The role of CD4 cell count as discriminatory measure to guide chemoprophylaxis against Pneumocystis jirovecii pneumonia in human immunodeficiency virus-negative immunocompromised patients: A systematic review

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.

Analysis of Mutations in Pneumocystis jirovecii Dihydropteroate Synthase and Dihydropteroate Reductase Genes Among Non-HIV Patients in China

Purpose

Pneumocystis jirovecii pneumonia (PJP) shows a high fatality rate in non-HIV patients. However, there are limited data on P. jirovecii drug resistance-related gene mutations in these patients. This study aimed to describe the prevalence of mutations in the dihydrofolate reductase (DHFR) and dihydropteroate synthase (DHPS) genes of P. jirovecii in non-HIV patients in China, providing a reference for drug usage.

Methods

We analyzed the polymorphisms of DHPS and DHFR genes from 45 non-HIV patients in China, including P. jirovecii infection (n = 14) and P. jirovecii colonization (n = 31). This analysis also considered clinical characteristics, P. jirovecii burden, treatment response, and prognosis.

Results

Compared to the P. jirovecii colonization, P. jirovecii infection had significantly altered blood indicators (GR%, LY%, HGB, TP, ALB, CRP, P<0.05) with higher P. jirovecii burden (P<0.05) and worse prognosis (P<0.05). Additionally, patients with P. jirovecii infection were more susceptible to infections, such as the Epstein-Barr virus, Cytomegalovirus, Mycoplasma and Klebsiella pneumoniae. Although no known drug-resistance mutations were detected in the DHPS gene in this study, 10 nonsynonymous mutations were identified. Furthermore, 10 nonsynonymous and 2 synonymous mutations were found in the DHFR gene. However, these mutations were not associated with a worse prognosis.

Conclusion

Our results implied that TMP-SMX prophylaxis is still recommended for PJP in high-risk non-HIV patients in China.

High prevalence of pneumocystis pneumonia in interstitial lung disease: a retrospective study

BACKGROUND

Interstitial lung disease (ILD) is a new risk category for pneumocystis pneumonia (PCP) with a high mortality rate. The definite diagnostic criteria of PCP in ILD patients have not been established until now. The aims of this study were to identify potential risk factors of PCP in patients with ILD, and to evaluate the performance of metagenomic next-generation sequencing (mNGS), CD4 + T cell count, (1-3)-β-D-Glucan (BG) and lactate dehydrogenase (LDH) in the diagnosis of PCP in ILD patients.

METHODS

This is a retrospective, single-center, case-control study. ILD patients who underwent mNGS from December 2018 to December 2022 were included in the study. Based on the diagnosis criteria of PCP, these patients were divided into PCP-ILD and non-PCP-ILD groups. The potential risk factors for PCP occurrence in ILD patients were analysed via logistic regression. The diagnostic efficacy of mNGS was compared with serological biomarkers.

RESULTS

92 patients with ILD were enrolled, 31 of which had a definite PCP and were assigned to the PCP-ILD group while 61 were to the non-PCP-ILD group. The infection rate of PJ in ILD patients was 33.7% (31/92). The history of glucocorticoid therapy, CD4 + T cell count, BG level and traction bronchiectasis on HRCT were associated with PCP occurrence in ILD patients. LDH level did not reach statistical significance in the logistic regression analysis. mNGS was confirmed as the most accurate test for PCP diagnosis in ILD patients.

CONCLUSION

ILD is a new risk group of PCP with high PCP prevalence. Clinicians should pay close attention to the occurrence of PCP in ILD patients who possess the risk factors of previous glucocorticoid therapy, decreased CD4 + T cell count, increased BG level and absence of traction bronchiectasis on HRCT. mNGS showed the most excellent performance for PCP diagnosis in ILD patients. Peripheral blood CD4 + T cell count and BG level are alternative diagnostic methods for PCP in ILD patients. However, the diagnostic value of serum LDH level was limited in ILD patients.

Unintended Consequences: Risk of Opportunistic Infections Associated With Long-term Glucocorticoid Therapies in Adults

Glucocorticoids are widespread anti-inflammatory medications used in medical practice. The immunosuppressive effects of systemic glucocorticoids and increased susceptibility to infections are widely appreciated. However, the dose-dependent model frequently used may not accurately predict the risk of infection in all patients treated with long-term glucocorticoids. In this review, we examine the risks of opportunistic infections (OIs) in patients requiring glucocorticoid therapy by evaluating the influence of the glucocorticoid dose, duration, and potency, combined with biological and host clinical factors and concomitant immunosuppressive therapy. We propose strategies to prevent OIs, which involve screening, antimicrobial prophylaxis, and immunizations. While this review focuses on patients with autoimmune, inflammatory, or neoplastic diseases, the potential risks and preventative strategies are likely applicable to other populations. Clinicians should actively assess the benefit-harm ratios of systemic glucocorticoids and implement preventive efforts to decrease their associated infections complications.

