Rapid Diagnosis of Pneumocystis jirovecii Pneumonia and Respiratory Tract Colonization by Next-Generation Sequencing.

OBJECTIVES: To describe the epidemiology of Pneumocystis jirovecii pneumonia and colonization diagnosed by next-generation sequencing (NGS) and explore the usefulness of the number of P. jirovecii sequence reads for the diagnosis of P. jirovecii pneumonia. METHODS: We examined the NGS results for P. jirovecii in respiratory samples collected from patients and analysed their clinical, radiological and microbiological characteristics. RESULTS: Among 285 respiratory samples collected over a 12-month period (January to December 2022), P. jirovecii sequences were detected in 56 samples from 53 patients. Fifty (94.3%) of the 53 patients were HIV-negative. Following our case definitions, 37 (69.8%) and 16 (30.2%) of the 53 patients had P. jirovecii infection and colonization respectively. P. jirovecii infection was associated with presence of underlying disease with immunosuppression (94.6% vs 18.8%, P < 0.05), positive serum 1,3-ß-D-glucan (41.2% vs 0%, P < 0.01) and higher number of P. jirovecii sequence reads (P < 0.005). In contrast, P. jirovecii colonization was associated with the male sex (93.8% vs 54.1%, P < 0.01), another definitive infectious disease diagnosis of the respiratory tract (43.8% vs 2.7%, P < 0.001) and higher survival (100% vs 67.6%, P < 0.01). Although P. jirovecii pneumonia was associated with higher number of P. jirovecii reads in respiratory samples, only a sensitivity of 82.14% and a specificity of 68.75% could be achieved. CONCLUSION: Detection of P. jirovecii sequences in respiratory samples has to be interpreted discreetly. A combination of clinical, radiological and laboratory findings is still the most crucial in determining whether a particular case is genuine P. jirovecii pneumonia.

[Clinical features and death risk factors of pneumocystis jirovecii pneumonia in kidney disease patients with immunosuppressive therapy].

To investigate the clinical features and death risk factors of pneumocystis jirovecii pneumonia (PJP) in kidney disease patients with immunosuppressive patients. A Retrospective case series study was performed in 52 PJP patients with kidney disease who received immunosuppressive therapy in Nephrology or Respiratory department of Peking University First Hospital from January 1, 2006 to August 31, 2021. Patients were divided into survival group (36 cases) and death group (16 cases) according to their clinical outcomes. Univariate analysis was performed to compare the differences of clinical features between the two groups. Multivariate logistic regression model was used to analyze the death risk factors. The results showed that the median serum creatinine was 192.5 (109.8, 293.7) µmol/L, and the incidence of acute kidney injury was 63.5% (33/52). Univariate analysis showed that age (t=1.197,P=0.030), C-reactive protein level (t=2.378,P=0.022), time from onset to diagnosis (χ2=6.62,P=0.010), PJP severity (χ2=5.482,P=0.019), complicated with septic shock (χ2=3.997,P=0.046), mechanical ventilation (χ2=11.755,P=0.001), and blood purification therapy (χ2=4.748,P=0.029) were statistically significant. There were no statistically significant differences between the two groups in gender, duration and dosage of hormone therapy before PJP onset, intravenous methylprednisolone pulse therapy, immunosuppressant use, and serum creatinine level before and after hospitalization for anti-PJP treatment (all P>0.05). Multivariate analysis showed that the time from onset to diagnosis of PJP was >10 days (OR=40.945, 95%CI: 1.738-451.214; P=0.021) and severe PJP (OR=25.502, 95%CI: 1.426-74.806; P=0.028) was an independent death risk factor for kidney disease complicated with PJP of immunosuppressive therapy. In conclusion, the time from onset to diagnosis of PJP and PJP severity are independent death risk factors in patients with kidney disease complicated with PJP of immunosuppressive therapy. Close attention should be paid to oxygenation condition and early diagnosis can prevent the aggravation of PJP and improve the 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.

Risk factors for Pneumocystis jirovecii pneumonia after kidney transplantation: A systematic review and meta-analysis.

