Current epidemiology of Pneumocystis pneumonia

Duration of systemic antifungal therapy for patients with invasive fungal diseases: A reassessment

Invasive fungal diseases are associated with significant morbidity and mortality, especially among immunocompromised patients, and often prompt for rapid and aggressive treatment aiming cure. Due to the expanding magnitude of patients burdened by chronic immunosuppression and affected by fungal diseases, the diversity of clinical settings has risen. This often results in prolonged therapy (induction, consolidation and maintenance) associated with potentially severe side effects, and clinicians face the challenging decisions of when and how to stop anti-fungal therapy. Adequate duration of therapy is poorly defined, hampered by the lack of dedicated trials to the question, the heterogeneity of cases (type of fungal pathogen, localization of infection, underlying host conditions) and various confounding factors that may influence the clinical response (e.g. persistence vs recovery of immunosuppression, impact of surgery). In this review, we aim to evaluate the existing data underlying the guidelines and recommendations of treatment duration for the most frequent invasive fungal diseases (cryptococcal meningitis, Pneumocystis pneumonia, invasive aspergillosis, invasive candidiasis and mucormycosis), as well as specific localizations of deep-seated diseases (osteo-articular or central nervous system diseases and endocarditis) and emerging considerations and strategies.

Association between respiratory pathogens and severe clinical outcomes in people living with HIV-1 and pulmonary infections: A 180-day longitudinal cohort study

BACKGROUND

Many respiratory pathogens have been identified in people living with HIV-1 and pulmonary infection, but their impact on clinical outcomes remains largely unclear.

METHODS

Metagenomic sequencing and traditional laboratory diagnostics were applied to identify bacterial, viral, and fungal respiratory pathogens. Clinical outcomes were assessed by (i) mortality or ICU transfer during hospitalization, and (ii) 30-day re-hospitalization and 180-day mortality after hospital discharge.

RESULTS

Microbiological analyses of bacterial, viral and fungal pathogens in 237 in-patients with HIV-1 and pulmonary infections revealed Pneumocystis jirovecii (58 %) as the most prevalent respiratory pathogen, followed by Cytomegalovirus (39 %), Mycobacterium tuberculosis (22 %), Talaromyces marneffei (17 %), and Epstein-Barr virus (16 %). Fifty-six patients (24 %) were coinfected with bacterial, viral and fungal pathogens, referred to as bacterial+fungal+viral coinfections. Risk factors for bacterial+fungal+viral coinfections (RR=8.41, 95 %CI: 4.2-14.3), severe pneumonia (RR=13.6, 95 %CI: 8.14-19.3), and elevated C-reactive protein levels (RR=6.42, 95 %CI: 1.58-10.13) were significantly associated with mortality or ICU transfer during hospitalization. After hospital discharge, 38 patients (16 %) were rehospitalized within 30 days. Antiretroviral therapy reduced the risk of 30-day rehospitalization (HR=0.21, p = 0.01). During the 180-day follow-up, 13 patients (5.5 %) died. Survival analyses identified severe pneumonia and age ≥ 60 years as risk factors for 180-day mortality.

CONCLUSIONS

Multiple pulmonary coinfections are associated with severe outcomes in in-patients with HIV-1 infection. Effective management of both HIV-1 and pulmonary infections is crucial to reduce hospitalization rates and mortality risk.

An overview of the laboratory diagnosis of Pneumocystis jirovecii pneumonia

Pneumocystis jirovecii (P. jirovecii) is a fungal pathogen associated with significant morbidity in immunocompromised patients, including both HIV- and non-HIV-infected patients. The nonspecific clinical and radiological presentation makes clinical diagnostic challenging, emphasizing the need for accurate laboratory diagnostic tests. However, P. jirovecii does not grow in routine culture media, which presents diagnostic challenges in the laboratory as well. Recent publications from the European Organization for Research and Treatment of Cancer and the Mycoses Study Group Education and Research Consortium continue to rely on direct detection of P. jirovecii organisms in tissues and respiratory samples to define proven P. jirovecii pneumonia (PCP) even as the sensitivity of these methods are lower. Novel, standardized methods are needed to improve the clinical and laboratory diagnosis and management of PCP. This minireview provides an overview of current diagnostic tests for PCP and emerging applications that aim at filling existing diagnostic gaps and providing more accurate and less invasive diagnoses for this significant disease.

Risk of Pneumocystis jirovecii Pneumonia in Patients With HIV in Taiwan: Evidence from a Cross-sectional Study

BACKGROUND/AIM

Studies have demonstrated that patients with HIV are at a higher risk of Pneumocystis jirovecii pneumonia (PJP). Epidemiological knowledge of the risk of PJP among patients with HIV infection is lacking. This study aimed to assess the risk of PJP among patients with HIV.

PATIENTS AND METHODS

This cross-sectional study was conducted using the National Health Insurance Research Database of Taiwan. The participants were 18,929 patients with new-onset HIV infection from 2002 to 2015. Each patient was matched with four HIV-negative patients for age, sex, insured salary, urbanization status, Charlson Comorbidity Index score, and year of enrollment. The logistic regression with adjustment for relevant variables was performed to analyze the risk of PJP among patients with HIV at the 3-year follow-up. Sensitivity analysis was performed to compare the risk of PJP among different cohorts (patients with chronic kidney disease) and at different follow-up periods (6-month, 1-year, and 2-year follow-up).

RESULTS

Patients with HIV had a higher risk of PJP [adjusted odds ratio (aOR)=199.36; 95% confidence interval (CI)=119.47-332.66] than HIV-negative individuals at the 3-year follow-up. Male patients had a higher risk of PJP (aOR=1.62; 95%CI=1.18-2.24) than female patients. Patients with chronic obstructive pulmonary disease (COPD) had a higher risk of PJP (aOR=1.74; 95%CI=1.27-2.39) at the 3-year follow-up.

CONCLUSION

Patients with HIV had a higher risk of PJP. Male patients had a higher risk of PJP than female patients. The risk of PJP was higher among patients with COPD.

Re-challenging pralsetinib following recovery from pneumocystis jirovecii pneumonia in a lung cancer patient: a Case Report

Background

Pneumocystis jirovecii pneumonia (PJP), an opportunistic infection, is commonly observed in immunocompromised individuals, particularly those with cancer, and is known for its significant morbidity and mortality rates. Pralsetinib is a highly specific inhibitor that targets advanced or metastatic non-small cell lung cancer (NSCLC) characterized by RET-fusion positivity. The incidence of PJP infection in patients receiving pralsetinib was found to be infrequent. However, there is currently a lack of consensus regarding the rechallenge of pralsetinib in patients who have fully recovered from PJP.

Case presentation

In this case study, a 60-year-old patient diagnosed with stage IV lung adenocarcinoma and carrying a KIF5B-RET fusion gene underwent pralsetinib treatment as the fourth-line therapy. Subsequently, the patient developed a fever and dyspnea 2.5 months later. However, the patient did not exhibit a positive response to the empirical antibiotic therapy administered. The computed tomography findings indicated widespread ground-glass opacities with numerous cystic lesions in both lungs, along with patchy consolidations in the lower right lung. The diagnosis of PJP was conclusively confirmed through bronchoalveolar lavage. The patient's condition was effectively treated with a combination of oral trimethoprim/sulfamethoxazole and intravenous caspofungin along with clindamycin. The patient fully recovered from PJP. Subsequently, he underwent a rechallenge with pralsetinib, and as of the latest follow-up, no evidence of progressive disease has been observed.

Conclusion

This case report emphasizes the significance for physicians to be cognizant of the potential hazard of PJP development in cancer patients undergoing pralsetinib treatment, particularly in those who are unresponsive to empirical antibiotic therapy. Prompt identification and timely intervention are essential to achieve better outcomes in patients with pralsetinib-induced PJP. Furthermore, it highlights the scenario where patients who have fully recovered from moderate-to-severe pralsetinib-induced PJP may undergo pralsetinib re-administration without requiring alternative treatment options.

The role of trimethoprim/sulfamethoxazole in preventing opportunistic infections in systemic lupus erythematosus patients receiving low-level immunosuppressive treatment: an open-label, randomized, controlled trial

OBJECTIVE

Systemic lupus erythematosus (SLE) patients receiving immunosuppressive therapy are at risk for opportunistic infections (OIs), particularly Pneumocystis pneumonia (PCP). This study aimed to evaluate the effectiveness of trimethoprim/sulfamethoxazole (TMP/SMX) as primary prophylaxis against OIs and its adverse effects in SLE patients receiving low-level immunosuppressive treatment in a real-world setting.

METHODS

This open-label randomized controlled trial enrolled SLE patients receiving low-level immunosuppressive treatment at Ramathibodi Hospital between May 2021 and December 2022. Patient demographics and relevant clinical data were collected. Participants were randomized 1:1 to receive TMP/SMX or no prophylaxis, with dose adjustments according to renal function. The incidences of TMP/SMX-sensitive OIs and adverse events were monitored for 12 months post-enrollment.

