Unremitting Asthma as a Presentation of Pulmonary Nocardiosis: A Case Report

Severe, refractory asthma requires a combination of multiple maintenance inhalers and medications including high-dose inhaled corticosteroids and immunomodulators to achieve control of symptoms. The use of inhaled corticosteroids, however, increases the susceptibility of opportunistic bacterial infections, such as Nocardia, resulting in pulmonary nocardiosis. This case describes a 46-year-old patient with a history of severe, refractory asthma who presented with progressively worsening asthma exacerbation symptoms. She was treated with immunomodulators, high-dose inhaled corticosteroids and oral steroids, and several courses of antibiotics. CT imaging revealed bibasilar peri-bronchial thickening and tree-in-bud nodularity in the right lower lobe. Pulmonary cultures collected from bronchoscopy grew Nocardia nova complex. This was a rare case of persistent asthma exacerbation by N. nova complex bronchopulmonary infection. Broad differentials should be considered in patients with severe, refractory asthma who were previously controlled and were found to fail treatment therapies. Immunocompromised patients with chronic lung disease are at higher risk of severe infection with disseminated nocardiosis. These patients have a higher mortality and morbidity risk if early diagnosis of pulmonary nocardiosis does not occur.

Development of the dipeptidyl peptidase 4 family and its association with lung diseases: a narrative review

Background and Objective

Dipeptidyl peptidase (DPP)4 is a member of a subfamily of serine peptidase S9. DPP4, expressed as a type II transmembrane protein, has a wide tissue distribution and is most active in the lung and small intestine. Many substrates of DPP4 have been identified, including neuropeptides, chemokines, and glucagon-like peptide-1 (GLP-1) and gastric inhibitory polypeptides (GIPs). DPP4 inhibitors are clinically useful in the treatment of type 2 diabetes mellitus. DPP9, an N-terminal dipeptide targeting enzyme with proline or alanine, may have DPP4-like activity. DPP9 is ubiquitously expressed at human and rodent messenger RNA (mRNA) levels and therefore may play a role in the immune system and epithelial cells. It has been shown that DPP9 plays an important signaling role in the regulation of survival and proliferation pathways and is also involved in cell migration, apoptosis, and cell adhesion. In recent years, there has been further progress in DPP9 inhibition through activation of apoptosis by the inflammasome sensor protein Nlrp1b. This study aims to investigate the association of DPP4 family members and DPP9 with lung disease.

Methods

The literature search was initiated using the PubMed database. We searched for the content (DPP4) AND (Lung Diseases), (DPP9) AND (Lung Diseases), from which we filtered the literature we needed.

Key Content and Findings

Given the high biological activity of the DPP4 family, their involvement in various lung diseases is highly relevant. There is growing evidence for the importance of DPP4 and DPP9 of the DPP4 family in lung diseases, which are closely associated with diseases such as asthma, lung infections, pulmonary fibrosis (PF), and lung cancer.

Conclusions

This review summarizes most of the current evidence that DPP4/9 is associated with lung disease. Within the DPP4 family, the role of DPP4 in particular in respiratory disease is important.

COPD in People with HIV: Epidemiology, Pathogenesis, Management, and Prevention Strategies

Chronic obstructive pulmonary disease (COPD) is a progressive respiratory disorder characterized by airflow limitation and persistent respiratory symptoms. People with HIV (PWH) are particularly vulnerable to COPD development; PWH have demonstrated both higher rates of COPD and an earlier and more rapid decline in lung function than their seronegative counterparts, even after accounting for differences in cigarette smoking. Factors contributing to this HIV-associated difference include chronic immune activation and inflammation, accelerated aging, a predilection for pulmonary infections, alterations in the lung microbiome, and the interplay between HIV and inhalational toxins. In this review, we discuss what is known about the epidemiology and pathobiology of COPD among PWH and outline screening, diagnostic, prevention, and treatment strategies.

Pulmonary infections in patients with acute myeloid leukemia receiving frontline treatment with hypomethylating agents

Pulmonary infections (PIs) are a major complication of Acute Myeloid Leukemia (AML) treated with hypomethylating agents (HMA). We retrospectively evaluated 147 AML patients treated frontline with HMA in 2 Centers. Total number of HMA cycles was 1397. There were 88 episodes of PI in 64 patients (43.5%). Thirty-five/147 patients at risk (23.8%) developed at least 1 episode of early PI (during cycles 1-2). Median OS in patients who developed early PI was 3.3 months (95% CI 0.8 - 5.8) versus 10.5 months (95% CI 8.4 - 12.7) in patients without PI or with PI beyond the 2nd cycle (p < .001). Early PIs were an independent factor predicting lower survival (OR 1.94, 95% CI 1.28 - 2.93; p = .002). In conclusion, early PIs are common in AML patients receiving HMA and are associated with an unfavorable outcome. The results of our study raise the issue of a tailored infection prevention strategy.

Role of Fine Needle Aspiration Cytology in the Rapid Diagnosis of Pulmonary Infections in Renal Allograft Recipients with Respiratory Failure

Background

Renal transplantation is the treatment of choice in patients with end-stage renal disease. However, allograft recipients are at a higher risk of infection due to immunosuppressive therapies. This study aimed to analyze the utility of fine needle aspiration cytology (FNAC) lung in the etiological diagnosis of pulmonary infections in renal allograft recipients with respiratory failure.

Materials and Methods

This is a retrospective study done in post-renal transplant patients presenting with pulmonary infections and respiratory failure in the past 7 years, in whom image-guided lung FNAC was done for diagnosis.

Results

A total of 35 renal allograft recipients presenting with respiratory failure and having focal or diffuse pulmonary opacities (lesions) on radiological imaging were subjected to lung FNAC. The mean age of the patients was 41.1 ± 11.8 years (range 19-72), with the majority being males (n = 28, 80%); six (17.1%) of them were on invasive ventilation. The diagnostic yield of FNAC in our cohort was 77.1% (27 out of 35). Microorganisms were isolated in 21 cases (60%), with Nocardia being the most common (nine cases, 25.7%), Mycobacterial tuberculosis identified in six patients (17.1%), Aspergillus in three (8.6%), and one (2.9%) each had atypical Mycobacterium, zygomycetes, and Cryptococcus. FNAC suggested viral cytopathic effect in five patients, and cytomegalovirus (CMV) quantitative polymerase chain reaction test was found positive in four of these. One case was diagnosed as adenocarcinoma lung.

Conclusion

Lung FNAC is a useful for establishing the etiological diagnosis of pulmonary lesions in renal transplant patients with respiratory failure.

Cyclodextrins and Their Polymers Affect Human Serum Albumin's Interaction with Drugs Used in the Treatment of Pulmonary Infections

Respiratory infectious diseases have challenged medical communities and researchers. Ceftriaxone, meropenem and levofloxacin are widely used for bacterial infection treatment, although they possess severe side effects. To overcome this, we propose cyclodextrin (CD) and CD-based polymers as a drug delivery system for the drugs under consideration. CD polymers demonstrate higher binding affinity for levofloxacin (Ka ≈ 10⁵ M) compared to drug-CD complexes. CDs slightly alter the drugs' affinity for human serum albumin (HSA), whereas CD polymers increase the drugs' binding affinity up to 100 times. The most significant effect was observed for more the hydrophilic drugs ceftriaxone and meropenem. The drug's encapsulation in CD carriers leads to a decrease in the degree of change in the protein's secondary structure. The drug-CD carrier-HSA complexes demonstrate satisfying antibacterial activity in vitro, and even a high binding affinity does not decrease the drug's microbiological properties after 24 h. The proposed carriers are promising for a drug form with a prolonged drug release.