BACKGROUND AND OBJECTIVE: Pneumocystis jirovecii pneumonia (PJP), an opportunistic infection, often leads to an increase in hospitalization time and mortality rates in kidney transplant (KT) recipients. However, the risk factors associated with PJP in KT recipients remain debatable. Therefore, we conducted this meta-analysis to identify risk factors for PJP, which could potentially help to reduce PJP incidence and improve outcome of KT recipients. METHODS: We systematically retrieved relevant studies in PubMed, EMBASE, and the Cochrane Library up to November 2023. Pooled odds ratios (ORs) or mean differences (MDs) and the corresponding 95% confidence intervals (CIs) were calculated to assess the impact of potential risk factors on the occurrence of PJP. RESULTS: 27 studies including 42383 KT recipients were included. In this meta-analysis, age at transplantation (MD = 3.48; 95% CI = .56-6.41; p = .02), cytomegalovirus (CMV) infection (OR = 4.00; 95% CI = 2.53-6.32; p = .001), BK viremia (OR = 3.38; 95% CI = 1.70-6.71; p = .001), acute rejection (OR = 3.66; 95% CI = 2.44-5.49; p = .001), ABO-incompatibility (OR = 2.51; 95% CI = 1.57-4.01; p = .001), estimated glomerular filtration rate (eGFR) (MD = -14.52; 95% CI = -25.37- (-3.67); p = .009), lymphocyte count (MD = -.54; 95% CI = -.92- (-.16); p = .006) and anti-PJP prophylaxis (OR = .53; 95% CI = .28-.98; p = .04) were significantly associated with PJP occurrence. CONCLUSION: Our findings suggest that transplantation age greater than 50 years old, CMV infection, BK viremia, acute rejection, ABO-incompatibility, decreased eGFR and lymphopenia were risk factors for PJP.

Predictive models-assisted diagnosis of AIDS-associated Pneumocystis jirovecii pneumonia in the emergency room, based on clinical, laboratory, and radiological data.

We assessed predictive models (PMs) for diagnosing Pneumocystis jirovecii pneumonia (PCP) in AIDS patients seen in the emergency room (ER), aiming to guide empirical treatment decisions. Data from suspected PCP cases among AIDS patients were gathered prospectively at a reference hospital's ER, with diagnoses later confirmed through sputum PCR analysis. We compared clinical, laboratory, and radiological data between PCP and non-PCP groups, using the Boruta algorithm to confirm significant differences. We evaluated ten PMs tailored for various ERs resource levels to diagnose PCP. Four scenarios were created, two based on X-ray findings (diffuse interstitial infiltrate) and two on CT scans ("ground-glass"), incorporating mandatory variables: lactate dehydrogenase, O2sat, C-reactive protein, respiratory rate (> 24 bpm), and dry cough. We also assessed HIV viral load and CD4 cell count. Among the 86 patients in the study, each model considered either 6 or 8 parameters, depending on the scenario. Many models performed well, with accuracy, precision, recall, and AUC scores > 0.8. Notably, nearest neighbor and naïve Bayes excelled (scores > 0.9) in specific scenarios. Surprisingly, HIV viral load and CD4 cell count did not improve model performance. In conclusion, ER-based PMs using readily available data can significantly aid PCP treatment decisions in AIDS patients.

Protocol for the systematic review of the Pneumocystis jirovecii-associated pneumonia in non-HIV immunocompromised patients.

INTRODUCTION: Pneumocystis jirovecii pneumonia (PJP) is a well-known and frequent opportunistic infection in HIV patients. However, there has been an increase in the number of reports of PJP in other immunosuppressed patients with autoimmune inflammatory disorders or because of chemotherapy and high doses of steroids, especially when used in combination as part of immunosuppressive therapy. OBJECTIVE: Despite the increasing importance of PJP in non-HIV patients, there is a lack of comprehensive and updated information on the epidemiology, pathogenesis, diagnosis, microbiology, treatments, and prophylaxis of this infection in this population. Therefore, the objective of this systematic review is to synthesize information on these aspects, from a perspective of evidence-based medicine. METHODS: The protocol is prepared following the preferred reporting items for systematic reviews and meta-analyses (PRISMA-P) guidelines. We will perform a systematic review of literature published between January 2010 and July 2023, using the databases PubMed, Google Scholar, ScienceDirect, and Web of Science. In addition, manual searches will be carried out through related articles, and references to included articles. The main findings and clinical outcomes were extracted from all the eligible studies with a standardized instrument. Two authors will independently screen titles and abstracts, review full texts, and collect data. Disagreements will be resolved by discussion, and a third reviewer will decide if there is no consensus. We will synthesize the results using a narrative or a meta-analytic approach, depending on the heterogeneity of the studies. EXPECTED RESULTS: It is expected that this systematic review will provide a comprehensive and up-to-date overview of the state-of-the-art of PJP in non-HIV patients. Furthermore, the study will highlight possible gaps in knowledge that should be addressed through new research. CONCLUSIONS: Here, we present the protocol for a systematic review which will consider all existing evidence from peer-reviewed publication sources relevant to the primary and secondary outcomes related to diagnosing and managing PJP in non-HIV patients.

