A prospective clinical evaluation of the diagnostic accuracy of the SARS-CoV-2 rapid antigen test using anterior nasal samples.

INTRODUCTION: The diagnostic accuracy of antigen testing of anterior nasal (AN) samples for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has not been evaluated in the Japanese population. This study assessed the diagnostic accuracy of the Roche SARS-CoV-2 rapid antigen test (rapid antigen test) using AN samples. METHODS: Two AN samples and one nasopharyngeal (NP) sample were collected from individuals undergoing screening for SARS-CoV-2 infection. The results of the rapid antigen test and the reverse-transcription polymerase chain reaction (RT-PCR) test using AN samples were compared to those of RT-PCR tests using NP samples. RESULTS: Samples were collected from 800 participants, 95 and 110 of whom tested positive for SARS-CoV-2 on RT-PCR tests of AN and NP samples, respectively. The overall sensitivity/specificity of the AN rapid antigen test and AN RT-PCR were 72.7%/100% and 86.4%/100%, respectively. In symptomatic cases, the sensitivities of the AN rapid antigen test and AN RT-PCR were 84.7% and 94.9%, respectively. In asymptomatic cases, the sensitivities of the AN rapid antigen test and AN RT-PCR were 58.8% and 76.5%, respectively. The sensitivity of the AN rapid antigen test was over 80% in cases with cycle threshold (Ct) values < 25; it significantly decreased with an increase in the Ct values (p < 0.001). CONCLUSION: The rapid antigen test with AN samples had a favorable sensitivity, especially in symptomatic cases or in cases with Ct values < 25. It gave no false-positive results. Compared with AN-RT PCR, the AN rapid antigen test had a modestly lower sensitivity in asymptomatic cases.

Minute lesions of alveolar damage in lungs of patients with stable idiopathic pulmonary fibrosis.

AIMS: To investigate the mechanisms underlying the acute exacerbation of idiopathic pulmonary fibrosis, and in particular the role of minute lesions of alveolar damage. METHODS AND RESULTS: We examined surgical lung biopsy samples from 38 patients with stable idiopathic pulmonary fibrosis, and evaluated the association between the foci and development of acute exacerbation. Mild extravasation, probably resulting from lung injury and intra-alveolar oedema fluid, were observed in narrow areas of architecturally intact lung tissue. Minute lesions of alveolar damage were detected in these areas. Alveolar epithelial cells in these lesions were injured. Hypoxia-inducible factor-2α-positive macrophages, tumour necrosis factor-α-positive macrophages and neutrophils had accumulated in alveolar spaces in and around these lesions. Cases were classified into patients without (17) and with (21) minute lesions of alveolar damage. Development to acute exacerbation (five cases) occurred only in patients with minute lesions of alveolar damage (P = 0.03). CONCLUSIONS: The formation of minute lesions of alveolar damage may be initiated by hypoxia, and such lesions play important roles in the development of acute exacerbation.

[Resection of chest wall tumors].

Forty-six consecutive patients with chest wall tumors undergoing resection between 1981 and 2012 were analyzed. There were 29 male and 17 female patients, with ages ranging from 15 to 77 years. Seventeen patients had primary malignant neoplasms, 22 had benign tumors, and 7 metastases. The primary malignant tumors were located in the ribs in 16 patients and sternum in one. They were resected en bloc in all patients. Reconstruction was with Gore-Tex( expanded polytetrafluoroethylene:ePTFE) in 13 patients. There was no operative death and 1 hospital death. All patients with benign tumors survived. All patients with metastases died within 3 years. Seven patients with primary malignant neoplasms without reconstruction survived, while 5 of 10 patients undergoing reconstruction died between 5 and 99 months. Aggressive resection for a chest wall tumor with reliable reconstruction can be accomplished safely, and wide resection is a potentially curative treatment.

[A case of mediastinal growing teratoma syndrome with acute megakaryoblastic leukemia].

