Pneumocystis pneumonia

Increased risk of Pneumocystis jirovecii colonization in rheumatoid arthritis patients on biologics and Janus kinase inhibitor

BACKGROUND

The prevalence of Pneumocystis jirovecii (PJ) pneumonia among rheumatic patients is rising. PJ colonization serves as a reservoir for transmission and precedes the development of PJ pneumonia. We aim to clarify the association of PJ colonization in patients of rheumatoid arthritis (RA) treated with biologics or Janus kinase inhibitors (JAKi).

METHODS

A prospective cohort study was performed from March 2021 to July 2022 in the rheumatology outpatient department of National Cheng Kung University Hospital. We obtained oral-wash samples from asymptomatic RA patients treated with biologic disease-modifying antirheumatic drugs (bDMARDs) and JAKi. A real-time quantitative polymerase chain reaction assay focusing on the mitochondrial large subunit ribosomal ribonucleic acid gene of PJ was applied to detect colonization.

RESULTS

One hundred and ten RA patients were enrolled. Adjusted odds ratios (ORs) of PJ colonization were 6.40 (95% CI 1.34-30.57, p-value =0.02) in patients receiving bDMARDs or JAKi. Specifically, in patients treated with bDMARDs the adjusted OR was 8.08 (95% CI 1.57-41.51, p-value=0.012), and a trend toward developing PJ colonization was further identified in patients receiving JAKi (adjusted OR: 4.79, 95% CI 0.89-25.91, p=0.069). Among patients treated with bDMARDs or JAKi, medication duration >3 years and age >60 y/o are risk factors for PJ colonization.

CONCLUSION

RA patients on bDMARDs or JAK inhibitors have an approximately 6-fold higher risk of developing P. jirovecii colonization. Patients treated with bDMARDs had an 8-fold higher risk of P. jirovecii colonization. Risk factors of PJ colonization are medication duration >3 years and age > 60 y/o.

Intermittent Versus Daily Trimethoprim/Sulfamethoxazole Regimens for Pneumocystis Pneumonia Prophylaxis: A Systematic Review and Meta-analysis

Background

In immunocompromised individuals, trimethoprim/sulfamethoxazole (TMP/SMX) for Pneumocystis pneumonia (PCP) prophylaxis has adverse events, and the optimal dosage is unclear. The objective of this study was to assess efficacy and safety of intermittent versus daily TMP/SMX for PCP prophylaxis.

Methods

This systematic review included randomized controlled trials (RCTs) indexed in the Cochrane Central Register of Controlled Trials, PubMed, Ichushi, or Embase databases, published from database inception to September 2023. The inclusion criteria were adults taking intermittent or daily TMP/SMX for PCP prophylaxis. Risk of bias was assessed using the Cochrane risk-of-bias tool. The primary outcomes were PCP incidence, PCP-related mortality, and adverse events requiring temporary or permanent TMP/SMX discontinuation.

Results

Four RCTs (N = 2808 patients) were included. PCP incidence did not differ significantly between the intermittent and daily regimen groups (risk ratio [RR], 1.17 [95% confidence interval {CI}, .89-1.53]; certainty: very low). There was no PCP-related mortality in the 3 RCTs reporting its outcome. Compared with the daily regimen group, the intermittent regimen group experienced significantly fewer adverse events requiring temporary or permanent TMP/SMX discontinuation (RR, 0.51 [95% CI, .42-.61]; certainty: low).

Conclusions

This systematic review and meta-analysis suggests that intermittent TMP/SMX regimens for PCP prophylaxis may be more tolerable than daily regimens and may have similar efficacy. Further RCTs are needed to apply this to current practice. Clinical Trials Registration. PROSPERO (CRD42022359102).

Development of RPA-Cas12a assay for rapid and sensitive detection of Pneumocystis jirovecii

Pneumocystis jirovecii is a prevalent opportunistic fungal pathogen that can lead to life-threatening Pneumocystis pneumonia in immunocompromised individuals. Given that timely and accurate diagnosis is essential for initiating prompt treatment and enhancing patient outcomes, it is vital to develop a rapid, simple, and sensitive method for P. jirovecii detection. Herein, we exploited a novel detection method for P. jirovecii by combining recombinase polymerase amplification (RPA) of nucleic acids isothermal amplification and the trans cleavage activity of Cas12a. The factors influencing the efficiency of RPA and Cas12a-mediated trans cleavage reaction, such as RPA primer, crRNA, the ratio of crRNA to Cas12a and ssDNA reporter concentration, were optimized. Our RPA-Cas12a-based fluorescent assay can be completed within  30-40 min, comprising a 25-30 min RPA reaction and a 5-10 min trans cleavage reaction. It can achieve a lower detection threshold of 0.5 copies/µL of target DNA with high specificity. Moreover, our RPA-Cas12a-based fluorescent method was examined using 30 artificial samples and demonstrated high accuracy with a diagnostic accuracy of 93.33%. In conclusion, a novel, rapid, sensitive, and cost-effective RPA-Cas12a-based detection method was developed and demonstrates significant potential for on-site detection of P. jirovecii in resource-limited settings.

CD4, but not Cxcr6, is necessary for control of Pneumocystis murina infection

CD4+ T cells are critical to control of Pneumocystis infection, and Cxcr6 has been shown to be upregulated in these cells during infection, but the roles of CD4 and Cxcr6 in this setting are undefined. To explore this, mice deficient in CD4 or Cxcr6 expression were utilized in a co-housing mouse model that mimics the natural route of Pneumocystis infection. Organism load and anti-Pneumocystis antibodies were assayed over time, and immunohistochemistry, flow cytometry, and quantitative PCR were used to characterize host immune responses during infection. CD4 was found to be necessary for clearance of Pneumocystis murina, though partial control was seen in it's absence; based on ThPOK expression, double negative T cells with T helper cell characteristics may be contributing to this control. Using a Cxcr6 deficient mouse expressing gfp, control of infection in the absence of Cxcr6 was similar to that in heterozygous control mice. It is noteworthy that gfp + cells were seen in the lungs with similar frequencies between the 2 strains. Interferon-ɣ and chemokine/ligands Cxcr3, Cxcl9, and Cxcl10 increased during P. murina infection in all models. Thus, CD4, but not Cxcr6, is needed for clearance of P. murina infection.

Trimethoprim-sulfamethoxazole combined with echinocandins versus trimethoprim-sulfamethoxazole alone for Pneumocystis pneumonia in patients without human immunodeficiency virus infection: A nationwide retrospective cohort study

BACKGROUND

Although combination therapy of echinocandins with trimethoprim-sulfamethoxazole (TMP-SMX) has been reported for patients with Pneumocystis jirovecii pneumonia (PCP), the effectiveness of this combination therapy in patients with PCP without human immunodeficiency virus (HIV) infection remains unknown.

METHODS

Data from the Japanese Diagnosis Procedure Combination inpatient database was used to identify non-HIV patients who underwent their first hospitalisation for PCP between April 2012 and March 2022. The patients were divided into those treated with TMP-SMX alone and those treated with TMP-SMX combined with echinocandins. We performed propensity-score overlap-weighting analysis to estimate in-hospital mortality.

RESULTS

Among the 1324 eligible patients, 122 received TMP-SMX plus echinocandins, while 1202 received TMP-SMX alone. The propensity-score overlap-weighting analysis showed that the combination therapy was not associated with reduced in-hospital mortality in comparison with TMP-SMX alone (22.2 % vs. 26.9 %; risk difference, 4.6 %; 95 % confidence interval, -6.1 %-15.3 %; P = 0.398).

CONCLUSIONS

Echinocandins combined with TMP-SMX may not improve in-hospital mortality due to PCP in patients without HIV infection.

Clinical course and prognostic factors of Pneumocystis pneumonia with respiratory failure in non-HIV patients

Background

Compared with Human Immunodeficiency Virus (HIV) patients, non-HIV patients with Pneumocystis pneumonia (PCP) have more rapid onset, more rapid progression, and higher mortality.

Objectives

To investigate the predictive value of variables obtained upon hospital admission for in-hospital death and 90-day outcomes in non-HIV-PCP patients with respiratory failure (RF).