Dismal prognosis of Pneumocystis jirovecii pneumonia in patients with multiple myeloma

Patients with multiple myeloma (MM) are at high risk for infections, including opportunistic infections such as Pneumocystis jirovecii pneumonia (PJP). We conducted a retrospective analysis of patients with MM developing PJP over a 6-year period between January 2016 and December 2021 at the University Hospital of Würzburg by screening cases of microbiologically documented PJP. A total of 201 positive results for P. jirovecii in respiratory specimens were retrospectively retrieved through our microbiology database. Of these cases, 13 patients with MM fulfilled the definition of probable PJP according to EORTC fungal disease definitions. We observed two peaks in PJP incidence, one after stem cell transplantation during first-line treatment (n = 5) and the other in heavily pretreated patients with six or more prior lines of therapy (n = 6). There was high morbidity with nine (69%) patients admitted to the ICU, seven of whom (78%) required mechanical ventilation, and high mortality (62%, n = 8). Notably, only two of the 13 patients (15%) had received PJP prophylaxis. The main reason for discontinuation of prophylaxis with trimethoprim-sulfamethoxazole was grade IV neutropenia. The observed morbidity and mortality of PJP in MM patients are significant and even higher than reported for patients with other hematologic malignancies. According to most current guidelines, the use of prophylaxis would have been clearly recommended in no more than three (23%) of the 13 patients. This illustrates the need to critically reconsider the indications for PJP prophylaxis, which remain incompletely defined.

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.

[Diagnosis and therapy of granulomatosis with polyangiitis and microscopic polyangiitis-2023: consensus of the Austrian society of nephrology (ÖGN) and Austrian society of rheumatology (ÖGR)]

ANCA-associated vasculitides (AAV) are rare, complex systemic diseases that are often difficult to diagnose, because of unspecific clinical symptoms at presentation. However, the clinical course may be very dramatic and even life-threatening, necessitating prompt diagnosis and treatment.Therefore, it is important to increase disease awareness among physicians and support colleagues who are not confronted with these rare diseases on a regular basis. Here, the Austrian Society of Nephrology (ÖGN) and the Austrian Society of Rheumatology (ÖGR) provide a joint consensus on how to best diagnose and manage patients with granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA).

Risk factors associated with Pneumocystis jirovecii pneumonia in non-HIV immunocompromised patients and co-pathogens analysis by metagenomic next-generation sequencing

BACKGROUND

Pneumocystis jirovecii pneumonia (PJP) is one of the most common opportunistic infections in immunocompromised patients. However, the accurate prediction of the development of PJP in non-HIV immunocompromised patients is still unclear.

METHODS

Non-HIV immunocompromised patients confirmed diagnosis of PJP by the clinical symptoms, chest computed tomography and etiological results of metagenomic next-generation sequencing (mNGS) were enrolled as observation group. Another group of matched non-HIV immunocompromised patients with non-PJP pneumonia were enrolled to control group. The risk factors for the development of PJP and the co-pathogens in the bronchoalveolar lavage fluid (BALF) detected by mNGS were analyzed.  RESULTS: A total of 67 (33 PJP, 34 non-PJP) participants were enrolled from Fujian Provincial Hospital. The ages, males and underlying illnesses were not significantly different between the two groups. Compared to non-PJP patients, PJP patients were more tends to have the symptoms of fever and dyspnea. The LYM and ALB were significantly lower in PJP patients than in non-PJP patients. Conversely, LDH and serum BDG in PJP patients were significantly higher than in non-PJP controls. For immunological indicators, the levels of immunoglobulin A, G, M and complement C3, C4, the numbers of T, B, and NK cells, had no statistical difference between these two groups. Logistic multivariate analysis showed that concomitant use of corticosteroids and immunosuppressant (OR 14.146, P = 0.004) and the lymphocyte counts < 0.7 × 10⁹/L (OR 6.882, P = 0.011) were risk factors for the development of PJP in non-HIV immunocompromised patients. 81.82% (27/33) and 64.71% (22/34) mixed infections were identified by mNGS in the PJP group and non-PJP group separately. CMV, EBV and Candida were the leading co-pathogens in PJP patients. The percentages of CMV and EBV identified by mNGS in PJP group were significantly higher than those in the control group(p < 0.005).  CONCLUSIONS: Clinicians should pay close attention to the development of PJP in non-HIV immunocompromised patients who possess the risk factors of concomitant use of corticosteroids and immunosuppressant and the lymphocyte counts < 0.7 × 10⁹/L. Prophylaxis for PJP cannot rely solely on CD4⁺ T counts in non-HIV immunocompromised patients. Whether CMV infection increases the risk of PJP remains to be further investigated.

Pneumocystis pneumonia in patients with Cushing's syndrome: A French multicenter retrospective study

OBJECTIVE

Pneumocystis pneumonia (PcP) is an opportunistic infection occurring in immunocompromised patients. Cushing's syndrome (CS) impairs the immune system, and several authors have reported PcP in patients with CS. The present study aimed to characterize PcP occurring in a CS context and its management in French tertiary centers, in order to highlight the similarities in clinical presentation and treatment according to whether prophylaxis is implemented or not.