We report a case of a 38-year-old man who was diagnosed with a mediastinal germ cell tumor. After induction chemotherapy, the tumor marker levels normalized, but the tumor itself continued to grow. Surgical resection was performed successfully, but the patient developed acute megakaryoblastic leukemia 6 months later, and induction and consolidation therapies failed to achieve remission. Leukemia cells invaded the central nervous system following hematopoietic stem cell transplantation, and the patient died 5 months after being diagnosed with leukemia. This very rare case of a mediastinal germ cell tumor met the criteria for "growing teratoma syndrome", against a background of acute megakaryoblastic leukemia.

Comparing the cobas Influenza A/B Nucleic acid test for use on the cobas Liat System (Liat) with rapid antigen tests for clinical management of Japanese patients at the point of care.

BACKGROUND: Rapid diagnosis of influenza is critical in preventing the spread of infection and ensuring patients quickly receive antiviral medication to reduce the severity and duration of influenza symptoms, whilst controlling the spread of the causative virus. In Japan patients are often administered anti-influenza medication following a positive rapid antigen detection test (RADT) result. However, the sensitivity of RADTs can lead to false negative results. The cobas® Influenza A/B Nucleic acid test for use on the cobas Liat® System (Liat) is a molecular point-of-care method that can provide a more sensitive alternative to RADTs for rapid influenza diagnosis and treatment. METHODS: In this prospective multicenter study, diagnostic performance of the Liat test was compared with RADTs in patients presenting with influenza-like-illness. Test performance was also assessed by time since symptom onset. RESULTS: Of 419 patients enrolled, 413 were evaluable for all designated tests. Most patients had type-A infection, and only one patient had influenza type B. In 413 patients, the sensitivity and specificity (95% CI) of the Liat test were 99.5% (97.2-99.9%) and 99.5% (97.4-99.9%), respectively, and were 79.7% (73.5-84.7%) and 95.4% (91.7-97.5%) for RADTs. For patients tested <12 hours from symptom onset, the Liat test had significantly higher sensitivity than RADTs (p<0.0001). CONCLUSION: Overall, compared with standard of care RADTs, the Liat test was more sensitive and specific in children and adults, particularly in the early stages of infection. Greater sensitivity can enable earlier diagnosis and may better inform appropriate antiviral treatment decisions.

Clinical Performance of the cobas Liat SARS-CoV-2 & Influenza A/B Assay in Nasal Samples.

BACKGROUND AND OBJECTIVE: Point-of-care type molecular diagnostic tests have been used for detecting SARS-CoV-2, although their clinical utility with nasal samples has yet to be established. This study evaluated the clinical performance of the cobas Liat SARS-CoV-2 & Influenza A/B (Liat) assay in nasal samples. METHODS: Nasal and nasopharyngeal samples were collected and were tested using the Liat, the cobas 6800 system and the cobas SARS-CoV-2 & Influenza A/B (cobas), and a method developed by National Institute of Infectious Diseases, Japan (NIID). RESULTS: A total of 814 nasal samples were collected. The Liat assay was positive for SARS-CoV-2 in 113 (13.9%). The total, positive, and negative concordance rate between the Liat and cobas/NIID assays were 99.3%/98.4%, 99.1%/100%, and 99.3%/98.2%, respectively. Five samples were positive only using the Liat assay. Their Ct values ranged from 31.9 to 37.2. The Ct values of the Liat assay were significantly lower (p < 0.001) but were correlated (p < 0.001) with those of other molecular assays. In the participants who tested positive for SARS-CoV-2 on the Liat assay using nasopharyngeal samples, 88.2% of their nasal samples also tested positive using the Liat assay. CONCLUSION: The Liat assay showed high concordance with other molecular assays in nasal samples. Some discordance occurred in samples with Ct values > 30 on the Liat assay.

Clinical evaluation of the cobas® MTB-RIF/INH reagent and the cobas® 6800 for the detection of isoniazid and rifampicin resistance.