Methods

This was a single center retrospective study in a tertiary care institution over 15 years. It included all adults inpatients (≥18 years old) with laboratory confirmed non-HIV-PCP with RF who were discharged or died from Peking University First Hospital between April 1st, 2007 and November 1st, 2022. Epidemiological, clinical, laboratory, imaging and outcome data were collected from patient records.

Results

In this study, a total of 146 non-HIV-PCP patients with RF were included. There were 57 patients (39%) died during hospitalization, 44 patients (53%) died in Intensive care unit (ICU). A total of 137 patients completed 90 days of follow-up, of which 58 (42.3%) died. The multivariable regression analysis revealed that a CD8+ T cell count <115/μl (P=0.009), bronchoalveolar lavage fluid (BALF)-neutrophil percentage ≥50% (P=0.047), the time from corticosteroids withdrawal to symptom onset ≤5 days (P=0.012), and the time from visit to initiation of sulfonamides ≥2 days (P=0.011) were independent risk factors for in-hospital death. Furthermore, a CD8+ T cell count < 115/μl (P=0.001) and the time from visit to initiation of sulfonamides therapy ≥2 days (P=0.033) was independently associated with 90-day all-cause death.

Conclusions

A low CD8+ T cell count in peripheral blood, a high percentage of BALF-neutrophils, a short time from corticosteroids withdrawal to symptom onset, and a long time from visit to initiation of sulfonamides are associated with poor prognosis in non-HIV-PCP patients with RF.

Immune checkpoint inhibitor increased mortality in lung cancer patients with Pneumocystis jirovecii pneumonia: a comparative retrospective cohort study

Introduction

Pneumocystis jirovecii pneumonia (PJP) is a life-threatening infection in immunocompromised individuals. Immune checkpoint inhibitor (ICI) has brought significant survival benefit in lung cancer patients. Although the few studies showed there was high mortality in PJP patients with ICI use, these studies had no comparative control groups.

Methods

A retrospective study was conducted to compare the mortality in PJP patients with lung cancer between those treated with ICI and a concurrent control group treated without ICI.

Results

A total number of 20 non-human immunodeficiency virus (HIV) patients with confirmed PJP and co-existing lung cancer were included in the current study, and classified into ICI group (n=9) and non-ICI group (n=11).There was a clear trend to a shorter onset of PJP in ICI group than non-ICI group (118.9 ± 60.9 vs 253.0 ± 185.1 days), although without statistical significance (p=0.053). Bronchoscopic alveolar lavage fluid were collected from all patients and used to identify Pneumocystis jirovecii. In both groups, metagenomics next-generation sequencing (mNGS) were the most used diagnostic techniques. Within 28 days after the onset of PJP, mortality was significantly higher in the ICI group than non-ICI group (33.3% vs 0, p=0.042).

Conclusion

Lung cancer patients with ICI use had a higher mortality rate after PJP infection than patients without ICI use. Prospective studies with larger sample size and a multi-center design are warranted to further verify the present results.

Breakthrough Pneumocystis jirovecii Pneumonia in an Allogeneic Hematopoietic Stem Cell Transplant Recipient

Pneumocystis carinii pneumonia (PCP), which is currently referred to as Pneumocystis jirovecii pneumonia, is an opportunistic fungal infection that commonly affects immunocompromised patients, and it is potentially fatal. Individuals at risk include those whose host immunity has been altered by underlying disease states, such as HIV and cancer patients, as well as transplant recipients and those taking immunosuppressive medications. Here, we present a case of a breakthrough PCP infection of an adult allogeneic hematopoietic stem cell transplant patient who was infected despite prophylaxis with inhaled pentamidine. The patient's transplant course was complicated by acute graft-versus-host disease (GVHD), which was treated with tacrolimus, prednisone, beclomethasone, and budesonide. Treatments for GVHD, which include immunosuppressive therapies, are a risk factor for PCP. Thus, the patient was on prophylactic treatment with inhaled pentamidine. The case presents challenges that immunocompromised patients face, particularly those undergoing allogeneic hematopoietic stem cell transplantation. While the patient received prophylactic treatment, there was still a breakthrough PCP infection. We highlight the risks this infection can cause and the need to promptly address these infections to prevent complications and optimize prophylactic regimens.

Pneumocystis jirovecii pneumonia in paediatric acute lymphoblastic leukaemia: A report from the multi-international clinical trial AIEOP-BFM ALL 2009

Pneumocystis jirovecii can cause life-threatening pneumonia (PjP), and patients with haematological malignancies are at high risk of this infection. Prophylactic measures have significantly decreased morbidity and mortality, but there is a paucity of contemporary data on the incidence and clinical course of PjP in well-defined and homogenous patient populations, such as children suffering from acute lymphoblastic leukaemia (ALL). In the multi-international trial AIEOP-BFM ALL2009, PjP was diagnosed in six children (incidence 1/1000) and was associated with insufficient prophylaxis in five of them. Although none of the patients died of PjP, the long-term impact of the infection is unclear.

Clinical Characteristics and Prognostic Predictors of Pneumocystis Jirovecii Pneumonia in Patients with and without Chronic Pulmonary Disease: A Retrospective Cohort Study

Objective

Pneumocystis jirovecii pneumonia (PJP) is a severe respiratory infection caused by Pneumocystis jirovecii in immunocompromised hosts. The role of P. jirovecii colonization in the development or progression of various pulmonary diseases has been reported. Our aim was to explore serial change in serum biomarkers and the independent risk factors for mortality in patients with and without chronic pulmonary diseases who developed PJP.

Methods

We performed a retrospective study to select patients with Pneumocystis jirovecii pneumonia between January 1, 2012, and December 31, 2021. Information regarding demographics, clinical characteristics, underlying diseases, laboratory tests, treatment, and outcomes was collected. Univariate and multivariate logistic regression analyses were used to identify independent predictors of in-hospital mortality.

Results

A total of 167 patients diagnosed with PJP were included in the study: 53 in the CPD-PJP group and 114 in the NCPD-PJP group. The number of patients with PJP showed an increasing trend over the 10-year period. A similar trend was observed for in-hospital mortality. Independent risk factors associated with death in the NCPD-PJP group were procalcitonin level (adjusted OR 1.08, 95% CI 1.01-1.16, P=0.01), pneumothorax (adjusted OR 0.07, 95% CI 0.01-0.38, P=0.002), neutrophil count (adjusted OR 1.27, 95% CI 1.05-1.53, P=0.01) at 14 days, and hemoglobin level (adjusted OR 0.94, 95% CI 0.91-0.98; P=0.002) at 14 days after admission. The risk factor associated with death in the CPD-PJP group was neutrophil count (adjusted OR 1.19, 95% CI 0.99-1.43; P=0.05) at 14 days after admission.

Conclusion

The risk factors for death were different between patients with PJP with and without chronic pulmonary disease. Early identification of these factors in patients with PJP and other underlying diseases may improve prognosis.

Description of a Murine Model of Pneumocystis Pneumonia

Pneumocystis pneumonia is a serious lung infection caused by an original ubiquitous fungus with opportunistic behavior, referred to as Pneumocystis jirovecii. P. jirovecii is the second most common fungal agent among invasive fungal infections after Candida spp. Unfortunately, there is still an inability to culture P. jirovecii in vitro, and so a great impairment to improve knowledge on the pathogenesis of Pneumocystis pneumonia. In this context, animal models have a high value to address complex interplay between Pneumocystis and the components of the host immune system. Here, we propose a protocol for a murine model of Pneumocystis pneumonia. Animals become susceptible to Pneumocystis by acquiring an immunocompromised status induced by iterative administration of steroids within drinking water. Thereafter, the experimental infection is completed by an intranasal challenge with homogenates of mouse lungs containing Pneumocystis murina. The onset of clinical signs occurs within 5 weeks following the infectious challenge and immunosuppression can then be withdrawn. At termination, lungs and bronchoalveolar lavage (BAL) fluids from infected mice are analyzed for fungal load (qPCR) and immune response (flow cytometry and biochemical assays). The model is a useful tool in studies focusing on immune responses initiated after the establishment of Pneumocystis pneumonia.

