Pneumocystis pneumonia associated with human immunodeficiency virus

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

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.

No Statistically Apparent Difference in Antifungal Effectiveness Observed Among Trimethoprim/Sulfamethoxazole Plus Clindamycin or Caspofungin, and Trimethoprim/Sulfamethoxazole Monotherapy in HIV-Infected Patients with Moderate to Severe Pneumocystis Pneumonia: Results of an Observational Multicenter Cohort Study

INTRODUCTION

Pneumocystis pneumonia is a common opportunistic infection in patients with HIV/AIDS, and is a leading cause of death in this population. Early selection of effective treatment is therefore critical to reduce mortality. We conducted a clinical trial to compare the effectiveness and safety of three different antifungal treatment regimens in HIV-infected patients with moderate to severe PCP.

METHODS

Our study was a multicenter, observational prospective clinical trial. We recruited 320 HIV-infected patients with moderate to severe PCP, and stratified these subjects into a trimethoprim/sulfamethoxazole (TMP-SMX) monotherapy group, a TMP-SMX plus clindamycin group, and a TMP-SMX plus caspofungin group. Patients were invited to participate in 12 weeks of follow-up. Outcomes included the difference in overall mortality and the proportion of overall positive response to treatment in the three groups at weeks 4 and 12, the difference in treatment duration, and the proportion of adverse events among the three groups during the study period.

RESULTS

The probability of survival not statistically different among three treatment groups. Mortality in the TMP-SMX monotherapy group (group 1) was 15/115 (13.04%) vs. 20/83 (24.10%) in the TMP-SMX plus clindamycin group (group 2) vs. 24/107 (22.43%) in the TMP-SMX plus caspofungin group (group 3) at week 12 (p = 0.092). The overall positive response rate to treatment in the three groups was 24.14%, 34.94%, and 38.32%, respectively, at week 4, and 33.91%, 38.55%, and 44.86%, respectively, at week 12. No significant difference in the overall positive response rate to treatment at either week 4 or week 12 was noted (p = 0.061, p = 0.246). Rates of changes to therapy were 6.50% (8/123) in group 1, 3.40% (3/87) in group 2, and 2.70% (3/110) in group 3, and did not differ significantly among the three groups (p = 0.376). There were also no significant differences in adverse events among the three treatment groups of patients with moderate to severe PCP.

CONCLUSIONS

Our results indicate that there are no significant statistical differences among the three studied treatment regimens in terms of antifungal effectiveness in HIV-infected patients with moderate to severe PCP. TMP-SMX monotherapy is a convenient, cheap, and effective therapeutic drug regimen to treat HIV-infected patients with moderate to severe PCP, and is an appropriate treatment strategy in resource-limited settings.

CLINICAL TRIAL REGISTRATION

www.ClinicalTrials.gov , ID: ChiCTR1900021195. Registered on February 1, 2019.

Low cut-off value of serum (1,3)-beta-D-glucan for the diagnosis of Pneumocystis pneumonia in non-HIV patients: a retrospective cohort study

Background

Non-human immunodeficiency virus (HIV) Pneumocystis pneumonia (PCP) is a fulminant disease with an increasing incidence. The serum beta-d-glucan (BDG) assay is used as an adjunct to the diagnosis of PCP; however, the cut-off value for this assay is not well-defined, especially in the non-HIV PCP population. Therefore, we aimed to identify the assay cut-off value for this population.

Methods

In this retrospective observational study, we reviewed the medical records of all patients (≥ 18 years old) with clinical suspicion of PCP who underwent evaluation of respiratory tract specimens between December 2008 and June 2014 at Kameda Medical Center. We created a receiver operating characteristic curve and calculated the area under the curve to determine the cut-off value for evaluating the inspection accuracy of the BDG assay.

Results

A total of 173 patients were included in the study. Fifty patients showed positive results in specimen staining, loop-mediated isothermal amplification assay, and polymerase chain reaction test, while 123 patients showed negative results. The receiver operating characteristic analyses suggested that the BDG cut-off level was 8.5 pg/mL, with a sensitivity and specificity of 76% and 76%, respectively.

Conclusions

The Wako-BDG cut-off value for the diagnosis of non-HIV PCP is 8.5 pg/mL, which is lower than the classical cut-off value from previous studies. Clinicians should potentially consider this lower BDG cut-off value in the diagnosis and management of patients with non-HIV PCP.