A retrospective study of intravenous pentamidine for Pneumocystis jirovecii pneumonia prophylaxis in adult patients with hematologic malignancies-its utility during respiratory virus pandemics.

OBJECTIVES: In hematology, prophylaxis for Pneumocystis jirovecii pneumonia (PCP) is recommended for patients undergoing hematopoietic stem cell transplantation and in selected categories of intensive chemotherapy for hematologic malignancies. Trimethoprim-sulfamethoxazole (TMP-SMX) is the recommended first-line agent; however, its use is not straightforward. Inhaled pentamidine is the recommended second-line agent; however, aerosolized medications were discouraged during respiratory virus outbreaks, especially during the COVID-19 pandemic, in view of potential contamination risks. Intravenous (IV) pentamidine is a potential alternative agent. We evaluated the effectiveness and tolerability of IV pentamidine use for PCP prophylaxis in adult allogeneic hematopoietic stem cell transplantation recipients and patients with hematologic malignancies during COVID-19. RESULTS: A total of 202 unique patients who received 239 courses of IV pentamidine, with a median of three doses received (1-29). The largest group of the patients (49.5%) who received IV pentamidine were undergoing or had received a hematopoietic stem cell transplant. The most common reason for not using TMP-SMX prophylaxis was cytopenia (34.7%). We have no patients who had breakthrough PCP infection while on IV pentamidine. None of the patients developed an infusion reaction or experienced adverse effects from IV pentamidine. CONCLUSIONS: Pentamidine administered IV monthly is safe and effective.

A case of hypercalcemia from Pneumocystis jirovecii in an immunosuppressed non-HIV patient.

BACKGROUND: The prevalence of non-HIV related Pneumocystis jirovecii pneumonia (PJP) is increasing with use of immunosuppressive therapies. There are case reports of solid organ transplant recipients on immunosuppressive therapy presenting with mild hypercalcemia, leading to a diagnosis of PJP. Recent studies have shown efficacy of PJP prophylaxis for patients treated with rituximab with a favourable adverse effect profile. CASE PRESENTATION: A 78-year-old male with a history of PR3-ANCA vasculitis, chronic kidney disease and heart failure with reduced ejection fraction presented to our tertiary care hospital with a two-week history of confusion and non-productive cough. Background immunosuppression with rituximab was completed every six months. The patient was found to have hypercalcemia and new infiltrates and ground glass opacities on cross-sectional imaging. Bronchoscopy was performed that was positive for Pneumocystis jirovecii. He was treated with 21 days of trimethoprim-sulfamethoxazole and prednisone with resolution of symptoms and hypercalcemia. CONCLUSIONS: Herein, we present a novel case of PJP in a non-transplant recipient preceded by hypercalcemia. Our case demonstrates the importance for a high suspicion for PJP in chronically immunosuppressed patients on rituximab presenting with PTH-independent hypercalcemia.

Fungal microbiota in newborn infants with and without respiratory distress syndrome.

