Diagnostic accuracy of direct reverse transcription-polymerase chain reaction using guanidine-based and guanidine-free inactivators for SARS-CoV-2 detection in saliva samples.

This study aimed to evaluate diagnostic accuracy of SARS-CoV-2 RNA detection in saliva samples treated with a guanidine-based or guanidine-free inactivator, using nasopharyngeal swab samples (NPS) as referents. Based on the NPS reverse transcription-polymerase chain reaction (RT-PCR) results, participants were classified as with or without COVID-19. Fifty sets of samples comprising NPS, self-collected raw saliva, and saliva with a guanidine-based, and guanidine-free inactivator were collected from each group. In patients with COVID-19, the sensitivity of direct RT-PCR using raw saliva and saliva treated with a guanidine-based and guanidine-free inactivator was 100.0%, 65.9%, and 82.9%, respectively, with corresponding concordance rates of 94.3% (κ=88.5), 82.8% (κ=64.8), and 92.0% (κ=83.7). Among patients with a PCR Ct value of <30 in the NPS sample, the positive predictive value for the three samples was 100.0%, 80.0%, and 96.0%, respectively. The sensitivity of SARS-CoV-2 RNA detection was lower in inactivated saliva than in raw saliva and lower in samples treated with a guanidine-based than with a guanidine-free inactivator. However, in individuals contributing to infection spread, inactivated saliva showed adequate accuracy regardless of the inactivator used. Inactivators can be added to saliva samples collected for RT-PCR to reduce viral transmission risk while maintaining adequate diagnostic accuracy.

Examination of the utility of cryobiopsy for tuberculous pleurisy in thoracoscopy: A report of seven cases.

Thoracoscopy under local anaesthesia is effective for the diagnosis of tuberculous pleurisy (TP), mesothelioma and pleural metastases of lung cancer, etc. It has recently been reported that cryobiopsy is useful for obtaining sufficient tissue, achieving a greater depth, and avoiding crush artefact than biopsy forceps. However, the utility of the tissue obtained by cryobiopsy for culture for diagnosing TP is unknown. We compared positivity rates of tissue culture obtained by biopsy forceps and cryobiopsy in seven TP patients. The median tissue size was 2 mm by biopsy forceps and 6 mm by cryobiopsy. The pathological diagnostic rate of pleural tissue was 85.7% with biopsy forceps and 100% with cryobiopsy. However, the positivity rate of tissue culture was 57.1% with biopsy forceps and 28.5% with cryobiopsy. Since rapid freezing with a cryoprobe makes it difficult for bacteria to grow, it is possible that cryobiopsy might not be useful for obtaining a tissue culture in TP cases. However, since the sample size of this study was small, analysis of more cases is required to confirm our results.

High-flow nasal cannula for severe COVID-19 patients in a Japanese single-center, retrospective, observational study: 1 year of clinical experience.

High-flow nasal cannula (HFNC) can be effective in treating type 1 respiratory failure by reducing the severity of coronavirus disease 2019 (COVID-19). The purpose of this study was to assess the reduction of disease severity and safety of HFNC treatment in patients with severe COVID-19. We retrospectively observed 513 consecutive patients with COVID-19 admitted to our hospital from January 2020 to January 2021. We included patients with severe COVID-19 who received HFNC for their deteriorating respiratory status. HFNC success was defined as improvement in respiratory status after HFNC and transfer to conventional oxygen therapy, while HFNC failure was defined as transfer to non-invasive positive pressure ventilation or ventilator, or death after HFNC. Predictive factors associated with failure to prevent severe disease were identified. Thirty-eight patients received HFNC. Twenty-five (65.8%) patients were classified in the HFNC success group. In the univariate analysis, age, history of chronic kidney disease (CKD), non-respiratory sequential organ failure assessment (SOFA) ≥ 1, oxygen saturation to fraction of inspired oxygen ratio (SpO2/FiO2) before HFNC ≤ 169.2, were significant predictors of HFNC failure. Multivariate analysis revealed that SpO2/FiO2 value before HFNC ≤ 169.2 was an independent predictor of HFNC failure. No apparent nosocomial infection occurred during the study period. Appropriate use of HFNC for acute respiratory failure caused by COVID-19 can reduce the severity of severe disease without causing nosocomial infection. Age, history of CKD, non-respiratory SOFA before HFNC ≤ 1, and SpO2/FiO2 before HFNC ≤ 169.2 were associated with HFNC failure.

Thin bronchoscopic cryobiopsy using a nasobronchial tube.

BACKGROUND: Transbronchial lung cryobiopsy is useful when diagnosing lung lesions. However, prevention of associated bleeding complications is essential. This study aimed to evaluate the safety and efficacy of our novel bronchoscopic cryobiopsy technique, which uses a long nasobronchial tube to prevent blood flooding the central airway. METHODS: Patients with localized or diffuse lung lesions were prospectively enrolled and underwent cryobiopsy using a 1.9 mm diameter cryoprobe and a 4.0 mm diameter thin bronchoscope under conscious sedation. For cryobiopsy, a long silicone tube (inner diameter, 5.0 mm) was advanced through the nose to the target bronchus, then wedged to drain blood under thin-tube bronchoscopic control. The primary endpoint was the frequency of bleeding complications. RESULTS: Of the 80 patients initially enrolled, 73 that underwent at least one cryobiopsy were ultimately included. Mild bleeding during cryobiopsy occurred in 58 patients (79.5%), but there was no moderate or severe bleeding. Other complications occurred in four patients (two pneumothorax, one pneumomediastinum, and one pneumonia). Tube dislocation was noted in eight patients (11%). Cryobiopsy specimens were significantly larger than forceps biopsy specimens (9.0 mm2 vs. 2.7 mm2, P < .001) and allowed specific diagnoses in 50 patients (68.5%). CONCLUSIONS: Thin bronchoscopic cryobiopsy using a nasobronchial tube in consciously sedated patients is safe and effective. Trial registration Date of registration: 24/06/2019. UMIN-Clinical Trials Registry; Identifier: UMIN000037156 https://www.umin.ac.jp/ctr/index.htm.

