Management of Pneumocystis Jirovecii pneumonia in HIV infected patients: current options, challenges and future directions

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

INTRODUCTION

Pneumocystis jirovecii pneumonia (PJP) is a well-known and frequent opportunistic infection in HIV patients. However, there has been an increase in the number of reports of PJP in other immunosuppressed patients with autoimmune inflammatory disorders or because of chemotherapy and high doses of steroids, especially when used in combination as part of immunosuppressive therapy.

OBJECTIVE

Despite the increasing importance of PJP in non-HIV patients, there is a lack of comprehensive and updated information on the epidemiology, pathogenesis, diagnosis, microbiology, treatments, and prophylaxis of this infection in this population. Therefore, the objective of this systematic review is to synthesize information on these aspects, from a perspective of evidence-based medicine.

METHODS

The protocol is prepared following the preferred reporting items for systematic reviews and meta-analyses (PRISMA-P) guidelines. We will perform a systematic review of literature published between January 2010 and July 2023, using the databases PubMed, Google Scholar, ScienceDirect, and Web of Science. In addition, manual searches will be carried out through related articles, and references to included articles. The main findings and clinical outcomes were extracted from all the eligible studies with a standardized instrument. Two authors will independently screen titles and abstracts, review full texts, and collect data. Disagreements will be resolved by discussion, and a third reviewer will decide if there is no consensus. We will synthesize the results using a narrative or a meta-analytic approach, depending on the heterogeneity of the studies.

EXPECTED RESULTS

It is expected that this systematic review will provide a comprehensive and up-to-date overview of the state-of-the-art of PJP in non-HIV patients. Furthermore, the study will highlight possible gaps in knowledge that should be addressed through new research.

CONCLUSIONS

Here, we present the protocol for a systematic review which will consider all existing evidence from peer-reviewed publication sources relevant to the primary and secondary outcomes related to diagnosing and managing PJP in non-HIV patients.

Prevalence and Factors Associated with Delayed Initiation of Antiretroviral Therapy Among People Living with HIV in Nekemte Referral Hospital, Western Ethiopia

Background

Ethiopia has adopted the “Universal Test and Treat” strategy to its national policy in 2016 to put all people living with HIV/AIDS (PLHIV) on antiretroviral therapy (ART) regardless of their World Health Organization (WHO) clinical stage or CD4 cell count level. A significant percentage of PLHIV start therapy has been delayed despite the availability of ART, which results in poor treatment outcomes including HIV-related morbidity and mortality, and continued HIV transmission.

Methods

This cross-sectional study was conducted to determine the magnitude and associated factors of delayed ART initiation among PLHIV at ART Clinic, Nekemte Referral hospital, Western Ethiopia between January 1, 2020 and March 31, 2020 for the time period of January 1, 2016 to December 31, 2019. A consecutive sampling method was used to recruit 417 study subjects. The collected data were entered into Epi data version 3.1 and exported to STATA version 14 for statistical analysis. Logistic regression analysis was used to identify associated factors with delayed ART initiation among PLHIV. P-values<0.05 were used to declare significant association.

Results

A total of 417 PLHIV were included in the study. The mean age of study subjects was 33.49 (SD±9.81) years. The majority of participants attended formal education (77%) and were urban dwellers (82%). One-third (34%) of them initiated ART delayed, beyond 7 days of confirmed HIV diagnosis. Subjects with normal nutritional status (BMI=18.5–24.9kg/m²) (AOR=3.12, 95% CI=1.29–7.57; P=0.012), CD4 count ≥351cells/mm³ (AOR=2.89, 95% CI=1.27–6.58; P=0.011), tuberculosis (TBC) co-infection (AOR=2.76, 95% CI=1.13–6.70; P=0.025), use of traditional treatment (AOR=4.03, 95% CI=2.03–8.00; P<0.001) and did not know other ART user(s) (AOR=2.86, 95% CI=1.52–5.37; P=0.001) were significantly associated with delayed ART initiation.

Conclusion

Early HIV testing mechanisms and timely linkage to HIV care by advocating “Test-and-Treat” should be strengthened.

A theoretical study of chemical bonding and topological and electrostatic properties of the anti-leprosy drug dapsone

The theoretical charge density study for the gas phase of anti-leprosy drug Dapsone has been carried out in the light of the theory of atoms in molecules using density functional theory employing B3LYP(6-311G++(d, p) hybrid functional completed with dispersion corrections. The Hirshfeld surface analysis as well as fingerprint plots has been utilized to visualize and quantify the intermolecular contacts present in the molecule. The topological properties such as electron density and its Laplacian, delocalization index have been elucidated to throw light into the chemical bonding and atomic and molecular details. The electron localization function has been used to visualize and deduce information on the lone pair and the subshells of the Cl atom. The electrostatic potential visualizes the positive and negative electrostatic potential regions which are susceptible to nucleophilic and electrophilic attack. On the whole, this study provides an exact mechanism, interaction, and topological and electrostatic properties of the drug through theoretical insights which all will be a platform for our further investigation of the interaction between dapsone and dihydropteroate synthase (DHPS).