A contemporary investigation of burden and natural history of aspergillosis in people living with HIV/AIDS

BACKGROUND

Untreated HIV infection can lead to profound immunosuppression and increase susceptibility of people living with HIV/AIDS (PLHA) to aspergillosis.

OBJECTIVES

Reporting the burden and natural history of aspergillosis documented in PLHA admitted in five medical centres in Brazil.

PATIENTS AND METHODS

Clinical, epidemiological and laboratory data were collected in all sequential cases of proven or probable aspergillosis documented in PLHA hospitalised in five medical centres between 2012 and 2020.

RESULTS

We enrolled 25 patients ageing between 23 and 58 years (mean = 39) including 11 patients with invasive aspergillosis (IA) and 14 with chronic pulmonary aspergillosis (CPA). The prevalence rate of aspergillosis was 0.1% of 19.616 PLHA. Overall, 72.7% of patients with IA exhibited CD4 < 100 cells/mL and 42.8% of patients with CPA exhibited CD4 count >200 cells/mL. Most patients had a history of tuberculosis, especially those with CPA (85.7%). IA was documented after a mean of 16.5 days of hospitalisation, mainly in critically ill patients exposed to corticosteroids and broad-spectrum antibiotics. In the CPA group, a positive culture (71.4%) and radiological alterations were the most frequent findings supporting their diagnosis. Episodes of IA were mostly documented by tissue biopsies. Crude mortality rates were 72.7% and 42.8% in patients with IA and CPA, respectively.

CONCLUSIONS

Despite being considered an unusual complication in PLHA (0.1%), IA should be considered in patients with profound immunosuppression and pneumonia refractory to conventional therapy. CPA should be investigated in PLHA with chronic deterioration of pulmonary function and previous diagnosis of tuberculosis.

Bronchoalveolar Lavage in Diagnostic Evaluation of Pulmonary Diseases- An Institutional Experience

Background

Bronchoalveolar lavage (BAL) is a widely accepted investigative tool for the diagnosis of pulmonary lesions. This study was done to find out the usefulness of BAL in diagnosis of pulmonary lesions from central Indian patient population.

Methods

A cross-sectional prospective study was performed over a period of three years. All the BAL specimens of patients presenting to Department of Pulmonary Medicine and Tuberculosis during a period of January 2017 to December 2019 were included in the study. Cyto-histopathologic correlation was done, wherever available.

Results

Of total 277 cases, there were 178 (64.5%) males and 99 (35.5%) females. The age of patients ranged from 4 years to 82 years. In 92 (33%) cases, specific infective etiology could be identified on BAL cytology, the most common being tuberculosis (26%) followed by fungal infections (2%). Rarely, infections like nocardia, actinomycosis, and hydatidosis were also identified. Eight cases (3%) of malignancy were identified which included two cases of adenocarcinoma, one case of small cell carcinoma, three cases of poorly differentiated carcinoma, and two cases suspicious for malignancy. Some rare diagnoses like diffuse alveolar damage, pulmonary alveolar microlithiasis, and pulmonary alveolar proteinosis could be identified on BAL.

Conclusion

BAL is useful in primary diagnosis of infections and malignancies of lower respiratory tract. BAL may aid in diagnostic workup of diffuse lung diseases. A combination of clinical information, high-resolution computed tomography, and BAL analysis may furnish an assured diagnosis to the clinician and obviate need for invasive procedures.

Pulmonary Infections and Outcomes in AIDS Patients with Respiratory Failure: A 10-Year Retrospective Review

Background

Respiratory failure in acquired immunodeficiency syndrome (AIDS) patients was the leading cause of intensive care unit (ICU) admission in our center. We aimed to describe the pulmonary infections and outcomes for respiratory failure in AIDS patients.

Methods

A retrospective study was conducted on AIDS adult patients with respiratory failure who were admitted to the ICU in Beijing Ditan hospital, China, from January 2012 to December 2021. We investigated pulmonary infections complicated by respiratory failure in AIDS patients. The primary outcome was ICU mortality, and a comparison between survivors and nonsurvivors was performed. Multiple logistic regression analysis was used to identify predictors of ICU mortality. The Kaplan-Meier curve and Log rank test were used for survival analysis.

Results

A total of 231 AIDS patients were admitted to ICU with respiratory failure over a 10-year period with a male predominance (95.7%). Pneumocystis jirovecii pneumonia was the main etiology of pulmonary infections (80.1%). The ICU mortality was 32.9%. In multivariate analysis, ICU mortality was independently associated with invasive mechanical ventilation (IMV) [odds ratio (OR), 27.910; 95% confidence interval (CI, 8.392-92.818; p = 0.000) and the time before ICU admission (OR, 0.959; 95% CI, 0.920-0.999; p = 0.046). In the survival analysis, patients with IMV and later admission to ICU had a higher probability of mortality.

Conclusion

Pneumocystis jirovecii pneumonia was the primary etiology for respiratory failure in AIDS patients admitted to the ICU. Respiratory failure remains a severe illness with high mortality, and ICU mortality was negatively associated with IMV and later admission to ICU.

Pleural Space Infections

Pleural space infections have been a well-recognized clinical syndrome for over 4000 years and continue to cause significant morbidity and mortality worldwide. However, our collective understanding of the causative pathophysiology has greatly expanded over the last few decades, as have our treatment options. The aim of this paper is to review recent updates in our understanding of this troublesome disease and to provide updates on established and emerging treatment modalities for patients suffering from pleural space infections. With that, we present a review and discussion synthesizing the recent pertinent literature surrounding the history, epidemiology, pathophysiology, diagnosis, and management of these challenging infections.

Mycobacterium abscessus: insights from a bioinformatic perspective

Mycobacterium abscessus is a nontuberculous mycobacterium, associated with broncho-pulmonary infections in individuals suffering from cystic fibrosis, bronchiectasis, and pulmonary diseases. The risk factors for transmission include biofilms, contaminated water resources, fomites, and infected individuals. M. abscessus is extensively resistant to antibiotics. To date, there is no vaccine and combination antibiotic therapy is followed. However, drug toxicities, low cure rates, and high cost of treatment make it imperfect. Over the last 20 years, bioinformatic studies on M. abscessus have advanced our understanding of the pathogen. This review integrates knowledge from the analysis of genomes, microbiomes, genomic variations, phylogeny, proteome, transcriptome, secretome, antibiotic resistance, and vaccine design to further our understanding. The utility of genome-based studies in comprehending disease progression, surveillance, tracing transmission routes, and epidemiological outbreaks on a global scale has been highlighted. Furthermore, this review underlined the importance of using computational methodologies for pinpointing factors responsible for pathogen survival and resistance. We reiterate the significance of interdisciplinary research to fight M. abscessus. In a nutshell, the outcome of computational studies can go a long way in creating novel therapeutic avenues to control M. abscessus mediated pulmonary infections.