METHODS

This was a multicenter retrospective study conducted in several French University Hospitals and Cancer Centers. Patients with PcP and confirmed CS regardless of etiology were included. We excluded patients with other known causes of acquired immunodeficiency with increased risk of PcP.

RESULTS

Twenty-five patients were included. CS etiology was neoplastic in 84.0% of cases. CS clinical presentation associated predominant catabolic signs (76.0%), hypokalemia (91.7%) and lymphopenia (89.5%). CS was intense in most patients, with mean plasma cortisol levels at diagnosis of 2.424±1.102nmol/L and urinary free cortisol>10× the upper limit of normal in 85.0%. In all patients, PcP onset followed introduction of cortisol blockers, at a median 5.5 days. Patients were treated with 1 to 3 cortisol blockers, mainly metyrapone (88%), which significatively lowered plasma cortisol levels to 667±541nmol/L at the onset of PcP (P<0.001). PcP occurred in 7 patients despite prophylaxis. Finally, 60.0% patients were admitted to intensive care, and 20.0% died of PcP.

CONCLUSION

High mortality in patients with PcP implies that clinicians should be better informed about this rare infectious complication. Prophylaxis remains controversial, requiring comparative studies.

Previous corticosteroid exposure associates with an increased Pneumocystis jirovecii pneumonia mortality among HIV-negative patients: a global research network with a follow-up multicenter case-control study

Background

HIV-negative patients have substantial mortality from Pneumocystis jirovecii pneumonia (PJP). We lack predictors of HIV-negative PJP-associated mortality.

Objective

We aim to characterize the role of prior corticosteroid exposure in PJP-related mortality.

Methods

We queried a global research network to identify adult HIV-negative patients with PJP with or without corticosteroid exposure in the preceding year before diagnosis (n = 8,021). We performed a propensity score-matched analysis to adjust baseline patient characteristics and analyzed outcomes. We follow-up the results with a multicenter ten years retrospective case-control cohort of HIV-negative patients tested for PJP by PCP Direct Fluorescent Antigen. We used a Cox proportional hazards model for survival analysis.

Results

1822 HIV-negative propensity-scored matched patients with prior corticosteroid exposure had significantly increased 10 weeks (16% versus 9%, p < 0.0001) and one-year mortality after PJP diagnosis (23% versus 14%, p < 0.0001). (1→3)-β-D-glucan (197.6 ± 155.8 versus 63 ± 0 pg/ml, p = 0.014), ferritin levels (1227 ± 2486 versus 768 ± 1060 mcg/l, p = 0.047), lymphopenia (1.5 ± 1.5 versus 2.0 ± 1.6 10³ cells/µl, p < 0.0001) and hypoxia (SatO₂: 86.7% versus 91.6%, p < 0.0001) were higher or worse in those with prior steroid use. Patients who died were more likely to have previously received dexamethasone (35% versus 16%, p < 0.001) or prednisone (49% versus 29%, p < 0.001). Adjusted Cox proportional-hazard model validation showed an independently increased mortality at 10 weeks (HR: 3.7, CI: 1.5-9.2, p = 0.004) and 1 year (HR: 4.5, CI: 2.0-10.4, p < 0.0001) among HIV-negative patients with previous corticosteroid exposure.

Conclusion

Preceding corticosteroids in HIV-negative patients with PJP are associated with higher mortality. A higher fungal burden may influence corticosteroid-mediated mortality. Assessment of PJP prophylaxis must become a standard clinical best practice when instituting corticosteroid therapy courses.

Immune Biomarkers in the Peripheral Blood and Tumor Microenvironment of Classical Hodgkin Lymphoma Patients in Relation to Tumor Burden and Response to Treatment

In classical Hodgkin lymphoma (cHL), the malignant cells represent only a small fraction of the tumor. Yet, they orchestrate a lymphocyte-dominated tumor microenvironment (TME) that supports their survival and growth. The systemic effects of this local immunomodulation are not fully elucidated. Here, we aimed at characterizing circulating lymphocytes and plasma proteins in relation to clinical parameters and treatment effect. Peripheral blood (PB) samples were obtained from 48 consecutive patients at diagnosis and at 2 time points after successful primary treatment. Single-cell suspensions were prepared from lymph node (LN) biopsies obtained for routine diagnostic purposes. Twenty healthy individuals were included as controls. Cells from PB and LN were analyzed by flow cytometry, and plasma proteins by Proximity Extension Assay. We found that the frequencies of T and B cells positively correlated between the LN and the PB compartments. Compared to controls, cHL patients had higher frequencies of proliferating T cells as well as higher expression of programmed death (PD)-1 and cytotoxic T lymphocyte antigen (CTLA)-4 in circulating T cells, and lower naive T-cell frequencies. Advanced-stage patients had fewer NK cells with a functionally impaired phenotype. Differences in the immune profile were observed in patients with a high tumor burden and with high inflammation, respectively. Most of these deviations disappeared after standard first-line treatment. Patients who received radiotherapy involving the mediastinum had low T-cell counts for a prolonged period. Our findings suggest that the immunomodulation of lymphocytes in the TME of cHL might affect immune biomarkers in the PB.

