Pneumocystisinfection in humans: diagnosis and treatment

The Clinical Value of Metagenomic Next-Generation Sequencing in Pneumocystis jirovecii Pneumonia

Background

The incidence of Pneumocystis jirovecii pneumonia (PJP) is increasing.

Methods

108 patients were analysed retrospectively at the Wuhan Union Hospital. The patients were classified into the PJP group or the P. jirovecii colonisation (PJC) group based on clinical diagnosis. Clinical data included demographics, laboratory examinations, treatment, and outcomes.

Results

A notable difference in the fungal load was seen between two groups, with median reads of 3215.79 vs. 5.61 in two groups, respectively (P<0.001). The optimal threshold value for discriminating P. jirovecii infection between colonisation for mNGS was six, and serum (1,3)-β-D-glucan (BDG) was 47.6 pg/mL. Besides, the positive detection rate of mNGS for co-pathogens in PJP patients was significantly higher than that of culture (88.16% vs. 22.37%, P<0.0001). Epstein-Barr virus and cytomegalovirus were the most common pathogens of co-infection in PJP patients. The antibiotic therapy in PJP patients was adjusted according to the mNGS results, of which seventeen (22.37%) were downgraded, 38 (50.0%) patients were upgraded, and 21 (27.63%) were unchanged. And almost all patients showed significant improvement in C-reactive protein.

Conclusion

mNGS is a promising and valuable technique with good performance for differentiating P. jirovecii infection and colonisation, the detection of pathogens, and antibiotic treatment.

Levels of soluble TNF receptors (sTNFR1 and sTNFR2) increase with clinical worsening of patients and are related to COVID-19 mortality

The present study aimed to inspect the serum levels of the soluble receptors, sTNFR1 and sTNFR2, in patients with COVID-19. The large production of inflammatory cytokines is an essential process in the pathogenesis of COVID-19. TNF is a multifaceted proinflammatory cytokine which has soluble and membrane receptors. Thus, knowing the role of these receptors will help better understand this disease's immunopathogenesis. We included 131 patients confirmed for SARS-CoV-2, separated into three groups: ward patients without O2 support, group A (n = 14); ward patients with O2 support, group B (n = 85), and patients in an intensive care unit (ICU), group C (n = 32), making up the receptors dosed by flow cytometry. The results showed that sTNFR1 and sTNFR2 are associated with disease severity, being higher in group C when compared to group A. As for the levels of receptors and their relationship with the degree of lung involvement, we found higher values of sTNFR1 in patients in group 1 (pulmonary involvement < 25%), suggesting that inflammatory processes related to TNF are not necessarily associated with the primary site of infection. When we analysed the patients who passed away compared to those who recovered, both receptors significantly increased the mortality numbers. These findings suggest a relevant influence of soluble receptors in the inflammatory processes involved in the pathogenesis of COVID-19. Wherefore, we suggest using these receptors as biomarkers of severity and mortality of the disease.

Negative serum (1,3) -β-D-glucan has a low power to exclude Pneumocystis jirovecii pneumonia (PJP) in HIV-uninfected patients with positive qPCR

OBJECTIVE

The current study evaluated the diagnostic performance of serum (1,3)-beta-D Glucan (BDG) in differentiating PJP from P. jirovecii-colonization in HIV-uninfected patients with P. jirovecii PCR-positive results.

METHODS

This was a single-center retrospective study between 2019 and 2021. The diagnosis of PJP was based on the following criteria: detection of P. jirovecii in sputum or BAL specimen by qPCR or microscopy; Meet at least two of the three criteria: (1) have respiratory symptoms of cough and/or dyspnea, hypoxia; (2) typical radiological picture findings; (3) receiving a complete PJP treatment. After exclusion, the participants were divided into derivation and validation cohorts. The derivation cohort defined the cut-off value of serum BDG. Then, it was verified using the validation cohort.

RESULTS

Two hundred and thirteen HIV-uninfected patients were enrolled, with 159 PJP and 54 P. jirovecii-colonized patients. BDG had outstanding specificity, LR, and PPV for PJP in both the derivation (90.00%, 8.900, and 96.43%) and the validation (91.67%, 9.176, and 96.30%) cohorts at ≥ 117.7 pg/mL. However, it had lower sensitivity and NPV in the derivation cohort (89.01% and 72.97%), which was even lower in the validation cohort (76.47% and 57.89%). Of note, BDG ≥ 117.7 pg/mL has insufficient diagnostic efficacy for PJP in patients with lung cancer, interstitial lung disease (ILD) and nephrotic syndrome. And although lymphocytes, B cells, and CD4+ T cells in PJP patients were significantly lower than those in P. jirovecii-colonized patients, the number and proportion of peripheral blood lymphocytes did not affect the diagnostic efficacy of serum BDG.

CONCLUSIONS

Serum BDG ≥ 117.7 pg/mL could effectively distinguish P. jirovecii-colonization from infection in qPCR-positive HIV-uninfected patients with infectious diseases, solid tumors (excluding lung cancer), autoimmune or inflammatory disorders, and hematological malignancies. Of note, for patients with lung cancer, ILD, and nephrotic diseases, PJP should be cautiously excluded at BDG < 117.7 pg/mL.

A machine learning diagnostic model for Pneumocystis jirovecii pneumonia in patients with severe pneumonia

BACKGROUND

The diagnosis of Pneumocystis jirovecii pneumonia (PCP) in patients presenting with severe pneumonia is challenging and delays in treatment were associated with worse prognosis. This study aimed to develop a rapid, easily available, noninvasive machine learning diagnostic model for PCP among patients with severe pneumonia.

METHODS

A retrospective study was performed in West China Hospital among consecutive patients with severe pneumonia who had undergone bronchoalveolar lavage for etiological evaluation between October 2010 and April 2021. Factors associated with PCP were identified and four diagnostic models were established using machine learning algorithms including Logistic Regression, eXtreme Gradient Boosting, Random Forest (RF) and LightGBM. The performance of these models were evaluated by the area under the receiver operating characteristic curve (AUC).

RESULTS

Ultimately, 704 patients were enrolled and randomly divided into a training set (n = 564) and a testing set (n = 140). Four factors were ultimately selected to establish the model including neutrophil, globulin, β-D-glucan and ground glass opacity. The RF model exhibited the greatest diagnostic performance with an AUC of 0.907. The calibration curve and decision curve analysis also demonstrated its accuracy and applicability.

CONCLUSIONS

We constructed a PCP diagnostic model in patients with severe pneumonia using four easily available and noninvasive clinical indicators. With satisfying diagnostic performance and good clinical practicability, this model may help clinicians to make early diagnosis of PCP, reduce the delays of treatment and improve the prognosis among these patients.