Clinical Characteristics and Predictors of In-Hospital Mortality among Older Patients with Acute Heart Failure

Acute Heart Failure (AHF)-related hospitalizations and mortality are still high in western countries, especially among older patients. This study aimed to describe the clinical characteristics and predictors of in-hospital mortality of older patients hospitalized with AHF. We conducted a retrospective study including all consecutive patients ≥65 years who were admitted for AHF at a single academic medical center between 1 January 2008 and 31 December 2018. The primary outcome was all-cause, in-hospital mortality. We also analyzed deaths due to cardiovascular (CV) and non-CV causes and compared early in-hospital events. The study included 6930 patients, mean age 81 years, 51% females. The overall mortality rate was 13%. Patients ≥85 years had higher mortality and early death rate than younger patients. Infections were the most common condition precipitating AHF in our cohort, and pneumonia was the most frequent of these. About half of all hospital deaths were due to non-CV causes. After adjusting for confounding factors other than NYHA class at admission, infections were associated with an almost two-fold increased risk of mortality, HR 1.74, 95% CI 1.10-2.71 in patients 65-74 years (p = 0.014); HR 1.83, 95% CI 1.34-2.49 in patients 75-84 years (p = 0.001); HR 1.74, 95% CI 1.24-2.19 in patients ≥85 years (p = 0.001). In conclusion, among older patients with AHF, in-hospital mortality rates increased with increasing age, and infections were associated with an increased risk of in-hospital mortality. In contemporary patients with AHF, along with the treatment of the CV conditions, management should be focused on timely diagnosis and appropriate treatment of non-CV factors, especially pulmonary infections.

Use of 18F-FDG PET/CT to Differentiate Ectopic Adrenocorticotropic Hormone-Secreting Lung Tumors From Tumor-Like Pulmonary Infections in Patients With Ectopic Cushing Syndrome

Background

Ectopic adrenocorticotropic hormone (ACTH)-secreting lung tumors represent the most common cause of ectopic Cushing syndrome (ECS). Pulmonary opportunistic infections are associated with ECS. The present study aimed to evaluate the usefulness of ¹⁸F-FDG PET/CT for differentiating ectopic ACTH-secreting lung tumors from tumor-like pulmonary infections in patients with ECS.

Methods

We retrospectively reviewed the imaging data of 24 patients with ECS who were suspected to have ACTH-secreting lung tumors and underwent ¹⁸F-FDG PET/CT between 2008 and 2019. Eleven patients with lung tumors and 4 with pulmonary infections also had additional somatostatin receptor imaging (^99mTc-HYNIC-TOC SPECT/CT or ⁶⁸Ga-DOTATATE PET/CT).

Results

In total, 18 patients had lung tumors and six had pulmonary infections. The primary source of ECS remained occult in the six patients with pulmonary infections. The maximum standardized uptake value (SUV_max) for pulmonary infections was significantly higher than that for tumors (P = 0.008). Receiver operating characteristic analysis revealed that a cut-off SUV_max of 4.95 helped in differentiating ACTH-secreting lung tumors from infections with 75% sensitivity and 94.4% specificity. For the 11 patients with ACTH-lung tumors, somatostatin receptor imaging (SRI) was positive in 6; while for the 4 with pulmonary infections, SRI was positive in 2. The sensitivity and specificity of somatostatin receptor imaging (SRI) for detecting ACTH-secreting lung tumor was 54.5% and 50%.

Conclusions

Our findings suggest that pulmonary infections exhibit significantly higher FDG uptake than ACTH-secreting lung tumors in ¹⁸F-FDG PET/CT. An SUV_max cut-off value of 4.95 may be useful for differentiating the two conditions. Our results also suggested that SRI may not be an effective tool for differentiating the two conditions given the relatively low specificity.

Antibiotic Treatment of Pulmonary Infections: An Umbrella Review and Evidence Map

Background: Considering the global burden of pulmonary infections, there is an urgent need for optimal empirical antimicrobial therapy strategies for pulmonary infections, which should rely on reliable evidence. Therefore, we aim to investigate the optimal treatment options for pulmonary infections in adults and assess the strength of that evidence. Methods: We searched PubMed, Embase, the Cochrane Library, and China Biology Medicine disc to identify systematic reviews and meta-analyses of randomized controlled trials (RCTs) focusing on antimicrobial treatments for pulmonary infections. The outcomes of the included meta-analyses should include all-cause mortality or clinical treatment success. For each meta-analysis, we estimated relative risk (RR) with 95% CI. We also created an evidence map to show the efficacy of each antimicrobial treatment strategy and the certainty of the evidence. Results: Twenty-six meta-analyses and two new RCTs were included that contained 31 types of antimicrobial therapy strategies. We found that carbapenems were related to lower mortality than other β-lactams or fluoroquinolones alone or in combination with aminoglycosides for HAP patients (RR 0.76, 95% CI: 0.58-0.99). There was no statistical difference in all-cause mortality between the other antimicrobial therapy strategies. As for clinical cure, treatment with fluoroquinolones was associated with better success versus macrolides or β-lactams alone for CAP patients in both the intention-to-treat (ITT) population (RR 1.22, 95% CI: 1.02-1.47) and clinically evaluable (CE) population (RR 1.37, 95% CI: 1.11-1.68). Treatment with carbapenems showed a better clinical cure over non-carbapenems for VAP patients (RR 1.21, 95% CI: 1.05-1.4). Adjunctive inhaled antibiotics compared with intravenous antibiotics alone showed a benefit for VAP (RR 1.2, 95% CI: 1.05-1.35). In addition, adjunctive nebulized aminoglycoside for nosocomial pneumonia was associated with a higher cure rate versus intravenous antibiotics alone in the ITT population (RR 1.28, 95% CI: 1.04-1.57), while no statistical difference in clinical cure was observed between other intervention groups. Conclusions: We cannot evaluate which antibiotic is the best choice for the treatment of pulmonary infection. Carbapenems or adjunctive inhaled antibiotics showed a reasonable choice for HAP or VAP. However, we do not find a statistical difference between most antimicrobial therapy strategies for CAP patients.

Prospective selected biomarkers in COVID-19 diagnosis and treatment

COVID-19 has become a global health concern, due to the high transmissible nature of its causal agent and lack of proper treatment. Early diagnosis and nonspecific medical supports of the patients appeared to be effective strategy so far to combat the pandemic caused by COVID-19 outbreak. Biomarkers can play pivotal roles in timely and proper diagnosis of COVID-19 patients, as well as for distinguishing them from other pulmonary infections. Besides, biomarkers can help in reducing the rate of mortality and evaluating viral pathogenesis with disease prognosis. This article intends to provide a broader overview of the roles and uses of different biomarkers in the early diagnosis of COVID-19, as well as in the classification of COVID-19 patients into multiple risk groups.

Epidemiology, Clinical Features, and Outcomes of Coccidioidomycosis, Utah, 2006-2015

On the basis of a 1957 geographic Coccidioides seropositivity survey, 3 counties in southwestern Utah, USA, were considered coccidioidomycosis-endemic, but there has been a paucity of information on the disease burden in Utah since. We report findings from a recent clinical and epidemiologic study of coccidioidomycosis in Utah. To describe clinical characteristics, we identified all coccidioidomycosis cases in an integrated health system in the state during 2006-2015. For epidemiologic analysis, we used cases reported to the Utah Department of Health during 2009-2015. Mean state incidence was 1.83 cases/100,000 population/year. Washington County, in southwestern Utah, had the highest incidence, 17.2 cases/100,000 population/year. In a generalized linear model with time as a fixed effect, mean annual temperature, population, and new construction were associated with regional variations in incidence. Using these variables in a spatiotemporal model, we estimated the adjusted regional variation by county to predict areas where Coccidioides infections might increase.