Concurrent Infection with SARS-CoV-2 and Pneumocystis jirovecii in Immunocompromised and Immunocompetent Individuals

Coronavirus disease 2019 (COVID-19) may occur with concurrent infections caused by bacterial and fungal microorganisms. This systematic review evaluated studies reporting concomitant COVID-19 and Pneumocystis jirovecii pneumonia (PJP). We found 39 patients (74% male, median age: 56.8 (range: 11-83) years), including 66% immunosuppressed individuals (23% HIV-infected and 41% on long-term corticosteroid therapy). Patients were characteristically severely ill (mechanical ventilation: 70%), associated with 41% mortality. The median lymphocyte count was 527 cells/mm3 (range: 110-2200), and the median CD4+ T cell count was 206 cells/mm3 (range: 8-1021). We identified three patterns of concurrent COVID-19 and P. jirovecii infection. The first pattern (airway colonization with a low burden of P. jirovecii) does not seem to modify the COVID-19 course of illness. However, P. jirovecii superinfection, typically occurring weeks after COVID-19 diagnosis as a biphasic illness, and P. jirovecii coinfection characteristically results in progressive multilobar pneumonia, which is associated with poor outcomes. To support this categorization, we reported three patients with concurrent PJP and COVID-19 identified in our institution, presenting these clinical scenarios. The diagnosis of PJP requires a high index of suspicion, since clinical and radiological characteristics overlap with COVID-19. Observational studies are necessary to determine the PJP burden in patients with COVID-19 requiring hospitalization.

Pneumocystis jirovecii Disease: Basis for the Revised EORTC/MSGERC Invasive Fungal Disease Definitions in Individuals Without Human Immunodeficiency Virus

BACKGROUND

Pneumocystis jirovecii pneumonia (PCP) causes substantive morbidity in immunocompromised patients. The EORTC/MSGERC convened an expert group to elaborate consensus definitions for Pneumocystis disease for the purpose of interventional clinical trials and epidemiological studies and evaluation of diagnostic tests.

METHODS

Definitions were based on the triad of host factors, clinical-radiologic features, and mycologic tests with categorization into probable and proven Pneumocystis disease, and to be applicable to immunocompromised adults and children without human immunodeficiency virus (HIV). Definitions were formulated and their criteria debated and adjusted after public consultation. The definitions were published within the 2019 update of the EORTC/MSGERC Consensus Definitions of Invasive Fungal Disease. Here we detail the scientific rationale behind the disease definitions.

RESULTS

The diagnosis of proven PCP is based on clinical and radiologic criteria plus demonstration of P. jirovecii by microscopy using conventional or immunofluorescence staining in tissue or respiratory tract specimens. Probable PCP is defined by the presence of appropriate host factors and clinical-radiologic criteria, plus amplification of P. jirovecii DNA by quantitative real-time polymerase chain reaction (PCR) in respiratory specimens and/or detection of β-d-glucan in serum provided that another invasive fungal disease and a false-positive result can be ruled out. Extrapulmonary Pneumocystis disease requires demonstration of the organism in affected tissue by microscopy and, preferably, PCR.

CONCLUSIONS

These updated definitions of Pneumocystis diseases should prove applicable in clinical, diagnostic, and epidemiologic research in a broad range of immunocompromised patients without HIV.

An Usual Presentation of Pneumocystis jirovecii Pneumonia in a Woman Treated With Immune Checkpoint Inhibitor

We describe a case of Pneumocystis jirovecii pneumonia in an 18-year-old female individual with refractory primary mediastinal B-cell lymphoma treated with the immune checkpoint inhibitor pembrolizumab. She received 11 doses of pembrolizumab without immune-related adverse events (irAEs) before the diagnosis of P. jirovecii pneumonia. However, prophylactic trimethoprim/sulfamethoxazole was discontinued 6 months of postautologous stem cell transplant per standard guidelines. This case report highlights the importance of judicious infectious disease evaluation while on immune checkpoint inhibitor therapy as symptoms can often mimic irAEs. Furthermore, the benefits of immunosuppressive therapy for the treatment of presumptive irAEs must be weighed against the possible increased risk for opportunistic infections.

A Comprehensive Evaluation of Risk Factors for Pneumocystis Jirovecii Pneumonia in Adult Solid Organ Transplant Recipients: a Systematic Review and Meta-Analysis

BACKGROUND

There is no consensus guidance on when to reinitiate Pneumocystis jirovecii pneumonia (PJP) prophylaxis in solid organ transplant (SOT) recipients at increased risk. The 2019 American Society of Transplantation Infectious Diseases Community of Practice (AST IDCOP) guidelines suggested to continue or reinstitute PJP prophylaxis in those receiving intensified immunosuppression for graft rejection, CMV infection, higher dose of corticosteroids, or prolonged neutropenia.