BACKGROUND: Pneumocytis jirovecii infection in preterm newborns has recently been associated with neonatal respiratory distress syndrome and bronchopulmonary dysplasia. Changes in the bacterial microbiota of the airways have also been described in infants with bronchopulmonary dysplasia. However, until now there has been no information on the airway mycobiota in newborns. The purpose of this study was to describe the airway mycobiota in term and preterm newborns and its possible association with respiratory distress syndrome. METHODS: Twenty-six matched preterm newborns with and without respiratory distress syndrome were studied, as well as 13 term babies. The identification of the fungal microbiota was carried out using molecular procedures in aspirated nasal samples at birth. RESULTS: The ascomycota phylum was identified in 89.7% of newborns, while the basidiomycota phylum was found in 33.3%. Cladosporium was the predominant genus in both term and preterm infants 38.4% vs. 73% without statistical differences. Candida sake and Pneumocystis jirovecii were only found in preterm infants, suggesting a potential relationship with the risk of prematurity. CONCLUSIONS: This is the first report to describe the fungal microbiota of the airways in term and preterm infants with and without respiratory distress syndrome. Although no differences have been observed, the number of cases analyzed could be small to obtain conclusive results, and more studies are needed to understand the role of the fungal microbiota of the airways in neonatal respiratory pathology.

Diagnosis model of early Pneumocystis jirovecii pneumonia based on convolutional neural network: a comparison with traditional PCR diagnostic method.

BACKGROUND: Pneumocystis jirovecii pneumonia (PJP) is an interstitial pneumonia caused by pneumocystis jirovecii (PJ). The diagnosis of PJP primarily relies on the detection of the pathogen from lower respiratory tract specimens. However, it faces challenges such as difficulty in obtaining specimens and low detection rates. In the clinical diagnosis process, it is necessary to combine clinical symptoms, serological test results, chest Computed tomography (CT) images, molecular biology techniques, and metagenomics next-generation sequencing (mNGS) for comprehensive analysis. PURPOSE: This study aims to overcome the limitations of traditional PJP diagnosis methods and develop a non-invasive, efficient, and accurate diagnostic approach for PJP. By using this method, patients can receive early diagnosis and treatment, effectively improving their prognosis. METHODS: We constructed an intelligent diagnostic model for PJP based on the different Convolutional Neural Networks. Firstly, we used the Convolutional Neural Network to extract CT image features from patients. Then, we fused the CT image features with clinical information features using a feature fusion function. Finally, the fused features were input into the classification network to obtain the patient's diagnosis result. RESULTS: In this study, for the diagnosis of PJP, the accuracy of the traditional PCR diagnostic method is 77.58%, while the mean accuracy of the optimal diagnostic model based on convolutional neural networks is 88.90%. CONCLUSION: The accuracy of the diagnostic method proposed in this paper is 11.32% higher than that of the traditional PCR diagnostic method. The method proposed in this paper is an efficient, accurate, and non-invasive early diagnosis approach for PJP.

Evaluation of analyte-specific reagents for the direct detection of Pneumocystis jirovecii.

Pneumocystis jirovecii pneumonia (PJP) is a serious and sometimes fatal infection occurring in immunocompromised individuals. High-risk patients include those with low CD4 counts due to human immunodeficiency virus infection and transplant recipients. The incidence of PJP is increasing, and rapid detection of PJP is needed to effectively target treatment and improve patient outcomes. A common method used is an immunofluorescent assay (IFA), which has limitations, including labor costs, low sensitivity, and requirement for expert interpretation. This study evaluates the performance of the DiaSorin Molecular Pneumocystis jirovecii analyte-specific reagent (ASR) in a laboratory-developed test (LDT) for the direct detection of P. jirovecii DNA without prior nucleic acid extraction. Respiratory samples (n = 135) previously tested by IFA from 111 patients were included. Using a composite standard of in-house IFA and reference lab PJP PCR, the percent positive agreement for the LDT using the DiaSorin ASR was 97.8% (90/92). The negative percent agreement was 97.7% (42/43). The lower limit of detection of the assay was determined to be 1,200 copies/mL in bronchoalveolar lavage fluid. Analytical specificity was assessed using cultures of oropharyngeal flora and common respiratory bacterial and fungal pathogens. No cross-reactivity was observed. Our study suggests that the DiaSorin Pneumocystis ASR accurately detects P. jirovecii DNA and demonstrates improved sensitivity compared to the IFA method. IMPORTANCE: Our study is unique compared to other previously published studies on the DiaSorin analyte-specific reagent (ASR) because we focused on microbiological diagnostic methods commonly used (immunofluorescent assay) as opposed to pathology findings or reference PCR. In addition, in our materials and methods, we describe the protocol for the use of the DiaSorin ASR as a singleplex assay, which will allow other users to evaluate the ASR for clinical use in their lab.

