Switching from weak to strong cortical attachment of microtubules accounts for the transition from nuclear centration to spindle elongation in metazoans.

The centrosome is a major microtubule organizing center in animal cells. The position of the centrosomes inside the cell is important for cell functions such as cell cycle, and thus should be tightly regulated. Theoretical models based on the forces generated along the microtubules have been proposed to account for the dynamic movements of the centrosomes during the cell cycle. These models, however, often adopted inconsistent assumptions to explain distinct but successive movements, thus preventing a unified model for centrosome positioning. For the centration of the centrosomes, weak attachment of the astral microtubules to the cell cortex was assumed. In contrast, for the separation of the centrosomes during spindle elongation, strong attachment was assumed. Here, we mathematically analyzed these processes at steady state and found that the different assumptions are proper for each process. We experimentally validated our conclusion using nematode and sea urchin embryos by manipulating their shapes. Our results suggest the existence of a molecular mechanism that converts the cortical attachment from weak to strong during the transition from centrosome centration to spindle elongation.

Amikacin liposome inhalation suspension for Mycobacterium avium complex pulmonary disease: A subgroup analysis of Japanese patients in the randomized, phase 3, CONVERT study.

BACKGROUND: CONVERT, a randomized, active-controlled, global, Phase 3 trial demonstrated that patients with treatment-refractory Mycobacterium avium complex (MAC) pulmonary disease were more likely to achieve culture conversion with amikacin liposome inhalation suspension (ALIS) plus guideline-based therapy (GBT) versus those continuing on GBT alone. This subgroup analysis reports the efficacy and safety of ALIS in Japanese patients enrolled in CONVERT. METHODS: Japanese patients aged ≥20 years with treatment-refractory MAC pulmonary disease from Japanese sites were included. Patients were randomized to receive once-daily 590 mg ALIS + GBT or GBT alone; patients converting by Month 6 remained in the study to complete 12-month treatment followed by a 12-month off-treatment period. Nonconverters exited the study at Month 8. The primary endpoint was the proportion of patients achieving culture conversion by Month 6. RESULTS: Of the 59 Japanese patients screened, 48 were randomized to receive ALIS + GBT (n = 34) or GBT alone (n = 14), and 41/48 (85.4 %) were women. The mean (standard deviation) age of patients was 64.5 (8.6) years, and 83.3 % of patients had bronchiectasis at baseline. By Month 6, sputum culture conversion was cumulatively achieved in 9/34 (26.5 %) patients receiving ALIS + GBT versus none receiving GBT alone. Treatment-emergent adverse events were reported in 94.1 % and 100.0 % of patients receiving ALIS + GBT and GBT alone, respectively. No deaths were reported. CONCLUSIONS: The efficacy observed in the Japanese subpopulation was largely consistent with that in the overall CONVERT study population, with more patients achieving culture conversion with ALIS + GBT versus GBT alone. Safety profiles were similar between the overall population and the Japanese subpopulation. CLINICAL TRIAL REGISTRATION: NCT02344004.

[A Case of Advanced Lung Adenocarcinoma in an Elderly Patient Who Maintained Responsiveness after Discontinuation of Immune Checkpoint Inhibitors].

An 81-year-old woman was admitted to our hospital because of an abnormal opacity on the chest radiograph. She was diagnosed with cT3N3M1a, Stage ⅣA left lower lung lobe adenocarcinoma, and the PD-L1(22C3)expression was high (tumor proportion score[TPS]: 100%). She was administered with pembrolizumab monotherapy because her performance status(PS)was PS 1. After 4 courses, she had a partial response(PR), but her treatment had to be discontinued because of cutaneous adverse effects. After 6 months, the tumor regrew, and atezolizumab monotherapy was provided. Another cutaneous adverse event occurred, and treatment was discontinued again. However, a complete response(CR)was maintained for approximately 2 years and 6 months after discontinuation of treatments.

Practical Utility of a Clinical Pathway for Older Patients with Aspiration Pneumonia: A Single-Center Retrospective Observational Study.

