Severe co-infection caused by difficult-to-diagnose hypermucoviscous Klebsiella pneumoniae K1-ST82 in a patient with COVID-19: a case report.

BACKGROUND: Co-infection with Klebsiella pneumoniae presents a significant concern in hospitalized patients with coronavirus disease (COVID-19), increasing the risk of severe disease progression. Hypervirulent (hv) and hypermucoviscous (hm) K. pneumoniae (Kp) has gained prominence in Asia due to its capacity to cause invasive community-acquired infections. However, recognition of hvKp/hmKp co-infections in the context of COVID-19 remains limited. We report a severe case of rapidly progressing co-infection with hmKp exhibiting "difficult-to-diagnose" phenotypes in a hospitalized patient with COVID-19. CASE PRESENTATION: A 61-year-old woman with COVID-19 initially exhibited mild symptoms resembling the common cold. However, her condition rapidly deteriorated over 7 days, leading to hospital admission with the development of dyspnea. The patient required supplemental oxygen, antibiotic treatment, and mechanical ventilation. Gram-negative bacteria with atypical phenotypes were isolated from alveolar lavage fluid and blood cultures. Both strains formed small, glossy, non-lactose-fermenting colonies on clinically relevant media and were susceptible to ampicillin. Conventional biochemical tests failed to identify the Enterobacteriales strains owing to the urease-negative phenotype. Consequently, the identification of K. pneumoniae was difficult until matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis was performed. A positive string test indicated mucoviscosity, but with variability in the material used for stretching colonies. Whole-genome sequencing performed on the MiSeq and GridION platforms revealed the blood-derived strain JARB-RN-0063 as belonging to serotype K1 and sequence type (ST) 82. The hvKp-associated genes rmpA and iroCD were located on a 5.0-Mb chromosome, and iucABCD-iutA was identified on a 217.9-kb IncFIB(K)/IncR-type plasmid. Therefore, JARB-RN-0063 was genetically classified as hvKp with a Kleborate virulence score of 3. The intrinsic penicillinase gene blaSHV was defective owing to an IS1F element insertion, resulting in the strain being atypically susceptible to ampicillin. CONCLUSIONS: This is the first case of severe COVID-19-associated co-infection with a difficult-to-diagnose K. penummoniae strain. Notably, co-infection by the hmKp K1-ST82 clone exhibited atypical phenotypes, including stunted growth, non-lactose fermentation, urease-negative reaction, ampicillin susceptibility, and abnormal mucoviscosity, posing diagnostic challenges for clinical laboratories and impedes the identification of hvKp/hmKp. Delayed identification may worsen patient outcomes, highlighting the need for increased clinical awareness of such difficult-to-diagnose clones to prevent deterioration.

TMEM2 suppresses TLR3-mediated IFN-ß/ISG56/CXCL10 expression in BEAS-2B bronchial epithelial cells.

BACKGROUND: Bronchial epithelial cells are at the front line of viral infections. Toll-like receptor 3 (TLR3) cascade causes the expression of interferon (IFN)-ß and IFN-stimulated genes (ISGs), which in turn induce an antiviral response. Members of the transmembrane protein (TMEM) family are expressed in various cell types. Although the prognostic value of TMEM2 in various cancers has been reported, its association with infectious diseases remains unknown. In this study, we investigated the effects of TMEM2 on antiviral immunity in BEAS-2B bronchial epithelial cells. METHODS AND RESULTS: TMEM2 protein was found in the cytoplasm of normal human bronchial epithelial cells and differed between organs using immunohistochemistry. Cultured BEAS-2B cells were transfected with TMEM2 siRNA, followed by administration of TLR3 ligand polyinosinic-polycytidylic acid (poly IC) or recombinant human (r(h)) IFN-ß. The expression of TMEM2, IFN-ß, ISG56, C-X-C motif chemokine ligand 10 (CXCL10) and hyaluronan were evaluated appropriately by western blotting, quantitative reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay. TMEM2 expression was not altered by poly IC stimulation. Knockdown of TMEM2 increased poly IC-induced expression of IFN-ß, CXCL10, and ISG56, while IFN-ß-induced expression of ISG56 and CXCL10 were not changed by TMEM2 knockdown. The hyaluronan concentration in the medium was decreased by either TMEM2 knockdown or poly IC, but additive or synergistic effects were not observed. CONCLUSIONS: TMEM2 knockdown enhanced TLR3-mediated IFN-ß, CXCL10, and ISG56 expression in BEAS-2B cells. This implies that TMEM2 suppresses antiviral immune responses and prevents tissue injury in bronchial epithelial cells.