RESULTS

The trial was terminated early due to a high rate of adverse drug reactions (ADRs) associated with TMP/SMX. In total, 138 SLE patients receiving low-level immunosuppressive treatment were enrolled. Most patients (98.4%) were in disease remission. No TMP/SMX-sensitive OIs were observed in either group during the 12-month follow-up period. Among individuals receiving TMP/SMX, 10/70 (14.3%) developed ADRs. Of these 10 patients, eight experienced grade 1 ADRs, and two had grade 3 ADRs; all declined to resume prophylaxis. There were no deaths in the study.

CONCLUSIONS

During the 12-month follow-up period, no TMP/SMX-sensitive OIs occurred in SLE patients receiving low-level immunosuppressive therapy, suggesting that primary prophylaxis with TMP/SMX may not significantly benefit this population. The high rate of ADRs observed underscores the need for clinicians to carefully consider the risks and benefits of TMP/SMX prophylaxis in these patients.

Comparative efficacy and safety of Pneumocystis jirovecii pneumonia prophylaxis regimens for people living with HIV: a systematic review and network meta-analysis of randomized controlled trials

BACKGROUND

Pneumocystis jirovecii pneumonia (PCP) is a common opportunistic infection among people living with HIV (PWH), particularly among new and untreated cases. Several regimens are available for the prophylaxis of PCP, including trimethoprim-sulfamethoxazole (TMP-SMX), dapsone-based regimens (DBRs), aerosolized pentamidine (AP), and atovaquone.

OBJECTIVES

To compare the efficacy and safety of PCP prophylaxis regimens in PWH by network meta-analysis.

METHODS

DATA SOURCES: Embase, MEDLINE, and CENTRAL from inception to June 21, 2023.

STUDY ELIGIBILITY CRITERIA

Comparative randomized controlled trials (RCTs).

PARTICIPANTS

PWH.

INTERVENTIONS

Regimens for PCP prophylaxis either compared head-to-head or versus no treatment/placebo.

ASSESSMENT OF RISK OF BIAS

Cochrane risk-of-bias tool for RCTs 2.

METHODS OF DATA SYNTHESIS

Title or abstract and full-text screening and data extraction were performed in duplicate by two independent reviewers. Data on PCP incidence, all-cause mortality, and discontinuation due to toxicity were pooled and ranked by network meta-analysis. Subgroup analyses of primary versus secondary prophylaxis, by year, and by dosage were performed.

RESULTS

A total of 26 RCTs, comprising 55 treatment arms involving 7516 PWH were included. For the prevention of PCP, TMP-SMX was ranked the most favourable agent and was superior to DBRs (risk ratio [RR] = 0.54; 95% CI, 0.36-0.83) and AP (RR = 0.53; 95% CI, 0.36-0.77). TMP-SMX was also the only agent with a mortality benefit compared with no treatment/placebo (RR = 0.79; 95% CI, 0.64-0.98). However, TMP-SMX was also ranked as the most toxic agent with a greater risk of discontinuation than DBRs (RR = 1.25; 95% CI, 1.01-1.54) and AP (7.20; 95% CI, 5.37-9.66). No significant differences in PCP prevention or mortality were detected among the other regimens. The findings remained consistent within subgroups.

CONCLUSIONS

TMP-SMX is the most effective agent for PCP prophylaxis in PWH and the only agent to confer a mortality benefit; consequently, it should continue to be recommended as the first-line agent. Further studies are necessary to determine the optimal dosing of TMP-SMX to maximize efficacy and minimize toxicity.

Features and global impact of invasive fungal infections caused by Pneumocystis jirovecii: A systematic review to inform the World Health Organization fungal priority pathogens list

This systematic review evaluates the current global impact of invasive infections caused by Pneumocystis jirovecii (principally pneumonia: PJP), and was carried out to inform the World Health Organization Fungal Priority Pathogens List. PubMed and Web of Science were used to find studies reporting mortality, inpatient care, complications/sequelae, antifungal susceptibility/resistance, preventability, annual incidence, global distribution, and emergence in the past 10 years, published from January 2011 to February 2021. Reported mortality is highly variable, depending on the patient population: In studies of persons with HIV, mortality was reported at 5%-30%, while in studies of persons without HIV, mortality ranged from 4% to 76%. Risk factors for disease principally include immunosuppression from HIV, but other types of immunosuppression are increasingly recognised, including solid organ and haematopoietic stem cell transplantation, autoimmune and inflammatory disease, and chemotherapy for cancer. Although prophylaxis is available and generally effective, burdensome side effects may lead to discontinuation. After a period of decline associated with improvement in access to HIV treatment, new risk groups of immunosuppressed patients with PJP are increasingly identified, including solid organ transplant patients.

Pneumocystis pneumonia in French intensive care units in 2013-2019: mortality and immunocompromised conditions

PURPOSE

The recent epidemiology of Pneumocystis pneumonia (PCP) requiring intensive care unit (ICU) admission and the associated spectrum of immunocompromising conditions are poorly described.

METHODS

We analyzed all adult PCP cases admitted to French ICUs via the French medical database system (PMSI), over the period from 2013 to 2019.

RESULTS

French ICUs admitted a total of 4055 adult patients with PCP. Among all hospitalized PCP cases, the proportion requiring ICU admission increased from 17.8 in 2014 to 21.3% in 2019 (P < 0.001). The incidence of severe PCP rose from 0.85 in 2013 to 1.32/100,000 adult inhabitants in 2019 (P < 0.0001), primarily due to the proportion of HIV-negative patients that increased from 60.6% to 74.4% (P < 0.0001). Meanwhile, the annual number of severe PCP cases among patients with HIV infection remained stable over the years. In-hospital mortality of severe PCP cases was 28.5% in patients with HIV infection and 49.7% in patients without. Multivariable logistic analysis showed that patients with HIV infection had a lower adjusted risk of death than patients without HIV infection (Odds Ratio [OR]: 0.30, 95% confidence interval [95CI]: 0.17-0.55). Comorbidities or conditions strongly associated with hospital mortality included the patient's age, Simplified Acute Physiologic Score II, congestive heart failure, coagulopathy, solid organ cancer, and cirrhosis. A vast array of autoimmune inflammatory diseases affected 19.9% of HIV-negative patients.

CONCLUSIONS

The number of PCP cases requiring ICU admission in France has risen sharply. While the yearly count of severe PCP cases in HIV-infected patients has remained steady, this rise predominantly affects cancer patients, with a recent surge observed in patients with autoimmune inflammatory diseases, affecting one in five individuals.

Pneumothorax as a Prelude: Unveiling Concurrent HIV and Pneumocystis jirovecii Pneumonia in a Diagnostic Journey

Pneumocystis jirovecii pneumonia (PCP) is a life-threatening condition found in immunocompromised individuals, especially in human immunodeficiency virus (HIV) positive patients. Here, we report a case of PCP in a presumably immunocompetent 25-year-old male patient who presented with a one-month history of chest pain, dyspnea, and a nonproductive cough with recent development of night sweats. The patient recently immigrated to the United States without any known medical or family history. A chest radiograph revealed moderate pneumothorax for which a chest tube was placed. A chest computed tomography (CT) scan revealed diffuse lung disease with multiple thin- and thick-walled cystic lesions on a background of diffuse ground-glass opacities. Based on these radiologic findings and subsequent positive HIV serology, there was a high suspicion of PCP. Bronchoalveolar lavage was performed, and PCR for Pneumocystis jirovecii was positive. Appropriate treatment was initiated, and the patient recovered well. Through this report, we aim to highlight the importance of recognizing the various clinical and radiologic findings of PCP even in patients with no overt risk factors. Prompt and targeted treatment could mitigate morbidity and mortality associated with this opportunistic pathogen.

Clinical and Radiological Features of Pneumocystis jirovecii Pneumonia in Children: A Case Series

BACKGROUND

Pneumocytis jirovecii pneumonia (PJP) has high mortality rates in immunocompromised children, even though routine prophylaxis has decreased in incidence. The aim of this case series is to present the radiological and clinical pathway of PJP in a pediatric population.

DESCRIPTION OF CASES

All PJP cases in non-HIV/AIDS patients diagnosed at Istituto Giannina Gaslini Pediatric Hospital in Genoa (Italy) from January 2012 until October 2022 were retrospectively evaluated. Nine cases were identified (median age: 8.3 years), and of these, 6/9 underwent prophylaxis with trimethoprim/sulfamethoxazole (TMP/SMX; five once-a-week schedules and one three times-a-week schedule), while 3/9 did not receive this. PJP was diagnosed by real-time PCR for P. jirovecii-DNA in respiratory specimens in 7/9 cases and two consecutive positive detections of β-d-glucan (BDG) in the serum in 2/9 cases. Most patients (6/8) had a CT scan with features suggestive of PJP, while one patient did not undergo a scan. All patients were treated with TMP/SMX after a median time from symptoms onset of 3 days. In 7/9 cases, empirical TMP/SMX treatment was initiated after clinical suspicion and radiological evidence and later confirmed by microbiological data. Clinical improvement with the resolution of respiratory failure and 30-day survival included 100% of the study population.

DISCUSSION

Due to the difficulty in obtaining biopsy specimens, PJP diagnosis is usually considered probable in most cases. Moreover, the severity of the clinical presentation often leads physicians to start TMP/SMX treatment empirically. BDG proved to be a useful tool for diagnosis, and CT showed good accuracy in identifying typical patterns. In our center, single-day/week prophylaxis was ineffective in high-risk patients; the three-day/week schedule would, therefore, seem preferable and, in any case, should be started promptly in all patients who have an indication of pneumonia.