Trial registration: The participants were retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06895-x.

Diagnostic Challenges of Pneumocystis Pneumonia during the COVID-19 Pandemic: A Case of a Young Patient with Ground Glass Opacities and Pulmonary Embolism on Chest CT

The coronavirus disease 2019 (COVID-19) pandemic is wreaking havoc across the globe. This pandemic has given rise to a mindset where physicians tend to neglect other causes of pneumonia, especially if the patient presents with signs and symptoms commonly associated with COVID-19. Herein, we report a case of a young man presenting to the emergency department with common clinical, radiological, and laboratory features of COVID-19 pneumonia such as shortness of breath, hypoxia, pulmonary embolism, elevated D-dimer, and bilateral ground glass opacities on computed tomography of the chest but was later diagnosed with Pneumocystis pneumonia that was treated with appropriate antibiotics and corticosteroids. This case highlights the importance of performing a thorough clinical history and differentiating the clinical and radiological features of COVID-19 pneumonia from pneumonia of other etiologies.

Pneumocystis Pneumonia: Immunity, Vaccines, and Treatments

For individuals who are immunocompromised, the opportunistic fungal pathogen Pneumocystis jirovecii is capable of causing life-threatening pneumonia as the causative agent of Pneumocystis pneumonia (PCP). PCP remains an acquired immunodeficiency disease (AIDS)-defining illness in the era of antiretroviral therapy. In addition, a rise in non-human immunodeficiency virus (HIV)-associated PCP has been observed due to increased usage of immunosuppressive and immunomodulating therapies. With the persistence of HIV-related PCP cases and associated morbidity and mortality, as well as difficult to diagnose non-HIV-related PCP cases, an improvement over current treatment and prevention standards is warranted. Current therapeutic strategies have primarily focused on the administration of trimethoprim-sulfamethoxazole, which is effective at disease prevention. However, current treatments are inadequate for treatment of PCP and prevention of PCP-related death, as evidenced by consistently high mortality rates for those hospitalized with PCP. There are no vaccines in clinical trials for the prevention of PCP, and significant obstacles exist that have slowed development, including host range specificity, and the inability to culture Pneumocystis spp. in vitro. In this review, we overview the immune response to Pneumocystis spp., and discuss current progress on novel vaccines and therapies currently in the preclinical and clinical pipeline.

Clinical characteristics and prevalence of dihydropteroate synthase gene mutations in Pneumocystis jirovecii-infected AIDS patients from low endemic areas of China

Pneumocystis pneumonia (PCP) is an opportunistic and potentially life-threatening infection of AIDS patients caused by the fungus Pneumocystis jirovecii (P. jirovecii). Trimethoprim-sulfamethoxazole (TMP-SMX) is the most commonly used drug combination in the treatment and prophylaxis of PCP. However, with long-term use of this combination, mutations in the dihydropteroate synthase (DHPS) gene of P. jirovecii bring about the development of resistance. Data on the prevalence of P. jirovecii and its DHPS mutants in China, especially in low endemic areas, are still limited. Thus, in the present study, we measured the P. jirovecii infection rate among HIV-positive and AIDS (HIV/AIDS) patients with suspected PCP and investigated the relationship between CD4+ T cell count and PCP occurrence. As well as the polymerase chain reaction (PCR) analysis and sequencing, the restriction fragment length polymorphism (RFLP) method was used to analyze DHPS point mutation in P. jirovecii strains. P. jirovecii was detected in 40.82% of cases. The clinical symptoms and signs of PCP were not typical; with decreasing CD4+ T cell counts, PCP infection in HIV/AIDS patients increased. In only one case (1.67%), the patients' DHPS gene could not be cut by the Acc I restriction enzyme. Furthermore, mutation at codon 171 was detected in 11 cases and no mutation was found at codon 57. Patients treated with sulfamethoxazole combined with Voriconazole or Caspofungin exhibited favorable results. After treatment, the symptoms of dyspnea were alleviated, and chest computed tomography findings showed the improvement of lung shadows. These indicated that the prevalence of DHPS mutations in P. jirovecii isolates in AIDS-PCP patients in the region was low. Thus, the contribution of gene mutations to treatment failure requires further research.