A Pilot Study of Echinocandin Combination with Trimethoprim/Sulfamethoxazole and Clindamycin for the Treatment of AIDS Patients with Pneumocystis Pneumonia

Background and Objectives

Pneumocystis pneumonia (PCP) is a common opportunistic infection in acquired immune deficiency syndrome (AIDS) patients that continues to result in a high mortality rate. To develop a better treatment strategy and improve PCP prognosis, a cohort study was conducted to evaluate the therapeutic potential of echinocandin treatment for AIDS patients with PCP (AIDS-PCP).

Methods

The AIDS-PCP patients were analyzed in our retrospective cohort study that were hospitalized in The First Affiliated Hospital of Zhejiang University during 2013–2018. The antifungal effects of echinocandins were evaluated in two subgroups that were classified by oxygenation as a proxy for the disease state: PaO₂/FiO₂ > 200 mmHg and PaO₂/FiO₂ ≤ 200 mmHg. Intergroup comparisons and survival curves were used to evaluate the effectiveness of the two AIDS-PCP treatment regimens.

Results

During the follow-up, 182 AIDS-PCP patients were diagnosed and analyzed in the study. After excluding 55 patients with other superinfections and five patients that were treated with HAART, the remaining 122 patients were enrolled in the study. The group treated with echinocandins combined with trimethoprim-sulfamethoxazole (TMP-SMZ) and clindamycin exhibited a lower mortality rate (9.62%, 5/52) than did the group with TMP-SMZ and clindamycin treatment (20%, 14/70). For AIDS-PCP patients in the PaO₂/FiO₂ > 200 mmHg subgroup, treatment with echinocandins combined with TMP-SMZ and clindamycin significantly reduced their mortality rate (4.44% (2/45) vs. 18.18% (10/55), P = 0.035).

Conclusion

The results of this study indicate that treatment with echinocandins in combination with the standard TMP-SMZ and clindamycin regimen can improve the prognosis and reduce the mortality rate in patients with mild to moderate AIDS-PCP disease.

Pneumocystis jirovecii Pneumonia and Human Immunodeficiency Virus Co-Infection in Western Iran

BACKGROUND

The human immunodeficiency virus (HIV) is one of the greatest health challenges facing worldwide. The virus suppresses the immune system of the patient. The purpose of this study was to describe the epidemiology of Pneumocystis jirovecii colonization, rarely found in normal people, in patients with stage 4 HIV infection in Kermanshah, Iran, from Mar 1995 to Feb 2016.

METHODS

In this retrospective study, we surveyed medical records of stage 4 HIV-positive patients with Pneumocystis admitted to Behavioral Counseling Center of Kermanshah. Several parameters were analyzed including demographic characteristics, body mass index (BMI), treatment regimen, diagnostic methods, presenting signs and symptoms, presence of co-pathogens (bacteria, viruses, or fungi), and nadir of CD4 T-cell count before and after treatment.

RESULTS

During the study period, 114 HIV-positive patients were analyzed, of whom 93 were male and 21 were female, respectively. Of 114 cases, 26 (22.8%) patients had Pneumocystis. All 26 colonized patients had CD4 cell counts below 200 cells/mm3 (range 9-186). The median CD4 count increased from 91 cells/mm³ pre-trimethoprim/sulfamethoxazole (TMP/SMX) to an estimated 263 cells/mm³ after starting (TMP/SMX). BMI was normal in the majority of the patients (85%) and coughs, sputum, and chest pain (19; 73%) followed by dyspnea, weakness, and lethargy (7; 27%) were the most common presentations of fungal pneumonia.

CONCLUSION

HIV/AIDS-infected patients are an environmental reservoir of P. jirovecii infection that might transmit the infection from one person to another via the airborne route. In addition, rapid identification of such individuals may reduce the morbidity and mortality rate of this disease.

