Exploring the Differences in Pneumocystis Pneumonia Infection Between HIV and Non-HIV Patients

Abstract

Pneumocystis pneumonia (PCP) is one of the most common opportunistic infections worldwide that affects the lung. Pneumocystis leads to pneumonia, caused by Pneumocystis jirovecii, formerly known as Pneumocystis carinii. In recent decades, PCP has been a major health problem for human immunodeficiency virus (HIV) patients and is responsible for most of mortality and morbidity. However, the increasing number of immunosuppressive-related diseases has led to outbreaks in other patient populations, raising the concern for PCP as it becomes a major concern among those patients. These changes led to marked changes in the prevalence and mortality rates of PCP. Huge variations in those parameters among HIV and non-HIV patients have been seen also. Historically, the diagnosis was made by staining and direct visualization of the organism within the bronchoalveolar lavage (BAL) fluid. The diagnosis is now made by microscopic examination and a real-time polymerase chain reaction (PCR) of BAL. Serum (1,3)-β-D-glucan, which is a component of the Pneumocystis jirovecii cell wall that distinguishes it from other fungi, has become an important diagnostic tool. Early diagnosis and treatment play a vital role in the patient's survival and in the infection outcome; hence, empirical PCP therapy should be started immediately when the infection is suspected without waiting for the results of the diagnostic test. Steroids play an important role in the treatment of HIV patients, especially patients who present with hypoxia and respiratory failure. Prophylaxis is very effective and should be given to all patients at high risk of PCP. Antiretroviral therapy (ART) should be started as soon as possible in newly diagnosed HIV-infected patients with PCP, and the immune status of immunocompromised patients with PCP should be improved by temporarily withholding immunosuppressive drugs or reducing their doses.

Thirteen Cases of Pulmonary Pneumocystis in HIV-Negative Patients

“…Clinicians now advise preventative medication for select patient groups due to the demonstrated effectiveness of primary prophylaxis in the treatment of AIDS [2].…”

“…Its prognosis remains poor, and it appears to be on the increase in patients who are seronegative for the human immunodeficiency virus (HIV), solid organ transplant recipients, patients treated for hematologic malignancies (mainly lymphoproliferative), patients with autoimmune or inflammatory diseases, and those receiving long-term corticosteroids. These pneumonias are associated with higher morbidity and mortality than AIDS (30%-60% versus 10% for HIV-infected patients), hence the need for early detection and treatment [2].…”

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

“…The clinical presentation of PJP may differ between patients with and without HIV infection [ 8 ], which may influence early detection and initiation of appropriate treatment [ 9 ]. Studies have shown that PJP in non-HIV patients experiences a more progressive clinical course, a poor prognosis, and a higher mortality rate (ranging from 30% to 60%) than in HIV patients [ 4 , 10 ].…”

Deep mutational scanning ofPneumocystis jiroveciidihydrofolate reductase reveals allosteric mechanism of resistance to an antifolate

“…In this group, the disease caused by P. jirovecii has a mortality rate close to 60% despite the use of prophylaxis. This increase raises major concerns about the future of Pneumocystis pneumonia in vulnerable populations [29–31]. Furthermore, P. jirovecii has been detected in healthy, non-immunocompromised groups, and in up to 50% of the general population, implying a higher prevalence than previously estimated [26,32–35].…”