Published papers

BACKGROUND: Mycobacterium lentiflavum is a slow-growing non-tuberculous Mycobacterium that is often associated with an immunocompromised state and cervical lymphadenitis in young children. However, little is known about the clinical importance of pulmonary infection with M. lentiflavum in adults. METHODS: The medical records of all adults who met the diagnostic criteria of pulmonary M. lentiflavum disease at Keio University Hospital and Fukujuji Hospital from 2001 to 2015 were reviewed. In addition, the PubMed database was searched to identify further reported cases in non-HIV adults. RESULTS: Five cases of pulmonary M. lentiflavum disease were identified in the medical records search and 11 additional cases were identified in the literature review. Eleven of the total 16 cases were female, and 15 of 16 cases showed a nodular/bronchiectatic pattern on chest computed tomography imaging. No cases showed an aggressive clinical course of pulmonary M. lentiflavum disease, although one patient died of an exacerbation of underlying vasculitis and bacterial pneumonia. CONCLUSIONS: The clinical characteristics of pulmonary M. lentiflavum disease in adult patients were identified. This disease mainly affects females, displays a nodular/bronchiectatic pattern on chest computed tomography imaging, and does not demonstrate an aggressive clinical course. Further larger studies are needed to reveal detailed clinical features.

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.

BACKGROUND: The clinical course of coronavirus disease (COVID-19) is diverse, and the usefulness of phenotyping in predicting the severity or prognosis of the disease has been demonstrated overseas. This study aimed to investigate clinically meaningful phenotypes in Japanese COVID-19 patients using cluster analysis. METHODS: From April 2020 to May 2021, data from inpatients aged ≥ 18 years diagnosed with COVID-19 and who agreed to participate in the study were collected. A total of 1322 Japanese patients were included. Hierarchical cluster analysis was performed using variables reported to be associated with COVID-19 severity or prognosis, namely, age, sex, obesity, smoking history, hypertension, diabetes mellitus, malignancy, chronic obstructive pulmonary disease, hyperuricemia, cardiovascular disease, chronic liver disease, and chronic kidney disease. RESULTS: Participants were divided into four clusters: Cluster 1, young healthy (n = 266, 20.1%); Cluster 2, middle-aged (n = 245, 18.5%); Cluster 3, middle-aged obese (n = 435, 32.9%); and Cluster 4, elderly (n = 376, 28.4%). In Clusters 3 and 4, sore throat, dysosmia, and dysgeusia tended to be less frequent, while shortness of breath was more frequent. Serum lactate dehydrogenase, ferritin, KL-6, D-dimer, and C-reactive protein levels tended to be higher in Clusters 3 and 4. Although Cluster 3 had a similar age as Cluster 2, it tended to have poorer outcomes. Both Clusters 3 and 4 tended to exhibit higher rates of oxygen supplementation, intensive care unit admission, and mechanical ventilation, but the mortality rate tended to be lower in Cluster 3. CONCLUSIONS: We have successfully performed the first phenotyping of COVID-19 patients in Japan, which is clinically useful in predicting important outcomes, despite the simplicity of the cluster analysis method that does not use complex variables.

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.

Mycoplasma pneumoniae infection is conventionally diagnosed using serum antibody testing, microbial culture, and genetic testing. Recently, immunochromatography-based rapid mycoplasma antigen test kits have been developed and commercialised for rapid diagnosis of M. pneumoniae infection. However, as these kits do not provide sufficient sensitivity and specificity, a rapid test kit with improved accuracy is desired. The present prospective study evaluated a rapid M. pneumoniae diagnostic system utilizing a newly developed silver amplification immunochromatography (SAI) system. We performed dilution sensitivity test and the prospective clinical study evaluating the SAI system. The subjects of the clinical study included both children and adults. All patients suspected to have mycoplasma pneumonia (169 patients) were sequentially enrolled. Twelve patients did not agree to participate and 157 patients were enrolled in the study. The results demonstrate excellent performance of this system with 90.4% sensitivity and 100.0% specificity compared with real-time polymerase chain reaction. When compared with loop-mediated isothermal amplification (LAMP) methods, the results also demonstrate a high performance of this system with 93.0% sensitivity and 100.0% specificity. The SAI system uses a dedicated device for automatic analysis and reading, making it highly objective, and requires less human power, supporting its usefulness in clinical settings.