We aimed to validate the performance of a newly developed real-time PCR assay using cobas® MTB-RIF/INH reagent on the cobas® 6800 system for detecting isoniazid (INH) and rifampicin (RIF) resistance, using Japanese Mycobacterium tuberculosis (MTB) isolates. In total, 119 mock sputum specimens spiked with resistant MTB were tested using the cobas® MTB-RIF/INH reagent. The whole genomes of all MTB isolates were sequenced by MiSeq and analysed for mutations/indels causing drug resistance. All isolates were tested for phenotypic drug susceptibility, then MTB negative sputa were collected and pooled to prepare mock sputum specimens for the study. The sensitivity and specificity for INH resistance at a concentration equal to 3 × the limit of detection were 77.8% and 90.0%, respectively; those for RIF resistance were 91.8% and 93.5%, respectively. The sensitivities for INH and RIF were statistically different (P = 0.014), but not the specificities (P = 0.624). Twenty-two false-susceptible and two false-resistant results were obtained in INH; meanwhile, six false-susceptible and three false-resistant results were obtained in RIF. False-resistance for INH and RIF was mainly due to disputed mutations. The cobas® MTB-RIF/INH reagent showed better performance than other rapid molecular tests.

[Iterative surgical resections for second primary and local recurrent lung cancer; comparison of lobectomy and limited resection].

During a 24-year period (1986-2009), 74 patients (3.5%) underwent iterative surgical resections for 2nd primary and recurrent lung cancer. Patients are classified to 5 groups: 20 2nd primary lung cancer patients undergoing lobectomy (A), 24 2nd primary lung cancer patients undergoing limited resection (B), 11 2nd primary bronchioloalveolar carcinoma (BAC) patients undergoing limited resection (C), 8 recurrent lung cancer patients undergoing lobectomy (D), and 11 recurrent lung cancer patients undergoing limited resection (E). There were 13 (65%) patients with pathological stage IA in group A, 20 (83%) in B, 11 (100%) in C, 2 (25%) in D, and 8 (73%) in E. There were 18 (90%) patients with adenocarcinoma in group A, 15 (63%) in B, 11 (100%) in C, 5 (63%) in D, and 9 (82%) in E. Overall hospital mortality was 5%, including 3 deaths in A and 1 death in D. Five-year and 10-year survival after the 2nd surgery was 55% and 55% in A, 63% and 50% in B, 100% and 100% in C, 57% and 37% in D, and 70% and 53% in E. These data showed that limited resections had low surgical risk and good long-term results. Limited resection appears to achieve better outcomes for 2nd primary and recurrent lung cancer and should be chosen whenever possible.

[Primary pulmonary synovial sarcoma confirmed by gene expression analysis].

We report a patient who was diagnosed with synovial sarcoma based on gene expression analysis. A 39-year-old male visited a local hospital due to left chest pain. Chest compued tomography (CT) showed a lung tumor located mainly at the lingula of the left lung, and extending to the bifurcation of the upper and lower lobar bronchi. Left pneumonectomy was performed. Pathological examination showed a mesenchymal tumor consisting of short-spindle, small, round cells, and the differentiation between synovial sarcoma and peripheral neuroectodermal tumor was necessary. RT-PCR to examine the gene expression of cells revealed a SYT-SSX fusion gene, and a diagnosis of primary synovial sarcoma of the lung was made.

Performance analysis of the anti-Ki67 antibody clone 30-9 for immunohistochemical staining of breast cancer.

BACKGROUND: Although Ki67 has important clinical relevance in breast cancer, its assessment results vary according to assay due to differences in both analytical and interpretation processes. We aimed to validate the performance of anti-Ki67 antibody clone 30-9 by comparison with clone MIB-1 and to investigate utility of the image analysis system in Ki67 assessment using clinical breast cancer samples. METHODS: A series of sequential tissue sections was prepared from formalin-fixed paraffin-embedded blocks of surgically resected breast cancer specimens from 50 patients. The tissue sections were stained immunohistochemically with anti-Ki67 antibodies, 30-9 and MIB-1, as well as with hematoxylin and eosin for morphological analysis. We scanned all the stained slides with Ventana iScan HT and selected the Ki67 counting areas based on morphological findings. Three pathologists independently studied images of the counting areas to determine Ki67-positive rates. In addition, the images of 30-9-stained slides were analyzed using the image analysis system, VENTANA Virtuoso. RESULTS: Ki67-positive rates by 30-9 showed a strong correlation with those by MIB-1 for all pathologists (pathologist #1: r = 0.985, pathologist #2: r = 0.987, pathologist #3: r = 0.982). Between 30-9 and MIB-1, there was no significant difference of CV%, showing variabilities of Ki67-positive rates among pathologists. Ki67-positive rates showed a strong correlation between the image analytical values and the pathologist-counted median values (r = 0.952). CONCLUSIONS: The performance of 30-9 is equivalent to that of MIB-1 in Ki67 assessment of breast cancer. The image analysis system can substitute for or support visual counting by a pathologist.