Safety and effectiveness of sarilumab in Japanese patients with rheumatoid arthritis refractory to previous treatments: An interim analysis of a post-marketing surveillance.

OBJECTIVES: An interim analysis of post-marketing surveillance data to assess the safety and effectiveness of sarilumab in Japanese patients with rheumatoid arthritis refractory to previous treatment. METHODS: The interim analysis included patients who initiated sarilumab therapy between June 2018 and January 2021. The primary objective of this surveillance was safety. RESULTS: In total, 1036 patients were enrolled and registered by 12 January 2021 (interim cut-off date). Of these, 678 were included in the safety analysis [75.4% female; mean age (± standard deviation) 65.8 ± 13.0 years]. Adverse drug reactions, defined as adverse events classified as possibly or probably related to sarilumab, were reported in 170 patients (incidence: 25.1%), with white blood cell count decreased (4.4%) and neutrophil count decreased (1.6%) most frequently reported. Serious haematologic disorders (3.4%) and serious infections (including tuberculosis) (2.5%) were the most frequently reported priority surveillance items. No malignant tumour was reported. An absolute neutrophil count (ANC) below the minimum standard value did not increase the incidence of serious infections. CONCLUSIONS: Sarilumab was well tolerated, and no new safety signals were noted in this analysis. There was no difference in the frequency of serious infections between patients with an ANC below or above normal.

Safety of sarilumab in a Japanese population with rheumatoid arthritis by age group: Data from an interim analysis of a post-marketing surveillance study.

OBJECTIVES: Using data from a post-marketing surveillance, this interim subgroup analysis investigated the safety of sarilumab in younger (<65 years) and older patients (≥65 and ≥75 years) with rheumatoid arthritis. METHODS: During this interim analysis, patients who were treated with sarilumab in Japan were enrolled between June 2018-2021. Data collected by 12 January 2022 were analysed, with adverse drug events monitored over 52 weeks. RESULTS: Of 972 patients with available data, proportion of patients aged <65 years, ≥65 years and ≥75 years were 40.8%, 59.2% and 27.8%, respectively. Most patients (95.5%) received the standard 200 mg dose of sarilumab as the initial dose. Adverse drug reactions were reported in 24.6% of patients, with serious events accounting for 6.4% of cases. No malignancy and low incidences of adverse drug reactions of special interest were reported across all age groups (<65 years, 7.8%; ≥65 years, 8.2%; ≥75 years, 8.5%). When stratified by absolute neutrophil count above and below the lower limit of normal, there were no numerical differences in incidences of serious and non-serious infections between age groups. CONCLUSIONS: Regardless of age, sarilumab therapy was well tolerated by patients with rheumatoid arthritis, with no new safety signals reported in this study.

Clarithromycin expands CD11b+Gr-1+ cells via the STAT3/Bv8 axis to ameliorate lethal endotoxic shock and post-influenza bacterial pneumonia.

Macrolides are used to treat various inflammatory diseases owing to their immunomodulatory properties; however, little is known about their precise mechanism of action. In this study, we investigated the functional significance of the expansion of myeloid-derived suppressor cell (MDSC)-like CD11b+Gr-1+ cells in response to the macrolide antibiotic clarithromycin (CAM) in mouse models of shock and post-influenza pneumococcal pneumonia as well as in humans. Intraperitoneal administration of CAM markedly expanded splenic and lung CD11b+Gr-1+ cell populations in naïve mice. Notably, CAM pretreatment enhanced survival in a mouse model of lipopolysaccharide (LPS)-induced shock. In addition, adoptive transfer of CAM-treated CD11b+Gr-1+ cells protected mice against LPS-induced lethality via increased IL-10 expression. CAM also improved survival in post-influenza, CAM-resistant pneumococcal pneumonia, with improved lung pathology as well as decreased interferon (IFN)-γ and increased IL-10 levels. Adoptive transfer of CAM-treated CD11b+Gr-1+ cells protected mice from post-influenza pneumococcal pneumonia. Further analysis revealed that the CAM-induced CD11b+Gr-1+ cell expansion was dependent on STAT3-mediated Bv8 production and may be facilitated by the presence of gut commensal microbiota. Lastly, an analysis of peripheral blood obtained from healthy volunteers following oral CAM administration showed a trend toward the expansion of human MDSC-like cells (Lineage-HLA-DR-CD11b+CD33+) with increased arginase 1 mRNA expression. Thus, CAM promoted the expansion of a unique population of immunosuppressive CD11b+Gr-1+ cells essential for the immunomodulatory properties of macrolides.