Pneumocystis pneumonia in COVID-19 patients: A comprehensive review

The admitted patients of intensive care units with coronavirus disease 2019 (COVID-19) meet the challenges of subsequent infections. Opportunistic fungal infections such as Pneumocystis pneumonia (PCP) are among the important factors in the context of COVID-19 patients affecting illness severity and mortality. We reviewed the literature on COVID-19 patients with PCP to identify features of this infection. Although studies confirmed at least the presence of one immunosuppressive condition in half of PCP patients, this disease can also occur in immunocompetent patients who developed the immunosuppressive condition during Covid-19 treatment. The major risk factors associated with COVID-19 patients with PCP can be considered low lymphocyte counts and corticosteroid therapy. Diagnostic and treatment options are complicated by the overlapping clinical and radiologic characteristics of PCP and COVID-19 pneumonia. Therefore, physicians should comprehensively evaluate high-risk patients for PCP prophylaxis.

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

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-19's 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.

The medication for pneumocystis pneumonia with glucose-6-phosphate dehydrogenase deficiency patients

Pneumocystis pneumonia (PCP) is an opportunity acquired infection, which is usually easy to occur in patients with AIDS, organ transplantation, and immunosuppressive drugs. The prevention and treatment must be necessary for PCP patients with immunocompromise. And the oxidants are currently a typical regimen, including sulfanilamide, dapsone, primaquine, etc. Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-linked gene-disease that affects about 400 million people worldwide. The lack of G6PD in this population results in a decrease in intracellular glutathione synthesis and a weakening of the detoxification ability of the oxidants. As a result, oxidants can directly damage haemoglobin in red blood cells, inducing methemoglobin and hemolysis. When patients with G6PD deficiency have low immunity, they are prone to PCP infection, so choosing drugs that do not induce hemolysis is essential. There are no clear guidelines to recommend the drug choice of this kind of population at home and abroad. This paper aims to demonstrate the drug choice for PCP patients with G6PD deficiency through theoretical research combined with clinical cases.

Outcomes and Risk Factors for Mortality in Pneumocystis Pneumonia Patients with Rheumatoid Arthritis: A Multicenter Retrospective Cohort Study

OBJECTIVE

To evaluate outcomes and risk factors for death in patients with rheumatoid arthritis (RA) who developed Pneumocystis pneumonia (PCP).

METHODS

: We included RA patients who were diagnosed with PCP at seven participating community hospitals between July 2005 and October 2020. Clinical features were compared between survivors and non-survivors. Disease-modifying antirheumatic drugs (DMARDs) before PCP onset and after PCP recovery were also examined.

RESULTS

Seventy RA patients developed PCP, and among them, 60 (85.7%) received methotrexate (MTX) monotherapy (40%) or MTX combination therapy with other DMARDs (45.7%). PCP was more likely to occur after 12 months of MTX monotherapy and within 3 months of MTX combination therapy. Thirteen patients (18.6%) died despite PCP treatment. Multivariable logistic regression analysis revealed that coexisting RA-associated interstitial lung disease (RA-ILD; odds ratio [OR] 6.18, 95% confidence interval [CI] 1.17-32.63) and delayed PCP treatment with anti-Pneumocystis drugs (OR 15.29, 95% CI 1.50-156.15) are significant risk factors for PCP mortality in RA patients. Most survivors successfully resumed DMARD therapy without PCP prophylaxis; one recurrent PCP case was observed during follow-up (median, 4.1 years).

CONCLUSION

To avoid a treatment delay, RA patients should be followed-up for signs and symptoms of PCP development, especially those with RA-ILD.

Diagnostic Value of Bronchoalveolar Lavage Fluid Metagenomic Next-Generation Sequencing in Pneumocystis jirovecii Pneumonia in Non-HIV Immunosuppressed Patients

Introduction

This study aims to assess the value of metagenomic next-generation sequencing (mNGS) of bronchoalveolar lavage fluid (BALF) in the diagnosis of Pneumocystis jirovecii pneumonia (PJP) and its mixed infection in non-human immunodeficiency virus (HIV) immunosuppressed patients.

Methods

A total of 198 non-HIV immunosuppressed patients with severe pneumonia were enrolled, including 77 PJP patients and 121 patients infected by other pathogens. BALF-mNGS and traditional detection methods were used.

Results

The positive detection rate of various pathogens of BALF-mNGS was higher than that of the conventional methods, especially for mixed pathogens. The sensitivity and specificity of BALF-mNGS for the diagnosis of PJP were 97.40% and 85.12%, respectively. Compared with traditional methods, the sensitivity of BALF-mNGS was significantly higher than that of blood fungal G (BG)/lactate dehydrogenase (LDH) and BALF-microscopy (p<0.05), and its specificity was significantly higher than that of BG/LDH (p<0.05). In addition, the average detection time of BALF-mNGS (32.76 ± 10.32 h) was also significantly shorter than conventional methods (p<0.01), especially for mixed infections that were common in non-HIV immunosuppressed patients. In patients only detected as positive by BALF-mNGS, the underlying diseases mainly manifested as hematological malignancies with agranulocytosis and within 8 months after hematopoietic stem cell or solid organ transplantation.

Conclusions

BALF-mNGS technology is faster, more sensitive, and more comprehensive in detecting P. jirovecii and its mixed infection in immunosuppressed patients.

A Rare Case of Ulcerative Colitis with Severe Pneumocystis jirovecii Pneumonia and Cytomegalovirus Colitis: A Case Report and Literature Review

Pneumocystis jirovecii pneumonia (PJP) and cytomegalovirus (CMV) colitis are opportunistic infections that occur during immunosuppressive treatments for ulcerative colitis (UC). The prognosis of PJP and CMV colitis is very poor. We herein report a rare case of a 74-year-old UC patient with PJP and CMV colitis that was successfully treated with intensive therapy. PJP progresses rapidly, so the timing and choice of treatment are critical. Furthermore, a literature review of similar cases suggested that prophylactic therapy for opportunistic infections might be important, especially in the elderly. This case will serve as a reference for successful treatment in future cases.

Quantitative PCR to Discriminate Between Pneumocystis Pneumonia and Colonization in HIV and Non-HIV Immunocompromised Patients