METHODS

A literature search was conducted evaluating all literature from existence through April 22, 2020 using MEDLINE and EMBASE. (PROSPERO: CRD42019134204) RESULTS:: A total of 30 studies with 413 276 SOT recipients were included. The following factors were associated with PJP development: acute rejection (pooled odds ratio (pOR) = 2.35 (1.69, 3.26), study heterogeneity index (I)= 23.4%), cytomegalovirus (CMV)-related illnesses (pOR = 3.14 (2.30, 4.29), I=48%), absolute lymphocyte count < 500 cells/mm (pOR = 6.29[3.56, 11.13], I 0%), BK-related diseases (pOR = 2.59[1.22, 5.49], I 0%), HLA mismatch ≥ 3 (pOR = 1.83 [1.06, 3.17], I= 0%), rituximab use (pOR =3.03 (1.82, 5.04); I =0%) and polyclonal antibodies use for rejection (pOR = 3.92 [1.87, 8.19], I= 0%). On the other hand, sex, CMV mismatch, interleukin-2 inhibitors, corticosteroids for rejection, and plasmapheresis were not associated with developing PJP.

CONCLUSION

PJP prophylaxis should be considered in SOT recipients with lymphopenia, BK-related infections and rituximab exposure in addition to the previously mentioned risk factors in the AST IDCOP guidelines.

X-Linked Hyper IgM Syndrome Manifesting as Recurrent Pneumocystis jirovecii Pneumonia: A Case Report

We reported a Chinese boy with X-linked hyper IgM (XHIGM) syndrome, manifesting as recurrent and severe pneumonia caused by Pneumocystis jirovecii. His parents were healthy and unrelated. In August 2018, the 5-month-old boy manifested as cough and dyspnea, and then in July 2019, he was admitted because of the same symptoms. Immunological results of the two admissions both showed low IgG, low IgA, normal IgM and high levels of 1,3-β-D-glucan (BDG). Using next-generation sequencing (NGS), great reading counts of P. jirovecii were identified from the deep sputum in both admissions. Caspofungin combined with trimethoprim-sulfamethoxazole were used to anti-infection, and he recovered quickly. Whole-exome sequencing was performed for this family because of immune suppression, the disease-causing gene (exon 10-22 of CD40L) deletion for XHIGM syndrome was identified. NGS is beneficial for etiology diagnosis. Pneumocystis jirovecii pneumonia as an opportunistic infection could be recurrent in patients with XHIGM syndrome.

Lifelong, universal Pneumocystis jirovecii pneumonia prophylaxis: Patient uptake and adherence after kidney transplant

INTRODUCTION

Pneumocystis jirovecii pneumonia (PJP) is a significant cause of morbidity and mortality in transplant patients yet little is known about their adherence to prophylaxis. The goal of this study was to evaluate patient uptake and long-term adherence after implementing universal, lifelong PJP prophylaxis.

MATERIALS AND METHODS

This retrospective cohort study evaluated an adult kidney transplant program 18-months after initiating trimethoprim-sulfamethoxazole (TMP-SMX) 80/400 mg thrice-weekly following a cluster of PJP cases. The protocol incorporated multi-modal patient education and drug tolerability strategies to improve adherence, including a modified re-challenge strategy for TMP-SMX intolerance. Adherence was independently confirmed by the transplant pharmacist and nurse for each patient, with an a priori target ≥ 75% population on prophylaxis.

RESULTS

Initial uptake was high with 237/250 (94.8%) patients starting prophylaxis. Long-term maintenance was high with 192/237 (81.0%) patients remaining on prophylaxis at 18-months. Of the remaining 45 patients who initiated prophylaxis, 36/237 (15.2%) were non-adherent and 9/237 (3.8%) discontinued prophylaxis by 18-months. Reasons for non-adherence included gastrointestinal upset, fear of drug reactions and cost; but the majority of reasons were not delineated by the patients (31/36, 86.1%). There was a statistically significant increase in serum creatinine 3.3 µmol/L (0.3-6.3 µmol/L 95% CI) and potassium 0.08 mmol/L (0.03-0.15 mmol/L 95% CI) in those prescribed TMP-SMX with only 3/237 (1.3%) patients discontinuing TMP-SMX for an increase in creatinine.

CONCLUSION

High rates of patient uptake (94.8%) and long-term adherence (81.0%) were observed after implementing universal lifelong PJP prophylaxis. This may be due in part to the in-depth patient education and drug tolerability strategies employed.

Revision and Update of the Consensus Definitions of Invasive Fungal Disease From the European Organization for Research and Treatment of Cancer and the Mycoses Study Group Education and Research Consortium

BACKGROUND

Invasive fungal diseases (IFDs) remain important causes of morbidity and mortality. The consensus definitions of the Infectious Diseases Group of the European Organization for Research and Treatment of Cancer and the Mycoses Study Group have been of immense value to researchers who conduct clinical trials of antifungals, assess diagnostic tests, and undertake epidemiologic studies. However, their utility has not extended beyond patients with cancer or recipients of stem cell or solid organ transplants. With newer diagnostic techniques available, it was clear that an update of these definitions was essential.