ISG56 is involved in CXCL10 expression induced by TLR3 signaling in BEAS-2B bronchial epithelial cells.

Purpose and aim of the study: Bronchial epithelial cells play an important role in immune response against viral infections. Toll-like receptor 3 (TLR3) is a pathogen recognition receptor that recognizes viral double-stranded RNA (dsRNA). Activation of TLR3 induces the expression of interferon (IFN)-ß, and newly synthesized IFN-ß exhibits anti-viral activity by upregulating the expression of IFN-stimulated genes (ISGs). ISG56 encodes a multifunctional protein with tetratricopeptide motifs and is involved in anti-viral reactions through various mechanisms. Expression of chemokines such as CXCL10, which induces leukocyte chemotaxis, is essential for defense against airway microbes. However, regulation of chemokine expression by ISG56 in bronchial epithelial cells has not been fully investigated. The aim of this study was to examine the expression of ISG56 and its role in CXCL10 production in BEAS-2B bronchial epithelial cells treated with dsRNA.Materials and methods: BEAS-2B bronchial epithelial cells were treated with polyinosinic-polycytidylic acid (poly IC), a synthetic TLR3 ligand. The mRNA and protein expression levels of ISG 56 were analyzed by quantitative reverse transcription polymerase chain reaction and western blotting. The effect of knocking down TLR3, IFN-ß, and ISG56 was examined using RNA interference. The protein expression of CXCL10 in culture medium was measured using an enzyme-linked immunosorbent assay.Results: Poly IC induced ISG56 expression in a concentration- and time- dependent manner. RNA interference showed that ISG56 induction was inhibited by knockdown of TLR3 or IFN-ß and that ISG 56 knockdown decreased CXCL10 expression.Conclusions: ISG56 was induced by poly IC through TLR3/IFN-ß axis, and ISG56 may positively regulated CXCL10 expression in BEAS-2B cells. ISG56 may modulate anti-viral innate immunity, at least in part, by regulating the expression of CXCL10 in bronchial epithelial cells.

Obesity worsens the outcome of influenza virus infection associated with impaired type I interferon induction in mice.

Increasing evidence indicates that obesity is a risk factor for increased severity of influenza virus infection. However, its precise immunological mechanism is not fully understood. To investigate this, diet-induced obese (DIO) mice were established by feeding C57BL/6 male mice a high-fat diet for 16 weeks. DIO and lean control mice were infected intranasally with 3000 pfu of influenza A virus (IAV) (PR8/H1N1). Interestingly, we found adipose tissue located along the bronchus in naïve DIO mice. In addition, the Nos2 level was significantly higher and Arg1 level was significantly lower in lung macrophages of naïve DIO mice, consistent with an M1-skewed phenotype. The survival rate and body weight of DIO mice infected with IAV were significantly lower than those of lean control mice and associated with higher viral load in the lungs of DIO mice. Histopathological analysis demonstrated higher numbers of inflammatory cells in the lungs of DIO mice after IAV infection. Levels of cytokines, including TNF-α, IL-6, IL-10, and type I IFN (IFN-α and IFN-ß), in bronchoalveolar lavage fluid (BALF) were altered after IAV infection; in particular, IFN-α and IFN-ß levels were significantly suppressed in the BALF of DIO mice. In vitro, bone marrow-derived macrophages were stimulated with ligands of toll-like receptor (TLR) 7/8, a pattern recognition receptor for single-stranded RNA, and levels of TNF-α, IL-6, and IL-10 were similarly altered. In addition, levels of IFN-α and IFN-ß were significantly lower in culture supernatants of alveolar macrophages sorted from naïve DIO mice and infected with IAV, compared to those in macrophages sorted from lean control mice. Collectively, these results suggest that macrophages may be the main contributors to poor outcomes of influenza virus infection in obesity.

Prognostic values of the Berlin definition criteria, blood lactate level, and fibroproliferative changes on high-resolution computed tomography in ARDS patients.

