27. , when ALW-II-41-27 is administrated via intraperitoneal to mice prior to the administration of highly proinflammatory β-glucans in the lung, a significant reduction in TNF-alpha release was noted in the ALW-II-41-27 pre-treated group. Taken together, our data suggest that targeting host lung macrophage activation via EphA2 receptor-fungal β-glucans interactions with ALW-II-41-27 or other EphA2 receptor kinase targeting inhibitors might be an attractive and viable strategy to reduce detrimental lung inflammation associated with PJP.
Topics: Mice; Animals; Pneumocystis carinii; beta-Glucans; Receptor Protein-Tyrosine Kinases; Receptor, EphA2; Pneumonia, Pneumocystis; Macrophages; Pneumocystis; Immunocompromised Host; Benzamides; Niacinamide
PubMed: 38206037
DOI: 10.1128/aac.00811-23 -
Diagnostic Microbiology and Infectious... Mar 2024Accurate differentiation between Pneumocystis jirovecii (Pj) infection and colonization is crucial for effective treatment.
BACKGROUND
Accurate differentiation between Pneumocystis jirovecii (Pj) infection and colonization is crucial for effective treatment.
METHODS
From September 2016 to June 2022, 89 immunocompromised patients with unexplained lung infiltrates and clinical suspicion of Pj pneumonia were enrolled at Peking University People's Hospital. Bronchoalveolar lavage fluid (BALF) of these patients were detected by quantitative PCR (qPCR) and droplet digital PCR (ddPCR).
RESULTS
The performance of ddPCR was superior to qPCR in detecting Pj infection. Area under the curve was 0.97 (95 %CI: 0.94-1) for ddPCR of the BALF in all patients. The optimal threshold value for discriminating Pj infection from colonization by ddPCR was 13.98 copies/test, with a sensitivity of 97.96 %, specificity of 85.71 %. No obvious correlation between ddPCR copy number and disease severity was observed.
CONCLUSION
BALF ddPCR exhibits robust potential in detecting Pj and effectively discriminating colonization and infection.
Topics: Humans; Pneumonia, Pneumocystis; Pneumocystis carinii; Bronchoalveolar Lavage Fluid; Diagnosis, Differential; Real-Time Polymerase Chain Reaction; Sensitivity and Specificity
PubMed: 38184984
DOI: 10.1016/j.diagmicrobio.2023.116168 -
BMC Pulmonary Medicine Jan 2024Pneumocystis jirovecii pneumonia (PCP) could be fatal to patients without human immunodeficiency virus (HIV) infection. Current diagnostic methods are either invasive or... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Pneumocystis jirovecii pneumonia (PCP) could be fatal to patients without human immunodeficiency virus (HIV) infection. Current diagnostic methods are either invasive or inaccurate. We aimed to establish an accurate and non-invasive radiomics-based way to identify the risk of PCP infection in non-HIV patients with computed tomography (CT) manifestation of pneumonia.
METHODS
This is a retrospective study including non-HIV patients hospitalized for suspected PCP from January 2010 to December 2022 in one hospital. The patients were randomized in a 7:3 ratio into training and validation cohorts. Computed tomography (CT)-based radiomics features were extracted automatically and used to construct a radiomics model. A diagnostic model with traditional clinical and CT features was also built. The area under the curve (AUC) were calculated and used to evaluate the diagnostic performance of the models. The combination of the radiomics features and serum β-D-glucan levels was also evaluated for PCP diagnosis.
RESULTS
A total of 140 patients (PCP: N = 61, non-PCP: N = 79) were randomized into training (N = 97) and validation (N = 43) cohorts. The radiomics model consisting of nine radiomic features performed significantly better (AUC = 0.954; 95% CI: 0.898-1.000) than the traditional model consisting of serum β-D-glucan levels (AUC = 0.752; 95% CI: 0.597-0.908) in identifying PCP (P = 0.002). The combination of radiomics features and serum β-D-glucan levels showed an accuracy of 95.8% for identifying PCP infection (positive predictive value: 95.7%, negative predictive value: 95.8%).
CONCLUSIONS
Radiomics showed good diagnostic performance in differentiating PCP from other types of pneumonia in non-HIV patients. A combined diagnostic method including radiomics and serum β-D-glucan has the potential to provide an accurate and non-invasive way to identify the risk of PCP infection in non-HIV patients with CT manifestation of pneumonia.
TRIAL REGISTRATION
ClinicalTrials.gov (NCT05701631).
Topics: Humans; Pneumonia, Pneumocystis; Retrospective Studies; Pneumocystis carinii; Radiomics; beta-Glucans; HIV Infections; Glucans; Tomography
PubMed: 38167022
DOI: 10.1186/s12890-023-02827-4 -
Annals of Hematology Apr 2024Patients with multiple myeloma (MM) are at high risk for infections, including opportunistic infections such as Pneumocystis jirovecii pneumonia (PJP). We conducted a...
Patients with multiple myeloma (MM) are at high risk for infections, including opportunistic infections such as Pneumocystis jirovecii pneumonia (PJP). We conducted a retrospective analysis of patients with MM developing PJP over a 6-year period between January 2016 and December 2021 at the University Hospital of Würzburg by screening cases of microbiologically documented PJP. A total of 201 positive results for P. jirovecii in respiratory specimens were retrospectively retrieved through our microbiology database. Of these cases, 13 patients with MM fulfilled the definition of probable PJP according to EORTC fungal disease definitions. We observed two peaks in PJP incidence, one after stem cell transplantation during first-line treatment (n = 5) and the other in heavily pretreated patients with six or more prior lines of therapy (n = 6). There was high morbidity with nine (69%) patients admitted to the ICU, seven of whom (78%) required mechanical ventilation, and high mortality (62%, n = 8). Notably, only two of the 13 patients (15%) had received PJP prophylaxis. The main reason for discontinuation of prophylaxis with trimethoprim-sulfamethoxazole was grade IV neutropenia. The observed morbidity and mortality of PJP in MM patients are significant and even higher than reported for patients with other hematologic malignancies. According to most current guidelines, the use of prophylaxis would have been clearly recommended in no more than three (23%) of the 13 patients. This illustrates the need to critically reconsider the indications for PJP prophylaxis, which remain incompletely defined.
Topics: Humans; Pneumonia, Pneumocystis; Retrospective Studies; Pneumocystis carinii; Multiple Myeloma; Prognosis
PubMed: 38123879
DOI: 10.1007/s00277-023-05586-8