Pneumocystis pneumonia (PCP) is an opportunistic infection that commonly occurs in immunocompromised individuals. A definite diagnosis of PCP can be made only when the organism is identified in a respiratory specimen. It remains unclear whether qPCR can differentiate patients with PCP from those with Pneumocystis jirovecii colonization. In this study, we retrospectively collected data from HIV and non-HIV patients during 2013-2019. A diagnosis of definite, probable PCP, or PCP excluded was made based on clinical criteria, radiological reports, and three standard laboratory staining methods with blinding to qPCR data. Data from qPCR that was performed to determine the fungal burden (DNA copies/μl) in the BAL specimens of 69 HIV and 286 non-HIV patients were then obtained and reviewed. Receiver Operating Characteristic (ROC) curve analysis was performed to determine the upper and lower cut-off values for PCP diagnosis in HIV and non-HIV groups. In the non-HIV group, the lower cut-off value of 1,480 DNA copies/μl yielded a sensitivity of 100% (95% confidence interval [CI], 91.0-100), specificity of 72.9% (95% CI, 64.0-80.7), a positive predictive value (PPV) of 54.9% (95% CI, 47.6-62.1), and a negative predictive value (NPV) of 100% with Youden index of 0.73 for PCP diagnosis. In this group, the upper cut-off value of 9,655 DNA copies/μl showed the sensitivity of 100% (95% CI, 91.0-100) and specificity of 95.8% (95% CI, 90.4-98.6) with PPV of 88.6% (95% CI, 76.8-94.8) and a NPV of 100% with Youden index of 0.96 for PCP diagnosis. Regarding the HIV group, the lower cut-off value of 1,480 DNA copies/μl showed the sensitivity of 100% (95% CI, 92.5-100%) and specificity of 91.7% (95% CI, 61.5-99.8) with PPV of 97.9% (95% CI, 87.8-99.7) and a NPV of 100% with Youden index of 0.92 for PCP diagnosis. The sensitivity and specificity of the upper cut-off value of 12,718 DNA copies/μl in this group were 97.9% (95%CI, 88.7-100) and 100% (95%CI, 73.5-100), respectively. The values above the upper cut-off point had a PPV of 100% (95% CI, N/A) and a NPV of 92.3% (95% CI, 63.3-98.8) with Youden index of 0.98 for PCP diagnosis in the HIV group.

Can laboratory tests at the time of admission guide us to the prognosis of patients with COVID-19?

Introduction

To enhance the COVID-19 patients’ care and to optimize utilizing medical resources during the pandemic, relevant biomarkers are needed for prediction of the disease’s progression. The current study was aimed to determine the factors that affect the mortality of COVID-19 patients admitted in Baharloo hospital in Iran.

Methods

in the current retrospective study, 56 survived patients and 56 patients who were died (a total of 112 cases) because of COVID-19 infection were randomly selected from those who were admitted to Baharloo hospital. Each patient who was diagnosed with COVID-19 and had recovered from it matched with each non-survived patient in the term of age. Laboratory tests of all these patients at the time of admission were recorded and compared. All analyses performed using spss version 22 by considering α = 0.05 as a significant level.

Results

There was no statistical difference in the age and gender distribution between the two groups (p > 0.05). The prevalence of diabetes among survived patients was 37.5% and among non-survived patients was 26.8% and there was no statistical difference between two groups regarding this comorbidity (p = 0.22). Also, there was no statistical difference in the prevalence of hypertension and coronary heart diseases between two groups (p > 0.05). Lymphocyte percentage, blood oxygen level, and platelet (PLT) count was significantly higher in patients who had recovered (P < 0.05).

Conclusions

LDH level, Lymphocyte percentage, PLT count, and blood Oxygen saturation have associations with severe forms of COVID-19 infection and can be used as predictors to assess the patients who are suspected of infection with COVID-19 at the time of admission.

Pneumocystis jirovecii Disease: Basis for the Revised EORTC/MSGERC Invasive Fungal Disease Definitions in Individuals Without Human Immunodeficiency Virus

BACKGROUND

Pneumocystis jirovecii pneumonia (PCP) causes substantive morbidity in immunocompromised patients. The EORTC/MSGERC convened an expert group to elaborate consensus definitions for Pneumocystis disease for the purpose of interventional clinical trials and epidemiological studies and evaluation of diagnostic tests.

METHODS

Definitions were based on the triad of host factors, clinical-radiologic features, and mycologic tests with categorization into probable and proven Pneumocystis disease, and to be applicable to immunocompromised adults and children without human immunodeficiency virus (HIV). Definitions were formulated and their criteria debated and adjusted after public consultation. The definitions were published within the 2019 update of the EORTC/MSGERC Consensus Definitions of Invasive Fungal Disease. Here we detail the scientific rationale behind the disease definitions.

RESULTS

The diagnosis of proven PCP is based on clinical and radiologic criteria plus demonstration of P. jirovecii by microscopy using conventional or immunofluorescence staining in tissue or respiratory tract specimens. Probable PCP is defined by the presence of appropriate host factors and clinical-radiologic criteria, plus amplification of P. jirovecii DNA by quantitative real-time polymerase chain reaction (PCR) in respiratory specimens and/or detection of β-d-glucan in serum provided that another invasive fungal disease and a false-positive result can be ruled out. Extrapulmonary Pneumocystis disease requires demonstration of the organism in affected tissue by microscopy and, preferably, PCR.

CONCLUSIONS

These updated definitions of Pneumocystis diseases should prove applicable in clinical, diagnostic, and epidemiologic research in a broad range of immunocompromised patients without HIV.

Validation of the Pneumocystis pneumonia score in haematology patients with acute respiratory failure

Background

Pneumocystis pneumonia (PCP) is an important cause of acute respiratory failure (ARF) in immunocompromised patients, yet no actual clinical tool suitably identifies patients at risk. Recently, a multivariable prediction model has been proposed for haematology patients with ARF requiring intensive care unit (ICU) admission to assess the risk of PCP (PCP score). However, it has not yet been validated externally.

Methods

To validate the PCP score, a retrospective cohort study was conducted in two large designated haematology centres in Korea. One-hundred and forty haematology patients with ARF were admitted to ICU. They underwent aetiologic evaluations between July 2016 and June 2019. The predictive ability of the score was assessed with the receiver operating characteristic (ROC) curve analysis for both the discrimination and calibration of the score.

Results

Among the 141 patients, 13 (9.2%) were finally diagnosed of PCP. Although the median of PCP score in PCP group was higher than in non-PCP group (3.0 [interquartile range 0.0–4.0] vs. 2.0 [0.5–4.0]), the difference was not statistically significant (P = 0.679). The area under the ROC curve of the PCP score in our cohort was 0.535 (95% CI, 0.449–0.620), indicating no discriminatory ability. When using a cut-off of 3.0 the score, the result was 38.5% (95% CI, 13.9–68.4) sensitive and 7.03% (95% CI, 61.6–78.1) specific. The negative predictive value was 58.8% and positive predictive value was 59.8% for a 10% prevalence of PCP.

Conclusions

In this study, the PCP score was not useful to predict the risk of PCP in haematology patients with ARF. Further prospective validation studies are needed to validate the score’s use in routine clinical practice for the early diagnosis of PCP in haematology patients.

Characterization of Pneumocystis jirovecii pneumonia at three tertiary comprehensive hospitals in southern China

Due to the increasing use of immunosuppressant therapy, Pneumocystis jirovecii pneumonia (PJP) has become an emerging concern in human immunodeficiency virus (HIV)-negative patients. In this study, we conducted a retrospective study of 96 hospitalized patients with PJP from January 2015 to June 2019 at three tertiary comprehensive hospitals in Southern China. Information was collected regarding patient demographics, clinical manifestations, risk factors, laboratory analyses, radiological images, and treatment outcomes. PJP infection was most commonly found in middle-aged men. Kidney diseases (35.5%) and connective tissue diseases (38.7%) were the predominant risk factors for PJP. About half of the patients (48.4%) received glucocorticoid, immunosuppressant, and/or chemotherapy in a low dose or in a short-term (< 3 months). None of the patients had previously received trimethoprim-sulfamethoxazole (TMP-SMX) for PJP prophylaxis. All patients had two or more clinical manifestations (cough, dyspnea, fever, and chest pain). Biochemical investigations of CRP, ESR, PaO2, LDH, and KL-6 showed that over 90% of the patients exceeded the reference range of indicators. Our analyses revealed the dominant risk factors (HIV, kidney diseases, and connective tissue diseases) and the most consistent biochemical indicators (LDH, BG, and KL-6) for PJP. Moreover, early prophylaxis, diagnosis, and treatment should contribute to improve the survival of these PJP patients.