Missed opportunity to diagnose HIV with Pneumocystis carinii pneumonia as its sequela

Pneumocystis carinii pneumonia (PCP) is an opportunistic infection of the lung occurring primarily in patients with HIV infection with a CD4 cell count <200 mm3, solid organ transplant recipients and those taking immunosuppressive therapy. The 1980s heralded the HIV pandemic, turning PCP into a major medical and public health problem worldwide. Manifestations of unusual infections such as pneumocystis and Kaposi's sarcoma, were, after all, the first signs of the emerging pandemic to be recognised and may indeed, be the presenting feature of a previously undiagnosed HIV infection. With the advent of pneumocystis chemoprophylaxis and the initiation of highly active antiretroviral therapy, there has been a decreased incidence in developed countries, but it remains high in developing countries. Unfortunately, late presentation of HIV remains a problem resulting in significant morbidity and mortality. The authors report the case of a new diagnosis of HIV infection in a 45-year-old woman, presenting with a dry cough, dyspnoea, unintentional weight loss and PCP. Two weeks after commencing highly active antiretroviral therapy, she was diagnosed with immune reconstitution inflammatory syndrome. Research shows that stigma and discrimination in the healthcare setting contributes to keeping individuals from accessing HIV prevention, care and treatment services and adopting key preventive behaviours. The barriers to HIV testing and stigma eradication in primary care will be explored as well as missed opportunities to diagnosis HIV in primary care in individuals presenting with signs and symptoms of immunosuppression, in this case shingles.

Pneumocystis pneumonia in the twenty-first century: HIV-infected versus HIV-uninfected patients

Introduction: Pneumocystis pneumonia (PcP) has classically been described as a serious complication in patients infected with the human immunodeficiency virus (HIV). However, the emerging number of conditions associated with immunosuppression has led to its appearance in other patient populations. Areas covered: This article reviews the most recent publications on PcP in the HIV-infected and HIV-uninfected population, focusing on epidemiology, diagnostic, therapy and prevention. The data discussed here were mainly obtained from a non-systematic review using Medline and references from relevant articles including randomized clinical trials, meta-analyses, observational studies and clinical reviews. Expert opinion: The growing incidence of Pneumocystis infection in the HIV-uninfected population suggests the need for new global epidemiological studies in order to identify the true scale of the disease in this population. These data would allow us to improve diagnosis, therapeutic strategies, and clinical management. It is very important that both patients and physicians realize that HIV-uninfected patients are at risk of PcP and that rapid diagnosis and early initiation of treatment are associated with better prognosis. Currently, in-hospital mortality rates are very high: 15% for HIV-infected patients and 50% in some HIV-uninfected patients. Therefore, adequate preventive measures should be implemented to avoid the high mortality rates seen in recent decades.

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.

Diffusion of Pneumocystis jirovecii in the surrounding air of patients with Pneumocystis colonization: frequency and putative risk factors

In a prospective bicentric study, Pneumocystis jirovecii excretion and diffusion was explored in air samples collected in the rooms occupied by 17 Pneumocystis-colonized patients. P. jirovecii DNA was detected by real-time PCR in the air collected from 3 patients' rooms (17.6%), with identical genotypes in corresponding clinical and air samples. Pneumocystis DNA was detected for 2/3 patients with autoimmune disease treated with corticosteroids versus 1/6 patients with hematologic disease and 0/5 kidney transplant recipients. These data confirm the possible excretion of the fungus by Pneumocystis-colonized patients and thus bring additional arguments for the prevention of airborne transmission in hospital wards.

The diagnosis of multiple opportunistic infections in advanced stage AIDS: when Ockham's Razor doesn't cut it

In the advanced stage of AIDS, the diagnosis of the opportunistic infections may be challenging due to the high risk of performing invasive diagnostic methods in a patient with a critical clinical condition, as well as the correct interpretation of the results of microbiological exams. One of the challenges for the diagnosis and treatment of the opportunistic infections is that they may occur concomitantly in the same patient and they may mimic each other, leading to a high discrepancy between clinical and autopsy diagnoses. We describe the case of a 52-year-old man who was hospitalized because of weight loss, anemia, cough, and hepatosplenomegaly. During the investigation, the diagnosis of AIDS was made, and the patient developed respiratory failure and died on the fourth day of hospitalization. At autopsy, disseminated non-tuberculosis mycobacteriosis was found, affecting mainly the organs of the reticuloendothelial system. Also, severe and diffuse pneumonia caused by multiple agents (Pneumocystis jirovecii , Histoplasma capsulatum, suppurative bacterial infection, non-tuberculosis mycobacteria, and cytomegalovirus) was seen in a morphological pattern that could be called "collision pneumonia." The lesson from this case, revealed by the autopsy, is that in advanced AIDS, patients often have multiple opportunistic infections, so the principle of Ockham's razor-that a single diagnosis is most likely the best diagnosis-fails in this clinical context.