RATIONALE: The clinical features and prognosis of nontuberculous mycobacterial (NTM) pleuritis and pleural effusion combined with NTM lung disease (NTM-LD) remain unclear. OBJECTIVES: To investigate the clinical features and prognosis of NTM pleuritis. METHODS: This retrospective observational study included patients with NTM pleuritis from January 2001 to June 2018 across eight hospitals in Japan. NTM pleuritis was defined by a positive culture of NTM from pleural effusion. We matched patients with Mycobacterium complex lung disease (MAC-LD) without pleuritis by sex and age to obtain comparative data and investigated the association between clinical parameters and prognosis. RESULTS: We identified 64 patients with NTM pleuritis (median age, 73 years; 37 female). The median follow-up duration was 11 months, and 27 patients died. Patients with MAC pleuritis had a significantly worse survival compared to matched patients with MAC-LD without pleuritis. Multivariate analysis revealed that pleuritis (adjusted hazard ratio [aHR], 6.99; 95% confidence interval [CI], 2.58-19.00) and underlying pulmonary diseases (aHR, 3.01; 95% CI, 1.44-6.28) were independently associated with all-cause mortality in MAC-LD patients. CONCLUSIONS: The prognosis of MAC pleuritis is poorer than that of MAC-LD without pleuritis. Pleuritis is an independent prognostic factor in patients with MAC-LD.

BACKGROUND: Although recent studies have identified anti-glycopeptidolipid (GPL)-core IgA antibodies as a serodiagnostic test for Mycobacterium avium complex lung disease (MAC-LD), this test shows insufficient sensitivity. This study aimed to determine the clinical utility of these antibodies in assessing disease progression and the clinical characteristics of MAC-LD patients with negative antibody results. METHODS: We retrospectively reviewed the medical records of consecutive newly diagnosed, untreated MAC-LD patients in two referral hospitals. We evaluated the association of anti-GPL-core IgA antibody results with disease progression requiring treatment and the factors associated with negative antibody results. RESULTS: In total, 229 patients (161 females; median age, 71 years; 185 with nodular/bronchiectatic disease phenotype; 69 with cavitary lesions) were enrolled; 146 patients (64%) were anti-GPL-core IgA antibody-positive. Radiological severity scores were associated with anti-GPL-core IgA antibody titers. During the median 364-day follow-up, 114 patients (49.8%) required treatment. Multivariate Cox proportional hazards analysis showed that positive anti-GPL-core IgA antibody results, a younger age, the absence of malignancy, and the presence of cavitary lesions were associated with disease progression requiring treatment. Multivariate logistic analysis revealed that significant factors related to the negative antibody results included underlying pulmonary disease, lower radiological scores, chronic sinusitis, and macrolide monotherapy. CONCLUSION: In addition to cavitary lesions, anti-GPL-core IgA antibody positivity was associated with disease progression requiring treatment. Physicians should carefully use anti-GPL-core IgA antibody results for the diagnosis of patients with underlying pulmonary disease, chronic sinusitis, macrolide monotherapy, and lower radiological severity.