Beyond "Big Eaters": The Versatile Role of Alveolar Macrophages in Health and Disease

Macrophages act as immune scavengers and are important cell types in the homeostasis of various tissues. Given the multiple roles of macrophages, these cells can also be found as tissue resident macrophages tightly integrated into a variety of tissues in which they fulfill crucial and organ-specific functions. The lung harbors at least two macrophage populations: interstitial and alveolar macrophages, which occupy different niches and functions. In this review, we provide the latest insights into the multiple roles of alveolar macrophages while unraveling the distinct factors which can influence the ontogeny and function of these cells. Furthermore, we will highlight pulmonary diseases, which are associated with dysfunctional macrophages, concentrating on congenital diseases as well as pulmonary infections and impairment of immunological pathways. Moreover, we will provide an overview about different treatment approaches targeting macrophage dysfunction. Improved knowledge of the role of macrophages in the onset of pulmonary diseases may provide the basis for new pharmacological and/or cell-based immunotherapies and will extend our understanding to other macrophage-related disorders.

Pulmonary infections after renal transplantation: a prospective study from a tropical country

Pulmonary infection is a leading cause of morbidity and mortality in renal transplant recipients. In a prospective study, we characterized their epidemiology in a tropical country with high infectious disease burden. Adult renal transplant recipients presenting with pulmonary infections from 2015 to 2017 were evaluated using a specific diagnostic algorithm. 102 pulmonary infections occurred in 88 patients. 32.3% infections presented in the first year, 31.4% between 1 and 5, and 36.3% beyond 5 years after transplantation. Microbiological diagnosis was established in 69.6%, and 102 microorganisms were identified. Bacterial infection (29.4%) was most common followed by tuberculosis (23.5%), fungal (20.6%), Pneumocystis jiroveci (10.8%), viral (8.8%), and nocardial (6.9%) infections. Tuberculosis(TB) and bacterial infections presented throughout the post-transplant period, while Pneumocystis (72.7%), cytomegalovirus (87.5%) and nocardia (85.7%) predominantly presented after >12 months. Fungal infections had a bimodal presentation, between 2 and 6 months (33.3%) and after 12 months (66.7%). Four patients had multi-drug resistant(MDR) TB. In 16.7% cases, plain radiograph was normal and infection was diagnosed by a computed tomography imaging. Mortality due to pulmonary infections was 22.7%. On multivariate Cox regression analysis, use of ATG (HR-2.39, 95% CI: 1.20-4.78, P = 0.013), fungal infection (HR-2.14, 95% CI: 1.19-3.84, P = 0.011) and need for mechanical ventilation (9.68, 95% CI: 1.34-69.82, P = 0.024) were significant predictors of mortality in our patients. To conclude, community-acquired and endemic pulmonary infections predominate with no specific timeline and opportunistic infections usually present late. Nocardiosis and MDR-TB are emerging challenges.

Epidermal growth factor receptor-mutant pulmonary adenocarcinoma coexisting with tuberculosis: A case report

RATIONALE

Lung cancer and pulmonary infections can have similar clinical and radiographic manifestations. Treatment for the coexistence of epidermal growth factor receptor (EGFR)-mutant pulmonary adenocarcinoma and tuberculosis remains unclear.

PATIENT CONCERNS

We reported a case of EGFR-mutant lung adenocarcinoma (mimicking pulmonary infections) that coexisted with pulmonary tuberculosis during the course of the disease.

DIAGNOSES

The patient was initially diagnosed with pneumonia-like pulmonary adenocarcinoma with EGFR exon 19 deletions based on computed tomography scan, fiberoptic bronchoscopy, pathology, and genetic analysis, and then coexistence with active tuberculosis (TB) was confirmed via laboratory examinations and TB-DNA polymerase chain reaction.

INTERVENTIONS

Antibiotics and gefitinib were administered initially. A combination of gefitinib and anti-TB treatment was then administered when active TB was confirmed, and osimertinib was then prescribed because the disease was progressive and EGFR T790 M mutation was detected.

OUTCOMES

The patient has survived with a stable disease status to date.

LESSONS

Exploring and ruling out differential diagnoses between pulmonary malignancies and infectious diseases is vital for treatment decisions and outcomes. The combined gefitinib-anti-TB regimen was safe, though it needed modification.

Pulmonary infections in patients with and without hematological malignancies: diagnostic yield and safety of flexible bronchoscopy-a retrospective analysis

Background

Fiberoptic bronchoscopy (FOB) with broncho-alveolar lavage (BAL) is frequently performed in patients with hematological malignancies and pulmonary opacities. While the safety of the procedure in this patient population has been shown, data about the diagnostic yield widely differ between studies. Furthermore, data comparing diagnostic yield and safety of flexible bronchoscopy to narrow sources of pulmonary infections in patients with and without underlying hematological malignancy are lacking.

Methods

We carried out a retrospective analysis of bronchoscopies done for the diagnostic work-up of pulmonary infections. Diagnostic yield and the occurrence of complications in patients with and without hematological disease were compared.

Results

In total n=268 bronchoscopies were done in patients suffering from a hematological malignancy (HM) compared to n=408 bronchoscopies in patients without hematological malignancy (NHM). The overall diagnostic yield was similar and did not differ between the groups (HM: 67.2% vs. NHM: 64.7%; P=0.5622). However, when cultures positive for Candida were not considered as clinically relevant diagnostic yield was higher in the HM group (HM: 62.7% vs. NHM: 53.9%; P=0.0261) due to a higher detection rate of fungi and viruses (both P<0.001). Interestingly, the diagnostic yield for bacteria was not decreased by pre-treatment with antibiotics in either group (both P>0.05). There was no difference in the complication rate between the groups and most complications were considered as minor.

Conclusions

In summary, our data demonstrate similar diagnostic yield and safety of flexible bronchoscopy for diagnosing pulmonary infection in patients with and without underlying hematological malignancy.

Triple RNA-Seq Reveals Synergy in a Human Virus-Fungus Co-infection Model

High-throughput RNA sequencing (RNA-seq) is routinely applied to study diverse biological processes; however, when performed separately on interacting organisms, systemic noise intrinsic to RNA extraction, library preparation, and sequencing hampers the identification of cross-species interaction nodes. Here, we develop triple RNA-seq to simultaneously detect transcriptomes of monocyte-derived dendritic cells (moDCs) infected with the frequently co-occurring pulmonary pathogens Aspergillus fumigatus and human cytomegalovirus (CMV). Comparing expression patterns after co-infection with those after single infections, our data reveal synergistic effects and mutual interferences between host responses to the two pathogens. For example, CMV attenuates the fungus-mediated activation of pro-inflammatory cytokines through NF-κB (nuclear factor κB) and NFAT (nuclear factor of activated T cells) cascades, while A. fumigatus impairs viral clearance by counteracting viral nucleic acid-induced activation of type I interferon signaling. Together, the analytical power of triple RNA-seq proposes molecular hubs in the differential moDC response to fungal/viral single infection or co-infection that contribute to our understanding of the etiology and, potentially, clearance of post-transplant infections.

Preoperative serum 25-hydroxyvitamin D3 and the incidence of early pulmonary infection after pediatric living donor liver transplantation

BACKGROUND

Pulmonary infection is a common complication in pediatric living donor liver transplantation (LDLT) recipients. It has been suggested that vitamin D has a role in immune defense against infection. Therefore, we investigated the effect of preoperative serum 25-hydroxyvitamin D₃ (25(OH)D₃ ) on the risk of pneumonia in hospitalized patients undergoing LDLT.