Targeting species specific amino acid residues: Design, synthesis and biological evaluation of 6-substituted pyrrolo[2,3-d]pyrimidines as dihydrofolate reductase inhibitors and potential anti-opportunistic infection agents

To combine the potency of trimetrexate (TMQ) or piritrexim (PTX) with the species selectivity of trimethoprim (TMP), target based design was carried out with the X-ray crystal structure of human dihydrofolate reductase (hDHFR) and the homology model of Pneumocystis jirovecii DHFR (pjDHFR). Using variation of amino acids such as Met33/Phe31 (in pjDHFR/hDHFR) that affect the binding of inhibitors due to their distinct positive or negative steric effect at the active binding site of the inhibitor, we designed a series of substituted-pyrrolo[2,3-d]pyrimidines. The best analogs displayed better potency (IC₅₀) than PTX and high selectivity for pjDHFR versus hDHFR, with 4 exhibiting a selectivity for pjDHFR of 24-fold.

Burden of Fungal Infections in Colombia

Data with respect to the epidemiological situation of fungal diseases in Colombia is scarce. Thus, the aim of this study is to estimate the burden of fungal infections. A population projection for 2017 from the Colombian Department for National Statistics was used, as well as official information from the Ministry of Health and National Institute of Health. A bibliographical search for Colombian data on mycotic diseases and population at risk (chronic obstructive pulmonary disease, HIV infection/AIDS, cancer, and transplant patients) was done. The Colombian population for 2017 was estimated at 49,291,609 inhabitants, and the estimated number of fungal infections for Colombia in 2017 was between 753,523 and 757,928, with nearly 600,000 cases of candidiasis, 130,000 cases of aspergillosis, and 16,000 cases of opportunistic infection in HIV, affecting around 1.5% of the population. In conclusion, fungal infections represent an important burden of disease for the Colombian population. Different clinical, epidemiological, and developmental scenarios can be observed in which fungal infections occur in Colombia.

Importance of tissue sampling, laboratory methods, and patient characteristics for detection of Pneumocystis in autopsied lungs of non-immunosuppressed individuals

To understand the epidemiological significance of Pneumocystis detection in a lung tissue sample of non-immunosuppressed individuals, we examined sampling procedures, laboratory methodology, and patient characteristics of autopsy series reported in the literature. Number of tissue specimens, DNA-extraction procedures, age and underlying diagnosis highly influence yield and are critical to understand yield differences of Pneumocystis among reports of pulmonary colonization in immunocompetent individuals.

Approach to Fungal Infections in Human Immunodeficiency Virus-Infected Individuals: Pneumocystis and Beyond

Many fungi cause pulmonary disease in patients with human immunodeficiency virus (HIV) infection. Pathogens include Pneumocystis jirovecii, Cryptococcus neoformans, Aspergillus spp, Histoplasma capsulatum, Coccidioides spp, Blastomyces dermatitidis, Paracoccidioides brasiliensis, Talaromyces marneffei, and Emmonsia spp. Because symptoms are frequently nonspecific, a high index of suspicion for fungal infection is required for diagnosis. Clinical manifestations of fungal infection in HIV-infected patients frequently depend on the degree of immunosuppression and the CD4⁺ helper T cell count. Establishing definitive diagnosis is important because treatments differ. Primary and secondary prophylaxes depend on CD4⁺ helper T cell counts, geographic location, and local prevalence of disease.

