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BioRxiv : the Preprint Server For... Sep 2023spp. 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 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 may release EVs. Notably, EV uptake by indicated their potential involvement in nutrient acquisition and indicate 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.
PubMed: 37786700
DOI: 10.1101/2023.09.19.558454 -
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 -
BMJ Open Oct 2023We aimed to identify exercise tests that have been validated to support a safe discharge to home in patients with or without COVID-19. (Review)
Review
OBJECTIVES
We aimed to identify exercise tests that have been validated to support a safe discharge to home in patients with or without COVID-19.
STUDY DESIGN
Scoping review, using PRISMA-ScR reporting standards. Medline, PubMed, AMED, Embase, CINAHL and LitCovid databases were searched between 16 and 22 February 2021, with studies included from any publication date up to and including the search date.
INTERVENTION
Short exercise tests.
PRIMARY OUTCOME MEASURES
Safe discharge from hospital, readmission rate, length of hospital stay, mortality. Secondary outcomes measures: safety, feasibility and reliability.
RESULTS
Of 1612 original records screened, 19 studies were included in the analysis. These used a variety of exercise tests in patients with chronic obstructive pulmonary disease, suspected pulmonary embolism and pneumocystis carinii pneumonia, heart failure or critical illness. Only six studies had examined patients with COVID-19, of these two were still recruiting to evaluate the 1 min sit-to-stand test and the 40-steps test. There was heterogeneity in patient populations, tests used and outcome measures. Few exercise tests have been validated to support discharge decisions. There is currently no support for short exercise tests for triage of care in patients with COVID-19.
CONCLUSIONS
Further research is needed to aid clinical decision-making at discharge from hospital.
Topics: Humans; COVID-19; Patient Discharge; Exercise Test; Reproducibility of Results; Hospitals
PubMed: 37907292
DOI: 10.1136/bmjopen-2022-068169 -
Diagnostics (Basel, Switzerland) Aug 2023The objective of this study was to formulate and validate a prognostic model for postoperative severe pneumonia (SPCP) in kidney transplant recipients utilizing machine...
BACKGROUND
The objective of this study was to formulate and validate a prognostic model for postoperative severe pneumonia (SPCP) in kidney transplant recipients utilizing machine learning algorithms, and to compare the performance of various models.
METHODS
Clinical manifestations and laboratory test results upon admission were gathered as variables for 88 patients who experienced PCP following kidney transplantation. The most discriminative variables were identified, and subsequently, Support Vector Machine (SVM), Logistic Regression (LR), Random Forest (RF), K-Nearest Neighbor (KNN), Light Gradient Boosting Machine (LGBM), and eXtreme Gradient Boosting (XGB) models were constructed. Finally, the models' predictive capabilities were assessed through ROC curves, sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV), and F1-scores. The Shapley additive explanations (SHAP) algorithm was employed to elucidate the contributions of the most effective model's variables.
RESULTS
Through lasso regression, five features-hemoglobin (Hb), Procalcitonin (PCT), C-reactive protein (CRP), progressive dyspnea, and Albumin (ALB)-were identified, and six machine learning models were developed using these variables after evaluating their correlation and multicollinearity. In the validation cohort, the RF model demonstrated the highest AUC (0.920 (0.810-1.000), F1-Score (0.8), accuracy (0.885), sensitivity (0.818), PPV (0.667), and NPV (0.913) among the six models, while the XGB and KNN models exhibited the highest specificity (0.909) among the six models. Notably, CRP exerted a significant influence on the models, as revealed by SHAP and feature importance rankings.
CONCLUSIONS
Machine learning algorithms offer a viable approach for constructing prognostic models to predict the development of severe disease following PCP in kidney transplant recipients, with potential practical applications.
PubMed: 37685276
DOI: 10.3390/diagnostics13172735 -
Biomedicines Feb 2024This study aimed to develop a simple predictive model for early identification of the risk of adverse outcomes in kidney transplant-associated pneumonia (PCP) patients.
BACKGROUND
This study aimed to develop a simple predictive model for early identification of the risk of adverse outcomes in kidney transplant-associated pneumonia (PCP) patients.
METHODS
This study encompassed 103 patients diagnosed with PCP, who received treatment at our hospital between 2018 and 2023. Among these participants, 20 were categorized as suffering from severe PCP, and, regrettably, 13 among them succumbed. Through the application of machine learning techniques and multivariate logistic regression analysis, two pivotal variables were discerned and subsequently integrated into a nomogram. The efficacy of the model was assessed via receiver operating characteristic (ROC) curves and calibration curves. Additionally, decision curve analysis (DCA) and a clinical impact curve (CIC) were employed to evaluate the clinical utility of the model. The Kaplan-Meier (KM) survival curves were utilized to ascertain the model's aptitude for risk stratification.