Chest X-ray Features of HIV-Associated Pneumocystis Pneumonia (PCP) in Adults: A Systematic Review and Meta-analysis

Background

The performance of chest x-ray (CXR) features for Pneumocystis pneumonia (PCP) diagnosis has been evaluated in small studies. We conducted a systematic review and meta-analysis to describe CXR changes in adults with HIV-associated laboratory-confirmed PCP, comparing these with non-PCP respiratory disease.

Methods

We searched databases for studies reporting CXR changes in people >15 years old with HIV and laboratory-confirmed PCP and those with non-PCP respiratory disease. CXR features were grouped using consensus terms. Proportions were pooled and odds ratios (ORs) generated using random-effects meta-analysis, with subgroup analyses by CD4 count, study period, radiology review method, and study region.

Results

Fifty-one studies (with 1821 PCP and 1052 non-PCP cases) were included. Interstitial infiltrate (59%; 95% CI, 52%-66%; 36 studies, n = 1380; I2 = 85%) and ground-glass opacification (48%; 95% CI, 15%-83%; 4 studies, n = 57; I2 = 86%) were common in PCP. Cystic lesions, central lymphadenopathy, and pneumothorax were infrequent. Pleural effusion was rare in PCP (0%; 95% CI, 0%-2%). Interstitial infiltrate (OR, 2.3; 95% CI, 1.4-3.9; I2 = 60%), interstitial-alveolar infiltrate (OR, 10.2; 95% CI, 3.2-32.4; I2 = 0%), and diffuse CXR changes (OR, 7.3; 95% CI, 2.7-20.2; I2 = 87%) were associated with PCP diagnosis. There was loss of association with alveolar infiltrate in African studies.

Conclusions

Diffuse CXR changes and interstitial-alveolar infiltrates indicate a higher likelihood of PCP. Pleural effusion, lymphadenopathy, and focal alveolar infiltrates suggest alternative causes. These findings could be incorporated into clinical algorithms to improve diagnosis of HIV-associated PCP.

Comparing Polymerase Chain Reaction Testing of Nasopharyngeal Swab and Lower Respiratory Tract Specimens for the Diagnosis of Pneumocystis jirovecii Pneumonia

Using nasopharyngeal (NP) swab samples instead of lower respiratory tract specimens for polymerase chain reaction (PCR) to diagnose Pneumocystis jirovecii pneumonia (PJP) may be better tolerated and improve diagnostic accessibility. In this 2-year Australian retrospective cohort study of patients with clinically suspected PJP, P jirovecii PCR on NP swab samples had perfect specificity but low sensitivity (0.66).

Molecular Study of Pneumocystis jirovecii in Respiratory Samples of HIV Patients in Chile

Pneumocystis is an opportunistic fungus that causes potentially fatal pneumonia (PCP) in immunocompromised patients. The objective of this study was to determine the prevalence of P. jirovecii in HIV patients through phenotypic and molecular study, to investigate the genetic polymorphisms of P. jirovecii at the mitochondrial gene mtLSU and at the nuclear dihydropteroate synthase gene (DHPS), and by analysis of molecular docking to study the effect of DHPS mutations on the enzymatic affinity for sulfamethoxazole. A PCP prevalence of 28.3% was detected, with mtLSU rRNA genotypes 3 (33.3%) and 2 (26.6%) being the most common. A prevalence of 6.7% (1/15) mutations in the DHPS gene was detected, specifically at codon 55 of the amino acid sequence of dihydropteroate synthase. Molecular docking analysis showed that the combination of mutations at 55 and 98 codons is required to significantly reduce the affinity of the enzyme for sulfamethoxazole. We observed a low rate of mutations in the DHPS gene, and molecular docking analysis showed that at least two mutations in the DHPS gene are required to significantly reduce the affinity of dihydropteroate synthase for sulfamethoxazole.

Low-Dose vs Conventional-Dose Trimethoprim-Sulfamethoxazole Treatment for Pneumocystis Pneumonia in Patients Not Infected With HIV: A Multicenter, Retrospective Observational Cohort Study

BACKGROUND

Trimethoprim-sulfamethoxazole (TMP-SMX) is an effective treatment for Pneumocystis jirovecii pneumonia (PCP) in immunocompromised patients with and without HIV infection; however, a high incidence of adverse events has been observed. Low-dose TMP-SMX is a potentially effective treatment with fewer adverse events; however, evidence is limited.

RESEARCH QUESTION

What is the efficacy and safety of low-dose TMP-SMX for non-HIV PCP compared with conventional-dose TMP-SMX after adjusting for patient background characteristics?

STUDY DESIGN AND METHODS

In this multicenter retrospective cohort study, we included patients diagnosed with non-HIV PCP and treated with TMP-SMX between June 2006 and March 2021 at three institutions. The patients were classified into low-dose (TMP < 12.5 mg/kg/d) and conventional-dose (TMP 12.5-20 mg/kg/d) groups. The primary end point was 30-day mortality, and the secondary end points were 180-day mortality, adverse events grade 3 or higher per the Common Terminology Criteria for Adverse Events v5.0, and initial treatment completion rates. Background characteristics were adjusted using the overlap weighting method with propensity scores.

RESULTS

Fifty-five patients in the low-dose group and 81 in the conventional-dose group were evaluated. In the overall cohort, the average age was 70.7 years, and the proportion of women was 55.1%. The average dose of TMP-SMX was 8.71 mg/kg/d in the low-dose group and 17.78 mg/kg/d in the conventional-dose group. There was no significant difference in 30-day mortality (6.7% vs 18.4%, respectively; P = .080) or 180-day mortality (14.6% vs 26.1%, respectively; P = .141) after adjusting for patient background characteristics. The incidence of adverse events, especially nausea and hyponatremia, was significantly lower in the low-dose group (29.8% vs 59.0%, respectively; P = .005). The initial treatment completion rates were 43.3% and 29.6% in the low-dose and conventional-dose groups (P = .158), respectively.

INTERPRETATION

Survival was similar between the low-dose and conventional-dose TMP-SMX groups, and low-dose TMP-SMX was associated with reduced adverse events in patients with non-HIV PCP.

CLEC4A and CLEC12B C-type lectin receptors mediate interactions with Pneumocystis cell wall components

Introduction. C-type lectin receptors (CLRs) are prominently expressed on myeloid cells where they perform multiple functions including serving as pattern recognition receptors (PRRs) to drive innate as well as adaptive immunity to pathogens. Depending on the presence of a tyrosine-based signalling motif, CLR-microbial pathogen engagement may result in either anti- or pro-inflammatory signalling.Impact statement. In this manuscript, we report our laboratory study of two novel CLRs that recognize Pneumocystis murina cell wall homogenates (CWH) and a purified Pneumocystis carinii cell wall fraction (CWF).Aim. To study the potential of newly generated hFc-CLR fusions on binding to Pneumocystis murina CWHs and P. carinii CWFs and subsequent downstream inflammatory signalling analysis.Methods. Newly generated hFc-CLR fusion CLEC4A and CLEC12B were screened against P. murina CWHs and P. carinii CWFs preparations via modified ELISA. Immunofluorescence assay (IFA) was utilized to visualize hFc-CLR fusion binding against intact fixed fungal life forms to verify results. Quantitative PCR (q-PCR) analysis of lung mRNA from the mouse immunosuppressed Pneumocystis pneumonia (PCP) model versus uninfected mice was employed to detect possible changes in the respective Clec4a and Clec12b transcripts. Lastly, siRNA technology of both CLRs was conducted to determine effects on downstream inflammatory events in mouse macrophages stimulated in the presence of P. carinii CWFs.Results. We determined that both CLEC4A and CLEC12B hFc-CLRs displayed significant binding with P. murina CWHs and P. carinii CWFs. Binding events showed significant binding to both curdlan and laminarin, both polysaccharides containing β-(1,3) glucans as well as N-acetylglucosamine (GlcNAc) residues and modest yet non-significant binding to the negative control carbohydrate dextran. IFA with both CLR hFc-fusions against whole P. murina life forms corroborated these findings. Lastly, we surveyed the mRNA expression profiles of both CLRs tested above in the mouse immunosuppressed Pneumocystis pneumonia (PCP) model and determined that both CLRs were significantly up regulated during infection. Lastly, siRNA of both CLRs in the mouse RAW macrophage cell line was conducted and results demonstrated that silencing of Clec4a resulted in no significant changes in TNF-alpha generation in P. carinii CWF stimulated macrophages. On the contrary, silencing of Clec12b CLR resulted in significant decreases in TNF-alpha in RAW cells stimulated with the same CWF.Conclusion. The data presented here provide new members of the CLRs family recognizing Pneumocystis. Future studies using CLEC4A and/or CLEC12B deficient mice in the PCP mouse model should provide further insights into the host immunological response to Pneumocystis.