BACKGROUND: In the Berlin definition, acute respiratory distress syndrome (ARDS) is stratified into three stages according to oxygenation severity at the onset. The relevance between ARDS severity and prognosis varies among published reports and has not been verified, especially in Asian patients. METHODS: In this study, we examined the associations between the Berlin definition criteria and prognosis and clinical parameters, including high-resolution computed tomography (HRCT) scores of fibroproliferative changes of the lungs. One hundred fifty-three patients (45 females; mean age, 67 y/o), who met the Berlin definition and received treatment in our intensive care unit between January 2012 and December 2015, were enrolled. RESULTS: The severity of ARDS was mild in 42 patients, moderate in 71, and severe in 40. The underlying diseases included pneumonia in 56 patients and aspiration in 43. Forty-two (27.5%) patients were deceased within 30 days, and the 30-day mortality was 10% in mild ARDS, 23% in moderate, and 55% in severe, which were significantly different (P <  0.05). In the non-survivors, APACHE II, SOFA, and SAPS II scores were higher than in the survivors (P <  0.001). Multivariate analyses revealed that elevated blood lactate level (≥ 2.0 mmol/L) and increased HRCT scores were significantly associated with weaning failure and 30-day mortality of the patients with ARDS. CONCLUSIONS: These results suggested that the severity criteria in the Berlin definition might be associated with the prognosis of the patients. Blood lactate levels and HRCT score might be predictive of the outcome of patients with ARDS.

Simultaneous Detection of the T790M and L858R Mutations in the EGFR Gene by Oligoribonucleotide Interference-PCR.

A de novo single-nucleotide mutation in the EGFR gene can cause the development of lung cancer. EGFR tyrosine kinase inhibitors (EGFR-TKIs) are used for clinical treatment of such lung cancers, but acquired resistance often mitigates their efficacy. Accordingly, monitoring of de novo and acquired nucleotide mutations is essential for clinical treatment of lung cancers with EGFR-TKIs. Previously, we reported that oligoribonucleotide interference-PCR (ORNi-PCR) can accurately and cost-effectively detect single-nucleotide mutations. In this study, we applied ORNi-PCR to simultaneous detection of the de novo L858R and acquired T790M mutations in the EGFR gene in lung cancer cells. First, we established optimal experimental conditions for ORNi-PCR to simultaneously detect the two single-nucleotide mutations in genomic DNA from lung cancer cells. The conditions we established could also be used for ORNi-PCR using complementary DNA reverse-transcribed from extracted RNA. We found that ORNi-PCR could detect lung cancer cells possessing both single-nucleotide mutations among a large number of cells harboring wild-type sequences, even when the cancer cells constituted less than ~0.2% of all cells. Our findings demonstrate that ORNi-PCR can simultaneously detect multiple single-nucleotide mutations in a gene of interest and might therefore be useful for simultaneous detection of EGFR mutations in clinical examinations.

Anti-inflammatory roles of mesenchymal stromal cells during acute Streptococcus pneumoniae pulmonary infection in mice.

BACKGROUND: Pneumonia is the fourth leading cause of death worldwide, and Streptococcus pneumoniae is the most commonly associated pathogen. Increasing evidence suggests that mesenchymal stromal cells (MSCs) have anti-inflammatory roles during innate immune responses such as sepsis. However, little is known about the effect of MSCs on pneumococcal pneumonia. METHODS: Bone marrow-derived macrophages (BMDMs) were stimulated with various ligands in the presence or absence of MSC-conditioned medium. For in vivo studies, mice intranasally-inoculated with S. pneumoniae were intravenously treated with MSCs or vehicle, and various parameters were assessed. RESULTS: After stimulation with toll-like receptor (TLR) 2, TLR9 or TLR4 ligands, or live S. pneumoniae, TNF-α and interleukin (IL)-6 levels were significantly decreased, whereas IL-10 was significantly increased in BMDMs cultured in MSC-conditioned medium. In mice, MSC treatment decreased the number of neutrophils in bronchoalveolar lavage fluid (BALF) after pneumococcal infection, and this was associated with a decrease in myeloperoxidase activity in the lungs. Levels of proinflammatory cytokines, including TNF-α, IL-6, GM-CSF and IFN-γ, were significantly lower in MSC-treated mice, and the bacterial load in the lung after pneumococcal infection was significantly reduced. In addition, histopathologic analysis confirmed a decrease in the number of cells recruited to the lungs; however, lung edema, protein leakage into the BALF and levels of the antibacterial protein lipocalin 2 in the BALF were comparable between the groups. CONCLUSIONS: These results indicate that MSCs could represent a potential therapeutic application for the treatment of pneumonia caused by S. pneumoniae.