MATERIALS AND METHODS

This study was a retrospective review of patient records. Fifty consecutive pediatric patients (aged < 14 years) who underwent LDLT from January 2017 to December 2017 were included. Pulmonary infection in the early postoperative period was diagnosed using clinical, radiological, or laboratory criteria. Preoperative serum 25(OH)D₃ level, demographic characteristics, primary diagnosis, ascites, time to extubation, length of intensive care unit stay, and perioperative laboratory values were recorded. Vitamin D deficiency, insufficiency, and sufficiency were defined as a serum 25(OH)D₃ concentration of less than 10, 10 to 20, and more than 20 ng/mL, respectively. Associations between serum 25(OH)D₃ levels and pulmonary infection were analyzed.

RESULTS

Of 50 pediatric patients who underwent LDLT, 19 (38%) developed pulmonary infections in the early postoperative period. The mean serum 25(OH)D₃ level in these subjects was 18.7 ± 17.2 ng/mL (range, 3.0-70.0 ng/mL). Twenty patients (40%) had severe vitamin D deficiency (<10 ng/mL). The mean serum 25(OH)D₃ level was significantly decreased (9.3 ± 7.4 vs 24.5 ± 19.1 ng/mL, P = .002) in patients with pulmonary infection compared with those without pulmonary infection. Serum 25(OH)D₃ level as a continuous variable (odds ratio [OR], 0.90, 95% confidence interval [CI], 0.84-0.97, P = .008) and a classification variable (≤10 ng/mL) (OR, 7.42, 95% CI, 2.06-26.79, P = .002) were significantly associated with pulmonary infection in univariate analysis. After adjusting for other significant predictors (age, weight, and pediatric end-stage liver disease score), severe 25(OH)D₃ deficiency at presentation was independently associated with a higher risk of developing pulmonary infection in the early postoperative period (OR, 5.11, 95% CI, 1.30-20.16, P = .02).

CONCLUSIONS

25(OH)D₃ deficiency is common and inversely correlated with pulmonary infection within the first month after pediatric LDLT. Our results indicate that preoperative serum 25(OH)D₃ deficiency is a potential biomarker for early pulmonary infection after pediatric LDLT.

Role of bronchoalveolar lavage in diagnosing pulmonary infections and malignancies: Experience from a tertiary care center

BACKGROUND

Bronchoalveolar lavage (BAL), is a safe, minimally invasive procedure to sample the terminal airways and the lung parenchyma. Although frequently used, there is lack of contemporary literature regarding the diagnostic utility of BAL for various pulmonary diseases. This study was conducted to evaluate the utility of BAL in diagnosis of various pulmonary pathologies, both infectious and neoplastic.

METHODS

This was a retrospective study performed over a period of 2 years. All the BAL samples reported on cytology were studied, their clinical details were retrieved, and the corresponding smears were reviewed. Cyto-histopathologic correlation was done, wherever possible.

RESULTS

There were a total of 1835 cases (1153 men, 682 women; age, 8 months to 78 years). Of these, 19 (1%) cases were assessed as inadequate for opinion. In 348 (19%) cases, specific infective cause could be identified on BAL cytology alone. Tuberculosis and fungal infections could be diagnosed in 165 (9%) and 178 (9.7%) cases respectively. There were 46 (2.5%) neoplasms, including adenocarcinoma (n = 20), squamous cell carcinoma (n = 5), small cell carcinoma (n = 2), Langerhans cell histiocytosis (n = 1), suspicious for malignancy (n = 15) and metastatic carcinoma (n = 3). Some rare diagnoses were also reported on BAL cytology, including sarcoidosis, actinomycosis, leishmaniasis, pulmonary alveolar proteinosis and metastatic papillary carcinoma of the thyroid.

CONCLUSION

BAL is a safe and useful procedure for primary diagnosis of infections such as tuberculosis and fungal infections, which has special significance in developing nations where prevalence of such infections is high. In addition, BAL has the potential to diagnose both primary as well as secondary malignant lung lesions.

Pulmonary blastomycosis in rural Upstate New York: A case series and review of literature

In a rural medical center in Upstate New York, we observed an increase in pulmonary blastomycosis cases. Herein, we highlight the increased prevalence of blastomycosis in our region, and our experience with the diagnostic dilemma resulting in delayed diagnosis. This delay may have resulted in an increased mortality. A high index of suspicion may help hasten the diagnosis in an otherwise nonendemic area. A single-center retrospective case series of all patients diagnosed with culture-proven blastomycosis is reported at the Bassett Medical Center from 2007 to 2019. Eight cases of confirmed pulmonary blastomycosis were identified. All patients resided in a rural area along the Susquehanna River Basin. Only one case had a travel history to an endemic state. Males accounted for 100% of cases. There was a 50% mortality rate from acute respiratory distress syndrome. Bronchoalveolar lavage (BAL) reliably made the diagnosis. About 40% of patients had a false-negative blastomycosis serology. There was an average delay of 2.5 months from presentation to correct diagnosis due to a lack of consideration for blastomycosis. BAL resulted in a correct diagnosis, while serology was not reliable to exclude the diagnosis. Physicians should include blastomycosis in the diagnostic differential cases of nonresolving pneumonia in Upstate New York, an area not previously considered as endemic. Bronchoalveolar remains the evaluation method of choice if blastomycosis is suspected.

Comparison between Colistin Sulfate Dry Powder and Solution for Pulmonary Delivery

To assess the difference in the fate of the antibiotic colistin (COLI) after its pulmonary delivery as a powder or a solution, we developed a COLI powder and evaluated the COLI pharmacokinetic properties in rats after pulmonary administration of the powder or the solution. The amorphous COLI powder prepared by spray drying was characterized by a mass median aerodynamic diameter and fine particle fraction of 2.68 ± 0.07 µm and 59.5 ± 5.4%, respectively, when emitted from a Handihaler^®. After intratracheal administration, the average pulmonary epithelial lining fluid (ELF): plasma area under the concentration versus time curves (AUC) ratios were 570 and 95 for the COLI solution and powder, respectively. However, the same COLI plasma concentration profiles were obtained with the two formulations. According to our pharmacokinetic model, this difference in ELF COLI concentration could be due to faster systemic absorption of COLI after the powder inhalation than for the solution. In addition, the COLI apparent permeability (P_app) across a Calu-3 epithelium model increased 10-fold when its concentration changed from 100 to 4000 mg/L. Based on this last result, we propose that the difference observed in vivo between the COLI solution and powder could be due to a high local ELF COLI concentration being obtained at the site where the dry particles impact the lung. This high local COLI concentration can lead to a local increase in COLI P_app, which is associated with a high concentration gradient and could produce a high local transfer of COLI across the epithelium and a consequent increase in the overall absorption rate of COLI.

Chemotherapy-induced pulmonary complications in cancer: Significance of clinicoradiological correlation

Chemotherapy while revolutionizing cancer management by improving survival and quality of life; is also associated with several adverse effects. Lung is the most common organ affected in chemotherapy-related complications, due to either drug toxicity or more commonly due to infections caused by immunosuppression and less commonly due to immune-mediated injury. Radiology, when used in combination with clinical and lab data, can help reach the specific diagnosis or narrow down the differentials. The common radiological patterns of drug toxicity include pulmonary interstitial and airway infiltrates, diffuse alveolar damage, nonspecific interstitial pneumonia, eosinophilic pneumonia, cryptogenic organizing pneumonia, pulmonary hemorrhage, edema and hypertension. Cancer patients are immunosuppressed due to the underlying malignancy itself or due to therapy and are prone to a gamut of opportunistic infections including viral, bacterial, fungal and mycobacterial pathogens. Immune reconstitution inflammatory syndrome (IRIS), a well-known complication in HIV, is now being increasingly recognized in non-HIV patients with immunosuppression. Engraftment syndrome is specifically seen following hematopoietic stem cell transplant during neutrophil recovery phase. Pulmonary involvement is frequent, causing a radiological picture of noncardiogenic pulmonary edema. Thus, radiology in combination with clinical background and lab parameters helps in detecting and differentiating various causes of pulmonary complications. This approach can help alter potentially toxic treatment and initiate early treatment depending on the diagnosis.