Causes of Moderate and Severe Anaemia in a High-HIV and TB-Prevalent Adult Population in the Eastern Cape Province, South Africa

BACKGROUND

Anaemia affects one in four adults in South Africa, with a higher prevalence in persons with HIV and tuberculosis. The aim of this study is to characterise the causes of anaemia in primary care and a district hospital setting.

METHODS

A cross-sectional study design investigated a purposive sample of adult males and non-pregnant females at two community health centres and a hospital casualty and outpatients. Fingerpick blood haemoglobin was measured with HemoCueHb201+. Those with moderate and severe anaemia underwent clinical examination and laboratory tests.

RESULTS

Of 1327 patients screened, median age was 48 years, and 63.5% were female. Of 471 (35.5%) with moderate and severe anaemia on HemoCue, 55.2% had HIV, 16.6% tuberculosis, 5.9% chronic kidney disease, 2.6% cancer, and 1.3% heart failure. Laboratory testing confirmed 227 (48.2%) with moderate and 111 (23.6%) with severe anaemia, of whom 72.3% had anaemia of inflammation, 26.5% iron-deficiency anaemia, 6.1% folate deficiency, and 2.5% vitamin B12 deficiency. Overall, 57.5% had two or more causes of anaemia. Multivariate modelling showed that patients with severe anaemia were three times more likely to have tuberculosis (OR = 3.1, 95% CI = 1.5-6.5; p-value = 0.002). Microcytosis was present in 40.5% with iron deficiency, macrocytosis in 22.2% with folate deficiency, and 33.3% with vitamin B12 deficiency. The sensitivities of the reticulocyte haemoglobin content and % hypochromic red blood cells in diagnosing iron deficiency were 34.7% and 29.7%, respectively.

CONCLUSIONS

HIV, iron deficiency, and tuberculosis were the most prevalent causes of moderate and severe anaemia. The majority had multiple causes. Iron, folate, and vitamin B12 deficiencies should be identified by biochemical testing rather than by red cell volume.

The Burden of Pneumocystis Pneumonia Infection among HIV Patients in Ethiopia: A Systematic Review

Pneumocystis pneumonia (PCP) is a leading cause of death among patients with AIDS worldwide, but its burden is difficult to estimate in low- and middle-income countries, including Ethiopia. This systematic review aimed to estimate the pooled prevalence of PCP in Ethiopia, the second most densely populated African country. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were used to review published and unpublished studies conducted in Ethiopia. Studies that reported on the prevalence of PCP among HIV-infected patients were searched systematically. Variations between the studies were assessed by using forest plot and I-squared heterogeneity tests. Subgroup and sensitivity analyses were carried out when I2 > 50. The pooled estimate prevalence with 95% CI was computed using a random-effects model of analysis. Thirteen articles, comprising studies of 4847 individuals living with HIV, were included for analysis. The pooled prevalence of PCP was 5.65% (95% CI [3.74-7.56]) with high heterogeneity (I2 = 93.6%, p < 0.01). To identify the source of heterogeneity, subgroup analyses were conducted by study design, geographical region, diagnosis methods, and year of publication. PCP prevalence differed significantly when biological diagnostic methods were used (32.25%), in studies published before 2010 (32.51%), in cross-sectional studies (8.08%), and in Addis Ababa (14.05%). PCP prevalence differences of 3.25%, 3.07%, 3.23%, and 2.29% were recorded in studies based on clinical records, published since 2017, follow-up studies, and north-west Ethiopian studies, respectively. The prevalence of PCP is probably underestimated, as the reports were mainly based on clinical records. An expansion of biological diagnostic methods could make it possible to estimate the exact burden of PCP in Ethiopia.

Emerging and re-emerging fungal threats in Africa

The emergence of deadly fungal infections in Africa is primarily driven by a disproportionately high burden of human immunodeficiency virus (HIV) infections, lack of access to quality health care, and the unavailability of effective antifungal drugs. Immunocompromised people in Africa are therefore at high risk of infection from opportunistic fungal pathogens such as Cryptococcus neoformans and Pneumocystis jirovecii, which are associated with high morbidity, mortality, and related socioeconomic impacts. Other emerging fungal threats include Emergomyces spp., Histoplasma spp., Blastomyces spp., and healthcare-associated multi-drug resistant Candida auris. Socioeconomic development and the Covid-19 pandemic may influence shifts in epidemiology of invasive fungal diseases on the continent. This review discusses the epidemiology, clinical manifestations, and current management strategies available for these emerging fungal diseases in Africa. We also discuss gaps in knowledge, policy, and research to inform future efforts at managing these fungal threats.

Risk of Pneumocystis jirovecii Pneumonia among Solid Organ Transplant Recipients: A Population-Based Study

Few studies have comprehensively investigated the occurrence of Pneumocystis jirovecii pneumonia (PJP) among solid organ transplant (SOT) recipients. This study investigated the risk of PJP after organ transplantation. Each patient who underwent SOT was propensity-score-matched with four non-SOT individuals in terms of sex, age, insured salary, urbanization of residence, comorbidities, and year of enrollment. When considering the 3-year follow-up, the patients who had undergone SOT were at higher risk of PJP, with the adjusted odds ratio (aOR) being 17.18 (95% confidence interval (CI): 8.80-33.53). Furthermore, SOT recipients were also at higher PJP risk than the patients without SOT at 6 months, 1 year, and 2 years, with the aOR being 22.64 (95% CI: 7.53-68.11), 26.19 (95% CI: 9.89-69.37), and 23.06 (95% CI: 10.23-51.97), respectively. Patients comorbid with HIV infection, hematological malignancies, or vasculitis were at higher risk (aOR = 59.08, 95% CI = 20.30-171.92), (aOR = 11.94, 95% CI = 5.36-26.61), and (aOR = 21.72, 95% CI = 2.41-195.81), respectively. The recipients of SOT were at higher risk of PJP, and PJP can develop at any stage after transplantation. SOT recipients comorbid with HIV, hematologic malignancies, or vasculitis were at higher PJP risk.

Clinical Impact of Noninvasive Plasma Microbial Cell-Free Deoxyribonucleic Acid Sequencing for the Diagnosis and Management of Pneumocystis jirovecii Pneumonia: A Single-Center Retrospective Study

We present 23 cases of Pneumocystis jirovecii pneumonia (PCP) diagnosed with commercially available noninvasive plasma microbial cell-free deoxyribonucleic acid (mcfDNA) assay. Our findings suggest that plasma mcfDNA testing resulted in positive clinical impact for the diagnosis and treatment of PCP and coinfections in 82.6% of cases.

Fun with fungi: a comprehensive review of common fungal organisms encountered in cytology

The ability to detect and diagnose infection is essential in the practice of cytopathology. The identification of suppurative or granulomatous inflammation should prompt careful evaluation for infection. Many of the most commonly encountered fungal organisms demonstrate characteristic microscopic appearances that allow accurate identification even with routine cytology stains, particularly when considered in the context of clinical factors such as geographic location, social history, patient immune status, and symptoms. Given the vital role cytopathologists play in the accurate diagnosis or presumptive identification of infections, this review explores the epidemiology, clinical manifestations, and morphologic features of common fungal pathogens in addition to their differential diagnoses and ancillary testing methods.

Spatiotemporal Clusters and Trends of Pneumocystis Pneumonia in Korea

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.

Application of metagenomic next-generation sequencing in the diagnosis of pulmonary invasive fungal disease

Background

Metagenomic next-generation sequencing (mNGS) is increasingly being used to detect pathogens directly from clinical specimens. However, the optimal application of mNGS and subsequent result interpretation can be challenging. In addition, studies reporting the use of mNGS for the diagnosis of invasive fungal infections (IFIs) are rare.

Objective

We critically evaluated the performance of mNGS in the diagnosis of pulmonary IFIs, by conducting a multicenter retrospective analysis. The methodological strengths of mNGS were recognized, and diagnostic cutoffs were determined.

Methods

A total of 310 patients with suspected pulmonary IFIs were included in this study. Conventional microbiological tests (CMTs) and mNGS were performed in parallel on the same set of samples. Receiver operating characteristic (ROC) curves were used to evaluate the performance of the logarithm of reads per kilobase per million mapped reads [lg(RPKM)], and read counts were used to predict true-positive pathogens.

Result

The majority of the selected patients (86.5%) were immunocompromised. Twenty species of fungi were detected by mNGS, which was more than was achieved with standard culture methods. Peripheral blood lymphocyte and monocyte counts, as well as serum albumin levels, were significantly negatively correlated with fungal infection. In contrast, C-reactive protein and procalcitonin levels showed a significant positive correlation with fungal infection. ROC curves showed that mNGS [and especially lg(RPKM)] was superior to CMTs in its diagnostic performance. The area under the ROC curve value obtained for lg(RPKM) in the bronchoalveolar lavage fluid of patients with suspected pulmonary IFIs, used to predict true-positive pathogens, was 0.967, and the cutoff value calculated from the Youden index was −5.44.

Conclusions

In this study, we have evaluated the performance of mNGS-specific indicators that can identify pathogens in patients with IFIs more accurately and rapidly than CMTs, which will have important clinical implications.

Outcomes and Risk Factors for Mortality in Pneumocystis Pneumonia Patients with Rheumatoid Arthritis: A Multicenter Retrospective Cohort Study

OBJECTIVE

To evaluate outcomes and risk factors for death in patients with rheumatoid arthritis (RA) who developed Pneumocystis pneumonia (PCP).