METHODS

To achieve this, 10 working groups looked closely at imaging, laboratory diagnosis, and special populations at risk of IFD. A final version of the manuscript was agreed upon after the groups' findings were presented at a scientific symposium and after a 3-month period for public comment. There were several rounds of discussion before a final version of the manuscript was approved.

RESULTS

There is no change in the classifications of "proven," "probable," and "possible" IFD, although the definition of "probable" has been expanded and the scope of the category "possible" has been diminished. The category of proven IFD can apply to any patient, regardless of whether the patient is immunocompromised. The probable and possible categories are proposed for immunocompromised patients only, except for endemic mycoses.

CONCLUSIONS

These updated definitions of IFDs should prove applicable in clinical, diagnostic, and epidemiologic research of a broader range of patients at high-risk.

Low B cell counts as risk factor for infectious complications in systemic sclerosis after autologous hematopoietic stem cell transplantation

Background

Autologous hematopoietic stem cell transplantation (aHSCT) is a treatment option for a selected group of systemic sclerosis (SSc) patients with good available evidence but can be associated with considerable morbidity and mortality. The aim of this study was to describe infectious complications and distinct immune reconstitution patterns after aHSCT and to detect risk factors in lymphocyte subsets, which are associated with an elevated rate of infections after aHSCT.

Methods

Seventeen patients with SSc were included in this single-center retrospective cohort study. Clinical and laboratory data was collected before and for 12 months after aHSCT, including immunophenotyping of peripheral whole blood by fluorescence-activated cell sorting.

Results

Cytomegalovirus (CMV) reactivations were common in CMV-IgG-positive patients (50%) and needed treatment. Mycotic infections occurred in 17.6%. One patient died (resulting in a mortality of 5.9%) due to pneumonia with consecutive sepsis. All patients showed decreased T helper cells (CD3⁺/CD4⁺) and within the B cell compartment decreased post-switched memory B cells (CD19⁺/CD27⁺/IgD⁻) and elevated naïve B cells (CD19⁺/CD27⁻/IgD⁺) until 12 months after aHSCT. Patients who developed infections had significantly lower B cells before aHSCT than patients who did not develop infections.

Conclusion

After aHSCT, monitoring for infectious complications, especially for CMV reactivations, is crucial as the reconstitution of the immune system takes longer than 12 months. Low peripheral B cells might be a risk factor for an elevated infection rate.

CD4+ T cell lymphopenia predicts mortality from Pneumocystis pneumonia in kidney transplant patients

BACKGROUND

Pneumocystis jirovecii pneumonia (PcP) remains a life-threatening opportunistic infection after solid organ transplantation, even in the era of Pneumocystis prophylaxis. The association between risk of developing PcP and low CD4⁺ T cell counts has been well established. However, it is unknown whether lymphopenia in the context of post-renal transplant PcP increases the risk of mortality.

METHODS

We carried out a retrospective analysis of a cohort of kidney transplant patients with PcP (n = 49) to determine the risk factors for mortality associated with PcP. We correlated clinical and demographic data with the outcome of the disease. For CD4⁺ T cell counts, we used the Wilcoxon rank sum test for in-hospital mortality and a Cox proportional-hazards regression model for 60-day mortality.

RESULTS

In univariate analyses, high CRP, high neutrophils, CD4⁺ T cell lymphopenia, mechanical ventilation, and high acute kidney injury network stage were associated with in-hospital mortality following presentation with PcP. In a receiver-operator characteristic (ROC) analysis, an optimum cutoff of ≤200 CD4⁺ T cells/µL predicted in-hospital mortality, CD4⁺ T cell lymphopenia remained a risk factor in a Cox regression model.

CONCLUSIONS

Low CD4⁺ T cell count in kidney transplant recipients is a biomarker for disease severity and a risk factor for in-hospital mortality following presentation with PcP.

Predictive tools to determine risk of infection in kidney transplant recipients

Introduction: Infection represents a major complication after kidney transplantation (KT). Therapeutic drug monitoring is essentially the only approach for the adjustment of immunosuppression in current practice, with suboptimal results. The implementation of immune monitoring strategies may contribute to minimizing the risk of adverse events attributable to over-immunosuppression without compromising graft outcomes.Areas covered: The present review (based on PubMed/MEDLINE searches from database inception to November 2019) is focused on immune biomarkers with no antigen specificity (non-pathogen-specific), including serum levels of immunoglobulins and complement factors, peripheral blood lymphocyte subpopulations, soluble CD30, intracellular ATP production by stimulated CD4⁺ T-cells, and other cell-based immune assays. We also summarized recent advances in the use of replication kinetics of latent viruses to assess the functionality of T-cell immunity, with focus on the nonpathogenic anelloviruses. Finally, the composite risk scores reported in the literature are critically discussed.Expert opinion: Notable efforts have been made to develop an enlarging repertoire of immune biomarkers and prediction models, although most of them still lack technical standardization and external validation. Preventive interventions based on these tools (prolongation of prophylaxis, tapering of immunosuppression, or immunoglobulin replacement therapy in hypogammaglobulinemic patients) remain to be defined, ideally in the context of controlled trials.

