Analysis of SARS-CoV-2 PCR and Chest CT Findings at a Single Facility in Tokyo (Machida Municipal Hospital).

INTRODUCTION: The SARS-CoV-2 reverse transcription polymerase chain reaction (RT-PCR) test is useful for diagnosing COVID-19, and the RT-PCR positive rate is an important indicator for estimating the incidence rate and number of infections. COVID-19 pneumonia is also associated with characteristic findings on chest CT, which can aid in diagnosis. METHODS: We retrospectively evaluated patient background characteristics, the number of cases, the positivity rate, and chest CT findings for positive and negative cases in 672 patients who underwent RT-PCR for suspected COVID-19 at our hospital between April 3 and August 28, 2020. In addition, we compared trends in the positive rates at approximately weekly intervals with trends in the number of new infections in Machida City, Tokyo. RESULTS: The study included 323 men and 349 women, with a median age of 46 years (range: 1 month-100 years). RT-PCR findings were positive in 37 cases, and the positive rate was 5.51%. Trends in the positive rate at our hospital and the number of new COVID-19 cases in the city were similar during the study period. Among patients with positive results, 15 (40.5%) had chest CT findings, and 14 had bilateral homogeneous GGOs. Among patients with negative results, 190 had chest CT findings at the time of examination, and 150 were diagnosed with bacterial pneumonia or bronchitis, with main findings consisting of consolidations and centrilobular opacities. Only 11 of these patients exhibited bilateral homogeneous GGOs. CONCLUSION: Bilateral homogeneous GGOs are characteristic of COVID-19 pneumonia and may aid in the diagnosis of COVID-19.

Clinical utility of thoracoscopy in elderly tuberculous pleurisy patients under local anesthesia.

INTRODUCTION: Diagnosing tuberculous pleurisy is important in Japan because it currently has a moderate tuberculosis prevalence. However, physicians often have difficulty making a diagnosis. It was reported that thoracoscopy under local anesthesia is useful for the diagnosis of tuberculous pleurisy, but there are no reports focusing on elderly patients. METHODS: In this study, the usefulness of thoracoscopy under local anesthesia was evaluated in elderly patients. Among 170 patients who underwent thoracoscopy under local anesthesia at our hospital during 11 years from January 2008 to December 2018, those aged 75 years or older (n = 75) were investigated retrospectively. RESULTS: A total of 55 patients underwent thoracoscopy under local anesthesia for detailed examination of pleural effusion of unknown cause. Of these, 18 were diagnosed as tuberculous pleurisy. The median age was 82 years (range: 75-92 years). The diagnosis of tuberculous pleurisy was made in 11 patients in whom Mycobacterium tuberculosis was detected and in four patients whose pathological findings indicated epithelioid granuloma accompanied by caseous necrosis. Clinical diagnosis was made in the remaining three patients based on thoracoscopic findings of the pleural cavity and a high level of adenosine deaminase in pleural fluid. No serious complications attributable to the examination were observed in any patient. CONCLUSIONS: Thoracoscopy under local anesthesia was useful for the diagnosis of tuberculous pleurisy in elderly patients, with useful information being also obtained for the treatment of tuberculosis.

Impact of emphysema on sputum culture conversion in male patients with pulmonary tuberculosis: a retrospective analysis.

BACKGROUND: Although cigarette smoking may have a negative impact on the clinical outcome of pulmonary tuberculosis (PTB), few studies have investigated the impact of smoking-associated lung diseases. Emphysema is a major pathological finding of smoking-related lung damage. We aimed to clarify the effect of emphysema on sputum culture conversion rate for Mycobacterium tuberculosis (MTB). METHODS: We retrospectively studied 79 male patients with PTB confirmed by acid-fast bacillus smear and culture at Jikei University Daisan Hospital between January 2015 and December 2018. We investigated the sputum culture conversion rates for MTB after starting standard anti-TB treatment in patients with or without emphysema. Emphysema was defined as Goddard score ≥ 1 based on low attenuation area < - 950 Hounsfield Unit (HU) using computed tomography (CT). We also evaluated the effect on PTB-related CT findings prior to anti-TB treatment. RESULTS: Mycobacterial median time to culture conversion (TCC) in 38 PTB patients with emphysema was 52.0 days [interquartile range (IQR) 29.0-66.0 days], which was significantly delayed compared with that in 41 patients without emphysema (28.0 days, IQR 14.0-42.0 days) (p < 0.001, log-rank test). Multivariate Cox proportional hazards analysis showed that the following were associated with delayed TCC: emphysema [hazard ratio (HR): 2.43; 95% confidence interval (CI): 1.18-4.97; p = 0.015), cavities (HR: 2.15; 95% CI: 1.83-3.89; p = 0.012) and baseline time to TB detection within 2 weeks (HR: 2.95; 95% CI: 1.64-5.31; p < 0.0001). Cavities and consolidation were more often identified by CT in PTB patients with than without emphysema (71.05% vs 43.90%; p = 0.015, and 84.21% vs 60.98%; p = 0.021, respectively). CONCLUSIONS: This study suggests that emphysema poses an increased risk of delayed TCC in PTB. Emphysema detection by CT might be a useful method for prediction of the duration of PTB treatment required for sputum negative conversion.

[Usefulness of serum procalcitonin measurement in the diagnosis of respiratory infectious diseases].

The serum concentration of procalcitonin (PCT) is specifically elevated in severe bacterial infections. In Japan, PCT has been used as a serum marker for bacterial sepsis since February, 2006. However, the evidence of it in respiratory infectious diseases is limited. In the present study, we analyzed 57 episodes of systemic inflammatory response syndrome in 53 inpatients to investigate the usefulness of serum PCT measurement in respiratory infectious diseases. Although the sensitivity and a negative predictive value in common bacterial infections were low, the specificity and positive predictive value were 95% and 93%, respectively. This suggests that the significance of serum PCT measurement relies on confirming the diagnosis of common bacterial infections. Analysis using a receiver operating characteristic (ROC) curve demonstrated that serum PCT was a more reliable measure of bacterial sepsis than leukocyte counts in the peripheral blood or serum C-reactive protein. In cases of community-acquired pneumonia, except atypical pneumonia, the hospital mortality rate was significantly higher in PCT-positive patients than in PCT-negative patients (38% vs. 0%), indicating that serum PCT could be a factor predicting in-hospital death.

[A case of pulmonary aspergillosis subacutely forming a cavity during the course of microscopic polyangiitis].

A 77-year-old woman was referred to our department with hemoptysis. Microscopic polyangiitis (MPA) with resultant alveolar hemorrhage was diagnosed because of diffuse infiltrate of the right lung, proteinurea, renal dysfunction and the presence of MPO-ANCA. The disease responded well to corticosteroid therapy. She was discharged, but as corticosteroid was gradually tapered, an irregularly-shaped nodule appeared in the right upper lung field within 2 weeks. She was re-admitted because the nodule increased in size with cavity formation in spite of the administration of antibacterial agent. Pulmonary aspergillosis was diagnosed, since bronchial washing and transbronchial lung biopsy revealed the presence of Aspergillus fumigatus. Serum beta-D-glucan was decreased and the cavity was reduced in size, responding to the treatment with micafungin. However, she died later of systemic infection by a herpesvirus. We report this case because of the interesting course of pulmonary aspergillosis that subacutely formed a cavity.