METHODS

: We included RA patients who were diagnosed with PCP at seven participating community hospitals between July 2005 and October 2020. Clinical features were compared between survivors and non-survivors. Disease-modifying antirheumatic drugs (DMARDs) before PCP onset and after PCP recovery were also examined.

RESULTS

Seventy RA patients developed PCP, and among them, 60 (85.7%) received methotrexate (MTX) monotherapy (40%) or MTX combination therapy with other DMARDs (45.7%). PCP was more likely to occur after 12 months of MTX monotherapy and within 3 months of MTX combination therapy. Thirteen patients (18.6%) died despite PCP treatment. Multivariable logistic regression analysis revealed that coexisting RA-associated interstitial lung disease (RA-ILD; odds ratio [OR] 6.18, 95% confidence interval [CI] 1.17-32.63) and delayed PCP treatment with anti-Pneumocystis drugs (OR 15.29, 95% CI 1.50-156.15) are significant risk factors for PCP mortality in RA patients. Most survivors successfully resumed DMARD therapy without PCP prophylaxis; one recurrent PCP case was observed during follow-up (median, 4.1 years).

CONCLUSION

To avoid a treatment delay, RA patients should be followed-up for signs and symptoms of PCP development, especially those with RA-ILD.

Recommendations for prevention of infection in systemic autoimmune rheumatic diseases

OBJECTIVES

To develop recommendations for the prevention of infection in adult patients with systemic autoimmune rheumatic diseases (SARD).

METHODS

Clinical research questions relevant to the objective of the document were identified by a panel of experts selected based on their experience in the field. Systematic reviews of the available evidence were conducted, and evidence was graded according to the Scottish Intercollegiate Guidelines Network criteria. Specific recommendations were made.

RESULTS

Five questions were selected, referring to prevention of infection by Pneumocystis jirovecii with trimethoprim/sulfamethoxazole, primary and secondary prophylactic measures against hepatitis B virus, vaccination against human papillomavirus, vaccination against Streptococcus pneumoniae and vaccination against influenza virus, making a total of 18 recommendations, structured by question, based on the evidence found for the different SARD and/or expert consensus.

CONCLUSIONS

There is enough evidence on the safety and efficacy of vaccinations and other prophylactic measures against the microorganisms reviewed in this document to specifically recommend them for patients with SARD.

Massive Cavitation by Pneumocystis jirovecii in an Immunocompromised Patient

Since the development of antiretroviral therapy (ART) and antibiotic prophylaxis, the incidence of opportunistic infections in human immunodeficiency virus-acquired immunodeficiency syndrome (HIV-AIDS) has been drastically reduced. However, third-world countries remain a fertile ground for medication nonadherence and inappropriate patient follow-up. Here, we present the case of a 42-year-old male with a history of HIV who presented with worsening shortness of breath and atypical chest pain. A chest X-ray and chest computed tomography scan revealed a left parahilar cavitation measuring 86 mm in diameter. A percutaneous lung biopsy revealed Pneumocystis jirovecii. Appropriate antibiotics were started, and the patient’s clinical status significantly improved. This case illustrates the devastating consequences of uncontrolled HIV-AIDS. ART and prophylactic antibiotics remain the cornerstone of treatment to ameliorate progressive lung damage in patients.

Evolving epidemiology of pneumocystis pneumonia: Findings from a longitudinal population-based study and a retrospective multi-center study in Germany

Background

Pneumocystis pneumonia (PCP) is a life-threatening opportunistic infectious disease of immunocompromised patients. Its incidence has decreased worldwide in the past, but data concerning its recent epidemiology are lacking.

Methods

We retrospectively analyzed all German inpatient cases from January 1, 2014 to December 31, 2019, to describe the recent epidemiology, incidence, clinical course, mortality and underlying diseases of PCP. Simultaneously, we conducted a retrospective multi-center study at two German university hospitals, and analyzed PCP cases treated there to gain deeper insights on the basis of primary patient data.

Findings

The incidence of PCP significantly increased from 2·3 to 2·6 per 100,000 population from 2014 to 2019 (1,857 to 2,172 cases, +17·0%, p < 0·0001), as well as PCP-related deaths (516 to 615 cases, +19·2%, p = 0·011). The spectrum of underlying diseases changed: Risk groups with established chemoprophylaxis for PCP based on international guidelines (HIV, hematologic malignancies, and transplantation) showed a significant decrease in PCP cases and deaths. Others, especially those with solid malignancies, and autoimmune and pulmonary diseases showed a significant increase in case numbers and deaths. Data from the retrospective multi-center study added information regarding prophylaxis and diagnostics of PCP.

Interpretation

The incidence of PCP has reversed its trend, showing a significant increase in mortality on population level. Patients who were not previously considered in prophylactic measures are increasingly affected by PCP. This development deserves further investigation, and additional comprehensive guidelines for the use of chemoprophylaxis in new risk groups are needed.

Funding

Department of Nephrology and Hypertension, University Hospital Schleswig-Holstein, Kiel.

Proteomic Profiling and Functional Analysis of B Cell-Derived Exosomes upon Pneumocystis Infection

Pneumocystis is a life-threatening fungal pathogen that frequently causes fatal pneumonia (PCP) in immunocompromised individuals. Recently, B cells have been reported to play a crucial role in the pathogenesis of PCP through producing antibodies and activating CD4+ T cell response. Exosomes are nanoscale small extracellular vesicles abundant with protein cargo and can mediate immune response during infectious disease. In this study, using tandem mass tag-based quantitative proteomics coupled with bioinformatic analysis, we attempted to characterize exosomes derived from B lymphocytes in response to PCP. Several proteins were verified by parallel reaction monitoring (PRM) analysis. Also, the effects of B cell exosomes on CD4+ T cell response and phagocytic function of macrophages were clarified. Briefly, 1701 proteins were identified from B cell exosomes, and the majority of them were reported in Vesiclepedia. A total of 51 differentially expressed proteins of B cell exosomes were found in response to PCP. They were mainly associated with immune response and transcription regulation. PRM analysis confirmed the significantly changed levels of histone H1.3, vimentin, and tyrosine-protein phosphatase nonreceptor type 6 (PTPN6). Moreover, a functional study revealed the proinflammatory profile of B cell exosomes on CD4+ T cell response in PCP. Taken together, our results suggest the involvement of exosomes derived from B cells in cell-to-cell communication, providing new information on the function of B cells in response to PCP.

A Clinically Applicable Nomogram for Predicting the Risk of Invasive Mechanical Ventilation in Pneumocystis jirovecii Pneumonia

Objective

Pneumocystis jirovecii pneumonia (PCP) is a life-threatening disease associated with a high mortality rate among immunocompromised patient populations. Invasive mechanical ventilation (IMV) is a crucial component of treatment for PCP patients with progressive hypoxemia. This study explored the risk factors for IMV and established a model for early predicting the risk of IMV among patients with PCP.

Methods

A multicenter, observational cohort study was conducted in 10 hospitals in China. Patients diagnosed with PCP were included, and their baseline clinical characteristics were collected. A Boruta analysis was performed to identify potentially important clinical features associated with the use of IMV during hospitalization. Selected variables were further analyzed using univariate and multivariable logistic regression. A logistic regression model was established based on independent risk factors for IMV and visualized using a nomogram.

Results

In total, 103 patients comprised the training cohort for model development, and 45 comprised the validation cohort to confirm the model's performance. No significant differences were observed in baseline clinical characteristics between the training and validation cohorts. Boruta analysis identified eight clinical features associated with IMV, three of which were further confirmed to be independent risk factors for IMV, including age (odds ratio [OR] 2.615 [95% confidence interval (CI) 1.110-6.159]; p = 0.028), oxygenation index (OR 0.217 [95% CI 0.078-0.604]; p = 0.003), and serum lactate dehydrogenase level (OR 1.864 [95% CI 1.040-3.341]; p = 0.037). Incorporating these three variables, the nomogram achieved good concordance indices of 0.829 (95% CI 0.752-0.906) and 0.818 (95% CI 0.686-0.950) in predicting IMV in the training and validation cohorts, respectively, and had well-fitted calibration curves.

Conclusions

The nomogram demonstrated accurate prediction of IMV in patients with PCP. Clinical application of this model enables early identification of patients with PCP who require IMV, which, in turn, may lead to rational therapeutic choices and improved clinical outcomes.

Prevalence of Pneumocystosis in Sub-Saharan Africa and Helminth Immune Modulation

Sub-Saharan Africa is the region of the world with the highest prevalence of helminth infections. To protect themselves from the defensive mechanisms of their respective hosts, helminths modulate their immune responses. This modulation has relevant clinical and epidemiological consequences, including the inhibition of inflammatory processes that characterize infection by other microorganisms. Severe Pneumocystis pneumonia is characterized by an intense inflammatory reaction that can lead to death. Acquired immunodeficiency syndrome is the main predisposing factor to the development of pneumocystosis. Although the introduction of highly active antiretroviral therapy has led to a notable decline in the incidence of acquired immunodeficiency syndrome-associated complications, pneumocystosis continues to be an important global health problem. Despite the high incidence of human immunodeficiency virus infection in the sub-Saharan region, the prevalence of Pneumocystis pneumonia there has been lower than expected. Several factors, or combinations thereof, may contribute to this evolution. Here, we hypothesize the possible role of helminth immune modulation as an important issue at play. On the other hand, and looking ahead, we believe that the immune modulation achieved by helminths may be an important factor to consider during the design and evaluation processes of vaccines against Pneumocystis jirovecii to be used in Sub-Saharan Africa. The requirements of a balanced triggering of different types of immune responses for controlling the infection produced by this microorganism, as observed during experiments in animal models, support this final consideration.