Incidence and risk factors of Pneumocystis jirovecii pneumonia in Korean patients with inflammatory bowel disease

BACKGROUND AND AIM

Little is known whether routine prophylaxis against Pneumocystis jirovecii pneumonia (PJP) is needed in patients with inflammatory bowel disease (IBD) on immunosuppression, especially in Asian populations. We, therefore, sought to investigate the incidence and risk factors of PJP in patients with IBD in Korea.

METHODS

We investigated the incidence of PJP in patients with IBD and compared the characteristics of IBD patients with PJP episodes (IBD-PJP group) with those of matched controls (IBD-only group) using a large, well-characterized referral center-based cohort.

RESULTS

Among the 6803 IBD patients (3171 with Crohn's disease and 3632 with ulcerative colitis) enrolled in the Asan IBD Registry between June 1989 and December 2016, six patients (0.09%) were diagnosed with PJP. During the 57 776.0 patient-years of follow-up (median 7.2 years per patient), the incidence of PJP was 10.4 cases per 100 000 person-years, and none of these patients had received PJP prophylaxis. In case-control analysis, the IBD-PJP group (n = 6) showed significantly higher C-reactive protein level at diagnosis of IBD (P = 0.006), as well as higher exposure to corticosteroids (P = 0.017), than did controls (n = 24). In addition, the IBD-PJP group showed higher rates of double (50% vs 12.5%) or triple (33.3% vs 4.2%) immunosuppression than did controls, although these are not statistically significant.

CONCLUSIONS

Although the incidence of PJP in Korean patients with IBD is low, careful monitoring is necessary for the early detection of PJP. In addition to the patients receiving double or triple immunosuppression, PJP prophylaxis should be considered especially in patients with severe disease activities requiring corticosteroids.

High incidence of Pneumocystis jirovecii pneumonia in allogeneic hematopoietic cell transplant recipients in the modern era

BACKGROUND

International guidelines for Pneumocystis jirovecii pneumonia (PJP) prevention recommend prophylaxis for ≥6 months following allogeneic hematopoietic cell transplantation, and longer in patients with graft-versus-host disease (GVHD) or on immunosuppressive therapy (IST). These recommendations are based on cohorts of patients who did not routinely receive anti-thymocyte globulin (ATG) for GVHD prophylaxis.

METHODS

We performed a retrospective chart review of 649 patients, all of whom received ATG as part of GVHD prophylaxis.

RESULTS

The cumulative incidence of definite PJP was 3.52% at both 3 and 5 years (median follow up, 1648 days for survivors). PJP occurred in 13 non-GVHD patients between days 207 and 508, due in part to low CD4 T-cell counts (<200 CD4 T cells/µL). PJP occurred in eight GVHD patients between days 389 and 792, due in part to non-adherence to PJP prophylaxis guidelines (discontinuation of PJP prophylaxis at <3 months after discontinuation of IST). Breakthrough PJP infection was not observed in patients receiving prophylaxis with cotrimoxazole, dapsone or atovaquone, whereas three cases were observed with inhaled pentamidine.

DISCUSSION

In conclusion, for non-GVHD patients receiving ATG-containing GVHD prophylaxis, 6 months of PJP prophylaxis is inadequate, particularly if the CD4 T-cell count is <200 cells/µL or if there is a high incidence of PJP in the community. For patients with GVHD receiving ATG-containing GVHD prophylaxis, continuing PJP prophylaxis until ≥3 months post-discontinuation of IST is important. Cotrimoxazole, dapsone and atovaquone are preferred over inhaled pentamidine.

Hypercalcemia Heralding Pneumocystis jirovecii Pneumonia in an HIV-Seronegative Patient with Diffuse Cutaneous Systemic Sclerosis

Pneumocystis pneumonia (PCP) is a life-threatening fungal infection occurring in immunocompromised patients such as HIV-positive patients with low CD4 cell count or patients under heavy immunosuppressive therapy. We report the case of a 59-year-old male with severe diffuse cutaneous systemic sclerosis presenting with asthenia, dry cough and worsening shortness of breath for the last 15 days. Biological studies were remarkable for PTH-independent severe hypercalcemia with low 25-hydroxyvitamin D and a paradoxically elevated 1,25-dihydroxyvitamin D. Early bronchoalveolar lavage allowed for PCP diagnosis and targeted treatment. We discuss the underlying physiopathology and difficulties regarding prophylaxis and treatment.