MiR-150 levels are related to in-hospital mortality in non-HIV Pneumocystis pneumonia patients

Pneumocystis pneumonia (PCP) is a common opportunistic infection that occurs in immunocompromised patients. Compared with HIV patients, PCP in non-HIV patients tends to follow up a more urgent course and poorer prognosis. Therefore, markers that could predict survival of PCP patients in non-HIV population are of great value. MiRNA-150 has been widely studied in many diseases since it has been identified as a vital regulator of immune cell differentiation and activation. We thus conduct this study aiming to evaluate the prognostic value of miR-150 level in non-HIV PCP. First, the expression levels of miR-150 were compared between PCP patients and healthy volunteers. The miR-150 levels in immune cells were also detected in PCP mouse models. Then the prognostic value of miR-150 was further assessed in another PCP population (n = 72). The expression levels of miR-150 were measured by reverse transcription real-time PCR (RT-PCR) technique. Our data demonstrated significantly decreased miR-150 expression levels in PCP patients and mouse models compared to controls. The miR-150 levels also decreased in various immune cells of PCP mouse models. With a cut-off value of 3.48, the area under the curve, sensitivity, specificity of miR-150 to predicate PCP mortality were 0.845, 68.2% and 96.0%, respectively. In conclusion, miR-150 expression value might serve as a potential biomarker to identify PCP patients at high risk of death.

Exploratory mass cytometry analysis reveals immunophenotypes of cancer treatment-related pneumonitis

Anticancer treatments can result in various adverse effects, including infections due to immune suppression/dysregulation and drug-induced toxicity in the lung. One of the major opportunistic infections is Pneumocystis jirovecii pneumonia (PCP), which can cause severe respiratory complications and high mortality rates. Cytotoxic drugs and immune-checkpoint inhibitors (ICIs) can induce interstitial lung diseases (ILDs). Nonetheless, the differentiation of these diseases can be difficult, and the pathogenic mechanisms of such diseases are not yet fully understood. To better comprehend the immunophenotypes, we conducted an exploratory mass cytometry analysis of immune cell subsets in bronchoalveolar lavage fluid from patients with PCP, cytotoxic drug-induced ILD (DI-ILD), and ICI-associated ILD (ICI-ILD) using two panels containing 64 markers. In PCP, we observed an expansion of the CD16+ T cell population, with the highest CD16+ T proportion in a fatal case. In ICI-ILD, we found an increase in CD57+ CD8+ T cells expressing immune checkpoints (TIGIT+ LAG3+ TIM-3+ PD-1+), FCRL5+ B cells, and CCR2+ CCR5+ CD14+ monocytes. These findings uncover the diverse immunophenotypes and possible pathomechanisms of cancer treatment-related pneumonitis.

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.

Pneumocystis pneumonia in HIV-positive and non-HIV patients: a retrospective comparative study from a lower-middle income country

In this study, we compared the predisposing factors, key demographic and clinical characteristics, clinical outcomes, and factors associated with poor prognosis in pneumocystis pneumonia (PCP) infection among the human immunodeficiency virus (HIV)-positive and non-HIV patient populations. This retrospective analysis was conducted at the Aga Khan University Hospital, Karachi, via the collection and analysis of patient records with a diagnosis of "pneumocystosis" between January 2015 and October 2020. Additionally, the laboratory database was evaluated, and patients with a laboratory-confirmed diagnosis of PCP were included. During the study period, 52 laboratory-confirmed hospitalized PCP patients were identified. Of these, 23 and 29 patients were diagnosed using microscopy and polymerase chain reaction, respectively. 34.6% of our patients were HIV positive, with a median CD4 count of 20.5 cells/mm3 (range: 10.7-50.5). Other conditions identified were corticosteroid use, autoimmune diseases, malignancy, radiation, and chemotherapy. On chest imaging, consolidation was found in 30%, ground-glass opacities in 24%, and nodular infiltrates in 20% of the cases. HIV-positive patients had a lower hemoglobin level and a higher level of β-D-glucan at the time of admission, whereas non-HIV patients were found to have more co-morbid conditions than HIV patients. We observed no difference in clinical outcomes between the two populations. Factors associated with a poor prognosis among our patients included concomitant infections at the time of diagnosis, the need for invasive mechanical ventilation, and a longer duration of stay in the hospital as well as the intensive care unit.

Severe Community-Acquired Pneumonia in Immunocompromised Patients

Due to higher survival rates with good quality of life, related to new treatments in the fields of oncology, hematology, and transplantation, the number of immunocompromised patients is increasing. But these patients are at high risk of intensive care unit admission because of numerous complications. Acute respiratory failure due to severe community-acquired pneumonia is one of the leading causes of admission. In this setting, the need for invasive mechanical ventilation is up to 60%, associated with a high hospital mortality rate of around 40 to 50%. A wide range of pathogens according to the reason of immunosuppression is associated with severe pneumonia in those patients: documented bacterial pneumonia represents a third of cases, viral and fungal pneumonia both account for up to 15% of cases. For patients with an undetermined etiology despite comprehensive diagnostic workup, the hospital mortality rate is very high. Thus, a standardized diagnosis strategy should be defined to increase the diagnosis rate and prescribe the appropriate treatment. This review focuses on the benefit-to-risk ratio of invasive or noninvasive strategies, in the era of omics, for the management of critically ill immunocompromised patients with severe pneumonia in terms of diagnosis and oxygenation.

Pneumocystis jirovecii pneumonia in people living with HIV: a review

Pneumocystis jirovecii is a ubiquitous opportunistic fungus that can cause life-threatening pneumonia. People with HIV (PWH) who have low CD4 counts are one of the populations at the greatest risk of Pneumocystis jirovecii pneumonia (PCP). While guidelines have approached the diagnosis, prophylaxis, and management of PCP, the numerous studies of PCP in PWH are dominated by the 1980s and 1990s. As such, most studies have included younger male populations, despite PCP affecting both sexes and a broad age range. Many studies have been small and observational in nature, with an overall lack of randomized controlled trials. In many jurisdictions, and especially in low- and middle-income countries, the diagnosis can be challenging due to lack of access to advanced and/or invasive diagnostics. Worldwide, most patients will be treated with 21 days of high-dose trimethoprim sulfamethoxazole, although both the dose and the duration are primarily based on historical practice. Whether treatment with a lower dose is as effective and less toxic is gaining interest based on observational studies. Similarly, a 21-day tapering regimen of prednisone is used for patients with more severe disease, yet other doses, other steroids, or shorter durations of treatment with corticosteroids have not been evaluated. Now with the widespread availability of antiretroviral therapy, improved and less invasive PCP diagnostic techniques, and interest in novel treatment strategies, this review consolidates the scientific body of literature on the diagnosis and management of PCP in PWH, as well as identifies areas in need of more study and thoughtfully designed clinical trials.

Opportunistic Infections Post-Lung Transplantation: Viral, Fungal, and Mycobacterial

Opportunistic infections are a leading cause of lung transplant recipient morbidity and mortality. Risk factors for infection include continuous exposure of the lung allograft to the external environment, high levels of immunosuppression, impaired mucociliary clearance and decreased cough reflex, and impact of the native lung microbiome in single lung transplant recipients. Infection risk is mitigated through careful pretransplant screening of recipients and donors, implementation of antimicrobial prophylaxis strategies, and routine surveillance posttransplant. This review describes common viral, fungal, and mycobacterial infectious after lung transplant and provides recommendations on prevention and treatment.

Risk Factors for Pneumocystis jirovecii Pneumonia in Children With Systemic Lupus Erythematosus Exposed to Prolonged High-Dose Glucocorticoids

BACKGROUND

Pneumocystis jirovecii pneumonia (PJP) is a life-threatening opportunistic infection in immunocompromised children with systemic lupus erythematosus (SLE). Prophylaxis against PJP in high-risk children is crucial, but the risk factors for PJP in children with SLE are not adequately characterized. This study sought to identify the risk factors for PJP in long-term glucocorticoid-treated pediatric SLE patients.