Lactate dehydrogenase, an independent risk factor of severe COVID-19 patients: a retrospective and observational study

BACKGROUND

The World Health Organization has declared coronavirus disease 2019 (COVID-19) a public health emergency of global concern. Updated analysis of cases might help identify the risk factors of illness severity.

RESULTS

The median age was 63 years, and 44.9% were severe cases. Severe patients had higher APACHE II (8.5 vs. 4.0) and SOFA (2 vs. 1) scores on admission. Among all univariable parameters, lymphocytes, CRP, and LDH were significantly independent risk factors of COVID-19 severity. LDH was positively related both with APACHE II and SOFA scores, as well as P/F ratio and CT scores. LDH (AUC = 0.878) also had a maximum specificity (96.9%), with the cutoff value of 344.5. In addition, LDH was positively correlated with CRP, AST, BNP and cTnI, while negatively correlated with lymphocytes and its subsets.

CONCLUSIONS

This study showed that LDH could be identified as a powerful predictive factor for early recognition of lung injury and severe COVID-19 cases.

METHODS

We extracted data regarding 107 patients with confirmed COVID-19 from Renmin Hospital of Wuhan University. The degree of severity of COVID-19 patients (severe vs. non-severe) was defined at the time of admission according to American Thoracic Society guidelines for community acquired pneumonia.

Ability of quantitative PCR to discriminate Pneumocystis jirovecii pneumonia from colonization

Introduction.

Pneumocystis jirovecii pneumonia (PCP) is a severe disease affecting immunocompromised patients. Diagnosis is difficult due to the low sensitivity of direct examination and inability to grow the pathogen in culture. Quantitative PCR in bronchoalveolar lavage fluid (BAL) has high sensitivity, but limited specificity for distinguishing PCP from colonization.

Aim.

To assess the performance of an in-house quantitative PCR to discriminate between PCP and colonization.

Methodology.

This was a single-centre retrospective study including all patients with a positive PCR result for P. jirovecii in BAL between 2009 and 2017. Irrespective of PCR results, PCP was defined as the presence of host factors and clinical/radiological criteria consistent with PCP and (i) the presence of asci at direct examination of respiratory sample or (ii) anti-PCP treatment initiated with clinical response and absence of alternative diagnosis. Colonization was considered for cases who did not receive anti-PCP therapy with a favourable outcome or an alternative diagnosis. Cases who did not meet the above mentioned criteria were classified as ‘undetermined’.

Results.

Seventy-one patients with positive P. jirovecii PCR were included (90 % non-HIV patients). Cases were classified as follows: 37 PCP, 22 colonization and 12 undetermined. Quantitative PCR values in BAL were significantly higher in patients with PCP versus colonization or undetermined (P<0.0001). The cut-off of 5×10³ copies/ml was able to discriminate PCP cases from colonization with 97 % sensitivity, 82 % specificity, 90 % positive predictive value and 95 % negative predictive value.

Conclusions.

Our quantitative PCR for P. jirovecii in BAL was reliable to distinguish PCP cases from colonization in this predominantly non-HIV population.

Molecular characterization of Plasmodium falciparum antifolate resistance markers in Thailand between 2008 and 2016

BACKGROUND

Resistance to anti-malarials is a major threat to the control and elimination of malaria. Sulfadoxine-pyrimethamine (SP) anti-malarial treatment was used as a national policy for treatment of uncomplicated falciparum malaria in Thailand from 1973 to 1990. In order to determine whether withdrawal of this antifolate drug has led to restoration of SP sensitivity, the prevalence of genetic markers of SP resistance was assessed in historical Thai samples.

METHODS

Plasmodium falciparum DNA was collected from the Thailand-Myanmar, Thailand-Malaysia and Thailand-Cambodia borders during 2008-2016 (N = 233). Semi-nested PCR and nucleotide sequencing were used to assess mutations in Plasmodium falciparum dihydrofolate reductase (pfdhfr), P. falciparum dihydropteroate synthase (pfdhps). Gene amplification of Plasmodium falcipaurm GTP cyclohydrolase-1 (pfgch1) was assessed by quantitative real-time PCR. The association between pfdhfr/pfdhps mutations and pfgch1 copy numbers were evaluated.

RESULTS

Mutations in pfdhfr/pfdhsp and pfgch1 copy number fluctuated overtime through the study period. Altogether, 14 unique pfdhfr-pdfhps haplotypes collectively containing quadruple to octuple mutations were identified. High variation in pfdhfr-pfdhps haplotypes and a high proportion of pfgch1 multiple copy number (51% (73/146)) were observed on the Thailand-Myanmar border compared to other parts of Thailand. Overall, the prevalence of septuple mutations was observed for pfdhfr-pfdhps haplotypes. In particular, the prevalence of pfdhfr-pfdhps, septuple mutation was observed in the Thailand-Myanmar (50%, 73/146) and Thailand-Cambodia (65%, 26/40) border. In Thailand-Malaysia border, majority of the pfdhfr-pfdhps haplotypes transaction from quadruple (90%, 9/10) to quintuple (65%, 24/37) during 2008-2016. Within the pfdhfr-pfdhps haplotypes, during 2008-2013 the pfdhps A/S436F mutation was observed only in Thailand-Myanmar border (9%, 10/107), while it was not identified later. In general, significant correlation was observed between the prevalence of pfdhfr I164L (ϕ = 0.213, p-value = 0.001) or pfdhps K540E/N (ϕ = 0.399, p-value ≤ 0.001) mutations and pfgch1 gene amplification.

CONCLUSIONS

Despite withdrawal of SP as anti-malarial treatment for 17 years, the border regions of Thailand continue to display high prevalence of antifolate and anti-sulfonamide resistance markers in falciparum malaria. Significant association between pfgch1 amplification and pfdhfr (I164L) or pfdhps (K540E) resistance markers were observed, suggesting a compensatory mutation.

Genetic Polymorphisms of Superoxide Dismutase Locus of Pneumocystis jirovecii in Spanish Population

Objective:Pneumocystis pneumonia remains a major opportunistic infection in immunocompromised patients worldwide. Colonization with Pneumocystis jirovecii has recently gained attention as an important issue for understanding the complete cycle of human Pneumocystis infection. P. jirovecii Superoxide Dismutase (SOD) gene could be a molecular target with high clinical relevance, but the epidemiological information about SOD genotypes distribution is scarce. The aim of this work was to provide information about the prevalence of genotypes of Pneumocystis SOD among Spanish patients and to describe possible differences between colonized and Pneumocystis pneumonia patients.