A single-arm phase II study of nab-paclitaxel for patients with chemorefractory non-small cell lung cancer.

BACKGROUND: We aimed to evaluate the efficacy and safety of nab-paclitaxel in patients with refractory advanced non-small cell lung cancer who failed previous chemotherapy. METHODS: Patients were required to have an Eastern Cooperative Oncology Group performance status of 0-2 and adequate organ function. Patients received nab-paclitaxel, 100 mg/m2 i.v. on days 1, 8, and 15 every 4 weeks. The primary endpoint was the overall response rate. Secondary endpoints were the progression-free survival time, overall survival, and the toxicity profile. RESULTS: From July 2013 to July 2015, a total of 31 patients were enrolled. Fourteen patients received nab-paclitaxel as a second-line and 17 received it as an over third-line therapy. Each patient received a median of 5 treatment cycles (range, 1-11). The overall response rate was 19.3% (95% confidence interval, 9.1-36.2%) (complete response (n = 0), partial response (n = 6), stable disease (n = 17), and progressive disease (n = 8)). The median progression-free survival time was 4.5 months (95% confidence interval 3.5-6.3 months), median overall survival time was 15.7 months, and 1-year survival rate was 54.8%. Most common grade 3 or 4 non-hematological toxicities were elevated aspartate transaminase level (3.2%) and sensory neuropathy (9.6%). Neutropenia was the most common grade 3 or 4 adverse events (38.6%), and febrile neutropenia developed in 12.9% patients. No treatment-related deaths were observed in this study. CONCLUSION: Primary endpoint was met. Single agent nab-paclitaxel showed significant clinical efficacy and manageable toxicities for patients with chemorefractory advanced non-small cell lung cancer even if late line setting. TRIAL REGISTRATION: UMIN000011696 . The date of registration was July 11th, 2013.

The efficacy, safety, and feasibility of inhaled amikacin for the treatment of difficult-to-treat non-tuberculous mycobacterial lung diseases.

BACKGROUND: In multidrug regimens, including an intravenous aminoglycoside (e.g. amikacin [AMK]) is recommended for difficult-to-treat non-tuberculous mycobacterial (NTM) lung diseases. We aimed to evaluate the efficacy, safety, and feasibility of inhaled AMK therapy in patients with difficult-to-treat NTM lung diseases in a retrospective chart review. METHODS: The study population consisted of patients with NTM lung diseases who received combination therapy, including inhaled AMK therapy, at Keio University Hospital (Tokyo, Japan), from January 2014 through May 2016. A total of 26 cases, consisting of 23 Mycobacterium avium complex (MAC) and three Mycobacterium abscessus complex (MABC) infections cases, were included in this study. The efficacy, safety, and feasibility of inhaled AMK therapy were retrospectively investigated. The Research Ethics Committee of Keio University Hospital approved this study, and informed consent was obtained from all patients. RESULTS: All 26 patients were culture-positive at enrolment. Twenty-three of the 26 patients (88.5%), including 21/23 MAC patients (91.3%) and 2/3 MABC patients (66.7%), were administered inhaled AMK therapy for >3 months. The proportion of patients who had clinical symptoms, including, cough and sputum, declined after inhalation AMK therapy. Ten of the 23 patients (43.5%) who received AMK inhalation, including 8/21 MAC (38.1%) and 2/2 MABC patients (100%), showed sputum conversion, defined as at least three consecutive negative sputum cultures. Seven of the 23 patients, including, 5/21 MAC and 2/2 MABC patients, showed improvements in high-resolution computed tomography imaging of the chest. In addition, the serum AMK trough levels before the second inhalation were <1.2 µg/mL in all 26 patients, with no occurrence of severe adverse events, such as renal toxicity. One patient (3.8%) experienced auditory toxicity, in the form of tinnitus. However, this symptom was reversible, after temporary interruption of AMK, the patient was able to safely resume the therapy. CONCLUSIONS: Inhaled AMK therapy is an effective and feasible therapy for difficult-to-treat NTM lung disease.

Clinical and radiological characteristics of patients with late-onset severe restrictive lung defect after hematopoietic stem cell transplantation.