Diagnostic accuracy of magnetic resonance imaging in the evaluation of pulmonary infections in immunocompromised patients

Purpose

To evaluate the accuracy of magnetic resonance imaging (MRI) for diagnosing pulmonary infections in immunocompromised adults.

Material and methods

Computed tomography (CT) and MRI chest were performed in 35 immuno-compromised patients suspected of pulmonary infection. The MRI sequences that were performed included axial and coronal T2 half-Fourier acquisition single-shot turbo spin-echo (HASTE), spectrally attenuated inversion recovery (SPAIR), true fast imaging with steady-state free precession (TRUFI), and three-dimensional fast low angle shot (3D FLASH) using breath-hold and respiratory triggered BLADE (proprietary name for periodically rotated overlapping parallel lines with enhanced reconstruction). The presence of nodules, consolidations, and ground-glass opacities was evaluated. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for MRI using CT scan as a reference standard.

Results

The sensitivity of MRI in nodule detection was 50% overall and 75% for nodules measuring more than 5 mm. Consolidation was detected with 100% sensitivity. Sensitivity and PPV for the detection of ground-glass opacities (GGOs) were 77.7% and 53.8%, respectively. T2 HASTE axial had the fewest image artefacts. Respiratory triggered MR pulse sequence did not add any significant diagnostic information as compared to the non-respiratory triggered MR pulse sequences.

Conclusions

Sensitivity for detecting small nodules and GGOs on MR is poor; CT scan remains the imaging modality of choice for the evaluation of pulmonary infections in immunocompromised patients. However, MRI can be used in the follow-up imaging of these patients.

Pulmonary infections in patients with myelodysplastic syndromes receiving frontline azacytidine treatment

Pulmonary infections (PIs) are a major complication of patients with myelodysplastic syndromes (MDS). We retrospectively evaluated 234 MDS patients treated with azacytidine (AZA). The total number of AZA cycles was 2886 (median 8 cycles per patient). There were 111 episodes of PI (3.8% of AZA cycles) in 81 patients (34.6%). PIs were considered of fungal origin in 27 cases (24.3%), associated to bacteremia in 11 cases (9.9%), to influenza infection in two cases (1.8%) and of unknown origin in the remaining 71 cases (64.0%). Forty-five PI episodes were documented in cycles 1 to 4 of AZA (5.1% of 875 cycles) and the remaining 66 episodes beyond the fourth cycle (3.2% of 2011 cycles) (P = .017). Overall, a fungal PI was documented in 13/875 (1.5%) cycles 1 to 4 and in 13/2011 (0.6%) cycles beyond the fourth cycle (P = .001). A baseline chronic pulmonary disease was significantly associated to a higher risk of severe PIs. In the survival analysis, cases of PI in patients who progressed to acute leukemia (PAL) were excluded, in view of the predominant influence of PAL on the outcome of the patients. A PI unrelated to PAL documented during the first 4 AZA cycles was an independent factor predicting lower survival (OR, 2.13; 95% CI, 1.37-3.33; P = .001). In conclusion, PIs are common in MDS patients receiving AZA, in particular during the first cycles of treatment and are associated with an unfavorable outcome. The results of our study raise the issue of the need of a tailored infection prevention strategy.

Phase II Study of Single/Repeated Doses of Acumapimod (BCT197) to Treat Acute Exacerbations of COPD

Mitogen-activated protein kinase p38 is a key regulator in the inflammation pathway and is activated in the lungs of chronic obstructive pulmonary disease (COPD) patients. Acumapimod is a potent, selective, oral, p38 inhibitor under investigation for treatment of acute exacerbations of COPD (AECOPD). In this Phase II, double-blind, randomized, placebo-controlled dose-exploration study of acumapimod in patients with moderate or severe AECOPD (NCT01332097), patients presenting with AECOPD were randomized to receive single-dose acumapimod (20 mg or 75 mg) on Day 1, repeated single-dose acumapimod (20 mg or 75 mg) on Days 1 and 6, oral prednisone 40 mg (10 days), or placebo. Primary outcome: improvement in forced expiratory volume in 1 s (FEV₁) versus placebo at Day 5 (single doses) and Day 10 (repeated doses). N = 183 patients were randomized; 169 (92%) patients completed the study. Although the primary endpoint (FEV₁ at Day 10) was not met (p = 0.082), there was a significant improvement in FEV₁ with acumapimod repeat-dose 75 mg versus placebo at Day 8 (p = 0.022) which, though not a prespecified endpoint, was part of an overall trend. Differences at lower doses did not achieve significance. Mean change in FEV₁ AUC from baseline to Day 14 in the 75 mg repeat-dose group was significantly higher versus placebo (p = 0.02), prednisone (p = 0.01), and 20 mg single-dose groups (p = 0.015) (post-hoc analysis). EXACT-PRO showed numerical differences versus placebo that did not reach significance. Acumapimod was well tolerated. In conclusion, repeated single-dose acumapimod showed a clinically relevant improvement in FEV₁ over placebo at Day 8, along with consistent numerical differences in EXACT-PRO. These data can be used to determine dose regimens for a proof-of-clinical-concept trial.

Estimated Burden of Fungal Infections in Namibia

Namibia is a sub-Saharan country with one of the highest HIV infection rates in the world. Although care and support services are available that cater for opportunistic infections related to HIV, the main focus is narrow and predominantly aimed at tuberculosis. We aimed to estimate the burden of serious fungal infections in Namibia, currently unknown, based on the size of the population at risk and available epidemiological data. Data were obtained from the World Health Organization (WHO), Joint United Nations Programme on HIV/AIDS (UNAIDS), and published reports. When no data existed, risk populations were used to estimate the frequencies of fungal infections, using the previously described methodology. The population of Namibia in 2011 was estimated at 2,459,000 and 37% were children. Among approximately 516,390 adult women, recurrent vulvovaginal candidiasis (≥4 episodes /year) is estimated to occur in 37,390 (3003/100,000 females). Using a low international average rate of 5/100,000, we estimated 125 cases of candidemia, and 19 patients with intra-abdominal candidiasis. Among survivors of pulmonary tuberculosis (TB) in Namibia 2017, 112 new cases of chronic pulmonary aspergillosis (CPA) are likely, a prevalence of 354 post-TB and a total prevalence estimate of 453 CPA patients in all. Asthma affects 11.2% of adults, 178,483 people, and so allergic bronchopulmonary aspergillosis (ABPA) and severe asthma with fungal sensitization (SAFS) were estimated in approximately 179/100,000 and 237/100,000 people, respectively. Invasive aspergillosis (IA) is estimated to affect 15 patients following leukaemia therapy, and an estimated 0.13% patients admitted to hospital with chronic obstructive pulmonary disease (COPD) (259) and 4% of HIV-related deaths (108) — a total of 383 people. The total HIV-infected population is estimated at 200,000, with 32,371 not on antiretroviral therapy (ART). Among HIV-infected patients, 543 cases of cryptococcal meningitis and 836 cases of Pneumocystis pneumonia are estimated each year. Tinea capitis infections were estimated at 53,784 cases, and mucormycosis at five cases. Data were missing for fungal keratitis and skin neglected fungal tropical diseases such as mycetoma. The present study indicates that approximately 5% of the Namibian population is affected by fungal infections. This study is not an epidemiological study—it illustrates estimates based on assumptions derived from similar studies. The estimates are incomplete and need further epidemiological and diagnostic studies to corroborate, amend them, and improve the diagnosis and management of these diseases.