Methods: we developed a cross-sectional study analyzing broncho-alveolar lavage fluid samples from 30 Pneumocystis pneumonia patients, 30 colonized patients, and 20 controls using a nested PCR protocol designed to amplify the sodA gene of P. jirovecii. The diagnostic yield of SOD Nested PCR was evaluated against the routine practice of mtLSUrRNA Nested PCR, which is considered the gold standard.

Results: SOD locus was amplified in 90% of Pneumocystis pneumonia patients, 10% of colonized patients, and none of controls. Genotype SOD1 was observed in 11 cases (52.4%) and genotype SOD2 in 10 cases (47.6%). Genotype SOD2 was observed only in Pneumocystis pneumonia patients while the genotype SOD1 was observed in both colonized and Pneumocystis pneumonia patients.

Conclusions: This study provides epidemiological information about SOD genotypes distribution in Spain, showing a low genetic diversity and a predominant presence of genotype SOD1 in colonized patients. SOP Nested PCR was more sensitive and accurate assay in Pneumocystis pneumonia patients than in colonized individuals.

Changing Trends in the Epidemiology and Risk Factors of Pneumocystis Pneumonia in Spain

Objective: The information about the epidemiology of Pneumocystis pneumonia (PcP) in Europe is scarce, and in Spain there are only data nationwide on patients with HIV infection. This study has been carried out with the aim of knowing in our country the current epidemiological spectrum and the risk factors of PcP.

Methods: Observational, descriptive transversal study that included all patients admitted in Spain with diagnosis upon discharge of PcP registered in the National Health System's Hospital Discharge Records Database of Spain, between 2008 and 2012.

Results: Four thousand five hundred and fifty four cases of PcP were reported, 1,204 (26.4%) in HIV-negative patients. During the study period, mean annual incidence (cases per million) was 19.4, remaining globally stable, increasing from 4.4 to 6.3 in HIV-negative patients and decreasing from 15.5 to 13.4 among HIV-infected patients. Risk factors were identified in 85.5% of HIV-negative cases, the most frequent being hematological neoplams (29%), chronic lung diseases (15.9%), and non-hematological cancers (14.9%). Mean mortality and hospitalization cost were high (25.5% and 12,000 euros, respectively).

Conclusions: The results of this first nationwide study in Spain allow a change in the misconception that, after the AIDS epidemic, PcP is an infrequent disease, showing that today it is an emerging problem in patients without HIV infection. These findings underlines the need for increased efforts toward a better characterization of risk groups to improve prophylactic strategies and reduce the burden of disease.

Epidemiologic Trends and Clinical Features of Pneumocystis jirovecii Pneumonia in Non-HIV Patients in a Tertiary-Care Hospital in Korea over a 15-Year-Period

Subsequent to the increasing use of immunosuppressant therapy, Pneumocystis jirovecii pneumonia (PcP) has emerged as a life-threatening condition in human immunodeficiency virus (HIV)-negative patients. We investigated changes in epidemiological and clinical characteristics among PcP cases with and without HIV infections. Data of 424 patients diagnosed with PcP in a 2,700-bed Korean tertiary care hospital between February 2003 and April 2017 were retrospectively analyzed. The study included patients with compatible clinical findings in whom PcP was confirmed via direct immunofluorescence assay. The annual average number of cases increased from 12.2 (initial 5-year period) to 42.2 (recent 5-year period). In HIV-negative patients, hematologic malignancy (34.8%) and solid organ transplantation (32.9%) were the most frequent major underlying conditions, and immunosuppressive therapies including corticosteroids (342/362, 94.5%) and chemotherapy (122/362, 33.7%) were significantly associated with PcP infection (p ＜ 0.001 for both). The incidence of PcP has continued to increase among non-HIV-infected immunocompromised patients in recent years.

The association between Cytomegalovirus co-infection with Pneumocystis pneumonia and mortality in immunocompromised non-HIV patients

INTRODUCTION

Impact of Cytomegalovirus (CMV) co-infection pneumonia in non-HIV patients with Pneumocystis jirovecii pneumonia (PCP) is unclear.

OBJECTIVES

The aim of our study was to determine whether CMV co-infection is associated with an increased risk of mortality.

METHODS

Our study was conducted at Ege University Hospital, Turkey. We used molecular assays to diagnose Pneumocystis jirovecii in respiratory samples, and CMV in both respiratory and blood samples. We compared morbidity and mortality stratified by CMV co-infection status.

RESULTS

Between 2009 and 2015, 43 patients (mean age: 56.7 ± 15.3 years) were diagnosed with PCP. Only 3 of 43 patients had received PCP prophylaxis. We microbiologically confirmed CMV co-infection in 28 of 43 (65.1%) patients. Acute respiratory distress syndrome (ARDS) and requirement of mechanical ventilation were more common in the CMV co-infection group (P = .019 and P = .031 respectively), and duration of intensive care unit was also longer (P = .006). In univariate analyses, mortality at 30 days was higher in the CMV co-infection group as compared to the group with PCP alone (78.6% and 46.7% respectively; P = .046). In multivariate analyses, mortality was independently associated only with the presence of ARDS [OR: 6.22 95% CI 1.3-29.32] and the association with CMV co-infection was no longer significant [OR: 2.6 95% CI 0.49-13.72, P = .257].

CONCLUSION

The risk of mortality appears to be increased in the setting of CMV and PCP co-infection in HIV-uninfected immunocompromised patients. PCP prophylaxis use was lower than expected, suggesting low physician awareness of the risks of PCP in this population.

Drug-likeness of linear pentamidine analogues and their impact on the hERG K+channel – correlation with structural features

The pentamidines with S atoms or sulfanilide groups in the linker have favorable drug-likeness parameters and low toxicity.

HIV-related Pneumocystis jirovecii pneumonia managed with caspofungin and veno-venous extracorporeal membrane oxygenation rescue therapy

Patients with pneumocystis pneumonia have a risk of progressing to acute respiratory failure necessitating admission to intensive care. The case described is of a patient with a newly diagnosed HIV infection presenting with pneumocystis pneumonia. Despite initiating the appropriate pharmacological treatment the patient’s clinical condition deteriorated, and required both rescue pharmacological therapy with echinocandins as well as respiratory support with extracorporeal membrane oxygenation therapy. The patient recovered well on ventilator and circulatory support despite a long weaning process complicated by sequelae common to pneumocystis pneumonia. Following initialisation of antiretroviral therapy and step-down from an intensive care setting, the patient required further prolonged hospital stay for rehabilitation and mental health support before being discharged. This case reviews the novel pharmacological therapies and respiratory support strategies used in cases of pneumocystis pneumonia, including the clinical and psychological sequelae that may follow.