Genetic Vaccination as a Flexible Tool to Overcome the Immunological Complexity of Invasive Fungal Infections

The COVID-19 pandemic has highlighted genetic vaccination as a powerful and cost-effective tool to counteract infectious diseases. Invasive fungal infections (IFI) remain a major challenge among immune compromised patients, particularly those undergoing allogeneic hematopoietic bone marrow transplantation (HSCT) or solid organ transplant (SOT) both presenting high morbidity and mortality rates. Candidiasis and Aspergillosis are the major fungal infections among these patients and the failure of current antifungal therapies call for new therapeutic aids. Vaccination represents a valid alternative, and proof of concept of the efficacy of this approach has been provided at clinical level. This review will analyze current understanding of antifungal immunology, with a particular focus on genetic vaccination as a suitable strategy to counteract these diseases.

Additional C-type lectin receptors mediate interactions with Pneumocystis organisms and major surface glycoprotein

Introduction. Pathogen-associated molecular patterns' (PAMPs) are microbial signatures that are recognized by host myeloid C-type lectin receptors (CLRs). These CLRs interact with micro-organisms via their carbohydrate recognition domains (CRDs) and engage signalling pathways within the cell resulting in pro-inflammatory and microbicidal responses.Gap statement. In this article, we extend our laboratory study of additional CLRs that recognize fungal ligands against Pneumocystis murina and Pneumocystis carinii and their purified major surface glycoproteins (Msgs).Aim. To study the potential of newly synthesized hFc-CLR fusions on binding to Pneumocystis and its Msg.Methods. A library of new synthesized hFc-CLR fusions was screened against Pneumocystis murina and Pneumocystis carinii organisms and their purified major surface glycoproteins (Msgs) found on the respective fungi via modified ELISA. Immunofluorescence assay (IFA) was implemented and quantified to verify results. mRNA expression analysis by quantitative PCR (q-PCR) was employed to detect respective CLRs found to bind fungal organisms in the ELISA and determine their expression levels in the mouse immunosuppressed Pneumocystis pneumonia (PCP) model.Results. We detected a number of the CLR hFc-fusions displayed significant binding with P. murina and P. carinii organisms, and similarly to their respective Msgs. Significant organism and Msg binding was observed for CLR members C-type lectin domain family 12 member A (CLEC12A), Langerin, macrophage galactose-type lectin-1 (MGL-1), and specific intracellular adhesion molecule-3 grabbing non-integrin homologue-related 3 (SIGNR3). Immunofluorescence assay (IFA) with the respective CLR hFc-fusions against whole P. murina life forms corroborated these findings. Lastly, we surveyed the mRNA expression profiles of the respective CLRs tested above in the mouse immunosuppressed Pneumocystis pneumonia (PCP) model and determined that macrophage galactose type C-type lectin (Mgl-1), implicated in recognizing terminal N-acetylgalactosamine (GalNAc) found in the glycoproteins of microbial pathogens was significantly up-regulated during infection.Conclusion. The data herein add to the growing list of CLRs recognizing Pneumocystis and provide insights for further study of organism/host immune cell interactions.

Rapid electrochemical recognition of trimethoprim in human urine samples using new modified electrodes (CPE/Ag/Au NPs) analysing tunable electrode properties: experimental and theoretical studies

Pharmaceutical effluents are a serious environmental issue, which require to be treated by a suitable technique; thus, the electrochemical process is actively considered as a viable method for the treatment. In this work, new carbon paste electrodes (CPEs) were fabricated by compressing gold and silver nanoparticles (NPs), namely, CPE/Ag NPs, CPE/Au NPs, and CPE/Ag/Au NPs and then completely characterized by different analytical methods. The performance of the electrodes was studied after determining their surface area (×10^-6 cm²) as 4.17, 5.05, 5.27, and 5.12, producing high anodic currents for K₄[Fe(CN)₆] compared to the commercial electrode. This agrees with the results of impedance study, where the electron transfer rate constants (k_app, ×10^-3 cm s^-1) were determined to be 28.7, 42.6, 41.0, and 101.4 for CPE, CPE/Ag NPs, CPE/Au NPs, and CPE/Ag/Au NPs, respectively, through the Bode plot-phase shifts. This is consistent with the charge transfer resistance (R_CT, Ω), resulting as 171 for CPE/Ag/Au NPs < 395 for CPE/Ag NPs < 427 for CPE/Au NPs and < 742 for CPE. Therefore, these electrodes were employed to detect trimethoprim (TMP) since metallic NPs contribute good crystallinity, stability, conduciveness, and surface plasmon resonance to the CPE, convalescing the sensitivity; comprehensively, they were applied for its detection in real water and human urine samples, and the limit of detection (LOD) was as low as 0.026, 0.032, and 0.026 μmol L^-1 for CPE/Ag NPs, CPE/Au NPs, and CPE/Ag/Au NPs, respectively. In contrast, unmodified CPE was unable to detect TMP due to the lack of efficiency. The developed technique shows excellent electrochemical recovery of 92.3 and 97.1% in the urine sample. Density functional theory (DFT) was used to explain the impact of the metallic center in graphite through density of states (DOS).

Primary prophylaxis for Pneumocystis jirovecii pneumonia in patients receiving rituximab

BACKGROUND

Although previous studies suggested that rituximab increases the risk of Pneumocystis jirovecii pneumonia (PJP), it is uncertain whether its primary prophylaxis for PJP is justified.

RESEARCH QUESTION

Does the benefit of primary prophylaxis for PJP in patients receiving rituximab treatment outweigh the potential risk of the prophylaxis?

STUDY DESIGN AND METHODS

This retrospective study included 3524 patients (hematologic diseases=2500; rheumatic diseases=559; pre/post-solid organ transplantation=465) first exposed to rituximab between 2002 and 2018 in a tertiary referral center in South Korea. Patients were classified into a control group (n=2523) and a prophylaxis group (n=1001) according to the administration of prophylactic TMP-SMX during the first 28 days after the start of rituximab (intention-to-treat analysis). In addition, exposure to TMP-SMX was examined as a time-varying variable (time-varying analysis). Primary outcome was the prophylactic effect of TMP-SMX on the 1-year incidence of PJP. Inverse probability of treatment weights was applied to minimize the baseline imbalance. Secondary outcome included the incidence of adverse drug reactions (ADRs) related to TMP-SMX.

RESULTS

Over 2759.9 person-years, 92 PJP infections occurred, with a mortality rate of 27.2%. The prophylaxis group showed a significantly lower incidence of PJP (adjusted sub-distribution hazard ratio (aSHR), 0.20 [95% CI, 0.10-0.42]) than the control group. This result was consistent with the results of time-varying analysis, in which only one PJP infection occurred during TMP-SMX administration (aSHR, 0.01 [0.003-0.16]). The incidence of adverse drug reactions (ADRs) related to TMP-SMX was 18.1 (14.6-22.2)/100 person-years, and most were of mild-to-moderate severity. Based on ten severe ADRs, the number needed to harm was 101 (61.9-261.1), whereas the number needed to prevent one PJP infection was 32 (24.8-39.4).

INTERPRETATION

TMP-SMX prophylaxis significantly reduces PJP incidence with a tolerable safety profile in patients receiving rituximab treatment.

Epidemiology, mortality and effectiveness of prophylaxis for Pneumocystis jiroveci pneumonia among rheumatic patients: a territory-wide study

BACKGROUND

Pneumocystis jiroveci pneumonia (PJP) is an opportunistic infection affecting immunocompromised individuals. However, evidence regarding the burden and effectiveness of prophylaxis among rheumatic patients remains limited. Delineating the epidemiology and efficacy of prophylaxis among rheumatic patients is urgently needed.

METHODS

We performed a territory-wide cohort study of rheumatic patients in Hong Kong. All patients with a diagnosis of anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV), immune-mediated myositis (IMM), rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), systemic sclerosis (SSc), or spondyloarthritis (SpA) between 2015 and 2019 were included. Prevalence, frequency of prophylaxis and mortality of PJP were calculated. Number needed to treat (NNT) analysis was also performed.

RESULTS

Out of 21,587 patients (54% RA, 25% SLE, 13% SpA, 5% IMM, 2% AAV and 1% SSc), 1141 (5.3%) patients were prescribed PJP prophylaxis. 48/21,587 (0.2%) developed PJP. No patients who developed PJP received prophylaxis prior to infection. The incidence of PJP was highest among SSc, AAV, and IMM patients. Among these diseases, the majority of PJP occurred while patients were on glucocorticoids at daily prednisolone-equivalent doses of 15 mg/day (P15) or above. PJP prophylaxis was effective with NNT for SSc, AAV and IIM being 36, 48 and 114 respectively. There were 19 PJP-related mortalities and the mortality rate was 39.6%.