Ten Year Review of Pulmonary Nocardiosis: A Series of 55 Cases

Introduction

Nocardiosis is a rare opportunistic bacterial infection usually seen in immunosuppressed patients. It is caused by gram-positive, aerobic actinomycetes of the Nocardia genus. The most common site of infection is lungs; but it may affect other organs or even disseminate into blood.

Methods

In this a 10-year retrospective review, all diagnosed cases of Pulmonary Nocardiosis in a tertiary care hospital were included. The clinical and radiological characteristics, course of complications and lifesaving interventions, and disease outcome were evaluated.

Results

Among the 55 identified cases, most common risk factor was chronic steroid therapy (n=38; 69.1%). Among respiratory diseases, chronic obstructive pulmonary disease (n=13; 23.6%) and tuberculosis (n=12; 21.8%) were the most common. On chest radiograph, pleural effusion (n=23; 41.8%) and consolidation (n=22; 40.0%) were the common findings. Complications were observed in 32 (58.2%) patients with septicemia and respiratory failure being the most common (n=15; 46.8% in each). Dissemination occurred in 10 (31.2%) patients. The mortality rate of Nocardia is 34.5% (n=19).

Conclusion

The disease burden of Nocardia is underestimated by clinicians and researchers. Pulmonary Nocardia should always be a differential diagnosis of signs of lower respiratory tract infection and must be excluded in patients not responding to treatment of chronic obstructive pulmonary disease (COPD) and pulmonary tuberculosis. Early recognition and individualized management plan can ensure successful recovery.

Pulmonary Infections with Nontuberculous Mycobacteria, Catalonia, Spain, 1994-2014

In Spain, systematic reporting of pulmonary infections with nontuberculous mycobacteria is not mandatory. Therefore, to determine trends, we retrospectively identified cases for January 1994–December 2014 in Catalonia. Over the 21 years, prevalence increased and was associated with being male. Mycobacterium avium complex and M. abscessus prevalence increased; M. kansasii prevalence decreased.

Managing pulmonary complications in allogeneic hematopoietic stem cell transplantation

Introduction: Progress in allogeneic hematopoietic stem cell transplantation (HSCT) procedures has been associated with improved survival in HSCT recipients. However, they have also brought to light organ-specific complications, especially pulmonary complications. In this setting, pulmonary complications are consistently associated with poor outcomes, and improved management of these complications is required. Areas covered: We review the multiple infectious and noninfectious lung complications that occur both early and late after allogeneic HSCT. This includes the description of these complications, risk factors, diagnostic approach and outcome. A literature search was performed using PubMed-indexed journals. Expert commentary: Multiple lung complications after allogeneic HSCT can be diagnosed concomitantly and require a multidisciplinary approach. A specific clinical evaluation including a precise analysis of a lung CT scan is necessary. Management of these lung complications, especially the noninfectious ones, is impaired by the lack of prospective, randomized control trials, suggesting preventive strategies should be developed.

The Burden of Serious Fungal Infections in Cameroon

Fungal infections are frequent in Cameroon, and invasive fungal infections are sometimes detected, usually in HIV-infected patients. For these reasons, we have estimated the burden of fungal infections. Using published literature and population estimates for the at-risk group, we used deterministic modelling to derive national incidence and prevalence estimates for the most serious fungal diseases. HIV infection is common and an estimated 120,000 have CD4 counts <200 × 10⁶/mL and commonly present with opportunistic infection. Oesophageal candidiasis in HIV is common, and in poorly controlled diabetics. We estimate 6720 cases of cryptococcal meningitis, 9000 of Pneumocystis pneumonia, 1800 of disseminated histoplasmosis annually complicating AIDS, and 1200 deaths from invasive aspergillosis in AIDS, but there are no data. We found that 2.4% of adults have chronic obstructive pulmonary disease (COPD) and 2.65% have asthma, with "fungal asthma" affecting 20,000. Chronic pulmonary aspergillosis probably affects about 5000 people, predominantly after tuberculosis but also with COPD and other lung diseases. Also, tinea capitis in schoolchildren is frequent. Overall, an estimated 1,235,775 people are affected by a serious fungal infection. There is an urgent need for government and clinician attention, improved laboratory facilities, fungal diagnostic tests, and competent laboratory technicians, as well as all World Health Organization (WHO)-endorsed essential antifungal drugs to be made available, as only fluconazole is registered and available in the country.

Proof-of-Principle Study in a Murine Lung Infection Model of Antipseudomonal Activity of Phage PEV20 in a Dry-Powder Formulation

Bacteriophage therapy is a promising alternative treatment to antibiotics, as it has been documented to be efficacious against multidrug-resistant bacteria with minimal side effects. Several groups have demonstrated the efficacy of phage suspension in vivo to treat lung infections using intranasal delivery; however, phage dry-powder administration to the lungs has not yet been explored. Powder formulations provide potential advantages over a liquid formulation, including easy storage, transport, and administration. The purpose of this study was to assess the bactericidal activities of phage dry-powder formulations against multidrug-resistant (MDR) strain Pseudomonas aeruginosa FADDI-PA001 in a mouse lung infection model. Phage PEV20 spray dried with lactose and leucine produced an inhalable powder at a concentration of 2 × 10⁷ PFU/mg. P. aeruginosa lung infection was established by intratracheal administration of the bacterial suspension to neutropenic mice. At 2 h after the bacterial challenge, the infected mice were treated with 2 mg of the phage powder using a dry-powder insufflator. At 24 h after the phage treatment, the bacterial load in the lungs was decreased by 5.3 log₁₀ (P < 0.0005) in the phage-treated group compared with that in the nontreated group. Additionally, the phage concentration in the lungs was increased by 1 log₁₀ at 24 h in the treated group. These results demonstrate the feasibility of a pulmonary delivery of phage PEV20 dry-powder formulation for the treatment of lung infection caused by antibiotic-resistant P. aeruginosa.

The Role of Nucleotide-Binding Oligomerization Domain-Like Receptors in Pulmonary Infection

Pneumonia is caused by both viral and bacterial pathogens and is responsible for a significant health burden in the Unites States. The innate immune system is the human body's first line of defense against these pathogens. The recognition of invading pathogens via pattern recognition receptors leads to proinflammatory cytokine and chemokine production, followed by recruitment and activation of effector immune cells. The nonspecific inflammatory nature of the innate immune response can result in immunopathology that is detrimental to the host. In this review, we focus on one class of pattern recognition receptors, the nucleotide-binding oligomerization domain (NOD)-like receptors, specifically NOD1 and NOD2, and their role in host defense against viral and bacterial pathogens of the lung, including influenza, respiratory syncytial virus, Streptococcus pneumoniae, Chlamydophila pneumoniae, and Staphylococcus aureus. It is hoped that improved understanding of NOD1 and NOD2 activity in pneumonia will facilitate the development of novel therapies and promote improved patient outcomes.

Production of Inhalation Phage Powders Using Spray Freeze Drying and Spray Drying Techniques for Treatment of Respiratory Infections

PURPOSE

The potential of aerosol phage therapy for treating lung infections has been demonstrated in animal models and clinical studies. This work compared the performance of two dry powder formation techniques, spray freeze drying (SFD) and spray drying (SD), in producing inhalable phage powders.