AIM: Diabetes mellitus (DM) is a known risk factor for severe coronavirus disease 2019 (COVID-19), but the clinical impact of undiagnosed diabetes and prediabetes in COVID-19 are unclear particularly in Japan. We clarify the difference in clinical characteristics, including age, sex, body mass index and co-morbidities, laboratory findings and critical outcomes, in a large Japanese COVID-19 cohort without diabetes, with prediabetes, undiagnosed diabetes and diagnosed diabetes, and to identify associated risk factors. MATERIALS AND METHODS: This multicentre, retrospective cohort study used the Japan COVID-19 Task Force database, which included data on 2430 hospitalized COVID-19 patients from over 70 hospitals from February 2020 to October 2021. The prevalence of prediabetes, undiagnosed diabetes and diagnosed diabetes were estimated based on HbA1c levels or a clinical diabetes history. Critical outcomes were defined as the use of high-flow oxygen, invasive positive-pressure ventilation or extracorporeal membrane oxygenation, or death during hospitalization. RESULTS: Prediabetes, undiagnosed diabetes and diagnosed diabetes were observed in 40.9%, 10.0% and 23.0%, respectively. Similar to diagnosed diabetes, prediabetes and undiagnosed diabetes were risk factors for critical COVID-19 outcomes (adjusted odds ratio [aOR] [95% CI]: 2.13 [1.31-3.48] and 4.00 [2.19-7.28], respectively). HbA1c was associated with COVID-19 severity in prediabetes patients (aOR [95% CI]: 11.2 [3.49-36.3]), but not other groups. CONCLUSIONS: We documented the clinical characteristics and outcomes of Japanese COVID-19 patients according to HbA1c levels or diabetes co-morbidity. As well as undiagnosed and diagnosed diabetes, physicians should be aware of prediabetes related to COVID-19 severity.

Although most cases occur in immunocompromised individuals, anal tuberculosis can occur in the absence of HIV infection. Anal tuberculosis should be considered in the differential diagnosis of chronic or recurrent anal fistulas.

BACKGROUND: In Japan, Mycobacterium avium complex lung disease (MAC-LD) is the most common in nontuberculous mycobacterial lung disease. Patients often experience adverse events, resulting in the discontinuation of treatment, which causes treatment failure. The JADER (Japanese Adverse Drug Event Report) database is a database of adverse events that allows us to collect real-world data on adverse events. We can collect large-scale data cost-effectively and detect signals of potential adverse events such as reporting odds ratio (ROR) by using spontaneous reporting systems. In this study, we aimed to elucidate the adverse events of clarithromycin (CAM), ethambutol (EB), and rifampicin (RFP) using the JADER database. METHODS: We included cases of MAC-LD between April 2004 and June 2017. We investigated sex, age, and medications that may have caused the adverse events, outcomes, and time of onset. We calculated the safety signal index as the ROR. Time-to-event analysis was performed using the Weibull distribution. RESULTS: The total number of adverse events of CAM, EB, and RFP was 2780, with 806 patients. In the overall adverse events, hematologic and lymphatic disorders were the most common adverse events, with 17.3%, followed by eye disorders (16.6%), and hepatobiliary disorders (14.0%). The outcomes were as follows: recovery, 40.0%; remission, 27.1%; non-recovery, 11.2%; and death, 7.1%. Regarding the most common onset time of CAM, EB, and RFP was within 120 days at 40%, 181-300 days at 43.6%, and within 120 days at 88.5%. For CAM, the RORs of infections and infestations, hepatobiliary system disorders, and immune system disorders were 4.13 (95% confidence interval [CI], 2.3-7.44), 2.61 (95% CI, 1.39-4.91), and 2.38 (95% CI, 1.04-5.44). For EB, the ROR of eye disorders was 215.79 (95% CI, 132.62-351.12). For RFP, the RORs of renal and urinary tract disorders and investigations were 7.03 (95% CI, 3.35-14.77) and 6.99 (95% CI, 3.22-15.18). The β value of EB was 2.07 (95% CI, 1.48-2.76), which was classified as a wear-out failure type. CONCLUSIONS: For MAC-LD, the adverse event which has the highest ROR is infections and infestations in CAM, eye disorders in EB, renal and urinary tract disorders in RFP. Adverse events of EB occur after 180 days, whereas the adverse events of CAM and RFP occur early in the course of treatment.