The In Vitro Effects of Pentamidine Isethionate on Coagulation and Fibrinolysis

Pentamidine is bis-oxybenzamidine-based antiprotozoal drug. The parenteral use of pentamidine appears to affect the processes of blood coagulation and/or fibrinolysis resulting in rare but potentially life-threatening blood clot formation. Pentamidine was also found to cause disseminated intravascular coagulation syndrome. To investigate the potential underlying molecular mechanism(s) of pentamidine's effects on coagulation and fibrinolysis, we studied its effects on clotting times in normal and deficient human plasmas. Using normal plasma, pentamidine isethionate doubled the activated partial thromboplastin time at 27.5 µM, doubled the prothrombin time at 45.7 µM, and weakly doubled the thrombin time at 158.17 µM. Using plasmas deficient of factors VIIa, IXa, XIa, or XIIa, the concentrations to double the activated partial thromboplastin time were similar to that obtained using normal plasma. Pentamidine also inhibited plasmin-mediated clot lysis with half-maximal inhibitory concentration (IC50) value of ~3.6 μM. Chromogenic substrate hydrolysis assays indicated that pentamidine inhibits factor Xa and plasmin with IC50 values of 10.4 µM and 8.4 µM, respectively. Interestingly, it did not significantly inhibit thrombin, factor XIa, factor XIIIa, neutrophil elastase, or chymotrypsin at the highest concentrations tested. Michaelis-Menten kinetics and molecular modeling studies revealed that pentamidine inhibits factor Xa and plasmin in a competitive fashion. Overall, this study provides quantitative mechanistic insights into the in vitro effects of pentamidine isethionate on coagulation and fibrinolysis via the disruption of the proteolytic activity of factor Xa and plasmin.

Development of substituted pyrido[3,2-d]pyrimidines as potent and selective dihydrofolate reductase inhibitors for pneumocystis pneumonia infection

Pneumocystis pneumonia (PCP) caused by Pneumocystis jirovecii (pj) can lead to serious health consequences in patients with an immunocompromised system. Trimethoprim (TMP), used as first-line therapy in combination with sulfamethoxazole, is a selective but only moderately potent pj dihydrofolate reductase (pjDHFR) inhibitor, whereas non-clinical pjDHFR inhibitors, such as, piritrexim and trimetrexate are potent but non-selective pjDHFR inhibitors. To meet the clinical needs for a potent and selective pjDHFR inhibitor for PCP treatment, fourteen 6-substituted pyrido[3,2-d]pyrimidines were developed. Comparison of the amino acid residues in the active site of pjDHFR and human DHFR (hDHFR) revealed prominent amino acid differences which could be exploited to structurally design potent and selective pjDHFR inhibitors. Molecular modeling followed by enzyme assays of the compounds revealed 15 as the best compound of the series with an IC₅₀ of 80 nM and 28-fold selectivity for inhibiting pjDHFR over hDHFR. Compound 15 serves as the lead analog for further structural variations to afford more potent and selective pjDHFR inhibitors.

A quantitative systems pharmacology (QSP) model for Pneumocystis treatment in mice

BACKGROUND

The yeast-like fungi Pneumocystis, resides in lung alveoli and can cause a lethal infection known as Pneumocystis pneumonia (PCP) in hosts with impaired immune systems. Current therapies for PCP, such as trimethoprim-sulfamethoxazole (TMP-SMX), suffer from significant treatment failures and a multitude of serious side effects. Novel therapeutic approaches (i.e. newly developed drugs or novel combinations of available drugs) are needed to treat this potentially lethal opportunistic infection. Quantitative Systems Pharmacological (QSP) models promise to aid in the development of novel therapies by integrating available pharmacokinetic (PK) and pharmacodynamic (PD) knowledge to predict the effects of new treatment regimens.

RESULTS

In this work, we constructed and independently validated PK modules of a number of drugs with available pharmacokinetic data. Characterized by simple structures and well constrained parameters, these PK modules could serve as a convenient tool to summarize and predict pharmacokinetic profiles. With the currently accepted hypotheses on the life stages of Pneumocystis, we also constructed a PD module to describe the proliferation, transformation, and death of Pneumocystis. By integrating the PK module and the PD module, the QSP model was constrained with observed levels of asci and trophic forms following treatments with multiple drugs. Furthermore, the temporal dynamics of the QSP model were validated with corresponding data.

CONCLUSIONS

We developed and validated a QSP model that integrates available data and promises to facilitate the design of future therapies against PCP.