METHODS

This study encompassed 71 treatment episodes involving 64 children with prolonged (≥4 weeks) high-dose (≥20 mg/d prednisone) steroid regimens. Fourteen treatment episodes involved the PJP, whereas others did not. Risk factors for PJP were assessed through Cox regression. The predictive value of these factors was evaluated using receiver operating characteristic curves. The incidence of PJP in different risk groups was compared using the Kaplan-Meier method.

RESULTS

The creatinine (hazard ratio, 1.009; 95% confidence interval [CI], 1.001-1.017; p = 0.021) and the lowest lymphocyte count (hazard ratio, 0.007; 95% CI, 0.000-0.373; p = 0.014) were independent risk factors for PJP in children with SLE. The receiver operating characteristic curve showed that using creatinine greater than 72.5 μmol/L and the lowest lymphocyte count less than 0.6 × 109/L as risk predictors for PJP resulted in an area under the curve value of 0.934 (95% CI, 0.870-0.997; p < 0.001). The study revealed a significant increase in PJP prevalence (p < 0.001) in children with elevated creatinine levels and low lymphocyte count.

CONCLUSIONS

Elevated levels of creatinine and decreased lymphocyte count are identified as distinct risk factors for PJP in children with SLE who receive prolonged high-dose steroid therapy.

Pneumocystis jirovecii pneumonia mortality risk associated with preceding long-term steroid use for the underlying disease: A multicenter, retrospective cohort study

OBJECTIVE

Long-term steroid use increases the risk of developing Pneumocystis pneumonia (PcP), but there are limited reports on the relation of long-term steroid and PcP mortality.

METHODS

Retrospective multicenter study to identify risk factors for PcP mortality, including average steroid dose before the first visit for PcP in non-human immunodeficiency virus (HIV)-PcP patients. We generated receiver operating characteristic (ROC) curves for 90-day all-cause mortality and the mean daily steroid dose per unit body weight in the preceding 10 to 90 days in 10-day increments. Patients were dichotomized by 90-day mortality and propensity score-based stabilized inverse probability of treatment weighting (IPTW) adjusted covariates of age, sex, and underlying disease. Multivariate analysis with logistic regression assessed whether long-term corticosteroid use affected outcome.

RESULTS

Of 133 patients with non-HIV-PcP, 37 died within 90 days of initial diagnosis. The area under the ROC curve for 1-40 days was highest, and the optimal cutoff point of median adjunctive corticosteroid dosage was 0.34 mg/kg/day. Past steroid dose, underlying interstitial lung disease and emphysema, lower serum albumin and lower lymphocyte count, higher lactate dehydrogenase, use of therapeutic pentamidine and therapeutic high-dose steroids were all significantly associated with mortality. Underlying autoimmune disease, past immunosuppressant use, and a longer time from onset to start of treatment, were associated lower mortality. Logistic regression analysis after adjusting for age, sex, and underlying disease with IPTW revealed that steroid dose 1-40 days before the first visit for PcP (per 0.1 mg/kg/day increment, odds ratio 1.36 [95% confidence interval = 1.16-1.66], P<0.001), low lymphocyte counts, and high lactate dehydrogenase revel were independent mortality risk factor, while respiratory failure, early steroid, and sulfamethoxazole/trimethoprim for PcP treatment did not.

CONCLUSION

A steroid dose before PcP onset was strongly associated with 90-day mortality in non-HIV-PcP patients, emphasizing the importance of appropriate prophylaxis especially in this population.

CD40 Expression by B cells is Required for Optimal Immunity to Murine Pneumocystis Infection

CD40-CD40L interactions are critical for controlling Pneumocystis infection. However, which CD40-expressing cell populations are important for this interaction have not been well-defined. We used a cohousing mouse model of Pneumocystis infection, combined with flow cytometry and qPCR, to examine the ability of different populations of cells from C57BL/6 mice to reconstitute immunity in CD40 knockout (KO) mice. Unfractionated splenocytes, as well as purified B cells, were able to control Pneumocystis infection, while B cell depleted splenocytes and unstimulated bone-marrow derived dendritic cells (BMDCs) were unable to control infection in CD40 KO mice. Pneumocystis antigen-pulsed BMDCs showed early, but limited, control of infection. Consistent with recent studies that have suggested a role for antigen presentation by B cells, using cells from immunized animals, B cells were able to present Pneumocystis antigens to induce proliferation of T cells. Thus, CD40 expression by B cells appears necessary for robust immunity to Pneumocystis.

Sulfamethoxazole-trimethoprim for pneumocystis pneumonia prophylaxis, causes of discontinuation and thrombocytopenia observed during administration: A single-center retrospective study

INTRODUCTION

The development of pneumocystis pneumonia (PCP) has recently become a growing concern; thus, its prevention has become increasingly important. Sulfamethoxazole-trimethoprim (ST) is a cost-effective first-line and prophylactic treatment for PCP. However, ST administration criteria for PCP prophylaxis remain unclear and are often discontinued because of adverse events (AEs). In this study, we aimed to investigate the causes of ST discontinuation and the associated AEs using objective data.

METHODS

We retrospectively analyzed the data of 162 patients admitted to Kansai Medical University Hospital between January 2018 and December 2020, who received ST for PCP prophylaxis. We compared clinical characteristics, laboratory data, and incidence of AEs between ST non-discontinuation and ST discontinuation groups. Additionally, we divided the patients into non-developing and developing thrombocytopenia (≥ Grade 1) groups based on the investigation results.

RESULTS

No patients developed PCP while receiving ST. The most common causes of ST discontinuation were thrombocytopenia (37%), liver dysfunction (20%), and rash (18%). Multivariate analysis revealed thrombocytopenia (≥ Grade 1) as a factor significantly associated with ST discontinuation. Furthermore, we identified three factors correlated with thrombocytopenia (≥ Grade 1): age ≥50 years, lymphocyte count <1000/μL, and platelet count <180,000/μL.

CONCLUSIONS

Patients with the aforementioned factors are at higher risk of developing thrombocytopenia (≥ Grade 1) during ST administration for PCP prophylaxis. Therefore, platelet count monitoring is essential to enhance safety and efficacy of ST treatment. Nonetheless, further research is warranted to explore additional implications and interventions.

A regimen based on the combination of trimethoprim/sulfamethoxazole with caspofungin and corticosteroids as a first-line therapy for patients with severe non-HIV-related pneumocystis jirovecii pneumonia: a retrospective study in a tertiary hospital

BACKGROUND

Pneumocystis jirovecii pneumonia (PJP) is a life-threatening and severe disease in immunocompromised hosts. A synergistic regimen based on the combination of sulfamethoxazole-trimethoprim (SMX-TMP) with caspofungin and glucocorticosteroids (GCSs) may be a potential first-line therapy for PJP. Therefore, it is important to explore the efficacy and safety of this synergistic therapy for treating non-HIV-related PJP patients.

METHODS

We retrospectively analysed the data of 38 patients with non-HIV-related PJP at the First Affiliated Hospital of Xi'an Jiaotong University. Patients were divided into two groups: the synergistic therapy group (ST group, n = 20) and the monotherapy group (MT group, n = 18). All patients were from the ICU and were diagnosed with severe PJP. In the ST group, all patients were treated with SMX-TMP (TMP 15-20 mg/kg per day) combined with caspofungin (70 mg as the loading dose and 50 mg/day as the maintenance dose) and a GCS (methylprednisolone 40-80 mg/day). Patients in the MT group were treated only with SMX-TMP (TMP 15-20 mg/kg per day). The clinical response, adverse events and mortality were compared between the two groups.

RESULTS

The percentage of patients with a positive clinical response in the ST group was significantly greater than that in the MT group (100.00% vs. 66.70%, P = 0.005). The incidence of adverse events in the MT group was greater than that in the ST group (50.00% vs. 15.00%, P = 0.022). Furthermore, the dose of TMP and duration of fever in the ST group were markedly lower than those in the MT group (15.71 mg/kg/day vs. 18.35 mg/kg/day (P = 0.001) and 7.00 days vs. 11.50 days (P = 0.029), respectively). However, there were no significant differences in all-cause mortality or duration of hospital stay between the MT group and the ST group.