CONCLUSION

PJP is an uncommon but important infection among rheumatic patients, PJP prophylaxis is effective and should be considered in patients with SSc, AAV and IMM, especially those receiving glucocorticoid doses above P15.

Quantitative PCR to Discriminate Between Pneumocystis Pneumonia and Colonization in HIV and Non-HIV Immunocompromised Patients

Pneumocystis pneumonia (PCP) is an opportunistic infection that commonly occurs in immunocompromised individuals. A definite diagnosis of PCP can be made only when the organism is identified in a respiratory specimen. It remains unclear whether qPCR can differentiate patients with PCP from those with Pneumocystis jirovecii colonization. In this study, we retrospectively collected data from HIV and non-HIV patients during 2013-2019. A diagnosis of definite, probable PCP, or PCP excluded was made based on clinical criteria, radiological reports, and three standard laboratory staining methods with blinding to qPCR data. Data from qPCR that was performed to determine the fungal burden (DNA copies/μl) in the BAL specimens of 69 HIV and 286 non-HIV patients were then obtained and reviewed. Receiver Operating Characteristic (ROC) curve analysis was performed to determine the upper and lower cut-off values for PCP diagnosis in HIV and non-HIV groups. In the non-HIV group, the lower cut-off value of 1,480 DNA copies/μl yielded a sensitivity of 100% (95% confidence interval [CI], 91.0-100), specificity of 72.9% (95% CI, 64.0-80.7), a positive predictive value (PPV) of 54.9% (95% CI, 47.6-62.1), and a negative predictive value (NPV) of 100% with Youden index of 0.73 for PCP diagnosis. In this group, the upper cut-off value of 9,655 DNA copies/μl showed the sensitivity of 100% (95% CI, 91.0-100) and specificity of 95.8% (95% CI, 90.4-98.6) with PPV of 88.6% (95% CI, 76.8-94.8) and a NPV of 100% with Youden index of 0.96 for PCP diagnosis. Regarding the HIV group, the lower cut-off value of 1,480 DNA copies/μl showed the sensitivity of 100% (95% CI, 92.5-100%) and specificity of 91.7% (95% CI, 61.5-99.8) with PPV of 97.9% (95% CI, 87.8-99.7) and a NPV of 100% with Youden index of 0.92 for PCP diagnosis. The sensitivity and specificity of the upper cut-off value of 12,718 DNA copies/μl in this group were 97.9% (95%CI, 88.7-100) and 100% (95%CI, 73.5-100), respectively. The values above the upper cut-off point had a PPV of 100% (95% CI, N/A) and a NPV of 92.3% (95% CI, 63.3-98.8) with Youden index of 0.98 for PCP diagnosis in the HIV group.

The mycological and molecular study of Pneumocystis jiroveci pneumonia among HIV and non-HIV immunocompromised patients hospitalized in pulmonary units in Guilan, Northern Iran

Background and Objectives

Pneumocystis jirovecii pneumonia (PJP) is a serious infection that usually affects those with a weak immune system. Since the prevalence of this infection in Iran and in the world is not clearly defined, the present study aimed to evaluate the incidence, clinical spectrum, and demographic characteristics of PJP among HIV and non-HIV immunocompromised patients.

Materials and Methods

Bronchoalveolar Lavage (BAL) specimens were obtained from 3 groups of immunocompromised patients, including acquired immunodeficiency syndrome (AIDS) patients, diabetic patients, and patients receiving immunosuppressive therapies. All were hospitalized in pulmonary units. The specimens were examined using microscopic methods (Giemsa and calcofluor white staining) and the nested-PCR technique based on mtLSU-rRNA gene.

Results

A total of 120 BAL samples were collected. From 12.5% (5 from 40) of HIV-infected patients, 5% (2 from 40) of patients receiving immunosuppressive therapies, and 2.5% (1 from 40) of diabetic patients Pneumocystis jiroveci was isolated. There was not any association between the prevalence of PJP and the patient's gender (p= 0.557) and age (p= 0.681). Fever and dyspnea (n=7, 87.5%), nonproductive cough and abnormal auscultation sound (n=5, 62.5%), and also chills and weight loss (n=2, 25%) were the documented clinical symptoms of PJP. Also, the results showed that none of the samples had positive results for P. jiroveci with microscopic tests while using the nested-PCR method 8 samples had positive results.

Conclusion

Since PJP often causes symptoms that are similar to other illnesses, such as the flu or tuberculosis, clinical and laboratory findings should be used simultaneously for making the final decision on drug administration.

Multiplex Real-Time Polymerase Chain Reaction on Sputum for the Diagnosis of Pneumocystis jirovecii Pneumonia in Children: A Retrospective Study

Background

Pneumocystis jirovecii pneumonia (PCP) is a serious opportunistic infection in immunocompromised children. Real-time polymerase chain reaction (PCR) is widely used for the diagnosis of PCP due to its good accuracy. However, the diagnostic performance of multiplex real-time PCR on sputum in children with PCP has never been explored.

Methods

Medical records of 63 consecutive pediatric patients were analyzed retrospectively, including 13 cases with PCP and 50 with non-PCP pneumonia. Pneumocystis jirovecii (P. jirovecii) and other co-pathogens detected by multiplex real-time PCR in sputum samples were summarized. Using clinical composite diagnosis as the reference standard, we further compared the diagnostic performance of multiplex real-time PCR to combined serological markers (1,3)-β-D-glucan plus lactate dehydrogenase. Additionally, modifications of antimicrobial treatment for pediatric PCP patients after the report of multiplex real-time PCR results were reviewed.

Results

In children with PCP, nonproductive cough and shortness of breath were more common, lymphocyte count in peripheral blood was markedly lower, and serum levels of (1,3)-β-D-glucan and lactate dehydrogenase were much higher than non-PCP group. Multiplex real-time PCR reached a sensitivity of 100% in diagnosing PCP, which was better than serum (1,3)-β-D-glucan plus lactate dehydrogenase (76.9%). Its specificity (98.0%) significantly surpassed serum (1,3)-β-D-glucan plus lactate dehydrogenase (84.4%). Furthermore, multiplex real-time PCR showed a good performance in identifying co-pathogens in sputum of pediatric PCP patients. Cytomegalovirus, Epstein–Barr virus and Streptococcus pneumoniae were the most common co-pathogens in these patients. Initial antimicrobial treatment was modified in 76.9% of children with PCP after the report of PCR results.

Conclusion

Multiplex real-time PCR on sputum is a diagnostic tool with good performance for the identification of P. jirovecii as well as co-pathogens in children with PCP. Sputum may be an alternative to bronchoalveolar lavage fluid for PCR assay in children when bronchoscopic examination is not feasible.

Withholding Primary Pneumocystis Pneumonia Prophylaxis in Virologically Suppressed Patients With Human Immunodeficiency Virus: An Emulation of a Pragmatic Trial in COHERE

BACKGROUND

Using data from the COHERE collaboration, we investigated whether primary prophylaxis for pneumocystis pneumonia (PcP) might be withheld in all patients on antiretroviral therapy (ART) with suppressed plasma human immunodeficiency virus (HIV) RNA (≤400 copies/mL), irrespective of CD4 count.

METHODS

We implemented an established causal inference approach whereby observational data are used to emulate a randomized trial. Patients taking PcP prophylaxis were eligible for the emulated trial if their CD4 count was ≤200 cells/µL in line with existing recommendations. We compared the following 2 strategies for stopping prophylaxis: (1) when CD4 count was >200 cells/µL for >3 months or (2) when the patient was virologically suppressed (2 consecutive HIV RNA ≤400 copies/mL). Patients were artificially censored if they did not comply with these stopping rules. We estimated the risk of primary PcP in patients on ART, using the hazard ratio (HR) to compare the stopping strategies by fitting a pooled logistic model, including inverse probability weights to adjust for the selection bias introduced by the artificial censoring.

RESULTS

A total of 4813 patients (10 324 person-years) complied with eligibility conditions for the emulated trial. With primary PcP diagnosis as an endpoint, the adjusted HR (aHR) indicated a slightly lower, but not statistically significant, different risk for the strategy based on viral suppression alone compared with the existing guidelines (aHR, .8; 95% confidence interval, .6-1.1; P = .2).

CONCLUSIONS

This study suggests that primary PcP prophylaxis might be safely withheld in confirmed virologically suppressed patients on ART, regardless of their CD4 count.

Opportunistic Illnesses in Children With HIV Infection in the United States, 1997-2016

BACKGROUND

Among children with HIV infection, opportunistic illness (OI) rates decreased after introduction of highly active antiretroviral therapy (ART) in 1997. We evaluated whether such decreases have continued.

METHODS

Data from the Centers for Disease Control and Prevention's National HIV Surveillance System for children with HIV living in the US during 1997-2016 was used to enumerate infants experiencing the first OI by birth year and OIs among all children <13 years of age (stratified by natality). We calculated the time to first OI among infants using Kaplan-Meier methods.