Pneumocystis jiroveci in solid organ transplantation: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of Pneumocystis jiroveci fungal infection transplant recipients. Pneumonia (PJP) may develop via airborne transmission or reactivation of prior infection. Nosocomial clusters of infection have been described among transplant recipients. PJP should not occur during prophylaxis with trimethoprim-sulfamethoxazole (TMP-SMX). Without prophylaxis, PJP risk is greatest in the first 6 months after organ transplantation but may develop later. Risk factors include low lymphocyte counts, cytomegalovirus infection (CMV), hypogammaglobulinemia, treated graft rejection or corticosteroids, and advancing patient age (>65). Presentation typically includes fever, dyspnea with hypoxemia, and cough. Chest radiographic patterns generally reveal diffuse interstitial processes best seen by CT scans. Patients generally have PO₂  < 60 mm Hg, elevated serum lactic dehydrogenase (LDH), and elevated serum (1 → 3) β-d-glucan assay. Specific diagnosis uses respiratory specimens with direct immunofluorescent staining; invasive procedures may be required. Quantitative PCR is a useful adjunct to diagnosis. TMP-SMX is the drug of choice for therapy; drug allergy should be documented before resorting to alternative therapies. Adjunctive corticosteroids may be useful early. Routine PJP prophylaxis is recommended for at least 6-12 months post-transplant, preferably with TMP-SMX.

Pneumocystis jirovecii pneumonia prophylaxis in immunocompromised patients with systemic autoimmune diseases

Pneumocystis jirovecii (P. jirovecii) causes a potentially fatal pneumonia in immunocompromised individuals (Pneumocystis pneumonia or PcP), particularly in HIV-infected patients and those treated with immunosuppressive drugs, such as transplant patients and those with systemic autoimmune diseases. P. jirovecii colonization can be found in almost a third of patients with systemic autoimmune diseases. Although the incidence of PcP in such patients is usually low, mortality is quite high, ranging between 30% and 50% in the majority of autoimmune diseases. PcP development is almost always observed in patients not receiving prophylaxis for the infection. Despite the above, there are no clinical guidelines established for PcP prophylaxis in patients with autoimmune diseases treated with glucocorticoids, cytotoxic drugs, or more recently, biological agents. The objective of this review is to analyze the available data on the incidence of PcP and the effect of PcP prophylaxis in patients with autoimmune diseases that may be useful in clinical practice.

Prophylaxis and treatment of Pneumocystis Jirovecii pneumonia after solid organ transplantation

Pneumocystis jirovecii pneumonia (PJP) is an opportunistic infection diagnosed in immunocompromized patients. After solid organ transplantation, early infection has decreased as a result of effective prophylaxis, but late infections and even outbreaks caused by interpatient transmission of pneumocystis by air are present in the SOT community. Different risk factors for PJP have been described and several indications for PJP prophylaxis have to be considered by clinicians in patients even years after transplantation. Diagnosis of PJP is confirmed by microscopy and immunofluorescence staining of bronchial fluid but PCR as well as serum ß-D-Glucan analysis have become increasingly valuable diagnostic tools. Treatment of choice is Trimethoprim/sulfamethoxazole and early treatment improves prognosis. However, mortality of PJP in solid organ transplant patients is still high and many aspects including the optimal management of immunosuppression during PJP treatment require further investigations.

Lymphopenia is associated with late onset Pneumocystis jirovecii pneumonia in solid organ transplantation

BACKGROUND

Pneumocystis jirovecii pneumonia (PJP) affected 5%-15% of solid organ transplant (SOT) recipients prior to universal prophylaxis, classically with trimethoprim-sulfamethoxazole (TMP-SMX). Guidelines generally recommend 6-12 months of prophylaxis post-SOT, yet optimal duration and robust PJP risk stratification have not been established.

METHODS

A retrospective, single-center, case-control study of PJP among SOT recipients from January 1998 to December 2013 was conducted. Cases had positive PJ direct fluorescent antibody assay of respiratory specimens. Controls were matched 4:1 by nearest date of SOT. Univariate testing and multivariate logistic regressions were performed.

RESULTS

Fifteen cases were identified among 5505 SOT recipients (0.27% rate) and analyzed vs 60 controls. PJP occurred on average 6.1 years (range 0.9-13.8) post-SOT; no case was receiving PJP prophylaxis at diagnosis. Most were treated with reduced immunosuppression and TMP-SMX plus steroids (80%). Six patients (40%) required critical care; 3 (20%) died. There were no significant demographic differences, though cases tended to be older at SOT (54 vs 48 years, P = .1). In univariate analysis, prior viral infection was more common among cases (67% vs 37%, P = .08). Lower absolute lymphocyte count (ALC) at diagnosis date was strongly associated with PJP (400 vs 1230 × 106  cells/μL, P < .001); odds of infection were high with ALC ≤ 500 × 106 cells (OR 18.7, P < .01).

CONCLUSION

Pneumocystis jirovecii pneumonia is a rare, late complication of SOT with significant morbidity and mortality. Severe lymphopenia may be useful in identifying SOT recipients who warrant continued or reinstated PJP prophylaxis.