Introduction: Clinical pathways (CPWs) are patient management tools based on a standardized treatment plan aimed at improving quality of care. This study aimed to investigate whether CPW-guided treatment has a favorable impact on the outcomes of hospitalized older patients with aspiration pneumonia. Method: This retrospective study included patients with aspiration pneumonia, aged ≥ 65 years, and hospitalized at a community hospital in Japan. CPW implementation was arbitrarily determined by the attending physician upon admission. Outcomes were compared according to with or without the CPW (CPW-group and non-CPW groups). Propensity score (PS)-based analyses were used to control for confounding factors. Logistic regression analyses were conducted to evaluate the impact of CPW on the clinical course and outcomes. Results: Of 596 included patients, 167 (28%) received the CPW-guided treatment. The mortality rate was 16.4%. In multivariable model, CPW implementation did not increase the risk for total and 30-day mortality, and resulted in shorter antibiotic therapy duration (≤9 days) (PS matching (PSM): odds ratio (OR) 0.50, p = 0.001; inverse provability of treatment weighting (IPTW): OR 0.48, p < 0.001) and length of hospital stay (≤21 days) (PSM: OR 0.67, p = 0.05; IPTW: OR 0.66, p = 0.03). Conclusions: This study support CPW utility in this population.

Clinical manifestations of hospitalized influenza patients without risk factors: A prospective multicenter cohort study in Japan via internet surveillance.

INTRODUCTION: Influenza remains a clinically heavy burden worldwide. It is well known that some populations are at high risk of complications from influenza, whereas, even previously healthy people might suffer from severe influenza. The objective of this study was to clarify clinical manifestations of hospitalized patients without risk factors infected with influenza. METHODS: The clinical data for patients who were severely ill with influenza, and required hospitalization were gathered and analyzed between November 2014 and August 2020 (6 influenza seasons) using an internet-surveillance system. Among them, the patients who had no risk factors of complications from influenza were extracted. RESULTS: Finally, a total of 91 patients (9.0% of all influenza-related hospitalizations) without risk factors were analyzed. The no risk group was younger than the risk group, though other significant differences of clinical characteristics were not recognized between the groups. Pneumonia was the most common cause of hospitalization in the no risk group, and primary influenza viral pneumonia was the most common pneumonia. Antiviral drugs were administered in 96.7% of the no-risk group, and artificial ventilation was performed in 18.7%. In-hospital death was recorded for 3 patients without risk factors. CONCLUSIONS: Severe complications of influenza which required hospitalization may occur in a certain degree of patients with no risk factors. Efforts are needed to diagnose and treat influenza appropriately even in previously healthy younger patients. Continuous nationwide surveillance will be required to clarify risk factors for severe influenza even in previously healthy younger patients. (UMIN000015989).

Prognostic value of geriatric nutritional risk index for aspiration pneumonia: a retrospective observational cohort study.

BACKGROUND: The clinical characteristics and prognostic factors of aspiration pneumonia remain poorly defined. Geriatric nutrition risk index (GNRI) has recently been reported to exhibit a prognostic value for several diseases in older adults. AIMS: We investigated the clinical characteristics and prognostic significance of GNRI for aspiration pneumonia in older adult patients. METHODS: In this retrospective observational cohort study, conducted in a single-institute acute-phase community hospital, patients with aspiration pneumonia diagnosed at our institute between April 2014 and March 2016 were enrolled. Data on patient characteristics, microbiological findings, and clinical course were collected. The outcome was in-hospital mortality. Receiver operating characteristic curve (ROC) analysis was conducted to compare the predictive value of each parameter. Logistic regression analysis was performed to identify independent prognostic factors. RESULTS: Overall, 587 aspiration pneumonia patients aged ≥ 65 years were enrolled. Their mean age was 86 years. Among them, 97 (16.5%) died. In ROC analysis for in-hospital mortality, as compared to albumin, body mass index, and A-DROP score, GNRI had a greater area under the curve value, with a significant difference between GNRI and albumin (p = 0.0058). Male sex (p = 0.028), chronic heart failure (p = 0.023), history of malignancy (p = 0.0025), lower GNRI (p < 0.001), and initial antibiotic change (p < 0.001) were identified as independent adverse prognostic factors in multivariate analysis. DISCUSSION AND CONCLUSIONS: Our findings indicate that GNRI is a potential prognostic marker for older adults with aspiration pneumonia and may act as a proxy for disease severity. Our results support the use of GNRI in the clinical management of aspiration pneumonia.

A patient with mild respiratory COVID-19 infection who developed bilateral non-hemorrhagic adrenal infarction.