BACKGROUND: Late-onset noninfectious pulmonary complications (LONIPCs), which occur more than 3 months after allogeneic hematopoietic stem cell transplantation (HSCT), are major causes of morbidity and mortality after transplantation. Among LONIPCs, we occasionally treat patients with late-onset severe restrictive lung defect after HSCT; however, its clinical features have not been fully elucidated. METHODS: A retrospective chart review of a single center on cases of late-onset severe restrictive lung defect after HSCT was performed. Among 453 patients who survived longer than 100 days after allogeneic HSCT with evaluable spirometry data, 12 patients (2.6%) developed late-onset severe restrictive lung defect (i.e., vital capacity percent of predicted less than 60%). RESULTS: Median duration from transplantation to diagnosis of late-onset severe restrictive lung defect cases was 44.5 months. Major computed tomography (CT) finding was pleuroparenchymal thickening with volume loss, an evidence of fibrosis, predominantly in upper lobes (n = 7), which was consistent with pleuroparenchymal fibroelastosis. The remaining patients showed unclassifiable interstitial pneumonia pattern (n = 2) and airway-predominant pattern (n = 3). The diffusing capacity for carbon oxide tended to decrease, while the residual volume/total lung capacity ratio tended to increase after HSCT. Of 12 patients, 8 patients died and the median month from diagnosis to death was 33.5 months. Seven patients died of pulmonary or systemic infection, and one patient died due to relapse of the primary disease. CONCLUSION: Severe restrictive lung defect could develop in selected cases in the late-phase after HSCT and could be a unique clinical entity with specific radiographical findings.

Pneumococcal Infection Aggravates Elastase-Induced Emphysema via Matrix Metalloproteinase 12 Overexpression.

BACKGROUND: Acute exacerbation of chronic obstructive pulmonary disease (COPD)--typically caused by bacterial or viral infection--is associated with poor prognosis and emphysema progression through unknown mechanisms. We aimed to elucidate the mechanisms responsible for the poor prognosis and emphysema progression associated with COPD exacerbation. METHODS: We established a mouse model mimicking acute human COPD exacerbation, wherein mice with elastase-induced emphysema were intranasally infected with Streptococcus pneumoniae. RESULTS: In mice with elastase-induced emphysema, infection with S. pneumoniae resulted in increased mortality, an increased number of inflammatory cells in bronchoalveolar lavage fluid (BALF), and increased matrix metalloproteinase 12 (MMP-12) production in the lungs, as well as enhanced emphysema progression. The increased MMP-12 production was mostly due to alveolar type II cells, alveolar macrophages, and lymphocytes that aggregated around vessels and bronchioles. Dexamethasone treatment suppressed the mortality rate and number of inflammatory cells in BALF but not emphysema progression, possibly owing to the failure of MMP-12 suppression in the lungs, whereas treatment with the MMP inhibitor ONO-4817 dramatically suppressed both mortality rate and emphysema progression. CONCLUSIONS: These results suggest that MMP-12 production during COPD exacerbation results in increased mortality and emphysema progression. Our study identifies MMP-12 as a target to prevent further aggravation of COPD.

Histone Deacetylase Inhibition Protects Mice Against Lethal Postinfluenza Pneumococcal Infection.

OBJECTIVES: Secondary bacterial pneumonia following influenza virus infection is associated with high mortality, but the mechanism is largely unknown. Epigenetic gene regulation appears to play key roles in innate and adaptive immunity. We hypothesized that histone acetylation, a major epigenetic mechanism associated with transcriptionally active chromatin, might contribute to the poor outcome of postinfluenza pneumonia. DESIGN: Prospective experimental study. SETTING: University research laboratory. SUBJECTS: C57BL/6 male mice. INTERVENTIONS: Mice were infected intranasally with 1.0 × 10 colony-forming units of Streptococcus pneumoniae, 7 days after intranasal inoculation with five plaque-forming units of influenza virus A/H1N1/PR8/34. The mice were intraperitoneally injected with the histone deacetylase inhibitor trichostatin A (1 mg/kg) or vehicle once a day from 1 hour after pneumococcal infection throughout the course of the experiment. The primary outcome was survival rate. MEASUREMENTS AND MAIN RESULTS: Trichostatin A significantly suppressed histone deacetylase activity and significantly improved the survival rate of mice (56.3%) after postinfluenza pneumococcal infection when compared with vehicle-treated mice (20.0%), which was associated with a significant decrease in the total cell count of the bronchoalveolar lavage fluid. The interleukin-1ß level in the serum and the number of natural killer cells in the lungs were significantly lower in the trichostatin A-treated group. CONCLUSIONS: The histone deacetylase inhibitor trichostatin A protects mice against postinfluenza pneumonia possibly through multiple factors, including decreasing local cell recruitment into the lungs and suppressing systemic inflammation.