Pneumocystis jiroveci pneumonia in a patient taking Benepali for rheumatoid arthritis

We present a case of a 57-year-old woman who contracted Pneumocystis jiroveci pneumonia while on Benepali, the biosimilar version of etanercept for rheumatoid arthritis. She had seropositive erosive disease. She was admitted to clinic with a 2-week history of dyspnoea, dry cough and fever. Her initial examination showed her to be hypoxic on air with saturations of 77% and left basal crackles. Her admission chest X-ray showed fine reticular shadowing, with an initial suspicion of pulmonary fibrosis. She was empirically treated for community-acquired pneumonia but continued to deteriorate with a worsening type 1 respiratory failure. She was intubated and ventilated on intensive care. The suspicion was raised of P. jiroveci pneumonia given her immunosuppression, hypoxic presentation and chest X-ray changes. This was confirmed on sputum PCR. She was treated with a 3-week course of steroids and co-trimoxazole. She was discharged home after a 2-week admission.

An Unusual Case of Cystic Fibrosis Associated Pneumocystis jiroveci Pneumonia in an Infant

Pneumocystis jiroveci pneumonia (PJP) is one of the major infections in patients with impaired immunity. The entity is common in HIV-seropositive individuals but quite very rare in HIV-seronegative individuals especially children. We report here a case of 16-week-old HIV-seronegative infant with chief complaint of chronic cough of one month of evolution. Sweat chloride test for diagnosis of cystic fibrosis was positive. Bronchoalveolar lavage (BAL) fluid was collected and Pseudomonas aeruginosa was isolated on culture. Empirical antibiotic regimen comprising ceftriaxone and azithromycin was initiated that was switched to meropenem as per antimicrobial susceptibility report, but the patient did not improve. Subsequently, an immunofluorescence staining of BAL fluid was performed and P. jiroveci cysts were detected. Following a laboratory confirmation of Pneumocystis pneumonia, cotrimoxazole was added and the clinical condition of the patient significantly improved. This is an unusual case wherein unsuspected PJP occurred and since signs and symptoms of the patient persisted even after the initiation of antimicrobial therapy for Pseudomonas infection and resolved only after treatment for PJP was started, it suggests a causative role of P. jiroveci rather than colonization/contamination.

Pneumocystis pneumonia in HIV patients: a diagnostic challenge till date

HIV has become a major health problem in India, patients commonly succumb to opportunistic infections (OIs), respiratory infections being an important cause of morbidity and their accurate diagnosis is still a challenge. Our aim was to study the occurrence of Pneumocystis pneumonia (PCP) in HIV/AIDS patients with respiratory complaints attending ART clinic and to compare various diagnostic methodologies. One hundred and twenty five HIV/AIDS patients presenting with respiratory symptoms like cough, fever, breathlessness etc, were enrolled, and induced sputum samples were collected. Samples were homogenized using glass beads and Dithiothretol. Smears were prepared and examined by Immunoflourescent staining (IFAT), Gomori methanamine silver staining (GMSS), Toludine blue O staining (TBO) and Giemsa staining for Pneumocystis jiroveci. Among the 125 patients who presented with respiratory complaints, 34 cases (27.2%) were diagnosed as having PCP. All 34 cases were detected by IFAT followed by GMSS, Giemsa and Toludine blue O staining in decreasing order. The mean CD4 count was 67.27cells/μl. PCP has become an important health problem in HIV/AIDS patients with low CD4 counts in India. IFAT remains the most sensitive method for the detection of this uncultivable organism. In resource poor settings where an immunoflourecent microscope is not available, diagnosis of PCP still remains problematic.

Vitamin D as Supplemental Therapy for Pneumocystis Pneumonia

The combination of all-trans retinoic acid (ATRA) and primaquine (PMQ) has been shown to be effective for therapy of Pneumocystis pneumonia (PCP). Since a high concentration of ATRA has significant adverse effects, the possibility that vitamin D can be used to replace ATRA for PCP therapy was investigated. C57BL/6 mice were immunosuppressed by depleting CD4(+) cells and infected with Pneumocystis murina 1 week after initiation of immunosuppression. Three weeks after infection, the mice were treated orally for 3 weeks with vitamin D3 (VitD3) alone, PMQ alone, a combination of VitD3 and PMQ (VitD3-PMQ), or a combination of trimethoprim and sulfamethoxazole (TMP-SMX). Results showed that VitD3 (300 IU/kg/day) had a synergistic effect with PMQ (5 mg/kg/day) for therapy of PCP. Flow cytometric studies showed that this VitD3-PMQ combination recovered the CD11b(low) CD11c(high) alveolar macrophage population in mice with PCP as effectively as TMP-SMX. The VitD3-PMQ combination also reduced the massive infiltration of inflammatory cells into the lungs and the severity of lung damage. VitD3 was also shown to reduce the dose of TMP-SMX required for effective treatment of PCP. Taken together, results of this study suggest that a VitD3-PMQ combination can be used as an alternative therapy for PCP.