CONCLUSIONS

Compared with SMZ/TMP monotherapy, synergistic therapy (SMZ-TMP combined with caspofungin and a GCS) for the treatment of non-HIV-related PJP can increase the clinical response rate, decrease the incidence of adverse events and shorten the duration of fever. These results indicate that synergistic therapy is effective and safe for treating severe non-HIV-related PJP.

Precision-cut lung slices as an ex vivo model to study Pneumocystis murina survival and antimicrobial susceptibility

IMPORTANCE

Our study reveals the potential of precision-cut lung slices as an ex vivo platform to study the growth/survival of Pneumocystis spp. that can facilitate the development of new anti-fungal drugs.

Pneumocystis jirovecii Pneumonia in a Patient With Localized Mycosis Fungoides Not Receiving Immunosuppressive Treatment

Pneumocystis jirovecii pneumonia (PCP) is the most common opportunistic infection in patients with human immunodeficiency virus (HIV), but it may develop in patients without HIV, whose immune system is suppressed by anticancer or immunosuppressive agents even when indicating normal counts of CD4+ T cells. Mycosis fungoides (MF) is a primary cutaneous T-cell lymphoma, which is believed not to cause immunosuppressive conditions unless it develops leukosis or metastasis or is treated with anticancer drugs or systemic immunosuppressants. Here, we report a case of PCP in a patient with localized MF not receiving immunosuppressive treatment. The patient, a woman in her 70s, presented with persistent dyspnea. High-resolution computed tomography (HRCT) showed diffuse ground-glass opacities in both lungs. Bronchoalveolar lavage fluid was positive for P. jirovecii. Moreover, the cytomegalovirus antigenemia test was positive, whereas tests for anti-HIV and antihuman T-cell lymphotropic virus antibodies were negative. The patient was treated with trimethoprim-sulfamethoxazole, prednisolone, and ganciclovir, which gradually improved the symptoms and diminished diffuse ground-glass opacities on HRCT. This case exemplifies a rare presentation of PCP with mild MF that was not treated with chemotherapy or immunosuppressants. The possible mechanisms for the development of PCP are discussed.

Clinical characteristics and risk factors for late-onset pneumocystis jirovecii pneumonia in kidney transplantation recipients

BACKGROUND

Pneumocystis jirovecii pneumonia (PJP) is a common and troublesome complication of kidney transplantation. In the era of prophylaxis, the peak incidence of PJP after kidney transplantation and specific characteristics of late-onset PJP have always been debated.

METHODS

We performed a retrospective study by analysing the data of post-transplantation pneumonia in adult kidney transplantation recipients between March 2014 and December 2021 in The Affiliated First Hospital of University of Science and Technology of China (USTC). A total of 361 patients were included and divided into early-onset PJP, late-onset PJP and non-PJP groups. The characteristics of each group and related risk factors for the late-onset patients were investigated.

RESULTS

Some patients developed PJP 9 months later with a second higher occurrence between month 10 and 15 after transplantation. Compared with non-PJP, ABO-incompatible and cytomegalovirus (CMV) viremia were significantly associated with late onset of PJP in multivariate analysis. The use of tacrolimus, CMV viremia, elevated CD8(+) T cell percent and hypoalbuminemia were risk factors for late PJP. Receiver operating characteristic curve analysis demonstrated that a combination of those factors could increase the sensitivity of prediction remarkably, with an area under the curve of 0.82, a sensitivity of 80% and a specificity of 83%.

CONCLUSIONS

PJP could occur months after kidney transplantation. ABO-incompatible transplant recipients are at high risk of PJP. In the later stages of transplantation, CMV viremia, T lymphocyte subsets percentage and serum albumin levels should be monitored in patients using tacrolimus.

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.

Progress in the application of nanoparticles for the treatment of fungal infections: A review

The burden of fungal infections on human health is increasing worldwide. Aspergillus, Candida, and Cryptococcus are the top three human pathogenic fungi that are responsible for over 90% of infection-related deaths. Moreover, effective antifungal therapeutics are lacking, primarily due to host toxicity, pathogen resistance, and immunodeficiency. In recent years, nanomaterials have proved not only to be more efficient antifungal therapeutic agents but also to overcome resistance against fungal medication. This review will examine the limitations of standard antifungal therapy as well as focus on the development of nanomaterials.

Metagenomic next-generation sequencing of bronchoalveolar lavage fluid in non-severe and severe pneumonia patients

Metagenomic next-generation sequencing (mNGS) is widely used as a more promising technology than conventional tests. However, its clinical utility in the context of bronchoalveolar lavage fluid (BALF) samples for discriminating between non-severe and severe pneumonia is not well established. Thus, this study aimed to investigate the diagnostic performance of mNGS on BALF samples from 100 individuals suspected of pneumonia, and compared it with conventional microbiological tests (CMT) of BALF samples and the final clinical diagnosis. Twenty-seven cases of non-severe pneumonia and 73 cases of severe pneumonia patients were finally clinically diagnosed. Among 100 cases, diagnostic performance of mNGS and culture showed a significant difference; 65 cases had the same sample types, of which 25 cases were diagnosed as positive by mNGS only (38.46%) and 1 was diagnosed as positive by culture only (1.54%). Moreover, 24 cases were diagnosed positive in both mNGS and culture (36.92%) and 15 cases tested negative in both mNGS and culture (23.08%). Among 35 cases, 28 out of 35 cases were diagnosed as positive by mNGS, while only 4 out of 35 cases were diagnosed as positive by the indirect immunofluorescence method (IIFT). In addition, the positive rate of mNGS was higher than that of culture in cases regardless of prior antibiotic exposure. Mixed pathogens were found to be significantly more prevalent in severe pneumonia patients than in non-severe pneumonia patients. Importantly, among 38 cases who were diagnosed solely by mNGS, 25 patients experienced an improved outcome after physicians changed the therapy according to the mNGS results. In conclusion, the results showed that mNGS of BALF represents a potentially effective tool for detection of mixed pathogens in severe pneumonia.

Pneumocystis Pneumonia Infection Following the Initiation of Pembrolizumab Therapy for Lung Adenocarcinoma

Pneumocystis pneumonia (PCP) is an opportunistic infection that presents a ground-glass appearance in the lungs on chest radiography. Interstitial lung disease is a commonly reported adverse effect of immune checkpoint inhibitor (ICI) treatment; however, there are few reports of ICI treatment-associated PCP infection. A 77-year-old man with lung adenocarcinoma was administered pembrolizumab and hospitalized for dyspnea 2 weeks after treatment. Chest computed tomography showed bilateral ground-glass opacities in all lung lobes. PCP was therefore diagnosed, and steroids and sulfamethoxazole-trimethoprim were initiated. Following treatment, the patient's condition improved promptly. This report suggests that ICI treatment can cause PCP infection.

Evaluation of pulmonary abnormalities in recipients of hematopoietic cell transplants and cellular therapies

Hematopoietic cell transplant (HCT) and chimeric antigen receptor T-cell (CAR-T) therapy recipients are susceptible to multiple pulmonary complications that are caused by infectious and noninfectious processes. Numerous variables can be associated with specific pulmonary diseases including time from transplantation, presence of graft versus host disease (GVHD), underlying disease, and prolonged neutropenia and lymphocytopenia. Most pulmonary complications are infectious in origin, with bacterial pneumonia remaining the most common pulmonary infection, particularly before neutrophil engraftment. Invasive fungal infections continue to affect this patient population even when antifungal prophylaxis is used. Noninfectious pulmonary complications include a wide differential of pathologies in this population, and as clinical presentations of these various pulmonary disorders often overlap, clinicians frequently will use a multidisciplinary approach in diagnosing these abnormalities. Radiography, particularly with chest computed tomography (CT) imaging, is an essential tool in identifying pulmonary pathology and potential sources. While standard microbiological cultures of respiratory specimens are still utilized, their role is limited by low sensitivity and diagnostic yield. The likelihood of obtaining a diagnosis can be improved by using other microbiological assays, including fungal antigen tests and molecular diagnostic methods, particularly if specimens are collected via bronchoscopy. This review will highlight the more common causes of pulmonary diseases encountered after HCT and CAR-T and will examine the different methods in their diagnosis.