METHOD

A Pseudomonas podoviridae phage, PEV2, was incorporated into multi-component formulation systems consisting of trehalose, mannitol and L-leucine (F1 = 60:20:20 and F2 = 40:40:20). The phage titer loss after the SFD and SD processes and in vitro aerosol performance of the produced powders were assessed.

RESULTS

A significant titer loss (~2 log) was noted for droplet generation using an ultrasonic nozzle employed in the SFD method, but the conventional two-fluid nozzle used in the SD method was less destructive for the phage (~0.75 log loss). The phage were more vulnerable during the evaporative drying process (~0.75 log further loss) compared with the freeze drying step, which caused negligible phage loss. In vitro aerosol performance showed that the SFD powders (~80% phage recovery) provided better phage protection than the SD powders (~20% phage recovery) during the aerosolization process. Despite this, higher total lung doses were obtained for the SD formulations (SD-F1 = 13.1 ± 1.7 × 10(4) pfu and SD-F2 = 11.0 ± 1.4 × 10(4) pfu) than from their counterpart SFD formulations (SFD-F1 = 8.3 ± 1.8 × 10(4) pfu and SFD-F2 = 2.1 ± 0.3 × 10(4) pfu).

CONCLUSION

Overall, the SD method caused less phage reduction during the powder formation process and the resulted powders achieved better aerosol performance for PEV2.

Global survey on nebulization of antimicrobial agents in mechanically ventilated patients: a call for international guidelines

Nebulized antimicrobial agents are increasingly administered for treatment of respiratory infections in mechanically ventilated (MV) patients. A structured online questionnaire assessing the indications, dosages and recent patterns of use for nebulized antimicrobial agents in MV patients was developed. The questionnaire was distributed worldwide and completed by 192 intensive care units. The most common indications for using nebulized antimicrobial agent were ventilator-associated tracheobronchitis (VAT; 58/87), ventilator-associated pneumonia (VAP; 56/87) and management of multidrug-resistant, Gram-negative (67/87) bacilli in the respiratory tract. The most common prescribed nebulized agents were colistin methanesulfonate and sulfate (36/87, 41.3% and 24/87, 27.5%), tobramycin (32/87, 36.7%) and amikacin (23/87, 26.4%). Colistin methanesulfonate, amikacin and tobramycin daily doses for VAP were significantly higher than for VAT (p < 0.05). Combination of parenteral and nebulized antibiotics occurred in 50 (86%) of 58 prescriptions for VAP and 36 (64.2%) of 56 of prescriptions for VAT. The use of nebulized antimicrobial agents in MV patients is common. There is marked heterogeneity in clinical practice, with significantly different in use between patients with VAP and VAT. Randomized controlled clinical trials and international guidance on indications, dosing and antibiotic combinations to improve clinical outcomes are urgently required.

Regulation of lung immunity and host defense by the intestinal microbiota

Every year in the United States approximately 200,000 people die from pulmonary infections, such as influenza and pneumonia, or from lung disease that is exacerbated by pulmonary infection. In addition, respiratory diseases such as, asthma, affect 300 million people worldwide. Therefore, understanding the mechanistic basis for host defense against infection and regulation of immune processes involved in asthma are crucial for the development of novel therapeutic strategies. The identification, characterization, and manipulation of immune regulatory networks in the lung represents one of the biggest challenges in treatment of lung associated disease. Recent evidence suggests that the gastrointestinal (GI) microbiota plays a key role in immune adaptation and initiation in the GI tract as well as at other distal mucosal sites, such as the lung. This review explores the current research describing the role of the GI microbiota in the regulation of pulmonary immune responses. Specific focus is given to understanding how intestinal “dysbiosis” affects lung health.

Emergence of linezolid resistance in a clinical Staphylococcus capitis isolate from Jiangsu Province of China in 2012

Linezolid (LZD) is an important antimicrobial agent for the treatment of infections caused by Gram-positive organisms, including methicillin-resistant Staphylococci. And until now, LZD resistance in clinical is still rare. Here we reported the first case of LZD resistance Staphylococcus capitis in Jiangsu, China. This strain was isolated from a 92-year old female who received long-term and repeatedly antibiotics treatment because of recurrent pulmonary infections in August 2012. Isolated from blood, the Staphylococcus capitis showed a resistance to LZD with a minimal inhibitory concentration (MIC) of 64 µg/mL, and the followed gene detection showed that the isolates existed C2190T and C2561Y point mutations in the 23S rRNA. Moreover, the isolation was also found carrying the cfr gene.

Role of HRCT in detection and characterization of pulmonary abnormalities in patients with febrile neutropenia

Background:

Fever is of grave concern in the management of patients with neutropenia with early detection of a focus of infection being the major goal. As lungs are the most common focus, chest imaging is of vital importance. This Institute Review Board approved prospective study was undertaken to assess the usefulness of high resolution computed tomography (HRCT) in early detection and characterization of pulmonary abnormalities in febrile neutropenia.

Materials and Methods:

A total of 104 consecutive patients (M:F:75:29, age range 11–66 years) with fever of 38.2°C or more with an absolute neutrophil count <500/μl underwent HRCT chest. HRCT diagnosis was compared with final diagnosis based on ancillary investigations.

Results:

HRCT could detect pulmonary abnormalities in 93 patients (89.4%) with air space consolidation being the predominant finding (n = 57), followed by ground-glass opacities (Ground glass opacity (GGO), n = 49) and nodules (n = 39). HRCT could correctly characterize the infective lesions in 76 patients (81.7%). Presence of random or pleural-based nodules >10 mm with or without surrounding GGO or cavitations was sensitive (95.23%) and specific (96.7%) for fungal infection, while small (1–4 mm) random or centrilobular nodules with tree-in-bud appearance was sensitive (90%) and highly specific (97.02%) for tuberculosis. Diagnosis of pyogenic infection based on presence of air-space consolidation, pleural effusion, GGO or centrilobular nodules showed a sensitivity of 84.78% and specificity of 93.84%, whereas patchy or diffuse GGO, interstitial thickening and/or air-space consolidation showed high sensitivity (86.7%) and specificity (96.8%) for Pneumocystis jiroveci pneumonia.

Conclusion:

HRCT chest is an excellent modality in the diagnostic work-up of patients with febrile neutropenia allowing early detection and characterization of pulmonary abnormalities.

Community-acquired and nosocomial pneumonia

Pneumonia is one of the leading causes of morbidity, hospitalization, and mortality in both industrialized and developing countries. In particular, pulmonary infections acquired in the community, and pneumonias arising in the hospital setting, represent a major medical and economic problem and thus a continuous challenge to health care. For the radiologist, it is important to understand that community-acquired pneumonia (CAP) and nosocomial pneumonia (NP) share a number of characteristics, but should, in many respects be regarded as separate entities. CAP and NP arise in different populations, host different spectra of causative pathogens, and pose different challenges to both the clinician and the radiologist. CAP is generally seen in outpatients, is most frequently caused by Streptococcus pneumoniae, Mycoplasma pneumoniae, Haemophilus influenzae, and Chlamydia, and its radiologic diagnosis is relatively straightforward. NP, in contrast, develops in the hospital setting, is commonly caused by gram-negative bacteria, and may generate substantial problems for the radiologist. Overall, both for CAP and NP, imaging is an integral component of the diagnosis, important for classification and differential diagnosis, and helpful for follow-up.