[Surgical treatment for patients aged 80 years or older with primary lung cancer and differences in outcomes according to sex].

This study investigated the characteristics and long-term results of surgical treatment for primary lung cancer in patients aged 80 years or older, mainly based on difference between the sexes. Seventy-four patients aged 80 years or older who underwent surgical resection for primary lung cancer in our institute between 1986 and 2005 were retrospectively reviewed. Fifty-six patients were male and 18 were female. The median age of all patients was 81 years. Twenty-two males (39%) and 5 females (28%) had co-existing diseases preoperatively. Twenty-nine males (52%) and 17 females (94%) had adenocarcinoma. Forty-four males (79%) and 16 females (89%) had pathological stage I disease. Eleven males (20%) and 1 female (6%) developed postoperative complications that adversely affected the patient's morbidity and mortality. There was 1 surgical mortality (1.4%) and 1 hospital mortality (1.4%). The postoperative 5-year survival rate was 23% in 56 males and 58% in 18 females. The 5-year survival rate was 10% in 35 males underwent lobectomy, 58% in 20 males underwent wedge resection, and 70% in 15 females underwent lobectomy. These findings seems to indicate that long-term outcomes for males were worse than those for females. The data suggest that the indication of lobectomy should be more strictly limited in male patients than in female patients aged 80 years or older.

PIK3CA mutation, reduced AKT serine 473 phosphorylation, and increased ERα serine 167 phosphorylation are positive prognostic indicators in postmenopausal estrogen receptor-positive early breast cancer.

Although endocrine therapy is the most important treatment option in estrogen receptor (ER)-positive breast cancer, new strategies, such as molecular targeted agents together with endocrine therapy are required to improve survival. PIK3CA is the most frequent mutated gene in ER-positive early breast cancers, and PIK3CA mutation status is reported to affect activation of AKT and ERα. Moreover, recent studies demonstrate that patients had a better prognosis when tumors expressed ER, androgen receptor (AR), and vitamin D receptor (VDR). In this study, we examined expression of AR and VDR, phosphorylation of AKT serine (Ser) 473 (AKT phospho-Ser473) and ERα Ser167 (ERα phospho-Ser167) by immunohistochemistry in ER-positive, HER2-negative early breast cancer. PIK3CA gene mutations were also detected in genomic DNA extracted from tumor blocks. Correlations between these biological markers, clinicopathological factors and prognosis were analyzed. Levels of AKT phospho-Ser473 were significantly higher in premenopausal women than in postmenopausal women. In contrast, AR expression was significantly higher in postmenopausal women than in premenopausal women. PIK3CA mutations were detected in 47% in premenopausal women and 47% in postmenopausal women. Postmenopausal women with PIK3CA wild-type tumors had significantly worse disease-free survival than patients with PIK3CA mutant tumors. Low levels of AKT phospho-Ser473 and high levels of ERα phospho-Ser167 were strongly associated with increased disease-free survival in postmenopausal women. Evaluation of ERα activation, in addition to PIK3CA mutation status, might be helpful in identifying patients who are likely to benefit from endocrine therapy alone versus those who are not in postmenopausal ER-positive early breast cancer.

[Thymoma transformed to thymic carcinoma with brain and bone metastases 6 years after recurrence].

We report a man who developed brain and bone metastases 6 years after resection of recurrent thymoma. The patient underwent surgery for B2-thymoma [World Health Organization (WHO) classification] without microscopic capsular invasion at 50-year-old. The next year, he underwent the second surgery for recurrent B2-thymoma as pleural dissemination. Seven months after the second surgery, he developed recurrence of pleural dissemination. The patient refused any further aggressive treatment, including surgery, chemotherapy, and radiotherapy. The pleural disease did not increase over 6 years, then suddenly enlarged. Thereafter, the patient developed left hemiparesis due to brain metastases, followed by bone metastases. Immunochemical studies of the metastatic tumors demonstrated that these lesions seemed to be poorly differentiated thymic carcinoma (small cell carcinoma) on WHO classification. We concluded that the thymoma transformed to thymic carcinoma with brain and bone metastases during 6 years.