Treatment of Pneumocystis jirovecii pneumonia in HIV-infected patients: a review

INTRODUCTION

Pneumocystis pneumonia is a potentially life-threatening pulmonary infection that occurs in immunocompromised individuals and HIV-infected patients with a low CD4 cell count. Trimethoprim-sulfamethoxazole has been used as the first-line agent for treatment, but mutations within dihydropteroate synthase gene render potential resistance to sulfamide. Despite advances of combination antiretroviral therapy (cART), Pneumocystis pneumonia continues to occur in HIV-infected patients with late presentation for cART or virological and immunological failure after receiving cART. Areas covered: This review summarizes the diagnosis and first-line and alternative treatment and prophylaxis for Pneumocystis pneumonia in HIV-infected patients. Articles for this review were identified through searching PubMed. Search terms included: 'Pneumocystis pneumonia', 'Pneumocystis jirovecii pneumonia', 'Pneumocystis carinii pneumonia', 'trimethoprim-sulfamethoxazole', 'primaquine', 'trimetrexate', 'dapsone', 'pentamidine', 'atovaquone', 'echinocandins', 'human immunodeficiency virus infection', 'acquired immunodeficiency syndrome', 'resistance to sulfamide' and combinations of these terms. We limited the search to English language papers that were published between 1981 and March 2017. We screened all identified articles and cross-referenced studies from retrieved articles. Expert commentary: Trimethoprim-sulfamethoxazole will continue to be the first-line agent for Pneumocystis pneumonia given its cost, availability of both oral and parenteral formulations, and effectiveness or efficacy in both treatment and prophylaxis. Whether resistance due to mutations within dihydropteroate synthase gene compromises treatment effectiveness remains controversial. Continued search for effective alternatives with better safety profiles for Pneumocystis pneumonia is warranted.

Comparison of quantitative real-time PCR and direct immunofluorescence for the detection of Pneumocystis jirovecii

Background

Pneumocystis pneumonia (PCP) is a serious risk for HIV-positive patients. Asymptomatic infection or colonisation with P. jirovecii has been shown to occur frequently. PCR assays frequently identify such cases, due to their high sensitivity. Quantitative real-time PCR (qPCR) gene copy number cut-off values have been suggested to differentiate colonisation and infection; these need to be standardised for routine use. We compared the results of qPCR with an immunofluorescence assay (IFA) to determine a specific cut-off value.

Methods

From March 2005 through June 2009, induced sputum specimens were collected from adult patients who were clinically suspected of having PCP, at the Chris Hani Baragwanath Hospital in Gauteng, South Africa. Laboratory diagnosis of PCP was done by a conventional direct IFA and a qPCR assay. A receiver operating characteristic (ROC) analysis was performed to determine a suitable copy number cut-off value.

Results

P. jirovecii was identified in 51% (156/305) and 67% (204/305) of specimens using IFA and qPCR, respectively. The cut-off value for the qPCR that best predicted the IFA results was 78 copies/5 μl (area under ROC curve 0.92). The sensitivity and specificity of qPCR using this cut-off was 94.6% and 89.1%, respectively, compared with the IFA.

Discussion

The results of the ROC curve analysis indicate an excellent predictive value of the qPCR using the proposed cut-off. However, the IFA test is an imperfect gold standard and so this cut-off should not be used in isolation; clinical data should also contribute to the interpretation of the qPCR result.

Diagnosis of Pneumocystis jirovecii pneumonia with serum cell-free DNA in non-HIV-infected immunocompromised patients

Conventional respiratory tract specimens, such as bronchoalveolar lavage (BAL) fluid and induced sputum for diagnosing Pneumocystis jirovecii pneumonia (PCP) in immunocompromised patients are difficult to obtain. Besides, bronchoscopy is an invasive procedure that carries the risk of causing rapidly progressive respiratory insufficiency. By contrast, serum cell-free DNA (cfDNA) is easy to obtain and has been proven useful in diagnosing cancer, pregnancy associated complications, parasite infection and sepsis. In this study, we performed quantitative polymerase chain reaction (qPCR) to assess the diagnostic efficiency of using serum cfDNA, BAL fluid, and sputum DNA for PCP. Seventy-one patients (35 PCP patients and 36 non-PCP patients) were enrolled according to the clinical PCP diagnostic criteria. The sensitivity, specificity, positive predictive value, and negative predictive value of PCR using serum cfDNA were 68.6% (95% CI, 50.7–83.1), 97.2% (95% CI, 85.5–99.9), 96.0%, and 76.1%, respectively. PCR using BAL fluid and sputum had a high sensitivity (97.1% and 91.4%, respectively) but relatively low specificity (86.1% and 86.1%, respectively). The combination of the sputum PCR OR serum cfDNA PCR yielded a sensitivity of 97.1%.These results indicated that serum cfDNA might be a valuable method in PCP diagnosis.

Risk factors for Pneumocystis jirovecii pneumonia (PJP) in kidney transplantation recipients

Pneumocystis jirovecii pneumonia (PJP) is a potentially life-threatening infection that occurs in immunocompromised patients. The aim of this study was to evaluate risk factors for PJP in kidney transplantation recipients. We conducted a retrospective analysis of patient data from 500 consecutive kidney transplants performed at Severance Hospital between April 2011 and April 2014. Eighteen kidney transplantation recipients (3.6%) were diagnosed with PJP. In the univariate analysis, acute graft rejection, CMV infection, use of medication for diabetes mellitus, and lowest lymphocyte count were associated with PJP. Recipients who experienced acute graft rejection (odds ratio [OR] 11.81, 95% confidence interval [CI] 3.06–45.57, P < 0.001) or developed CMV infection (OR 5.42, 95% CI 1.69–17.39, P = 0.005) had high odds of PJP in multivariate analysis. In the acute graft rejection subgroup, patients treated with anti-thymocyte globulin (ATG) had significantly higher odds of PJP (OR 5.25, 95% CI 1.01–27.36, P = 0.006) than those who were not. Our data suggest that acute graft rejection and CMV infection may be risk factors for PJP in kidney transplant patients. The use of ATG for acute graft rejection may increase the risk of PJP.

Serious fungal infections in the Philippines

The Philippines is a low middle-income, tropical country in Southeast Asia. Infectious diseases remain the main causes of morbidity, including tuberculosis. AIDS/HIV prevalence is still low at <1%, but is rapidly increasing. Fungal disease surveillance has not been done, and its burden has never been estimated. This becomes more important as the population of immunocompromised patients increases, drawn from patients with AIDS, TB, malignancies, and autoimmune diseases requiring chronic steroid use. Using the methodology of the LIFE program (www.LIFE-worldwide.org), estimates were derived from data gathered from WHO, UNAIDS, Philippine Health Statistics 2011, Philippine Dermatological Society Health Information System database, HIV/AIDS and ART registry of the Philippines, epidemiological studies such as The TREAT Asia HIV Observational Database 2005, and personal communication. Aspergillosis and candidiasis were the top causes of fungal infections in the Philippines. Chronic pulmonary aspergillosis (CPA), drawn from the number of tuberculosis patients, affects 77,172 people. Allergic bronchopulmonary aspergillosis (ABPA) and severe asthma with fungal sensitization (SAFS) frequencies, which were derived from the number of asthmatic patients, affect 121,113 and 159,869 respectively. Recurrent vulvovaginal candidiasis (RVVC) affects 1,481,899 women. Other estimates were cryptococcal meningitis 84, Pneumocystis pneumonia 391, oral candidiasis 3,467, esophageal candidiasis 1,522 (all in HIV-infected people), invasive aspergillosis (IA) 3,085, candidemia 1,968, candida peritonitis 246, mucormycosis 20, fungal keratitis 358, tinea capitis 846 and mycetoma 97 annually. A total of 1,852,137 (1.9% of population) are afflicted with a serious fungal infection. Epidemiological studies are needed to validate these estimates, facilitating appropriate medical care of patients and proper prioritization of limited resources.