Clinical efficacy and safety of multidrug therapy including thrice weekly intravenous amikacin administration for Mycobacterium abscessus pulmonary disease in outpatient settings: a case series.

BACKGROUND: Mycobacterium abscessus (M. abscessus) pulmonary disease is a refractory chronic infectious disease. Options for treating M. abscessus pulmonary disease are limited, especially in outpatient settings. Among parenteral antibiotics against M. abscessus, intravenous amikacin (AMK) is expected to be an effective outpatient antimicrobial therapy. This study evaluated the clinical efficacy and safety of intravenous AMK therapy in outpatients with M. abscessus pulmonary disease. METHODS: This retrospective chart review of cases of M. abscessus pulmonary disease evaluated patient background data, AMK dosage and duration, sputum conversion, clinical symptoms radiological findings, and adverse events. M. massiliense was excluded on the basis of multiplex PCR assay. RESULTS: Thirteen patients (2 men and 11 women) with M. abscessus pulmonary disease were enrolled at 2 hospitals. The median age at the initiation of intravenous AMK treatment was 65 years (range: 50-86 years). Patients received a median AMK dose of 12.5 mg/kg (range: 8.3-16.2 mg/kg) for a median duration of 4 months (range: 3-9 months). The addition of intravenous AMK led to sputum conversion in 10 of 13 patients, and 8 patients continued to have negative sputum status 1 year after treatment. Approximately half of the patients showed improvement on chest high-resolution computed tomography. There were no severe adverse events such as ototoxicity, vestibular toxicity, and renal toxicity. CONCLUSIONS: Thrice weekly intravenous AMK administration in outpatient settings is effective and safe for patients with M. abscessus pulmonary disease.

Clinical characteristics of pulmonary Mycobacterium scrofulaceum disease in 2001-2011: A case series and literature review.

BACKGROUND: Mycobacterium scrofulaceum is a well-known pathogen associated with cervical lymphadenitis in children. However, pulmonary M. scrofulaceum disease is a rare condition with unknown clinical features. The present study aimed to clarify the clinical features of pulmonary M. scrofulaceum disease described in recent cases and reports. METHODS: We reviewed the medical records of all adult patients with pulmonary M. scrofulaceum disease at Keio University Hospital and the National Center for Global Health and Medicine Center Hospital between 2001 and 2011. We also conducted a review of the PubMed database to identify additional cases of pulmonary M. scrofulaceum disease in adults. RESULTS: Our study identified 8 cases of pulmonary M. scrofulaceum disease at the 2 identified institutions during our study period. Most cases were diagnosed in middle-aged and elderly men with underlying pulmonary diseases such as chronic obstructive pulmonary disease and Mycobacterium avium complex lung disease, as well as those with a history of pulmonary tuberculosis. In contrast, most previously reported cases identified through our literature review had a history of dust inhalation or underlying silicosis. Three of 8 cases at our institutions and 20 of 23 cases from the literature were treated with combination therapies. CONCLUSIONS: We conclude that in the recent histories of our institutions, pulmonary M. scrofulaceum disease has mainly occurred in patients with chronic pulmonary diseases. We further conclude that combination therapies that include clarithromycin might yield better patient outcomes.

Health-related quality of life is inversely correlated with C-reactive protein and age in Mycobacterium avium complex lung disease: a cross-sectional analysis of 235 patients.

BACKGROUND: Mycobacterium avium complex (MAC) lung diseases generally cause chronic disease in immunocompetent hosts. Although a few studies have examined health-related quality of life (HRQL) in patients with MAC lung disease, there have been no large studies. This study aimed to evaluate HRQL and its correlation with clinical outcomes in MAC lung disease. METHODS: A cross-sectional study was conducted at Keio University Hospital to investigate the factors associated with HRQL in pulmonary nontuberculous mycobacterial diseases. MAC lung diseases were diagnosed according to the 2007 ATS/IDSA guidelines for nontuberculous mycobacterial diseases. The 36-item short form health survey (SF-36) was administered to assess clinical outcomes. Clinical variables included treatment status, latest haematological data, and bacterial smear and culture results. RESULTS: The SF-36 scores for the 235 patients (median age, 69 years; 45 men and 190 women) with MAC lung disease, except for the bodily pain and mental health subscale scores, were significantly lower than the Japanese population norms. In the multivariable analyses, current treatment for MAC and a positive sputum smear or culture within the past year were significantly associated with lower SF-36 scores. C-reactive protein (CRP) and age showed stronger inverse correlations with SF-36 scores. CONCLUSIONS: HRQL, especially the physical component, was impaired in patients with MAC lung diseases; this appears to be related with current treatment status, positive sputum smear or culture within the previous year, and particularly CRP and age. Further studies including qualitative assessments are needed to investigate the efficacy of CRP as a marker for progression or treatment response in MAC lung disease. TRIAL REGISTRATION: Clinical trial registered with UMIN ( UMIN000007964 ).