High Prevalence of Pneumocystis jirovecii Dihydropteroate Synthase Gene Mutations in Patients with a First Episode of Pneumocystis Pneumonia in Santiago, Chile, and Clinical Response to Trimethoprim-Sulfamethoxazole Therapy

Mutations in the dihydropteroate synthase (DHPS) gene of Pneumocystis jirovecii are associated with the failure of sulfa prophylaxis. They can develop by selection in patients receiving sulfa drugs or be acquired via person-to-person transmission. DHPS mutations raise concern about the decreasing efficacy of sulfa drugs, the main available therapeutic tool for Pneumocystis pneumonia (PCP). The prevalence of Pneumocystis DHPS mutations was examined in Pneumocystis isolates from 56 sulfa-prophylaxis-naive adults with a first episode of PCP from 2002 to 2010 in Santiago, Chile. Their clinical history was reviewed to analyze the effect of these mutations on response to trimethoprim-sulfamethoxazole (TMP-SMX) therapy and outcome. Mutant genotypes occurred in 22 (48%) of 46 HIV-infected patients and in 5 (50%) of 10 HIV-uninfected patients. Compared to patients with a wild-type genotype, those with mutant genotypes were more likely to experience sulfa treatment-limiting adverse reactions and to have a twice-longer duration of mechanical ventilation if mechanically ventilated. Specific genotypes did not associate with death, which occurred in none of the HIV-infected patients and in 50% of the non-HIV-infected patients. Chile has a high prevalence of DHPS mutations, which were presumably acquired through interhuman transmission because patients were not on sulfa prophylaxis. These results contrast with the low prevalence observed in other Latin American countries with similar usage of sulfa drugs, suggesting that additional sources of resistant genotypes may be possible. The twice-longer duration of mechanical ventilation in patients with mutant DHPS genotypes suggests a decreased efficacy of TMP-SMX and warrants collaborative studies to assess the relevance of DHPS mutations and further research to increase therapeutic options for PCP.

Pneumocystis Pneumonia Concomitant with Ectopic ACTH Syndrome Caused by a Large Cell Neuroendocrine Carcinoma of the Thymus

We herein report the case of a 44-year-old man who was diagnosed with pneumocystis pneumonia (PCP) concomitant with ectopic adrenocorticotropic hormone (ACTH) syndrome, which had been caused by a large cell neuroendocrine carcinoma of the thymus. Chest computed tomography revealed ground-glass opacities in the lungs. PCP was diagnosed by a polymerase chain reaction with bronchoalveolar lavage. The levels of cortisol were slowly corrected with an adrenal enzyme inhibitor, and the exacerbation of PCP was successfully avoided. Our case indicates that in addition to prophylaxis, the early diagnosis of PCP and the slow correction of hypercortisolemia should be considered in order to prevent an exacerbation due to the reconstitution of the immune function in patients with ectopic ACTH syndrome.

Vaccine-Induced Immunogenicity and Protection Against Pneumocystis Pneumonia in a Nonhuman Primate Model of HIV and Pneumocystis Coinfection

BACKGROUND

The ubiquitous opportunistic pathogen Pneumocystis jirovecii causes pneumonia in immunocompromised individuals, including human immunodeficiency virus (HIV)-infected individuals, and pulmonary colonization with P. jirovecii is believed to be a cofactor in the development of chronic obstructive pulmonary disease. There is no vaccine for P. jirovecii; however, most adults are seropositive, indicating natural immune priming to this pathogen. We have shown that humoral response to a recombinant subunit of the P. jirovecii protease kexin (KEX1) correlates with protection from P. jirovecii colonization and pneumonia.

METHODS

Here we evaluated the immunogenicity and protective capacity of the recombinant KEX1 peptide vaccine in a preclinical, nonhuman primate model of HIV-induced immunosuppression and Pneumocystis coinfection.

RESULTS

Immunization with KEX1 induced a robust humoral response remained at protective levels despite chronic simian immunodeficiency virus/HIV-induced immunosuppression. KEX1-immunized macaques were protected from Pneumocystis pneumonia, compared with mock-immunized animals (P= .047), following immunosuppression and subsequent natural, airborne exposure to Pneumocystis

CONCLUSIONS

These data support the concept that stimulation of preexisting immunological memory to Pneumocystis with a recombinant KEX1 vaccine prior to immunosuppression induces durable memory responses and protection in the context of chronic, complex immunosuppression.