A 76-year-old woman was admitted to the emergency room of Nagano Municipal Hospital with the complain of severe back pain. Chest and abdominal enhanced computed tomography scans showed bilateral adrenal infarction and minute pulmonary nodules, but she had no respiratory symptoms. After admission, a family member of the patient was found to have been in close contact with a coronavirus disease 2019 (COVID-19) patient. Thus, polymerase chain reaction and antigen tests of severe acute respiratory syndrome coronavirus 2 were conducted, and both tests returned positive. D-dimer levels were normal on admission but increased 2 days thereafter. Anticoagulation therapy and steroid replacement were started, and the patient improved over about two weeks. One month after the onset of adrenal infarction, a rapid adrenocorticotropic hormone loading test was conducted, which revealed that the primary adrenal insufficiency due to adrenal infarction might have been caused by the COVID-19 infection. This case was rare and suggestive of adrenal infarction with COVID-19, which usually presents at the severe stage. In patients with COVID-19, attention should be paid to the onset of thrombosis, even with mild respiratory infection. We also suggest that patients with thrombosis should be suspected of having COVID-19 even in the absence of respiratory infectious symptoms in a situation of COVID-19 epidemic.

A phase 3, multicenter, single-arm, open-label study to assess the safety, tolerability, and immunogenicity of a single dose of 13-valent pneumococcal conjugate vaccine in Japanese participants aged 6-64 years who are considered to be at increased risk of pneumococcal disease and who are naive to pneumococcal vaccines.

BACKGROUND: This open-label, single-arm, phase 3 study evaluated safety and immunogenicity of the 13-valent pneumococcal conjugate vaccine (PCV13) in pneumococcal vaccine-naive Japanese individuals aged 6-64 years at increased risk of pneumococcal disease (PD). METHODS: Participants received 1 PCV13 dose. Reactogenicity events were recorded for 7 days (individuals aged 6- to 17-year-old) or 14 days (individuals aged 18 to 64 years old) postvaccination. Adverse events (AEs) were collected for 1 month postvaccination. Opsonophagocytic activity (OPA) and anticapsular immunoglobulin G (IgG) geometric mean concentrations (GMCs) were measured for vaccine serotypes before and 1 month postvaccination. Post hoc analyses compared immunogenicity in participants categorized as at-risk (immunocompetent but having chronic medical conditions associated with increased PD risk) or high-risk (immunocompromised due to diseases/conditions and/or medications). RESULTS: 206 participants aged 6- to 17-year-old (n = 53) and 18 to 64 years old (n = 153) completed the study. Reactogenicity events were generally mild to moderate in severity. AEs were reported in 16% (33/206) of participants; 1.0% (2/206) were severe. Six AEs were vaccine-related; most were associated with local reactions. No serious AEs occurred. Circulating antibody levels for all 13 serotypes increased postvaccination. OPA geometric mean fold rises (GMFRs) from prevaccination to 1 month postvaccination were 5.5-61.7; lower limits of the 2-sided, 95% CI were > 1 for all serotypes. IgG GMFRs were consistent with OPA analyses. In post hoc analyses, 55.8% (115/206) and 44.2% (91/206) of participants were categorized as at risk and at high risk of PD, respectively; OPA GMFRs from prevaccination to 1 month postvaccination were 3.9-635.1, with lower limits of the 2-sided 95% CIs > 1 for all 13 serotypes across these risk groups; IgG GMFRs were consistent with OPA analyses. CONCLUSIONS: PCV13 was well tolerated and immunogenic in Japanese individuals aged 6-64 years considered at increased risk of PD. Results were broadly comparable with past PCV13 studies in other Japanese and non-Japanese populations. Registration number: NCT03571607; JapicCTI-184024.

Efficacy and Safety of Favipiravir in Moderate COVID-19 Pneumonia Patients without Oxygen Therapy: A Randomized, Phase III Clinical Trial.

