A comprehensive clinical guide for Pneumocystis jirovecii pneumonia: a missing therapeutic target in HIV-uninfected patients

ABSTRACT

Introduction

Pneumocystis jirovecii is an opportunistic, human-specific fungus that causes Pneumocystis pneumonia (PCP). PCP symptoms are nonspecific. A patient with P. jirovecii and another lung infection faces a diagnostic challenge. It may be difficult to determine which of these agents is responsible for the clinical symptoms, preventing effective treatment. Diagnostic and treatment efforts have been made more difficult by the rising frequency with which coronavirus 2019 (COVID-19) and PCP co-occur.

Areas covered

Herein, we provide a comprehensive review of clinical and pharmacological recommendations along with a literature review of PCP in immunocompromised patients focusing on HIV-uninfected patients.

Expert Opinion

PCP may be masked by identifying co-existing pathogens that are not necessarily responsible for the observed infection. Patients with severe form COVID-19 should be examined for underlying immunodeficiency, and co-infections must be considered as co-infection with P. jirovecii may worsen COVID-19ʹs severity and fatality. PCP should be investigated in patients with PCP risk factors who come with pneumonia and suggestive radiographic symptoms but have not previously received PCP prophylaxis. PCP prophylaxis should be explored in individuals with various conditions that impair the immune system, depending on their PCP risk.

KEYWORDS:

• Clinical guidance
• COVID-19
• HIV-uninfected patients
• pharmacologic management
• Pneumocystis jirovecii
• pneumonia
• prophylaxis

Article highlights

• We suggest a step-wise approach to PCP diagnosis and treatment that may be easier to follow. When it is not possible to acquire a safe respiratory sample, treatment can be initiated based on the patient’s risk, clinical presentation, and presumptive diagnosis using serum diagnostic assays.

• PCP symptoms are non-specific and similar to those of various infectious pathogens of the respiratory system. Co-infections with P. jirovecii may worsen COVID-19ʹs severity and fatality.

• PCP should be investigated in patients with PCP risk factors who come with pneumonia and suggestive radiographic symptoms but have not previously received PCP prophylaxis.

• Standard precautions should be assigned to hospitalized patients diagnosed with PCP. Pre-emptive treatment is recommended because there is a possibility of developing full-blown PCP from colonisation if immunity deteriorates.

• The qPCR of BAL fluid samples is an essential technique for distinguishing colonization from PCP. When the C_t values are in the grey area, the qPCR result, in conjunction with other clinical and paraclinical characteristics, will assist in identifying whether the patient should be deemed to have PCP or be colonized with P. jirovecii. For the regular diagnosis of PCP, real-time PCR is highly suggested.

• A prompt diagnosis of PCP is necessary because even a short delay in starting treatment can significantly increase the risk that mortality will pass away.

Declaration of interests

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.