Myelotoxicity and kidney dysfunction related to the use of trimethoprim-sulfamethoxazole for the treatment of Pneumocystis jirovecii pneumonia: a case report of severe adverse events with a common drug.

Trimethoprim-sulfamethoxazole (TMP-SMX) is the primary therapeutic option for Pneumocystis jirovecii pneumonia (PCP). Gastrointestinal symptoms and cutaneous rash are common side effects, with hyperkalemia being uncommon in patients without kidney dysfunction, and myelotoxicity being even rarer. We present the case of a male patient with hypertension and a recent diagnosis of non-Hodgkin lymphoma, undergoing rituximab treatment for two months. He was admitted to the intensive care unit due to dyspnea, tachypnea, and pleuritic pain, requiring mechanical ventilation. Chest computed tomography showed bilateral and multilobed ground-glass opacities, compromising more than 80% of the lung parenchyma. Pulmonary tuberculosis and COVID-19 were ruled out. An angiotomography and Doppler ultrasound revealed an extensive pulmonary thrombus and deep venous thrombosis. Empiric treatment with TMP-SMX for PCP was initiated, but within four days, the patient experienced metabolic acidosis and severe hyperkalemia, necessitating hemodialysis. He also presented with progressive pancytopenia and critical levels of leukopenia and thrombocytopenia. The hypothesis of TMP-SMX-induced myelotoxicity was suspected. Considering the unavailability of an alternative treatment, it was opted to continue TMP-SMX and initiate a granulocyte-colony-stimulating factor. However, the patient maintained medullary deterioration, becoming refractory to the transfusion of blood derivates. On the 17th day of treatment, a clinical decision was made to suspend TMP-SMX, leading to improvements within 48 hours in marrow and kidney functions, metabolic acidosis, and hyperkalemia. Despite all efforts, the patient died after 35 days of hospitalization due to hospital-acquired infections. This case highlights the importance of clinicians recognizing potential myelotoxicity with TMP-SMX and promptly discontinuing the drug if necessary.

Alterations of lung microbiota in lung transplant recipients with pneumocystis jirovecii pneumonia.

BACKGROUND: Increasing evidence revealed that lung microbiota dysbiosis was associated with pulmonary infection in lung transplant recipients (LTRs). Pneumocystis jirovecii (P. jirovecii) is an opportunistic fungal pathogen that frequently causes lethal pneumonia in LTRs. However, the lung microbiota in LTRs with P. jirovecii pneumonia (PJP) remains unknow. METHODS: In this prospective observational study, we performed metagenomic next-generation sequencing (mNGS) on 72 bronchoalveolar lavage fluid (BALF) samples from 61 LTRs (20 with PJP, 22 with PJC, 19 time-matched stable LTRs, and 11 from LTRs after PJP recovery). We compared the lung microbiota composition of LTRs with and without P. jirovecii, and analyzed the related clinical variables. RESULTS: BALFs collected at the episode of PJP showed a more discrete distribution with a lower species diversity, and microbiota composition differed significantly compared to P. jirovecii colonization (PJC) and control group. Human gammaherpesvirus 4, Phreatobacter oligotrophus, and Pseudomonas balearica were the differential microbiota species between the PJP and the other two groups. The network analysis revealed that most species had a positive correlation, while P. jirovecii was correlated negatively with 10 species including Acinetobacter venetianus, Pseudomonas guariconensis, Paracandidimonas soli, Acinetobacter colistiniresistens, and Castellaniella defragrans, which were enriched in the control group. The microbiota composition and diversity of BALF after PJP recovery were also different from the PJP and control groups, while the main components of the PJP recovery similar to control group. Clinical variables including age, creatinine, total protein, albumin, IgG, neutrophil, lymphocyte, CD3+CD45+, CD3+CD4+ and CD3+CD8+ T cells were deeply implicated in the alterations of lung microbiota in LTRs. CONCLUSIONS: This study suggests that LTRs with PJP had altered lung microbiota compared to PJC, control, and after recovery groups. Furthermore, lung microbiota is related to age, renal function, nutritional and immune status in LTRs.