INTRODUCTION: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the cause of coronavirus disease 2019 (COVID-19), is an enveloped, single-stranded RNA virus. Favipiravir is an orally administrable antiviral drug whose mechanism of action is to selectively inhibit RNA-dependent RNA polymerase. A preliminary trial in COVID-19 patients reported significant improvements across a multitude of clinical parameters, but these findings have not been confirmed in an adequate well-controlled trial. We conducted a randomized, single-blind, placebo-controlled Phase III trial assessing the efficacy and safety of favipiravir in patients with moderate pneumonia not requiring oxygen therapy. METHODS: COVID-19 patients with moderate pneumonia (SpO2 ≥ 94%) within 10 days of onset of fever (temperature ≥ 37.5 °C) were assigned to receive either placebo or favipiravir (1800 mg twice a day on Day 1, followed by 800 mg twice a day for up to 13 days) in a ratio of 1:2. An adaptive design was used to re-estimate the sample size. The primary endpoint was a composite outcome defined as the time to improvement in temperature, oxygen saturation levels (SpO2), and findings on chest imaging, and recovery to SARS-CoV-2-negative. This endpoint was re-examined by the Central Committee under blinded conditions. RESULTS: A total of 156 patients were randomized. The median time of the primary endpoint was 11.9 days in the favipiravir group and 14.7 days in the placebo group, with a significant difference (p = 0.0136). Favipiravir-treated patients with known risk factors such as obesity or coexisting conditions provided better effects. Furthermore, patients with early-onset in the favipiravir group showed higher odds ratio. No deaths were documented. Although adverse events in the favipiravir group were predominantly transient, the incidence was significantly higher. CONCLUSIONS: The results suggested favipiravir may be one of options for moderate COVID-19 pneumonia treatment. However, the risk of adverse events, including hyperuricemia, should be carefully considered. TRIAL REGISTRATION: Clinicaltrials.jp number: JapicCTI-205238.

The usefulness of a combination of age, body mass index, and blood urea nitrogen as prognostic factors in predicting oxygen requirements in patients with coronavirus disease 2019.

INTRODUCTION: Risk factors for seriously ill coronavirus disease 19 (COVID-19) patients have been reported in several studies. However, to date, few studies have reported simple risk assessment tools for distinguishing patients becoming severely ill after initial diagnosis. Hence, this study aimed to develop a simple clinical risk nomogram predicting oxygenation risk in patients with COVID-19 at the first triage. METHODS: This retrospective study involved a chart review of the medical records of 84 patients diagnosed with COVID-19 between February 2020 and March 2021 at ten medical facilities. The patients were divided into requiring no oxygen therapy (non-severe group) and requiring oxygen therapy (severe group). Patient characteristics were compared between the two groups. We utilized univariate logistic regression analysis to confirm determinants of high risks of requiring oxygen therapy in patients with moderate COVID-19. RESULTS: Thirty-five patients ware in severe group and forty-nine patients were in non-severe group. In comparison with patients in the non-severe group, patients in the severe group were significantly older with higher body mass index (BMI), and had a history of hypertension and diabetes. Serum blood urea nitrogen (BUN), lactic acid dehydrogenase (LDH), and C-reactive protein (CRP) levels were significantly higher in the severe group. Multivariate analysis showed that older age, higher BMI, and higher BUN levels were significantly associated with oxygen requirements. CONCLUSIONS: This study demonstrated that age, BMI, and BUN were independent risk factors in the moderate-to-severe COVID-19 group. Elderly patients with higher BMI and BUN require close monitoring and early treatment initiation.

Corticosteroids for hospitalized patients with mild to critically-ill COVID-19: a multicenter, retrospective, propensity score-matched study.

Corticosteroids use in coronavirus disease 2019 (COVID-19) is controversial, especially in mild to severe patients who do not require invasive/noninvasive ventilation. Moreover, many factors remain unclear regarding the appropriate use of corticosteroids for COVID-19. In this context, this multicenter, retrospective, propensity score-matched study was launched to evaluate the efficacy of systemic corticosteroid administration for hospitalized patients with COVID-19 ranging in the degree of severity from mild to critically-ill disease. This multicenter, retrospective study enrolled consecutive hospitalized COVID-19 patients diagnosed January-April 2020 across 30 institutions in Japan. Clinical outcomes were compared for COVID-19 patients who received or did not receive corticosteroids, after adjusting for propensity scores. The primary endpoint was the odds ratio (OR) for improvement on a 7-point ordinal score on Day 15. Of 1092 COVID-19 patients analyzed, 118 patients were assigned to either the corticosteroid and non-corticosteroid group, after propensity score matching. At baseline, most patients did not require invasive/noninvasive ventilation (85.6% corticosteroid group vs. 89.8% non-corticosteroid group). The odds of improvement in a 7-point ordinal score on Day 15 was significantly lower for the corticosteroid versus non-corticosteroid group (OR, 0.611; 95% confidence interval [CI], 0.388-0.962; p = 0.034). The time to improvement in radiological findings was significantly shorter in the corticosteroid versus non-corticosteroid group (hazard ratio [HR], 1.758; 95% CI, 1.323-2.337; p < 0.001), regardless of baseline clinical status. The duration of invasive mechanical ventilation was shorter in corticosteroid versus non-corticosteroid group (HR, 1.466; 95% CI, 0.841-2.554; p = 0.177). Of the 106 patients who received methylprednisolone, the duration of invasive mechanical ventilation was significantly shorter in the pulse/semi-pulse versus standard dose group (HR, 2.831; 95% CI, 1.347-5.950; p = 0.006). In conclusion, corticosteroids for hospitalized patients with COVID-19 did not improve clinical status on Day 15, but reduced the time to improvement in radiological findings for all patients regardless of disease severity and also reduced the duration of invasive mechanical ventilation in patients who required intubation.Trial registration: This study was registered in the University hospital Medical Information Network Clinical Trials Registry on April 21, 2020 (ID: UMIN000040211).

