Incidence of Pneumocystis pneumonia in Immunocompromised Patients without Human Immunodeficiency Virus with Intravenous Pentamidine Prophylaxis: A Systematic Review and Meta-Analysis

Efficacy and safety of a low-dose sulfamethoxazole/trimethoprim regimen in preventing pneumocystis pneumonia: A retrospective study using a large-scale electronic medical record database

INTRODUCTION

Sulfamethoxazole/trimethoprim (ST) is a first-line drug for preventing pneumocystis pneumonia (PCP). Several small-scale studies have suggested the usefulness of the low-dose regimen of ST (200/40 mg/day) over the standard-dose one (400/80 mg/day). Thus, this study aimed to investigate the efficacy and safety of low-dose and standard-dose regimens of ST in preventing PCP in patients with non human immunodeficiency virus infection using a large-scale electronic medical record database.

METHODS

This retrospective study included patients who received ST prophylaxis for PCP registered in the RWD database between June 2007 and February 2023. Patients received either standard-dose (400/80 mg/day) or low-dose (200/40 mg/day) regimen groups. The incidence of cases initiated PCP therapeutic dose (ci-PCPTD) (ST ≥ 3600/720 mg/day) and adverse events (AEs) was evaluated, and risk factors for ci-PCPTD were investigated.

RESULTS

A total of 11,384 patients received the standard-dose, whereas 7973 received the low-dose regimen groups. No significant difference in the cumulative incidence of ci-PCPTD was observed between the standard-dose (0.67%) and low-dose regimen group (0.47%). Lung disease was a significant risk factor for ci-PCPTD. The cumulative incidence of ci-PCPTD in patients with acute exacerbation of interstitial pneumonia was 1.3% in both groups, and no significant difference was observed between the two groups. The low-dose regimen group had a lower incidence of all AEs than the standard-dose regimen group.

CONCLUSION

These results based on a large-scale electronic medical record database provide important evidence supporting the clinical significance of low-dose regimen of ST.

Cutaneous Pneumocystis Jirovecii Infection in an Allogeneic Stem Cell Transplant Recipient

Pneumocystis jirovecii is an opportunistic fungus that infects the lungs but can involve other organs, including the skin and lymph nodes. Risk factors include human immunodeficiency virus (HIV), solid organ/haematological malignancies and a CD4 cell count of fewer than 200 cells/μl. Pneumocystis jirovecii pneumonia (PJP) infection is reported less frequently these days with the advent of prophylaxis with trimethoprim-sulfamethoxazole (TMP-SMX). We report a case of extrapulmonary PJP infection in a patient while receiving pentamidine prophylaxis in a T-cell prolymphocytic leukaemia, who underwent an allogeneic stem cell transplant. There are plenty of reported cases of PJP on pentamidine prophylaxis; however, none had cutaneous PJP infection. Cutaneous P. jirovecii infection (CPJ) is an extrapulmonary infection that is rarely reported. Our patient's skin biopsy was inconclusive, but the skin nodules improved once he was initiated on TMP-SMX. Many transplant patients cannot tolerate TMP-SMX for various reasons and are placed on second-line prophylaxis for PJP, which does not prevent extrapulmonary PJP infections. Our case highlights the challenges of diagnosing such a rare infection in immunocompromised patients. Extrapulmonary PJP should be suspected in patients with a history of pulmonary PJP and persistent elevated Fungitell® levels in low CD4 counts.

LEARNING POINTS

Extrapulmonary Pneumocystis jirovecii pneumonia (PJP) infection can happen while receiving pentamidine prophylaxis.It is extremely rare to see a cutaneous infection, and no case has been reported in the last two decades.Trimethoprim-sulfamethoxazole (TMP-SMX) remains the first-line treatment for pulmonary and extrapulmonary PJP.

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 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.

Pneumocystis Pneumonia in Locally Advanced Breast Cancer Despite Prophylactic Use of Trimethoprim-Sulfamethoxazole During Prednisolone Treatment for a Pembrolizumab-Induced Immune-Related Adverse Event: A Case Report

Pneumocystis pneumonia (PCP) primarily affects immunosuppressed patients, with trimethoprim-sulfamethoxazole (TMP-SMX) commonly used for prophylaxis. However, there is insufficient information on PCP occurrence despite TMP-SMX prophylaxis. We encountered a 57-year-old woman with locally advanced breast cancer developing PCP despite prophylactic intake of TMP-SMX, during treatment with prednisolone for Stevens-Johnson syndrome (SJS) induced by pembrolizumab. This case underscores the need to pay attention to the possibility of PCP development even during TMP-SMX prophylaxis. Dosage and duration adjustments according to the patient's condition and weight may be required.