Lung adenocarcinoma and adrenocortical carcinoma in a patient with multiple endocrine neoplasia type 1.

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder caused by heterozygous germline mutations in the tumor suppressor gene MEN1, which encodes a nuclear protein, menin. MEN1 is characterized by the combined occurrence of tumors involving the pituitary gland, pancreatic islets, and parathyroid glands. Additionally, patients with MEN1 often exhibit adrenal tumors. Although most MEN1-associated tumors are benign, malignant lesions arising in these endocrine organs have been reported. Additionally, malignant diseases of non-endocrine organs concomitant with MEN1 have also been reported. Here, we report a rare case of a MEN1 patient who exhibited adrenocortical carcinoma (ACC) and lung adenocarcinoma (LAC). A 53-year-old Japanese woman was diagnosed with genetically proven MEN1 that initially manifested as parathyroid, pancreatic, and adrenal tumors. During the course of the disease, she developed LAC harboring the epidermal growth factor receptor gene mutations and cortisol-secreting ACC. Both tumors were surgically resected. The tumor cells were immunohistochemically negative for menin. Studies have suggested a causative link between MEN1 gene mutations and ACC, and menin expression may decrease in MEN1-related ACCs. In contrast, there are few reports suggesting a specific role of MEN1 gene mutations in LAC. Menin is often inactivated in the LACs of patients without MEN1. Thus, our patient's ACC probably occurred as part of MEN1, whereas the latter had no evident etiological association with her LAC. This case demonstrates the need for physicians to consider the potential development of malignant diseases originating from both endocrine and non-endocrine organs in MEN1 patients.

[Suturing left main bronchus in difficult lung resection for repeated and massive hemoptysis].

A 79-year-old man with repeated and massive hemoptysis due to bronchiectasis was admitted to our department for surgery. The patient had undergone left upper lobectomy for pulmonary tuberculosis, and descending aortic replacement for Stanford type B aortic dissection. The patient underwent occlusion of the left main bronchus by suturing through median sternotomy. The reasons we did not choose completion pneumonectomy were advanced age, poor physical condition immediately after hemorrhagic shock, and the difficulty of performing pneumonectomy due to previous surgery and anastomotic aneurysm of descending aorta. The postoperative course was uneventful and the patient left the hospital on the 16th postoperative day. The patient did not develop pneumonia or empyema thereafter, but died suddenly of unknown etiology 1.5 years postoperatively. Lung exclusion by suturing a bronchus is thought to be a useful alternative for repeated and massive hemoptysis without pneumonia in a case of difficult lung resection.

[Long-term results after recurrence of completely resected primary lung cancer].

The recurrence rate of complete surgical resection and the long-term results following recurrence have rarely been reported. Whether patients with recurrence could be cured is still unknown. Patients who underwent complete surgical resection for lung cancer from 1981 to 1999 (n=945) and were followed-up for more than 5 years were retrospectively reviewed. Recurrent diseases were treated by chemotherapy and/or radiotherapy when surgical treatment was not indicated. Postoperative 5-year survival in 585 patients (62%) without recurrence and in 360 patients (38%) with recurrent diseases were 84 and 27%, respectively. The recurrence rates of stage I patients (n=164), stage II (n=55), stage III (n=127) and stage IV (n=13) were 26, 52, 68 and 93%, respectively. The 5-year survival rates of these patients were 36, 23, 19 and 7%, respectively. The period between the operation and the first recurrence was approximately 2 (0-9) years and the patients with recurrence died in about 1 (0-9) year. Four patients actually survived more than 10 years after the first recurrence. The recurrence rate after complete surgical resection of lung cancer was 38% in all and it increased along with the advanced pathological stages.

Primary mediastinal lymph node malignancy with features suggestive of dendritic cell sarcoma.