Targeted Therapy in Rheumatoid-Arthritis-Related Interstitial Lung Disease

Rheumatoid arthritis (RA) is a chronic autoimmune multisystem inflammatory disease in which lung involvement is the most common extra-articular manifestation. Parenchymal lung involvement or interstitial lung disease (ILD) is a significant cause of morbidity and mortality and there is a paucity of evidence-based guidance on how to best treat RA-ILD. This review article aims to evaluate the evidence from cohort studies and best real word data from registries. Extensive discussion of the relative merits and drawbacks of glucocorticoids, various biologics, small molecules and anti-fibrotics is presented. The limited available guidelines in RA-ILD are also discussed and a rational treatment algorithm is offered.

The effect of COVID-19 on the frequency of Pneumocystis jirovecii pneumonia: a monocentric, retrospective, and observational study

BACKGROUND

Pneumocystis jirovecii pneumonia (PCP) and SARS-CoV2 share some similarities in their effects on the respiratory system, clinical presentation, and management. The COVID-19 pandemic required rapid action to curb transmission and mitigate its lethiferous impact. Non-pharmaceutical interventions (NPIs) were globally adopted. We hypothesized that these measures reduced the transmission and acquisition of P. jirovecii in both hospital and community settings.

METHODS

We conducted a retrospective observational study on 2950 respiratory specimens from patients with suspected pulmonary infection, analyzed at the Laboratory of Parasitology Unit of the Policlinico Tor Vergata of Rome, Italy, from January 2014 to December 2022.

RESULTS

We show a significant reduction in the frequency of PCP in the COVID-19 pandemic era compared to the previous period. Among the four sequence types of P. jirovecii identified, genotype 1 was the most prevalent (37%). We observed a non-significant trend of decreasing cases with genotype 1 and increasing cases with genotype 3 over the study period.

CONCLUSIONS

The nationwide implementation of NPIs against COVID-19 may have changed the microbiological landscape of exposure, thereby decreasing the exposure to P. jirovecii and consequently reducing the incidence of PCP.

Corticosteroids in the treatment of IgA nephropathy: lessons from the TESTING trial

IgA nephropathy (IgAN), the most common form of primary glomerulonephritis, is mainly observed in young adults and children. Clinical and basic studies indicate the role of immunity in IgAN pathogenesis; however, corticosteroid therapy has been controversial in past decades. The TESTING study, initiated in 2012, is an international, multicenter, double-blinded, randomized, placebo-controlled trial that aimed to evaluate oral methylprednisolone's safety and long-term efficacy under conditions of optimized supportive treatment in patients with IgAN whose risk of progression is high. After a decade of effort, the successful completion of the TESTING study showed that a 6- to 9-month course of oral methylprednisolone is an effective regimen to protect kidney function in high-risk patients with IgAN, but also demonstrated safety concerns. Compared with the full-dose regimen, the reduced-dose regimen was reported to be beneficial, with successfully increased safety. Overall, the TESTING trial provided more data regarding the treatment dosage and safety of corticosteroids, a cost-effective therapy, in IgAN, which have important implications for pediatric patients with IgAN. With a deeper understanding of the disease pathogenesis of IgAN, ongoing studies of novel therapeutic regimens would help further optimize the benefit-risk ratio.

Compounded sulfamethoxazole improved the prognosis of dermatomyositis patients positive with anti-melanoma differentiation-associated gene 5

OBJECTIVES

Mortality of dermatomyositis patients positive with anti-melanoma differentiation-related gene 5 antibody (anti-MDA5-DM) is alarming, especially during the first several months. Infection is an important cause of early death. As there are no reports regarding the effect of prophylactic use of compounded sulfamethoxazole (coSMZ; each tablet contains 400 mg of sulfamethoxazole and 80 mg of trimethoprim) in anti-MDA5-DM patients, we conducted this study to evaluate the efficacy of coSMZ in reducing the incidence of Pneumocystis jirovecii pneumonia (PJP).

METHODS

Consecutive patients with new-onset anti-MDA5-DM from June 2018 to October 2021 in our centre were retrospectively reviewed for >12 months. They were divided into two groups-coSMZ and non-coSMZ-based on the initial use of prophylactic coSMZ. Mortality and the incidence of severe infection within 12 months were compared between two groups.

RESULTS

Compared with the non-coSMZ group (n = 93), the coSMZ group (n = 121) had lower mortality (18.8% vs 51.1%; P < 0.001) and a lower incidence of PJP (6.8% vs 15.2%; P = 0.040) and fatal infection (16.1% vs 3.3%; P = 0.001) during the first 12 months from diagnosis. After adjusting for age, gender, disease duration, peripheral blood lymphocyte count, anti-MDA5 antibody titres, ground-glass opacity scores and treatments, an inverse association was revealed between the prophylactic use of coSMZ and incidence of PJP [adjusted odds ratio 0.299 (95% CI 0.102-0.878), P = 0.028].

CONCLUSION

Prophylactic use of coSMZ is an effective and safe way to improve the prognosis of anti-MDA5-DM patients by preventing the incidence of PJP.

A machine learning diagnostic model for Pneumocystis jirovecii pneumonia in patients with severe pneumonia

BACKGROUND

The diagnosis of Pneumocystis jirovecii pneumonia (PCP) in patients presenting with severe pneumonia is challenging and delays in treatment were associated with worse prognosis. This study aimed to develop a rapid, easily available, noninvasive machine learning diagnostic model for PCP among patients with severe pneumonia.

METHODS

A retrospective study was performed in West China Hospital among consecutive patients with severe pneumonia who had undergone bronchoalveolar lavage for etiological evaluation between October 2010 and April 2021. Factors associated with PCP were identified and four diagnostic models were established using machine learning algorithms including Logistic Regression, eXtreme Gradient Boosting, Random Forest (RF) and LightGBM. The performance of these models were evaluated by the area under the receiver operating characteristic curve (AUC).

RESULTS

Ultimately, 704 patients were enrolled and randomly divided into a training set (n = 564) and a testing set (n = 140). Four factors were ultimately selected to establish the model including neutrophil, globulin, β-D-glucan and ground glass opacity. The RF model exhibited the greatest diagnostic performance with an AUC of 0.907. The calibration curve and decision curve analysis also demonstrated its accuracy and applicability.

CONCLUSIONS

We constructed a PCP diagnostic model in patients with severe pneumonia using four easily available and noninvasive clinical indicators. With satisfying diagnostic performance and good clinical practicability, this model may help clinicians to make early diagnosis of PCP, reduce the delays of treatment and improve the prognosis among these patients.

Role of fungal burden in risk stratification of HIV-negative patients with Pneumocystis pneumonia: A 12-year, retrospective, observational, multicenter cohort

OBJECTIVES

This study aimed to explore the role of fungal burden in risk stratification of patients without HIV-negative patients with Pneumocystis pneumonia (PCP).

METHODS

This was a retrospective analysis of the characteristics associated with 30-day mortality in patients who were positive for P. jirovecii using polymerase chain reaction in bronchoalveolar lavage fluid between 2006 and 2017 in a multicenter cohort from Central Norway. The fungal burden was indicated by the cycle threshold (CT) values from semiquantitative real-time polymerase chain reaction targeting the β-tubulin gene.

RESULTS

We included 170 patients with proven or probable PCP. The all-cause 30-day mortality was 18.2%. After adjusting for host characteristics and premorbid corticosteroid use, a higher fungal burden was associated with a higher risk of dying: adjusted odds ratio 1.42 (95% confidence interval 0.48-4.25) for a CT value 31-36, increasing to odds ratio 5.43 (95% confidence interval 1.48-19.9) for a CT value ≤30 compared with patients with a CT value ≥37. The Charlson comorbidity index (CCI) improved the risk stratification: patients with a CT value ≥37 and CCI ≤2 had a 9% mortality risk compared with 70% among those with a CT value ≤30 and CCI ≥6. Comorbid cardiovascular disease, solid tumors, immunological disorders, premorbid corticosteroids, hypoxemia, abnormal leukocyte counts, low serum albumin, and C-reactive protein ≥100 were also independently associated with 30-day mortality. The sensitivity analyses did not suggest selection bias.

CONCLUSION

Fungal burden may improve the risk stratification of patients without HIV-negative patients with PCP.