Classroom Interventions and Foreign Language Anxiety: A Systematic Review With Narrative Approach.

Experimental studies have developed, conducted, and evaluated classroom interventions for foreign language anxiety (FLA) reduction. However, various characteristics of those classroom interventions make it difficult to synthesize the findings and apply them to practice. We conducted what is, to the best of our knowledge, the first systematic review on educational interventions for FLA. Six criteria were established for inclusion of studies. Using English keywords, we identified 854 potentially eligible studies through ProQuest and Scopus, 40 of which were finally included. All included studies were published from 2007 to 2020. The studies differed in type of intervention, duration of intervention, and scale to measure FLA. Our systematic review resulted in seven features of classroom interventions, categorized as student-student interactions, student-teacher interactions, self-management, and mood boosters; we also categorized interventions as either individual or interactional.

Clinical manifestations of adult patients requiring influenza-associated hospitalization: A prospective multicenter cohort study in Japan via internet surveillance.

INTRODUCTION: Influenza remains a clinically heavy burden worldwide. The objective of this study was to clarify clinical manifestations of severely ill patients infected with influenza. METHODS: The clinical data for patients who were severely ill with influenza, and required hospitalization were gathered and analyzed between November 2014 and August 2019 (5 influenza seasons) using an internet-surveillance system. RESULTS: A total of 924 patients were enrolled and analyzed. The median age was 78 years (IQR, 67-84), and the patients in the 2015-2016 season were significantly younger than those in other seasons. Pneumonia was the most common disease indicated as a cause for hospitalization, followed by a poor general condition and exacerbation of underlying respiratory diseases. Antiviral drugs were administered in 97.0% of the patients with peramivir being the most-frequently use antiviral. In-hospital death was recorded for 44 patients (4.8%). Multivariate analysis indicated that nursing home resident (OR: 6.554) and obesity (OR: 24.343) were independent predictors of in-hospital mortality. CONCLUSIONS: Complications of influenza infection remain a heavy burden especially among the elderly. Continuous nationwide surveillance will be required to grasp the actual situation of influenza epidemics. (UMIN000015989).

Corticosteroids as adjunctive therapy in the treatment of coronavirus disease 2019: A report of two cases and literature review.

The effect of systemic corticosteroids on clinical outcomes in patients with coronavirus disease 2019 (COVID-19) remains controversial. While the use of corticosteroids raises concerns regarding delayed viral clearance, secondary infections, and long-term complications that can lead to increased mortality, corticosteroids have the potential to reduce mortality if used appropriately. Herein, we report good outcomes in two patients with COVID-19 who received systemic corticosteroids as adjunctive therapy. An 83-year-old man with hypertension and smoking history and a 62-year-old man with a drinking habit were transferred to our hospital with a diagnosis of COVID-19. The patients developed general malaise and loss of appetite with persistent high fever. Despite the prescription of antiviral drugs, their hypoxemia progressed rapidly. However, after the introduction of systemic corticosteroids, their symptoms improved as the fever decreased, and their hypoxemia gradually improved. These results suggest that some patients with COVID-19 may benefit from the appropriate use of systemic corticosteroids as adjunctive therapy.

[A Case of Squamous Cell Lung Cancer in an Elderly Patient with Low PD-L1 Expression Effectively Treated with Nab-Paclitaxel(Nab-PTX)plus Carboplatin (CBDCA)plus Pembrolizumab for a Recurrence after Operation].