A rare case of docetaxel-induced myositis in a patient with a lung adenocarcinoma.

Docetaxel is a cytotoxic taxane frequently used to treat patients with various cancers, including non-small cell lung cancer (NSCLC). Docetaxel is known to cause acute myalgias, arthralgias, and neuropathy, but there have been few published case reports of myositis. Here, we describe a rare case of docetaxel-induced myositis diagnosed based on laboratory data, thigh magnetic resonance imaging (MRI), and electromyography (EEG). A 66-year-old male was admitted for thigh pain and fatigue that onset 1 week prior. He had been diagnosed with stage IVA (cT4N0M1a) NSCLC 3 years ago and had been started on docetaxel (60 mg/m2 intravenously every 3 weeks; fourth-line chemotherapy) 1 month earlier. After the second cycle, he developed both thigh pain and fatigue. On admission, his creatinine phosphokinase (CPK) level was elevated, thigh MRI revealed diffuse muscle edema, and EEG showed myogenic changes. We found no plausible cause for myositis except docetaxel. He was diagnosed with myositis and treated with oral prednisolone. His symptoms were relieved and the CPK level declined. Although rare, this case indicates that clinicians should consider the possibility of myositis as a complication in patients on docetaxel.

COVID-19 mRNA vaccine-related interstitial lung disease: Two case reports and literature review.

The Pfizer-BioNTech mRNA vaccine (BNT162b2) is an effective and well-tolerated coronavirus disease 2019 (COVID-19) vaccine. However, rare adverse events have been reported. We report two cases of COVID-19 mRNA vaccine-related interstitial lung disease (ILD). A 67-year-old man and a 70-year-old man with underlying ILD presented to our hospital with a few days of fever and respiratory symptoms after receiving the BNT162b2 vaccine. Drug-related pneumonitis due to the COVID-19 mRNA vaccine was diagnosed. One case was diagnosed with lymphocytic alveolitis by bronchoalveolar lavage fluid and transbronchial lung cryobiopsy. Both patients were successfully treated with corticosteroids, and they attended outpatient clinics thereafter. Although the safety and efficacy of COVID-19 vaccines have been established, further studies are needed to estimate long-term data and reports of rare adverse reactions. We present the clinical course of two cases, review previously published case reports on COVID-19 mRNA vaccine-related ILD and discuss the relevant findings.

Prolonged SARS-CoV-2 infection associated with long-term corticosteroid use in a patient with impaired B-cell immunity.

Corticosteroids are widely used to treat severe COVID-19, but in immunocompromised individuals, who are susceptible to persistent infection, long term corticosteroid use may delay viral clearance. We present a case of prolonged SARS-CoV-2 infection in a man with significantly impaired B-cell immunity due to non-Hodgkin lymphoma which had been treated with rituximab. SARS-CoV-2 shedding persisted, despite treatment with remdesivir. Viral sequencing confirmed the persistence of the same viral strain, ruling out the possibility of reinfection. Although SARS-CoV-2 IgG, IgA and IgM remained negative throughout the treatment period, after reduction of the corticosteroid dose, PCR became negative. Long-term corticosteroid treatment, especially in immunocompromised individuals, may result in suppression of cell-mediated immunity and prolonged SARS-CoV-2 infection.

Multiple endobronchial airway stents in a case of relapsing polychondritis - A rare entity.

Relapsing polychondritis (RP) is a rare multisystem condition. Nearly 50% of patients are suffering from airway involvement in RP and it can be fatal. Besides immunotherapies, endobronchial stenting has been found to be useful in the treatment. Insertion of endobronchial stents in patients with RP has it's own complications and has been associated with increasing morbidity and mortality. We describe placement of multiple endobronchial stents to prevent airway closure in a 76-year-old man with RP due to recurrent dyspnea. Insertion of multiple stents (6th stent) in the left main bronchus was necessary due to severe narrowing of the left main bronchus. Recurrence of airway involvement in RP is common. Early diagnosis and prompt treatment are essential to reduce the risk of life-threatening airway collapse. The insertion of multiple stents in this patient has resulted in improving symptoms, spirometry, and a return to daily activities.

Successful Resection of a Primary Dedifferentiated Tracheal Liposarcoma Causing Tracheal Stenosis.

A 68-year-old woman was admitted with a persistent cough and dyspnea that had persisted for 4 months prior. Chest computed tomography revealed a tumor protruding from the membranous portion of the trachea. She underwent tumor resection via rigid and flexible bronchoscopy to relieve the symptoms and obtain a diagnosis. After the procedure, she was diagnosed with tracheal liposarcoma. Three months after the procedure, she underwent complete surgical tumor resection. Liposarcoma is a mesenchymal tumor that usually develops in the extremities and the retroperitoneum. Tracheal liposarcoma is extremely rare. To the best of our knowledge, this is only the second reported case.