Trends in the Epidemiology of Pneumocystis Pneumonia in Immunocompromised Patients without HIV Infection

Abstract

The increasing morbidity and mortality of life-threatening Pneumocystis pneumonia (PCP) in immunocompromised people poses a global concern, prompting the World Health Organization to list it as one of the 19 priority invasive fungal diseases, calling for increased research and public health action. In response to this initiative, we provide this review on the epidemiology of PCP in non-HIV patients with various immunodeficient conditions, including the use of immunosuppressive agents, cancer therapies, solid organ and stem cell transplantation, autoimmune and inflammatory diseases, inherited or primary immunodeficiencies, and COVID-19. Special attention is given to the molecular epidemiology of PCP outbreaks in solid organ transplant recipients; the risk of PCP associated with the increasing use of immunodepleting monoclonal antibodies and a wide range of genetic defects causing primary immunodeficiency; the trend of concurrent infection of PCP in COVID-19; the prevalence of colonization; and the rising evidence supporting de novo infection rather than reactivation of latent infection in the pathogenesis of PCP. Additionally, we provide a concise discussion of the varying effects of different immunodeficient conditions on distinct components of the immune system. The objective of this review is to increase awareness and knowledge of PCP in non-HIV patients, thereby improving the early identification and treatment of patients susceptible to PCP.

Risk factors and multi-pathogen infections in kidney transplant recipients with omicron variant pneumonia: a retrospective analysis

“…In recent years, the SARS-CoV-2 pandemic has become a concern. SARS-CoV-2 can impair the host's immune system, increasing the risk of bacterial and fungal coinfections, including Pneumocystis jirovecii [19]. Therefore, SARS-CoV-2 infection has also become a risk factor for Pneumocystis jirovecii infection.…”

“…Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly transmissible and pathogenic coronavirus that emerged in late 2019 and has caused a pandemic of acute respiratory disease-coronavirus disease 2019(COVID- 19), and over 767 million confirmed cases have been reported to the World Health Organization (WHO), including approximately 6.94 million deaths. Although most infections in the general population are mild and have a good prognosis, kidney transplant recipients have poorer prognosis.…”

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

“…We performed a retrospective analysis of adult patients with non-HIV-PCP who were admitted to Peking University First Hospital requiring treatment for RF from April 2007 to October 2022. Patients who met the following criteria were enrolled in the study ( Xue et al., 2023 ): HIV test is negative ( Pegorie et al., 2017 ); Diagnostic criteria for PCP ( Enomoto et al., 2010 ; Ainoda et al., 2012 ; Vogel et al., 2012 ; Ricciardi et al., 2017 ): ① Cough, fever, dyspnea or hypoxemia and other clinical manifestations; ② Imaging findings consistent with PCP, such as ground-glass changes in both lungs or diffuse interstitial infiltration; ③ Pneumocystis jirovecii was detected in bronchoalveolar lavage fluid (BALF), sputum, bronchial flushing fluid, bronchial secretions and lung tissue ( Buchacz et al., 2016 ); The definition of RF ( Roussos and Koutsoukou, 2003 ).…”

“…Pneumocystis pneumonia (PCP) is a serious fungal infection that primarily affects immunocompromised individuals, such as those with Human Immunodeficiency Virus (HIV)/acquired immune deficiency syndrome (AIDS), cancer, or organ transplant recipients. With the extensive clinical application of tumor chemoradiotherapy, corticosteroids and immunosuppressants, the susceptible population of Pneumocystis jirovecii has gradually shifted from HIV infected individuals to non-HIV infected individuals ( Buchacz et al., 2016 ; Pegorie et al., 2017 ; Xue et al., 2023 ). Respiratory failure (RF) in non-HIV related PCP patients is the most common cause of intensive care unit (ICU) admission and an independent risk factor for death ( Maschmeyer et al., 2016 ), with a mortality rate of 50%-80% ( Festic et al., 2005 ; Limper et al., 2017 ).…”