RESULTS

Among infants born during 1997-2016, 711 first OIs were diagnosed. The percentage of the first OIs diagnosed in successive 5-year birth periods was: 60.0% (1997-2001), 24.6% (2002-2006), 11.3% (2007-2011), and 3.4% (2012-2016). For every OI, the number of first cases decreased nearly annually. Time to first OI increased in successive birth periods. Among children <13 years of age, 2083 OI were diagnosed, including Pneumocystis jiroveci pneumonia, candidiasis, recurrent bacterial infection, wasting syndrome, cytomegalovirus, lymphocytic interstitial pneumonitis, tuberculosis, nontuberculous mycobacteriosis and herpes simplex virus. The rate (#/1000 person-years) decreased overall (60-7.2) and for all individual OIs. Earlier during 1997-2016, rates for all OIs were higher among foreign-born than US-born children but later became similar for all OIs except tuberculosis.

CONCLUSIONS

Among children with HIV in the US, numbers and rates of all OIs decreased during 1997-2016. Earlier, OI rates were highest among non-US-born children but were later comparable with those among US-born children for all OIs except tuberculosis.

Recommendations for prevention of infection in systemic autoimmune rheumatic diseases

OBJECTIVES

To develop recommendations for the prevention of infection in adult patients with systemic autoimmune rheumatic diseases (SARD).

METHODS

Clinical research questions relevant to the objective of the document were identified by a panel of experts selected based on their experience in the field. Systematic reviews of the available evidence were conducted, and evidence was graded according to the Scottish Intercollegiate Guidelines Network criteria. Specific recommendations were made.

RESULTS

Five questions were selected, referring to prevention of infection by Pneumocystis jirovecii with trimethoprim/sulfamethoxazole, primary and secondary prophylactic measures against hepatitis B virus, vaccination against human papillomavirus, vaccination against Streptococcus pneumoniae and vaccination against influenza virus, making a total of 18 recommendations, structured by question, based on the evidence found for the different SARD and/or expert consensus.

CONCLUSIONS

There is enough evidence on the safety and efficacy of vaccinations and other prophylactic measures against the microorganisms reviewed in this document to specifically recommend them for patients with SARD.

Determining the burden of fungal infections in Zimbabwe

Zimbabwe currently faces several healthcare challenges, most notably HIV and associated infections including tuberculosis (TB), malaria and recently outbreaks of cholera, typhoid fever and COVID-19. Fungal infections, which are also a major public health threat, receive considerably less attention. Consequently, there is dearth of data regarding the burden of fungal diseases in the country. We estimated the burden of fungal diseases in Zimbabwe based on published literature and 'at-risk' populations (HIV/AIDS patients, survivors of pulmonary TB, cancer, chronic obstructive pulmonary disease, asthma and patients receiving critical care) using previously described methods. Where there was no data for Zimbabwe, regional, or international data was used. Our study revealed that approximately 14.9% of Zimbabweans suffer from fungal infections annually, with 80% having tinea capitis. The annual incidence of cryptococcal meningitis and Pneumocystis jirovecii pneumonia in HIV/AIDS were estimated at 41/100,000 and 63/100,000, respectively. The estimated prevalence of recurrent vulvovaginal candidiasis (RVVC) was 2,739/100,000. The estimated burden of fungal diseases in Zimbabwe is high in comparison to other African countries, highlighting the urgent need for increased awareness and surveillance to improve diagnosis and management.

Serious fungal diseases in Democratic Republic of Congo - Incidence and prevalence estimates

A literature review was conducted to assess the burden of serious fungal infections in the Democratic Republic of the Congo (DRC) (population 95,326,000). English and French publications were listed and analysed using PubMed/Medline, Google Scholar and the African Journals database. Publication dates spanning 1943-2020 were included in the scope of the review. From the analysis of published articles, we estimate a total of about 5,177,000 people (5.4%) suffer from serious fungal infections in the DRC annually. The incidence of cryptococcal meningitis, Pneumocystis jirovecii pneumonia in adults and invasive aspergillosis in AIDS patients was estimated at 6168, 2800 and 380 cases per year. Oral and oesophageal candidiasis represent 50,470 and 28,800 HIV-infected patients respectively. Chronic pulmonary aspergillosis post-tuberculosis incidence and prevalence was estimated to be 54,700. Fungal asthma (allergic bronchopulmonary aspergillosis and severe asthma with fungal sensitization) probably has a prevalence of 88,800 and 117,200. The estimated prevalence of recurrent vulvovaginal candidiasis and tinea capitis is 1,202,640 and 3,551,900 respectively.Further work is required to provide additional studies on opportunistic infections for improving diagnosis and the implementation of a national surveillance programme of fungal disease in the DRC.

Recent Trends in the Epidemiology of Fungal Infections

The breadth of fungi causing human disease and the spectrum of clinical presentations associated with these infections has widened. Epidemiologic trends display dramatic shifts with expanding geographic ranges, identification of new at-risk groups, increasing prevalence of resistant infections, and emergence of novel multidrug-resistant pathogenic fungi. Certain fungi have been transmitted between patients in clinical settings. Major health events not typically associated with mycoses resulted in larger proportions of the population susceptible to secondary fungal infections. Many health care-related, environmental, and socioeconomic factors have influenced these epidemiologic shifts. This review summarizes updates to clinically significant fungal pathogens in North America.

Prevention of infective complications in systemic lupus erythematosus: A systematic literature review for the APLAR consensus statements

Systemic lupus erythematosus (SLE) is a more common autoimmune rheumatic disease in the Asia-Pacific region. The prognosis of SLE remains unsatisfactory in some Asian countries because of delayed diagnosis, limited access to medications, increased complications and issues of tolerability and adherence to treatment. The Asia-Pacific League of Associations for Rheumatology SLE special interest group has recently published a set of consensus recommendations on the management of SLE for specialists, family physicians, specialty nurses, and other healthcare professionals in the Asia-Pacific region. This article reports a systematic literature review of the infective complications of SLE in Asia and evidence for prevention of these infections by pre-emptive antimicrobial therapy and vaccination.

Pneumocystis Pneumonia: Immunity, Vaccines, and Treatments

For individuals who are immunocompromised, the opportunistic fungal pathogen Pneumocystis jirovecii is capable of causing life-threatening pneumonia as the causative agent of Pneumocystis pneumonia (PCP). PCP remains an acquired immunodeficiency disease (AIDS)-defining illness in the era of antiretroviral therapy. In addition, a rise in non-human immunodeficiency virus (HIV)-associated PCP has been observed due to increased usage of immunosuppressive and immunomodulating therapies. With the persistence of HIV-related PCP cases and associated morbidity and mortality, as well as difficult to diagnose non-HIV-related PCP cases, an improvement over current treatment and prevention standards is warranted. Current therapeutic strategies have primarily focused on the administration of trimethoprim-sulfamethoxazole, which is effective at disease prevention. However, current treatments are inadequate for treatment of PCP and prevention of PCP-related death, as evidenced by consistently high mortality rates for those hospitalized with PCP. There are no vaccines in clinical trials for the prevention of PCP, and significant obstacles exist that have slowed development, including host range specificity, and the inability to culture Pneumocystis spp. in vitro. In this review, we overview the immune response to Pneumocystis spp., and discuss current progress on novel vaccines and therapies currently in the preclinical and clinical pipeline.

The prevalence of laboratory-confirmed Pneumocystis jirovecii in HIV-infected adults in Africa: A systematic review and meta-analysis

BACKGROUND

The epidemiology of Pneumocystis jirovecii, known to colonize the respiratory tract and cause a life-threatening HIV-associated pneumonia (PCP), is poorly described in Africa. We conducted a systematic review to evaluate P. jirovecii prevalence in African HIV-positive adults with or without respiratory symptoms.

METHODS

We searched Medline, Embase, Cochrane library, Africa-Wide, and Web of Science for studies employing PCR and/or microscopy for P. jirovecii detection in respiratory samples from HIV-positive adults in Africa between 1995 and 2020. Prevalence with respiratory symptoms was pooled using random-effect meta-analysis, and stratified by laboratory method, sample tested, study setting, CD4 count, and trimethoprim/sulfamethoxazole prophylaxis. Colonization prevalence in asymptomatic adults and in adults with non-PCP respiratory disease was described, and quantitative PCR (qPCR) thresholds to distinguish colonization from microscopy-confirmed PCP reviewed.

RESULTS

Thirty-two studies were included, with 27 studies (87%) at high risk of selection bias. P. jirovecii was detected in 19% [95% confidence interval (CI): 12-27%] of 3583 symptomatic and in 9% [95% CI: 0-45%] of 140 asymptomatic adults. Among symptomatic adults, prevalence was 22% [95% CI: 12-35%] by PCR and 15% [95% CI: 9-23%] by microscopy. Seven percent of 435 symptomatic adults had PCR-detected Pneumocystis colonization without evidence of PCP [95% CI: 5-10%, four studies]. One study established a qPCR cutoff of 78 copies/5μl of DNA in 305 induced sputum samples to distinguish Pneumocystis colonization from microscopy-confirmed PCP.

CONCLUSION

Despite widened access to HIV services, P. jirovecii remains common in Africa. Prevalence estimates and qPCR-based definitions of colonization are limited, and overall quality of studies is low.