Immune reconstitution inflammatory syndrome due to Mycobacterium avium complex successfully followed up using 18 F-fluorodeoxyglucose positron emission tomography-computed tomography in a patient with human immunodeficiency virus infection: A case report.

BACKGROUND: In human immunodeficiency virus (HIV)-infected patients, immune reconstitution inflammatory syndrome (IRIS) due to nontuberculous mycobacteria (NTM) infection is one of the most difficult types of IRIS to manage. 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) has been suggested as a useful tool for evaluating the inflammatory status of HIV-infected patients. We present the first case of Mycobacterium avium complex (MAC)-associated IRIS (MAC-IRIS) that was successfully followed up using 18F-FDG PET/CT. CASE PRESENTATION: A 44-year-old homosexual Japanese man was referred to our hospital with fever and dyspnea. He was diagnosed with Pneumocystis jiroveci pneumonia and found to be HIV positive. After the initiation of combined antiretroviral therapy (cART), the patient's mediastinal and bilateral hilar lymphadenopathy gradually enlarged, and bilateral infiltrates appeared in the upper lung fields. 18F-FDG PET/CT was performed five months after the initiation of cART and showed intense accumulation of fluorodeoxyglucose (FDG) corresponding to the lesions of infiltration as well as the mediastinal and bilateral hilar lymphadenopathy. A bronchial wash culture and pathology findings led to a diagnosis of MAC-IRIS. Anti-mycobacterial chemotherapy with rifampicin, ethambutol, clarithromycin, and levofloxacin was started. One year after the chemotherapy was initiated, there was a significant reduction in FDG uptake in the area of the lesions except in the mediastinal lymph node. This implied incomplete resolution of the MAC-IRIS-related inflammation. Anti-mycobacterial chemotherapy was continued because of the residual lesion. To date, the patient has not experienced a recurrence of MAC-IRIS, a period of nine months. CONCLUSION: We present a case of MAC-IRIS in an HIV-infected patient whose disease activity was successfully followed up using 18F-FDG PET/CT. Our data suggest that 18F-FDG PET/CT is useful for evaluating the disease activity of NTM-IRIS and assessing the appropriate duration of anti-mycobacterial chemotherapy for NTM-IRIS in HIV-infected patients.

Successful resumption of tocilizumab for rheumatoid arthritis after resection of a pulmonary Mycobacterium avium complex lesion: a case report.

BACKGROUND: Biological agents inhibiting TNF-α and other molecules involved in inflammatory cascade have been increasingly used to treat rheumatoid arthritis (RA). However, it remains controversial whether biological agents can be used safely in a patient with an underlying chronic infectious disease. CASE PRESENTATION: A 63-year-old woman who had been treated with tocilizumab (TCZ), anti-interleukin-6 receptor antibody, for RA presented to our outpatient clinic due to hemoptysis. She was diagnosed with pulmonary Mycobacterium avium complex (MAC) infection, and high-resolution computed tomography (HRCT) showed a single cavitary lesion in the right upper lobe. After diagnosis of pulmonary MAC disease, TCZ was discontinued and combination chemotherapy with clarithromycin, rifampicin, ethambutol and amikacin was started for MAC pulmonary disease. Since the lesion was limited in the right upper lobe as a single cavity formation, she underwent right upper lobectomy. As her RA symptoms were deteriorated around the operation, TCZ was resumed. After resumption of TCZ, her RA symptoms improved and a recurrence of pulmonary MAC infection has not been observed for more than 1 year. CONCLUSION: This case suggested that TCZ could be safely reintroduced after the resection of a pulmonary MAC lesion. Although the use of biological agents is generally contraindicated in patients with pulmonary MAC disease, especially in those with a fibrocavitary lesion, a multimodality intervention for MAC including both medical and surgical approaches may enable introduction or resumption of biological agents.