Unmasking Granulomatous Pneumocystis jirovecii Pneumonia with Nodular Opacity in an HIV-Infected Patient after Initiation of Antiretroviral Therapy

Pneumocystis jirovecii pneumonia (PJP) in patients with HIV infection can, in rare cases, present with pulmonary nodules that histologically involve granulomatous inflammation. This report describes an intriguing case of granulomatous PJP with pulmonary nodules after commencing antiretroviral therapy (ART) in an HIV-infected patient without respiratory signs or symptoms. Diagnosis of granulomatous PJP was only achieved through thoracoscopic lung biopsy. This case suggests that granulomatous PJP should be considered in the differential diagnosis of pulmonary nodules in HIV-infected patients for unmasking immune reconstitution inflammatory syndrome manifestation after initiation of ART.

Efficiency of interleukin 6 and interferon gamma in the differentiation of invasive pulmonary aspergillosis and pneumocystis pneumonia in pediatric oncology patients

OBJECTIVE

Invasive pulmonary aspergillosis (IPA) and Pneumocystis pneumonia (PCP) are two types of pulmonary fungal infection that are not easy to differentiate. The purpose of this study was to investigate the role of inflammatory cytokines in the differential diagnosis of IPA and PCP.

METHODS

A total of 227 pediatric oncology patients diagnosed with acute pneumonia were enrolled. They were divided into three groups: IPA, PCP, and 'others'. The cytokine levels in these groups were compared, including interferon (IFN)-γ, tumor necrosis factor (TNF)-α, interleukin (IL)-10, IL-6, IL-4, and IL-2.

RESULTS

Of the six cytokines, only IL-6 and IFN-γ levels were elevated in patients with acute pneumonia. IL-6 was comparable between patients with IPA and PCP (52.0 pg/ml vs. 25.8 pg/ml, p=0.092), while IFN-γ was much higher in patients with PCP (19.9 pg/ml vs. 8.9 pg/ml, p=0.001). The accuracy of IL-6 and the ratio of IL-6/IFN-γ in predicting IPA were 69.0% and 72.0%, respectively, while the accuracy of IFN-γ to predict PCP was 67.2%. IL-6 >140 pg/ml and IL-6/IFN-γ >9.0 presented specificities of 90% in predicting IPA, while IFN-γ >40 pg/ml presented specificity of 90% in predicting PCP.

CONCLUSIONS

IL-6 is predominantly elevated in IPA, while IFN-γ is significantly increased in PCP. These are helpful tools for the differential diagnosis of IPA and PCP.

Development and validation of a Pneumocystis jirovecii real-time polymerase chain reaction assay for diagnosis of Pneumocystis pneumonia

BACKGROUND

Pneumocystis jirovecii (PJ), a pathogenic fungus, causes severe interstitial Pneumocystis pneumonia (PCP) among immunocompromised patients. A laboratory-developed real-time polyermase chain reaction (PCR) assay was validated for PJ detection to improve diagnosis of PCP.

METHODS

Forty stored bronchoalveolar lavage (BAL) samples (20 known PJ positive [PJ+] and 20 known PJ negative [PJ-]) were initially tested using the molecular assay. Ninety-two sequentially collected BAL samples were then analyzed using an immunofluorescence assay (IFA) and secondarily tested using the PJ real-time PCR assay. Discrepant results were resolved by retesting BAL samples using another real-time PCR assay with a different target. PJ real-time PCR assay performance was compared with the existing gold standard (ie, IFA) and a modified gold standard, in which a true positive was defined as a sample that tested positive in two of three methods in a patient suspected to have PCP.

RESULTS

Ninety of 132 (68%) BAL fluid samples were collected from immunocompromised patients. Thirteen of 92 (14%) BALs collected were PJ+ when tested using IFA. A total of 40 BAL samples were PJ+ in the present study including: all IFA positive samples (n=13); all referred PJ+ BAL samples (n=20); and seven additional BAL samples that were IFA negative, but positive using the modified gold standard. Compared with IFA, the PJ real-time PCR had sensitivity, specificity, and positive and negative predictive values of 100%, 91%, 65% and 100%, respectively. Compared with the modified gold standard, PJ real-time PCR had a sensitivity, specificity, and positive and negative predictive values of 100%.

CONCLUSION

PJ real-time PCR improved detection of PJ in immunocompromised patients.

Relationship Between Pneumocystis carinii Burden and the Degree of Host Immunosuppression in an Airborne Transmission Experimental Model

To quantitatively assess the risk of contamination by Pneumocystis depending on the degree of immunosuppression (ID) of the exposed rat hosts, we developed an animal model, where rats went through different doses of dexamethasone. Then, natural and aerial transmission of Pneumocystis carinii occurred during cohousing of the rats undergoing gradual ID levels (receivers) with nude rats developing pneumocystosis (seeders). Following contact between receiver and seeder rats, the P. carinii burden of receiver rats was determined by toluidine blue ortho staining and by qPCR targeting the dhfr monocopy gene of this fungus. In this rat model, the level of circulating CD4(+) and CD8(+) T lymphocytes remained significantly stable and different for each dose of dexamethasone tested, thus reaching the goal of a new stable and gradual ID rat model. In addition, an inverse relationship between the P. carinii burden and the level of circulating CD4(+) or CD8(+) T lymphocytes was evidenced. This rat model may be used to study other opportunistic pathogens or even co-infections in a context of gradual ID.

Pneumocystis Pneumonia in Human Immunodeficiency Virus-infected Adults and Adolescents: Current Concepts and Future Directions

Pneumocystis jirovecii pneumonia (PCP) is one of the most common opportunistic infections in human immunodeficiency virus–infected adults. Colonization of Pneumocystis is highly prevalent among the general population and could be associated with the transmission and development of PCP in immunocompromised individuals. Although the microscopic demonstration of the organisms in respiratory specimens is still the golden standard of its diagnosis, polymerase chain reaction has been shown to have a high sensitivity, detecting Pneumocystis DNA in induced sputum or oropharyngeal wash. Serum β-D-glucan is useful as an adjunctive tool for the diagnosis of PCP. High-resolution computed tomography, which typically shows diffuse ground-glass opacities, is informative for the evaluation of immunocompromised patients with suspected PCP and normal chest radiography. Trimethoprim–sulfamethoxazole (TMP-SMX) is the first-line agent for the treatment of mild to severe PCP, although it is often complicated with various side effects. Since TMP-SMX is widely used for the prophylaxis, the putative drug resistance is an emerging concern.