Evaluation of effectiveness, hyperkalaemia, and hepatotoxicity of trimethoprim-sulphamethoxazole prophylaxis for Pneumocystis jirovecii pneumonia in paediatric patients: A single-centre retrospective study.

BACKGROUND: American guidelines recommend trimethoprim-sulphamethoxazole (TMP-SMX) for preventing Pneumocystis jirovecii pneumonia (PJP) in paediatric patients at doses of 5-10 mg/kg/d of the TMP component, administered either daily, three times weekly, or twice weekly. However, limited studies describe the effectiveness and safety of these prophylactic regimens. Our study aimed to assess the clinical effectiveness and incidence of adverse events associated with each TMP-SMX regimen in paediatric patients, and to identify risk factors for adverse events. METHODS: We collected data regarding the onset of PJP, hyperkalaemia, and hepatotoxicity in patients aged 0-18 years who underwent prophylaxis with TMP-SMX from July 2018 to June 2023. RESULTS: A total of 215 paediatric patients met the inclusion criteria. No patients developed PJP. Hyperkalaemia occurred in 14.7%, patients receiving TMP-SMX daily, 15.4% receiving it three times weekly, and 15.5% receiving it twice weekly. Hepatotoxicity was most frequent in patients receiving TMP-SMX twice weekly (19%), followed by those receiving it three times weekly (7.7%), and daily (5.9%). Younger patients were significantly more prone to developing hyperkalaemia or hepatotoxicity. Patients aged <1 year had the highest incidences of hyperkalaemia (56.5%), and those aged 1-2 years had the highest incidence of hepatotoxicity (25%). CONCLUSIONS: No patient developed PJP under various dosage prophylactic regimens of TMP-SMX. However, our findings suggest the need to monitor potassium levels and hepatic function in patients undergoing any of the three TMP-SMX regimens. In particular, patients aged <1 year old and 1-2 years old face a higher risk of hyperkalaemia and hepatotoxicity, respectively.

Effect of Pneumocystis jirovecii pneumonia prophylaxis on hematologic toxicity in patients receiving chemoradiation for primary brain tumors.

PURPOSE: Diffuse gliomas are managed with radiation and temozolomide; however, this therapy often results in hematologic toxicities. Patients undergoing chemoradiation also risk contracting Pneumocystis jirovecii pneumonia (PJP), and frequently receive prophylaxis against PJP during treatment. Independent of chemoradiation, some PJP prophylaxis drugs have the potential to cause myelosuppression, which could require cessation of chemotherapy. Here, we evaluate differences in the frequency of hematologic toxicities during chemoradiation when patients receive PJP prophylaxis. METHODS: This retrospective chart review evaluated patients with primary brain tumors treated with radiation and concurrent temozolomide. Analyses were performed to assess the effect of the type of PJP prophylaxis on risk for neutropenia, lymphopenia, or thrombocytopenia and the severity of these adverse effects as defined using the Common Terminology Criteria for Adverse Events. RESULTS: Of the 217 patients included in this analysis, 144 received trimethoprim-sulfamethoxazole (TMP/SMX) and 69 received pentamidine. Of the patients who received TMP/SMX, 15.3% developed an absolute neutrophil count < 1500 cells/µL compared with 7.2% of patients receiving pentamidine (p = 0.10). Platelet count < 100,000/µL occurred in 18.1% of patients who received TMP/SMX and 20.3% of patients who received pentamidine (p = 0.70). No significant differences in lymphocyte counts between therapies were seen. Severity of hematologic toxicities were similar between PJP prophylaxis groups. CONCLUSION: These findings suggest that the type of PJP prophylaxis does not significantly affect the risk for hematologic toxicity in brain tumor patients receiving radiation and temozolomide. Additional studies are merited to evaluate the higher rate of neutropenia in patients on TMP/SMX observed in this study.

A Case Report of Primaquine Associated Methemoglobinemia in a Man With Pneumocystis Jirovecii Pneumonia Following Cardiac and Renal Transplantation.