RESULTS
Hematological markers, namely Procalcitonin (PCT) and C-reactive protein (CRP)-to-albumin ratio (CAR), were identified through machine learning and multivariate logistic regression. These variables were subsequently utilized to formulate a predictive model, presented in the form of a nomogram. The ROC curve exhibited commendable predictive accuracy in both internal validation (AUC = 0.861) and external validation (AUC = 0.896). Within a specific threshold probability range, both DCA and CIC demonstrated notable performance. Moreover, the KM survival curve further substantiated the nomogram's efficacy in risk stratification.
CONCLUSIONS
Based on hematological parameters, especially CAR and PCT, a simple nomogram was established to stratify prognostic risk in patients with renal transplant-related PCP.
PubMed: 38397968
DOI: 10.3390/biomedicines12020366 -
Mycopathologia May 2024To describe the epidemiology of Pneumocystis jirovecii pneumonia and colonization diagnosed by next-generation sequencing (NGS) and explore the usefulness of the number...
OBJECTIVES
To describe the epidemiology of Pneumocystis jirovecii pneumonia and colonization diagnosed by next-generation sequencing (NGS) and explore the usefulness of the number of P. jirovecii sequence reads for the diagnosis of P. jirovecii pneumonia.
METHODS
We examined the NGS results for P. jirovecii in respiratory samples collected from patients and analysed their clinical, radiological and microbiological characteristics.
RESULTS
Among 285 respiratory samples collected over a 12-month period (January to December 2022), P. jirovecii sequences were detected in 56 samples from 53 patients. Fifty (94.3%) of the 53 patients were HIV-negative. Following our case definitions, 37 (69.8%) and 16 (30.2%) of the 53 patients had P. jirovecii infection and colonization respectively. P. jirovecii infection was associated with presence of underlying disease with immunosuppression (94.6% vs 18.8%, P < 0.05), positive serum 1,3-β-D-glucan (41.2% vs 0%, P < 0.01) and higher number of P. jirovecii sequence reads (P < 0.005). In contrast, P. jirovecii colonization was associated with the male sex (93.8% vs 54.1%, P < 0.01), another definitive infectious disease diagnosis of the respiratory tract (43.8% vs 2.7%, P < 0.001) and higher survival (100% vs 67.6%, P < 0.01). Although P. jirovecii pneumonia was associated with higher number of P. jirovecii reads in respiratory samples, only a sensitivity of 82.14% and a specificity of 68.75% could be achieved.
CONCLUSION
Detection of P. jirovecii sequences in respiratory samples has to be interpreted discreetly. A combination of clinical, radiological and laboratory findings is still the most crucial in determining whether a particular case is genuine P. jirovecii pneumonia.
Topics: Humans; Pneumonia, Pneumocystis; Male; High-Throughput Nucleotide Sequencing; Pneumocystis carinii; Female; Middle Aged; Aged; Adult; Aged, 80 and over; Respiratory System; Young Adult; Molecular Diagnostic Techniques
PubMed: 38704795
DOI: 10.1007/s11046-024-00849-y -
BMC Pulmonary Medicine Nov 2023Pneumocystis pneumonia (PCP) is a life-threatening pulmonary fungal infection that predominantly affects immunocompromised individuals, including kidney transplant...
BACKGROUND
Pneumocystis pneumonia (PCP) is a life-threatening pulmonary fungal infection that predominantly affects immunocompromised individuals, including kidney transplant recipients. Recent years have witnessed a rising incidence of PCP in this vulnerable population, leading to graft loss and increased mortality. Immunosuppression, which is essential in transplant recipients, heightens susceptibility to viral and opportunistic infections, magnifying the clinical challenge. Concurrently, the global impact of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been profound. Kidney transplant recipients have faced severe outcomes when infected with SARS-CoV-2, often requiring intensive care. Co-infection with COVID-19 and PCP in this context represents a complex clinical scenario that requires precise management strategies, involving a delicate balance between immunosuppression and immune activation. Although there have been case reports on management of COVID-19 and PCP in kidney transplant recipients, guidance on how to tackle these infections when they occur concurrently remains limited.
CASE PRESENTATIONS
We have encountered four kidney transplant recipients with concurrent COVID-19 and PCP infection. These patients received comprehensive treatment that included adjustment of their maintenance immunosuppressive regimen, anti-pneumocystis therapy, treatment for COVID-19 and other infections, and symptomatic and supportive care. After this multifaceted treatment strategy, all of these patients improved significantly and had favorable outcomes.
CONCLUSIONS
We have successfully managed four kidney transplant recipients co-infected with COVID-19 and PCP. While PCP is a known complication of immunosuppressive therapy, its incidence in patients with COVID-19 highlights the complexity of dual infections. Our findings suggest that tailored immunosuppressive regimens, coupled with antiviral and antimicrobial therapies, can lead to clinical improvement in such cases. Further research is needed to refine risk assessment and therapeutic strategies, which will ultimately enhance the care of this vulnerable population.
Topics: Humans; Pneumonia, Pneumocystis; COVID-19; Kidney Transplantation; Retrospective Studies; Transplant Recipients; SARS-CoV-2; Immunosuppressive Agents; Pneumocystis carinii
PubMed: 37990199
DOI: 10.1186/s12890-023-02764-2