The conventional diagnosis challenge: Real-time PCR and nested PCR correlation with the scoring system for individuals at high-risk of Pneumocystis jirovecii pneumonia

INTRODUCTION

Pneumocystis jirovecii is an opportunistic fungus that affects mainly people living with HIV (CD4 cell count lower than 200 cells/ml) and other immunosuppressed patients. Since P. jirovecii does not grow on routine mycological media, diagnosis of P. jirovecii pneumonia relies on indirect evidence of its presence in respiratory samples.

OBJECTIVES

To associate the results of direct immunofluorescence and two molecular methods with a score to predict P. jirovecii pneumonia in patients with AIDS.

MATERIALS AND METHODS

A prospective study was conducted with 40 patients. A respiratory sample collected before treatment was subjected to direct immunofluorescence using the Merifluor kit, to nested PCR targeting the mitochondrial large subunit ribosomal RNA, and to the VIASURE real-time PCR kit.

RESULTS

These three techniques revealed P. jirovecii in 6, 12, and 15 samples, respectively. All positive samples by direct immunofluorescence were positive by nested PCR, and all positive samples by nested PCR amplified by real-time PCR. There was a statistically significant association between the P. jirovecii pneumonia score and the molecular methods. Two patients were early diagnosed and responded well to treatment.

CONCLUSION

Molecular methods, especially real-time PCR, are recommended for early diagnosis of P. jirovecii pneumonia in AIDS patients.

Pneumocystis jirovecii pneumonia presenting as a large pulmonary mass in a patient with AIDS

Pneumocystis jirovecii pneumonia typically presents with diffuse bilateral infiltrates or ground-glass opacities. However, the radiographic pattern may be atypical. We report a case of a woman in her 40s who presented with multiple pulmonary masses and prolonged symptoms of non-productive cough, generalised weakness and fatigue. Serial chest CT performed prior to her presentation showed a large right lower lobe lung mass with multiple additional bilateral pulmonary nodules. Her workup revealed a new diagnosis of AIDS. Pathology of several CT-guided needle biopsies was consistent with Pneumocystis which was confirmed by microbial DNA sequencing. No additional pathogens were identified. Her clinical symptoms and radiographs improved significantly with trimethoprim-sulfamethoxazole and treatment of her HIV infection. Clinicians should evaluate for underlying immunodeficiency and seek infectious disease and pulmonary consultation early for consideration of alternative diagnoses when patients present with cough, dyspnoea and atypical chest radiographs, and initial pathological examination is unrevealing.

Co-Infection Talaromyces marneffei and Pneumocystis jirovecii in a Patient with Systemic Lupus Erythematosus

Talaromyces marneffei (TM) and Pneumocystis jirovecii (PJ) infection are opportunistic infections that typically affect individuals with compromised immune systems, such as those with HIV or immunodeficiency. However, these infections are rarely seen in patients with systemic lupus erythematosus (SLE). We present a case study of a 52-year-old woman diagnosed with SLE who developed a co-infection of TM and PJ after receiving glucocorticoids, mycophenolate mofetil (MMF), and belimumab therapy. The patient's pneumonia improved following treatment with voriconazole, clarithromycin, and compound sulfamethoxazole. This case highlights the potential risk of serious opportunistic infections in SLE patients receiving a combination of glucocorticoids, MMF, and belimumab. Close monitoring of lymphocyte count, immunoglobulin levels, and chest computed tomography scans can aid in the early detection of infections. To the best of our knowledge, this is the first reported case of TM and PJ co-infection in an SLE patient.

Diagnostic performance of metagenomic next-generation sequencing for Pneumocystis jirovecii pneumonia

OBJECTIVE

Pneumocystis jirovecii pneumonia (PJP) can be a life-threatening opportunistic infection. We aimed to evaluate the diagnostic accuracy of metagenomic next-generation sequencing (mNGS) for PJP.

METHODS

A comprehensive electronic literature search of Web of Knowledge, PubMed, Cochrane Library, CNKI and Wanfang data was performed. Bivariate analysis was conducted to calculate the pooled sensitivity, specificity, diagnostic odds ratio (DOR), the area under the summary receiver operator characteristic (SROC) curve and the Q-point value (Q*).

RESULTS

The literature search resulted in 9 studies with a total of 1343 patients, including 418 cases diagnosed with PJP and 925 controls. The pooled sensitivity of mNGS for diagnosis of PJP was 0.974 [95% confidence interval (CI), 0.953-0.987]. The pooled specificity was 0.943 (95% CI, 0.926-0.957), the DOR was 431.58 (95% CI, 186.77-997.27), the area under the SROC curve was 0.987, and the Q* was 0.951. The I2 test indicated no heterogeneity between studies. The Deek funnel test suggested no potential publication bias. Subgroup analyses showed that the area under the SROC curve of mNGS for diagnosis of PJP in immunocompromised and non-HIV patients was 0.9852 and 0.979, respectively.

CONCLUSIONS

Current evidence indicates that mNGS exhibits excellent accuracy for the diagnosis of PJP. The mNGS is a promising tool for assessment of PJP in both immunocompromised and non-HIV patients.

No long-term effect of past Pneumocystis jirovecii pneumonia on pulmonary function in people with HIV

OBJECTIVE

To assess the impact of past Pneumocystis jirovecii pneumonia (PJP) on the pulmonary diffusion capacity in people with HIV (PWH) with a history of advanced immunodeficiency.

DESIGN

Prospective cross-sectional study.

METHODS

Adult PWH with past PJP >1 year ago were included as the study group. The control group consisted of PWH with a nadir CD4 + lymphocyte count <200 cells/mm 3 , matched by age, sex, smoking status and time since HIV diagnosis. All PWH completed a pulmonary function test (PFT) consisting of pre-bronchodilation spirometry, body plethysmography and single-breath carbon monoxide transfer factor (TLCO) measurement. TLCO, diffusion impairment (defined as a TLCO Z -score <-1.645), total lung capacity (TLC) and forced expiratory volume in one second/forced vital capacity (FEV1/FVC) Z -scores were assessed. Multivariable regression analyses were conducted with Z -scores and odds of diffusion impairment as outcomes.

RESULTS

PFTs of 102 participants were analyzed, 51 of whom had past PJP with a median of 10 years since PJP. Mean TLCO Z -score and diffusion impairment rate did not differ significantly between groups ( P  = 0.790; P  = 0.650). Past PJP was not independently associated with TLCO Z -score [ β = 0.14; 95% confidence interval (CI) -0.30-0.57], diffusion impairment (odds ratio 1.00; 95% CI 0.36-2.75) nor TLC or FEV1/FVC Z -scores, whereas current (vs. never) smoking was associated with more diffusion impairment and lower TLCO Z -scores.

CONCLUSION

In our study, past PJP was not associated with long-term diffusion impairment. Our findings suggest that smoking plays a more important role in persistent pulmonary function impairment whereas PJP-related changes seem to be reversible.

Next-generation sequencing technology for the diagnosis of Pneumocystis pneumonia in an immunocompetent female: A case report

BACKGROUND

Pneumocystis pneumonia (PCP) is a serious fungal infection usually seen in patients with human immunodeficiency virus, and it is more frequently found and has a high fatality rate in immunocompromised people. Surprisingly, it rarely occurs in immunocompetent patients. However, the clinical diagnosis of this pathogen is made more difficult by the difficulty of obtaining accurate microbiological evidence with routine tests. This case reports a PCP patient with normal immune function who was diagnosed through next-generation sequencing (NGS).

CASE SUMMARY

A 23-year-old female who had no special disease in the past was admitted to the hospital with a persistent fever and cough. Based on the initial examination results, the patient was diagnosed with bipulmonary pneumonia, and empirical broad-spectrum antibiotic therapy was administered. However, due to the undetermined etiology, the patient's condition continued to worsen. She was transferred to the intensive care unit because of acute respiratory failure. After the diagnosis of Pneumocystis jirovecii infection through NGS in bronchoalveolar lavage fluid and treatment with trimethoprim/sulfamethoxazole and caspofungin, the patient gradually recovered and had a good prognosis.