We describe the case of a 51-year-old Caucasian man with a background of a cardiac and renal transplant who developed Enterocytozoon bieneusi colitis and pneumocystis jirovecii (PJP) pneumonia following treatment for suspected rejection. The patient developed methemoglobinemia which was attributed to primaquine. He was treated with intravenous methylene blue leading to clinical and biochemical resolution. We describe in detail the pathophysiological mechanism for methemoglobinemia and its treatment, in particular with methylene blue.

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.

CMV Infection and Lymphopenia: Warning Markers of Pneumocystis Pneumonia in Kidney Transplant Recipients.

Pneumocystis pneumonia (PcP) remains life-threatening in kidney transplant recipients (KTR). Our study investigated risk factors one-year before PcP. We conducted a monocentric, case-control study including all KTR at the Dijon University Hospital (France) with a diagnosis of PcP between 2005 and 2022 (cases), and matched control KTR with no history of PcP (3 controls/case). Among all 1,135 KTR, 57 cases (5%) and 169 matched-controls were included. PcP was associated with 18% mortality. Compared to controls, cases were older, with a higher immunological risk, and CMV infection was more frequent in the year preceding the occurrence of PcP (23% vs. 4%; p < 0.001). As early as 1 year before PcP, lymphocyte counts were lower and serum creatinine levels were higher in cases, but immunosuppressive regimens were not significantly different. Multivariable analysis identified lymphocyte count, serum creatinine level, being treated by immunosuppressive therapy other than anti-rejection drugs, and CMV infection in the year preceding the time PcP as independently associated with the occurrence of PcP. PcP was associated with an increased risk of subsequent chronic rejection (27% vs. 3%; p = 0.001) and return to dialysis (20% vs. 3%; p = 0.002). The occurrence of CMV infection and a low lymphocyte count could redefine the indications for continuation or reinitiation of anti-Pneumocystis prophylaxis.

Pneumocystis jirovecii pneumonia: a case report.

INTRODUCTION AND IMPORTANCE: Pneumocystis jirovecii (PJP) pneumonia is a serious life-threatening condition in immunocompromised individuals and is often associated with human immunodeficiency virus (HIV) + patients. We describe a case of PJP pneumonia which provided a diagnostic challenge in a patient who presented with no known risk factors leading to a delay in initiation of appropriate antibiotic therapy. CASE PRESENTATION: A 71-year-old previously healthy white/Caucasian male presented with subacute hypoxic respiratory failure due to multifocal pneumonia with diffuse bilateral ground glass opacities with consolidations despite prior treatment with antibiotics and steroids. He was admitted and started on intravenous broad-spectrum antibiotics but continued to deteriorate, eventually requiring intubation and transfer to the ICU. Bronchoscopy revealed PJP and treatment was initiated, but the patient developed refractory shock and multiorgan failure, and ultimately died. It was later discovered that he was HIV-1 positive. CLINICAL DISCUSSION: PJP, as a potential cause of his presentation, was not considered given that our patient lacked any overt risk factors for PJP pneumonia. He continued to worsen despite broad spectrum antibiotic therapy and hence bronchoscopy was pursued. His clinical profile, in hindsight, was suspicious for PJP pneumonia and early PJP-directed antibiotic therapy may have prevented a fatal outcome, as in this case. There was an element of cognitive bias across multiple providers which may have contributed to the delay in treatment despite his rapid clinical decline while on conventional pneumonia treatment protocol. His diagnosis was later evident when his BAL-DFA grew PJP in addition to his low levels of CD4 and CD8 cells. He was found to be HIV-1 positive five days after his death; there was a delay in this diagnosis since all positive HIV tests from the hospital are reported as 'pending' until the presumptive positive sample goes to the Connecticut Department of Public Health State laboratory for the confirmatory test. PJP-targeted therapies were initiated later in our patient's hospital course when the infection had progressed to refractory septic shock with multiorgan failure and eventual death. CONCLUSION: PJP pneumonia is a fatal disease if not recognized early in the course of illness, and the patient usually undergoes multiple antibiotic regimens before they are diagnosed and receive appropriate clinical care. The gold standard of diagnostic testing for PJP is by obtaining bronchial washings through a flexible bronchoscopy and the turnaround time for such results may take a few days to result. A significant proportion of patients may not have any overt risk factors of immunosuppression and early empiric treatment for PJP may be clinically appropriate as the delay in diagnosis may be associated with significant morbidity and mortality risk.

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.