Serum and bal beta-D-glucan for the diagnosis of Pneumocystis pneumonia in HIV positive patients

BACKGROUND/PURPOSE

The diagnosis of patients with pulmonary infiltrates and human immunodeficiency virus (HIV) infection remains a challenge. In current clinical practice the gold standard for Pneumocystis jirovecii pneumonia (PCP) diagnosis remains the identification of the organism in bronco alveolar lavage (BAL) using microscopy (e.g., silver stain). (1->3)-β -d-glucan (BG) is a polysaccharide that is present within the cell wall of Pneumocystis and other fungi.

METHODS

We analyzed serum and BAL lavage fluid from a cohort of 119 patients that did have HIV, a diagnosis of pneumonia and underwent bronchoscopy (FOB) for diagnosis of PCP.

RESULTS

The discriminative power of serum BG for the diagnosis of PCP in this group of patients was very high. Using a cutoff of 300 pg/mL, the sensitivity, specificity, positive predictive value(PPV) and negative predictive value (NPV) were 91%, 92%, 89% and 93% respectively. A model for ROC with just serum BG (N = 108) had an AUC of 0.95. Serum procalcitonin (PCT) and BAL BG were not as accurate for the diagnosis of PCP. For BAL BG using a cutoff of 783 pg/mL, the sensitivity,specificity, positive predictive value (PPV) and negative predictive value (NPV) were 72%, 79%,72% and 79% respectively. The differences between the medians for serum PCT between the group with a without PCP did not reach statistical significance (p = 0.6137).

CONCLUSION

The measurement of serum BG should be incorporated in the diagnostic work up of HIV positive patients with dyspnea and infiltrates on chest X X-ray. Our study confirms the diagnostic value of serum BG previously reported by others but we add a cutoff value that we believe is more accurate for patients with AIDS and suspicion of PCP.

Efficacy of caspofungin, a 1,3-β-D-glucan synthase inhibitor, on Pneumocystis carinii pneumonia in rats

Pneumocystis carinii pneumonia (PcP) is a common and potentially fatal opportunistic infection in immunosuppressed patients, and the standard trimethoprim-sulfamethoxazole (TMP-SMZ) treatment has serious side effects. The cell wall of the causative fungal pathogen is enriched in 1-3-β-D-glucan, providing an alternative therapeutic target. We directly compared the efficacy of the 1,3-β-D-glucan synthase inhibitor caspofungin to TMP-SMZ for promoting survival and reducing lung cyst number during the early phase of treatment in a rat model of PcP. Rats were immunosuppressed using dexamethasone for 8 weeks and PcP infection confirmed in test animals by lung print smear. The remaining rats were randomly divided into three control groups, a baseline group and two observed for 7 or 14 days, two caspofungin groups treated intravenously for 7 or 14 days (1 mg/kg/d), and 2 TMP-SMZ positive control groups treated by oral gavage for 7 or 14 days (300 mg/kg/d). Mortality was markedly reduced by both caspofungin and TMP-SMZ after 14 days (caspofungin: 20.0%, TMP-SMZ: 13.3%, Control: 40.0%). Body weight gain in caspofungin-treated rats after 7 (3.04 ± 3.54%) and 14 (4.27 ± 2.79%) days was similar to that in TMP-SMZ-treated rats (3.35 ± 1.88% and 5.85 ± 2.78%, respectively), whereas untreated controls showed weight loss. Lung weight to body weight ratio, and mean cyst number per 50 microscopic fields were significantly lower (all P < 0.05) in caspofungin-treated rats than untreated controls at both 7 and 14 days, and similar to those in the TMP-SMZ-treated rats (all P > 0.05 vs. caspofungin). Caspofungin exhibited similar efficacy to TMP-SMZ for enhancing survival and reducing lung edema and cyst load in a rat model of PcP, suggesting potential clinical utility against PcP.

High prevalence of Pneumocystis jirovecii colonization among HIV-positive patients in southern Brazil

A high prevalence of Pneumocystis jirovecii colonization was observed in patients positive for the human immunodeficiency virus (HIV) admitted to a tertiary hospital in southern Brazil between August 2012 and December 2012. Amplification of the mitochondrial large subunit ribosomal RNA gene in oropharyngeal samples through nested polymerase chain reaction identified P. jirovecii colonization in 26 of 58 (44.8%) HIV-positive patients admitted for causes other than Pneumocystis pneumonia. Colonization was more frequent among patients with an absolute CD4 count ≤200 cells/μl. These findings suggest that the HIV-infected population is a major reservoir and source of P. jirovecii infection and that identification of such individuals may contribute to future strategies for improving management of HIV-infected patients.

Pneumocystis jirovecii dihydropteroate synthase gene mutations in a group of HIV-negative immunocompromised patients with Pneumocystis pneumonia

The purpose of this study was to investigate dihydropteroate synthase (DHPS) mutations and their clinical context in non-HIV-infected patients with Pneumocystis pneumonia (PCP). DHPS genes in respiratory samples collected from HIV-negative patients with PCP presented between January 2008 and April 2011 were amplified by polymerase chain reaction (PCR) and sequenced. Basic clinical data from the medical records of the patients were also reviewed. The most common point mutations, which result in Thr55Ala and Pro57Ser amino acid substitutions, were not detected in the Pneumocystis jirovecii sampled from the HIV-negative patients. Two other point mutations, which result in nonsynonymous mutation, Asp90Asn and Glu98Lys, were identified in P. jirovecii from two patients. Among the patients, the levels of lactate dehydrogenase (LDH), C-reactive protein (CRP) and plasma (1-3) β-D-glucan were elevated in 75, 92.31 and 42.86% of patients, respectively. The percentage of circulating lymphocytes was significantly lower in non-survivors than in survivors [4.2%, interquartile range (IQR) 2.4-5.85 versus 10.1%, IQR 5.65-23.4; P=0.019]. The neutrophil proportion in bronchoalveolar lavage fluid (BALF) was significantly higher in non-survivors than in survivors (49.78±27.67 versus 21.33±15.03%; P=0.047). Thirteen patients had received adjunctive corticosteroids (1 mg/kg/day prednisone equivalent) and nine (69.23%) of them eventually experienced treatment failure. No common DHPS gene mutations of P. jirovecii were detected in the HIV-negative PCP patients. However, other mutations did exist, the significance of which remains to be further identified. The elevation of neutrophil counts in BALF and reduction of the number of lymphocytes in peripheral blood may be associated with poor outcome. The efficacy of adjunctive steroid therapy in HIV-negative patients with P. jirovecii infection requires further investigation.