Evidence for Proinflammatory β-1,6 Glucans in the Pneumocystis carinii Cell Wall

Inflammation is a major cause of respiratory impairment during Pneumocystis pneumonia. Studies support a significant role for cell wall β-glucans in stimulating inflammatory responses. Fungal β-glucans are comprised of d-glucose homopolymers containing β-1,3-linked glucose backbones with β-1,6-linked glucose side chains. Prior studies in Pneumocystis carinii have characterized β-1,3 glucan components of the organism. However, recent investigations in other organisms support important roles for β-1,6 glucans, predominantly in mediating host cellular activation. Accordingly, we sought to characterize β-1,6 glucans in the cell wall of Pneumocystis and to establish their activity in lung cell inflammation. Immune staining revealed specific β-1,6 localization in P. carinii cyst walls. Homology-based cloning facilitated characterization of a functional P. carinii kre6 (Pckre6) β-1,6 glucan synthase in Pneumocystis that, when expressed in kre6-deficient Saccharomyces cerevisiae, restored cell wall stability. Recently synthesized β-1,6 glucan synthase inhibitors decreased the ability of isolated P. carinii preparations to generate β-1,6 carbohydrate. In addition, isolated β-1,6 glucan fractions from Pneumocystis elicited vigorous tumor necrosis factor alpha (TNF-α) responses from macrophages. These inflammatory responses were significantly dampened by inhibition of host cell plasma membrane microdomain function. Together, these studies indicate that β-1,6 glucans are present in the P. carinii cell wall and contribute to lung cell inflammatory activation during infection.

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.

Multicenter study of trimethoprim/sulfamethoxazole-related hepatotoxicity: incidence and associated factors among HIV-infected patients treated for Pneumocystis jirovecii pneumonia

The incidence of hepatotoxicity related to trimethoprim/sulfamethoxazole (TMP/SMX) administered at a therapeutic dose may vary among study populations of different ethnicities and hepatotoxic metabolites of TMP/SMX may be decreased by drug-drug interaction with fluconazole. We aimed to investigate the incidence of hepatotoxicity and the role of concomitant use of fluconazole in HIV-infected patients receiving TMP/SMX for Pneumocystis jirovecii pneumonia. We reviewed medical records to collect clinical characteristics and laboratory data of HIV-infected patients who received TMP/SMX for treatment of P. jirovecii pneumonia at 6 hospitals around Taiwan between September 2009 and February 2013. Hepatotoxicity was defined as 2-fold or greater increase of aminotransferase or total bilirubin level from baselines. Roussel UCLAF Causality Assessment Method (RUCAM) was used to analyze the causality of drug-induced liver injuries. NAT1 and NAT2 acetylator types were determined with the use of polymerase-chain-reaction (PCR) restriction fragment length polymorphism to differentiate common single-nucleotide polymorphisms (SNPs) predictive of the acetylator phenotypes in a subgroup of patients. During the study period, 286 courses of TMP/SMX treatment administered to 284 patients were analyzed. One hundred and fifty-two patients (53.1%) developed hepatotoxicity, and TMP/SMX was considered causative in 47 (16.4%) who had a RUCAM score of 6 or greater. In multivariate analysis, concomitant use of fluconazole for candidiasis was the only factor associated with reduced risk for hepatotoxicity (adjusted odds ratio, 0.372; 95% confidence interval, 0.145–0.957), while serostatus of hepatitis B or C virus, NAT1 and NAT2 acetylator types, or receipt of combination antiretroviral therapy was not. The incidence of hepatotoxicity decreased with an increasing daily dose of fluconazole up to 4.0 mg/kg. We conclude that the incidence of TMP/SMX-related hepatotoxicity was 16.4% in HIV-infected Taiwanese patients who received TMP/SMX for pneumocystosis. Concomitant use of fluconazole was associated with decreased risk for TMP/SMX-related hepatotoxicity.

Diffuse Renal Cortical Echogenic Foci in a Patient With AIDS

Pneumocystis jirovecii is ubiquitous in the environment and is best known as the cause of Pneumocystis pneumonia (PCP) in immune-suppressed hosts. Extrapulmonary P. jirovecii is a rare complication of this opportunistic infection primarily seen in patients with immune-deficient states. Nephritis due to P. jirovecii was first described by Bargman in 1991 in a patient with atypical nephrocalcinosis found on conventional radiography. This case report presents a patient with Pneumocystis nephritis and describes the sonographic appearance as well as the advantages of sonography in the early detection of this uncommon condition.