CONCLUSION

This case emphasizes that, for patients with normal immune function the possibility of PCP infection, although rare, cannot be ignored. NGS plays an important role in the diagnosis of refractory interstitial pneumonia and acute respiratory failure.

How to diagnose and treat a non-HIV patient with Pneumocystis jirovecii pneumonia (PCP)?

BACKGROUND

Pneumocystis jirovecii Pneumonia (PCP) incidence is increasing in non-HIV infected patients. In contrast to PCP in patients infected with HIV, diagnosis is often delayed, and illness is associated with an increased mortality.

OBJECTIVE

To provide a comprehensive review of clinical presentation, risk factors, diagnostic strategies, and treatment options of PCP in non-HIV-infected patients.

SOURCES

Web-based literature review on PCP for trials, meta-analyses and systematic reviews using PubMed. Restriction to English language was applied.

CONTENT

Common underlying conditions in non-HIV-infected patients with PCP are haematological malignancies, autoimmune and inflammatory diseases, solid organ or haematopoietic stem cell transplant and prior exposure to corticosteroids. New risk groups include patients receiving monoclonal antibodies and immunomodulating therapies. Non-HIV-infected patients with PCP present with rapid onset and progression of pneumonia, increased duration of hospitalization and a significantly higher mortality rate than patients infected with HIV. PCP is diagnosed by a combination of clinical symptoms, radiological and mycological features. Immunofluorescence microscopy from bronchoalveolar lavage (BAL) or PCR testing CT imaging and evaluation of the clinical presentation are required. The established treatment regime consists of trimethoprim and sulfamethoxazole.

IMPLICATIONS

While the number of patients immunosuppressed for other causes than HIV is increasing, a simultaneous rise in PCP incidence is observed. In the group of non-HIV-infected patients, a rapid onset of symptoms, a more complex course, and a higher mortality rate are recorded. Therefore, time to diagnosis must be as short as possible to initiate effective therapy promptly. This review aims to raise awareness of PCP in an increasingly affected at-risk group and provide clinicians with a practical guide for efficient diagnosis and targeted therapy. Furthermore, it intends to display current inadequacies in research on the topic of PCP.

Pneumocystis jirovecii Pneumonia Diagnostic Approach: Real-Life Experience in a Tertiary Centre

Pneumocystis jirovecii pneumonia (PJP) in immunocompromised patients entails high mortality and requires adequate laboratory diagnosis. We compared the performance of a real time-PCR assay against the immunofluorescence assay (IFA) in the routine of a large microbiology laboratory. Different respiratory samples from HIV and non-HIV-infected patients were included. The retrospective analysis used data from September 2015 to April 2018, which included all samples for which a P. jirovecii test was requested. A total of 299 respiratory samples were tested (bronchoalveolar lavage fluid (n = 181), tracheal aspirate (n = 53) and sputum (n = 65)). Forty-eight (16.1%) patients fulfilled the criteria for PJP. Five positive samples (10%) had only colonization. The PCR test was found to have a sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 96%, 98%, 90% and 99%, compared to 27%, 100%, 100% and 87%, for the IFA, respectively. PJ-PCR sensitivity and specificity were >80% and >90% for all tested respiratory samples. Median cycle threshold values in definite PJP cases were 30 versus 37 in colonized cases (p < 0.05). Thus, the PCR assay is a robust and reliable test for the diagnosis PJP in all respiratory sample types. Ct values of ≥36 could help to exclude PJP diagnosis.

Impact of pneumocystosis on the Spanish health care system, 1997-2020: Profile of HIV and non-HIV immunocompromised patients

BACKGROUND

Pneumocystis jirovecii is an opportunistic fungus recognized for causing P. jirovecii pneumonia. The global prevalence is thought to be higher than 400,000 annual cases, although detailed information about epidemiological patterns is scarce.

METHODOLOGY

A retrospective longitudinal descriptive study was performed among patients with diagnosis of pneumocystosis according to Classification of Diseases 9th edition, Clinical Modification (code 136.3 for the cases from 1997 to 2015; and 10th edition code B59.0 for cases from 2016 to 2020 in Spanish public hospitals from 1 January 1997-31 December 2020.

RESULTS

A total of 25289 cases were diagnosed. The period incidence rate was 2.36 (95 % CI, 2.33-2.39) cases per 100,000 person-years. Infection was more frequent among men (72.2 %) than among women (27.8 %). Comorbidity was the main characteristic of this cohort. Up to 72.3 % of pneumocystis-infected patients (18293) had HIV coinfection. During the study period, there was a progressive decrease in the number of HIV coinfected cases as the group of patients without HIV infection increased, with the largest group in 2017. The lethality rate in the cohort was 16.7 %. The global cost was €229,234,805 and the average ( ± SD) cost per patient was €9065 ( ± 9315).

CONCLUSIONS

The epidemiology of pneumocystosis in Spain has changed in the last two decades. We noted in our study the possibility of a reemergence among non-HIV immunocompromised patients as patients with hematological and nonhematological neoplasia and other risk groups. The lethality of pneumocystosis continues to be high, and the underlying diseases are the main variable associated with lethality.

Schematic approach to the diagnosis of multifocal lung opacities in the emergency department

Radiologists in the emergency department must be prepared to deal with any type of disease in any organ at any time. Many entities involving the chest can result in patients' presenting at the emergency department. This chapter deals with entities that manifest with multifocal lung opacities and that can be mistaken for pneumonia. To facilitate their identification, this chapter approaches these entities by considering their most characteristic distribution on chest X-rays, the main diagnostic modality used for thoracic problems in the emergency department. Our schematic approach includes the key findings in patients' personal histories, clinical examination, laboratory tests, and imaging studies that can be available during the initial workup.

Clinical characteristics and risk factor analysis of Pneumocystis jirovecii pneumonia in patients with CKD: a machine learning-based approach

Patients with chronic kidney disease (CKD) who are being treated with immunosuppressive medications are at risk for developing Pneumocystis jirovecii pneumonia (PCP). We attempted to characterize the clinical aspects of PCP in CKD patients in order to alert high-risk patients with bad prognosis. A retrospective study of CKD patients was conducted from June 2018 to June 2022. Based on PCP diagnostic criteria, these patients were divided into PCP and non-PCP groups. Using univariate and multivariate logistic regression analysis, risk indicators were evaluated, and nomogram and decision tree were developed. Of the CKD patients screened for Pneumocystis carinii nucleic acid, 1512 were included. Two-hundred forty four (16.14%) were diagnosed with PCP. Of the PCP, 88.5% was receiving glucocorticoid (GC) therapy, of which 66.3% received more than 0.5 mg/kg GC. Multivariate analysis showed that membranous nephropathy (OR 2.35, 95% CI 1.45-3.80), immunosuppressive therapy (OR 1.94, 95% CI 1.06-3.69), and ground glass opacity of CT scanning (OR 1.71, 95% CI 1.10-2.65) were associated with increased risk of Pneumocystis carinii infection. The AUC of nomogram based on logistics regression was 0.78 (0.75-0.81). The mortality in patients with PCP was 32.40%. Univariate analysis and decision tree showed that pulmonary insufficiency (PO₂: OR 0.98, 95% CI 0.96-1.00), elevated APTT (OR 1.07, 95% CI 1.04-1.11), and reduced hemoglobin (OR 0.97, 95% CI 0.96-0.98) were associated with poor prognosis. PCP is not rare in CKD patients, particularly in those treated with immunosuppressive therapy. Considering the high mortality of the cases, further studies on the prevention and management of these patients are needed.

Opportunistic Infections Post-Lung Transplantation: Viral, Fungal, and Mycobacterial

Opportunistic infections are a leading cause of lung transplant recipient morbidity and mortality. Risk factors for infection include continuous exposure of the lung allograft to the external environment, high levels of immunosuppression, impaired mucociliary clearance and decreased cough reflex, and impact of the native lung microbiome in single lung transplant recipients. Infection risk is mitigated through careful pretransplant screening of recipients and donors, implementation of antimicrobial prophylaxis strategies, and routine surveillance posttransplant. This review describes common viral, fungal, and mycobacterial infectious after lung transplant and provides recommendations on prevention and treatment.