An 81-year-old man was admitted to our medical center for dyspnea. He underwent right upper lobectomy due to squamous cell lung cancer 5 years ago. Chest computed tomography(CT)revealed stenosis ofthe right main bronchus, and pathological diagnosis ofthe lesion was squamous cell carcinoma and PD-L1 expression was low(tumor proportion score [TPS]: 1%). Because his performance status(PS)was 1, he underwent 4 courses ofnab -paclitaxel(nab-PTX)plus carboplatin( CBDCA)plus pembrolizumab chemotherapy and pembrolizumab maintenance chemotherapy. The stenosis ofthe right main bronchus was clear after chemotherapy, and his dyspnea was improved. Chemotherapy using nab-PTX plus CBDCA plus pembrolizumab may become one of the therapeutic choices for the recurrence after operation of an elderly person with squamous cell lung carcinoma and low PD-L1 expression.

Severe Tetanus Complicated by Takotsubo Cardiomyopathy.

A 70-year-old woman was admitted to our hospital due to difficulty in moving her limbs. She had trismus and a necrotic and contaminated wound in her left lower leg. A diagnosis of tetanus was confirmed and intensive care was started. On the second day, her blood pressure fell and a ST segment elevation on electrocardiography (ECG) was detected. She was diagnosed with takotsubo cardiomyopathy by echocardiogram and improved undergoing conservative therapy.

Tuberculosis of the Wrist Accompanied with Calcium Pyrophosphate.

This is a rare case of tuberculosis (TB) complicated with pseudogout of the wrist joint in a non-immunocompromised 84-year-old female with a history of pulmonary tuberculosis. She was diagnosed with extrapulmonary tuberculosis of the wrist based on a polymerase chain reaction (PCR) study and synovial fluid aspiration in which the cytology was positive for acid-fast bacilli. Calcium pyrophosphate was also positive. We must be careful not to miss articular tuberculosis as it may mimic common inflammatory arthritis, such as pseudogout of the wrist. Even if the patient is positive for calcium pyrophosphate, this does not exclude the possibility of articular tuberculosis.

Outbreaks of influenza B infection and pneumococcal pneumonia at a mental health facility in Japan.

BACKGROUND: Japan has an aging population and an increasing number of patients who reside in long-term care and mental health facilities. Both pneumococcal pneumonia and influenza B infection outbreaks have been observed in these populations, although no reports have described concurrent outbreaks of pneumococcal pneumonia and influenza B infection in these facilities. CASE PRESENTATION: Six patients and two staffs were initially diagnosed with influenza B infection at a mental health facility on March 14, 2015. By March 21, influenza B infection was diagnosed in 26 patients and 10 staff; all individuals received anti-influenza drugs. On March 19, two patients were diagnosed with pneumococcal pneumonia, and seven patients had developed pneumococcal pneumonia by March 24. Six of these seven patients also had influenza B infection. All individuals who developed pneumococcal pneumonia were hospitalized and treated using ampicillin/sulbactam at our hospital, and their symptoms subsequently subsided. Among the seven pneumococcal strains that were frozen and stored, two strains were type 3 and five strains were type 11A/E. Pulsed-field gel electrophoresis testing revealed that each of the serum types were from the same clone. CONCLUSION: It appears that an outbreak of influenza B infection was followed by the spread of multi-clone pneumococcal pneumonia among elderly patients at a mental health facility. Therefore, it may be prudent to use vaccinations to prevent the spread of pneumococcal pneumonia among elderly patients and this diagnosis should be actively considered during outbreaks of influenza infection at elder care facilities.

Pediatric pulmonary tuberculoma with a solid pulmonary nodule detected on chest computed tomography.

A 14-year-old girl underwent a medical checkup for Mycobacterium tuberculosis infection because her grandmother had been diagnosed with pulmonary tuberculosis three months earlier. The interferon-gamma release assay (IGRA) showed a positive result. The patient's chest X-ray findings were normal. Chest computed tomography (CT) showed a single mass lesion in the right lower lobe of the lung. A sputum smear of acid-fast bacilli was positive; however, the polymerase chain reaction results for tuberculosis were negative. We diagnosed the patient with pulmonary tuberculosis based on the fact that she had come in contact with a tuberculosis patient. Six weeks later, a liquid culture examination for acid-fast bacilli was found to be positive and the acid-fast bacillus was identified as M. tuberculosis. The use of chest CT is not routinely recommended in all children suspected of having M. tuberculosis infection. However, IGRA-positive children who report frequent contact with infected individuals should undergo CT tomography if chest X-rays do not show any abnormal shadows.