A 56-year-old man underwent preoperative chest computed tomography to further evaluate a well defined mass in the middle lobe with subcarinal lymph node swelling. There was no pathological diagnosis established by either bronchoscopic biopsy specimens or computed tomography-guided percutaneous needle biopsy. The middle lobe and mediastinal lymph nodes were excised, then postoperative radiotherapy (60 Gy) was administered to the mediastinum. Results of histological and immunohistochemical study showed that the lung mass consisted of completely necrotic tissue and that the subcarinal lymph node was involved by malignant cells suggestive of dendritic cell sarcoma. Primary dendritic cell sarcoma of the mediastinal lymph node is extremely rare. Dendritic cell sarcoma is a neoplasm of reticular dendritic origin and includes both follicular dendritic cell sarcoma and interdigitating reticulum (or dendritic) cell sarcoma. These rare neoplasms may pose difficulty in pathologic diagnosis and treatment. Although our patient died of hepatic rupture due to dendritic cell sarcoma or gastric cancer metastases one year after surgery, complete surgical resection with or without postoperative radiotherapy may be an acceptable therapeutic option for localized dendritic cell sarcoma.

Comparative analysis of tumor angiogenesis and clinical features of 55 cases of pleomorphic carcinoma and adenocarcinoma of the lung.

BACKGROUND/AIM: Pleomorphic carcinoma (PC) of the lung is a rare tumor that usually has an aggressive clinical course and a poor prognosis. Clinical and pathological features remain unclear. The aim of this study was to determine whether tumor angiogenesis of PC is up-regulated compared to that in adenocarcinoma (AD). MATERIALS AND METHODS: We collected 55 cases of PC and AD in which the patients had undergone either lung resection or autopsy and immunohistochemically examined the expression of vascular endothelial growth factor (VEGF), hypoxia-inducible factor (HIF)-1α and microvessel density (MVD) in tissue specimens. RESULTS: VEGF was expressed in many cases of both PC and AD with no significant differences between the groups. In contrast, the expression of HIF-1α and MVD were significantly greater in PC than AD. Median survival time of the PC group was 14.7 months and significantly shorter than that of the AD group. CONCLUSION: MVD and expression of HIF-1α are associated with angiogenesis in PC and confer a poorer prognosis. Tumor angiogenesis provides significant prognostic information regarding clinical outcome in patients with PC.

Field survey of sex-reversals in the medaka, Oryzias latipes: genotypic sexing of wild populations.

The medaka, Oryzias latipes, has an XX/XY sex determination mechanism. A Y-linked DM domain gene, DMY, has been isolated by positional cloning as a prime candidate for the sex-determining gene. Furthermore, the crucial role of DMY during male development was established by studying two wild-derived XY female mutants. In this study, to find new DMY and sex-determination related gene mutations, we conducted a broad survey of the genotypic sex (DMY-negative or DMY-positive) of wild fish. We examined 2274 wild-caught fish from 40 localities throughout Japan, and 730 fish from 69 wild stocks from Japan, Korea, China, and Taiwan. The phenotypic sex type agreed with the genotypic sex of most fish, while 26 DMY-positive (XY) females and 15 DMY-negative (XX) males were found from 13 and 8 localities, respectively. Sixteen XY sex-reversals from 11 localities were mated with XY males of inbred strains, and the genotypic and phenotypic sexes of the F(1) progeny were analyzed. All these XY sex-reversals produced XY females in the F(1) generation, and all F(1) XY females had the maternal Y chromosome. These results show that DMY is a common sex-determining gene in wild populations of O. latipes and that all XY sex-reversals investigated had a DMY or DMY-linked gene mutation.

Cytotoxic T-lymphocyte activity specific for hemagglutinin (H) protein of canine distemper virus in dogs.

Cytotoxic T-lymphocyte (CTL) responses to hemagglutinin (H) protein of canine distemper virus (CDV) were evaluated in dogs using the replication-deficient adenovirus protein expression system. Skin fibroblasts were isolated from two dogs and were infected with recombinant adenovirus bearing the CDV-H gene (Ade-CDVH). CTL assay was performed using fibroblasts expressing CDV-H protein as target cells and peripheral blood lymphocytes (PBL) collected from the same dogs one week after immunization of CDV as effector cells. Specific cytotoxic activity was observed against autologous but not heterologous fibroblasts expressing CDV-H protein. These results indicate that the CTL epitope(s) were localized in the H protein.