Cost-effectiveness of Prophylaxis Against Pneumocystis jiroveci Pneumonia in Patients with Crohn's Disease

BACKGROUND

Emerging evidence suggests that Pneumocystis jiroveci pneumonia is occurring more frequently in Crohn's disease patients on immunosuppressive medications, especially corticosteroids. Considering its excess mortality and the efficacy of chemoprophylaxis in reducing P. jiroveci pneumonia in acquired immunodeficiency syndrome, there is debate without consensus on the need for chemoprophylaxis in Crohn's disease patients on corticosteroids.

AIMS

We sought to address this debate using insights from simulation modeling.

METHODS

We used a Markov microsimulation model to simulate the natural history of Crohn's disease in 1 million virtual patients receiving appropriate care and who faced P. jiroveci pneumonia risks that varied with corticosteroid use. We examined several chemoprophylaxis strategies and compared their population-level economic and clinical impact using various indices including costs, quality-adjusted life expectancy, and incremental cost-effectiveness ratios. We also performed several nested probabilistic sensitivity analyses to estimate the health and economic impact of chemoprophylaxis in patients on triple immunosuppressive therapy.

RESULTS

At the current PJP incidence, no PJP chemoprophylaxis was the preferred strategy from a population perspective. Considered chemoprophylactic strategies led to higher average costs and fewer P. jiroveci pneumonia cases. However, they also led to lower average quality-adjusted life expectancy and were thus dominated. Nevertheless, these alternative strategies became preferred with progressively higher risks of P. jiroveci pneumonia. Our results also suggest that PJP chemoprophylaxis may be cost-effective in patients on triple immunosuppressive therapy.

CONCLUSION

Our findings support a case-by-case consideration of P. jiroveci pneumonia chemoprophylaxis in Crohn's disease patients receiving corticosteroids.

Severe Pneumocystis jirovecii pneumonia in an idiopathic CD4+ lymphocytopenia patient: case report and review of the literature

INTRODUCTION

When diagnosing Pneumocystis jirovecii pneumonia (PJP), the clinical suspicion must be confirmed by laboratory tests. PJP is rarely described in patients with idiopathic CD4⁺ lymphocytopenia (ICL), a rare T-cell deficiency of unknown origin with persistently low levels of CD4⁺ T-cells (<300 µl^-1 or <20 % of total lymphocytes) but repeated negative human immunodeficiency virus (HIV) tests. We retrospectively analysed a case of an ICL patient with severe PJP associated with multiple opportunistic infections (OIs). We also reviewed the literature since 1986.

CASE PRESENTATION

A laboratory-confirmed case of PJP associated with invasive candidiasis and cytomegalovirus infection was reported in an ICL patient. Despite early treatment, the patient died of respiratory failure under polymicrobial pneumonia. According to the literature, the mortality rate of ICL patients is 10.4 % (33/316). In ICL patients, the risk of OI is 83.2 % (263/316), with viral infections being the most prevalent (58.2 %, 184/316), followed by fungal infections (52.2 %, 165/316) and mycobacterial infections (15.5 %, 49/316). Dysimmunity is reported in 15.5 % (49/316) of ICL patients. Among the fungal infections, cryptococcal infections are the most prevalent (24.1 %, 76/316), followed by candidiasis (15.5 %, 49/316) and PJP (7.9 %, 25/316).

CONCLUSIONS

The high risk of OIs underlines the importance of more vigorous preventative actions in hospitals. The response to therapy and the detection of early relapse of PJP may be monitored by several laboratory tests including quantitative PCR. It is essential to treat the ICL and to follow the guidelines concerning therapy and prophylaxis of OIs as given to HIV patients.

Practical guidelines: lung transplantation in patients with cystic fibrosis

There are no European recommendations on issues specifically related to lung transplantation (LTX) in cystic fibrosis (CF). The main goal of this paper is to provide CF care team members with clinically relevant CF-specific information on all aspects of LTX, highlighting areas of consensus and controversy throughout Europe. Bilateral lung transplantation has been shown to be an important therapeutic option for end-stage CF pulmonary disease. Transplant function and patient survival after transplantation are better than in most other indications for this procedure. Attention though has to be paid to pretransplant morbidity, time for referral, evaluation, indication, and contraindication in children and in adults. This review makes extensive use of specific evidence in the field of lung transplantation in CF patients and addresses all issues of practical importance. The requirements of pre-, peri-, and postoperative management are discussed in detail including bridging to transplant and postoperative complications, immune suppression, chronic allograft dysfunction, infection, and malignancies being the most important. Among the contributors to this guiding information are 19 members of the ECORN-CF project and other experts. The document is endorsed by the European Cystic Fibrosis Society and sponsored by the Christiane Herzog Foundation.