Examination of the utility of the COVID-19 detection kit, TRC Ready® SARS-CoV-2 i for nasopharyngeal swabs.

The reverse transcription polymerase chain reaction (RT-PCR) offers high sensitivity, but has some drawbacks, such as the time required for the RNA extraction. Transcription reverse-transcription concerted reaction (TRC) Ready® SARS-CoV-2 i is easy to use and can be performed in about 40 minutes. TRC Ready® SARS-CoV-2 i and real-time one-step RT-PCR using the TaqMan probe tests of cryopreserved nasopharyngeal swab samples from patients diagnosed with COVID-19 were compared. The primary objective was to examine the positive and negative concordance rates. A total of 69 samples cryopreserved at -80° C were examined. Of the 37 frozen samples that were expected to be RT-PCR positive, 35 were positive by the RT-PCR method. TRC Ready® SARS-CoV-2 i detected 33 positive cases and 2 negative cases. One frozen sample that was expected to be RT-PCR positive was negative on both TRC Ready® SARS-CoV-2 i and RT-PCR. In addition, one frozen sample that was expected to be RT-PCR positive was positive by the RT-PCR method and negative by TRC Ready® SARS-CoV-2 i. Of the 32 frozen samples that were expected to be RT-PCR negative, both the RT-PCR method and TRC Ready® SARS-CoV-2 i yielded negative results for all 32 samples. Compared with RT-PCR, TRC Ready® SARS-CoV-2 i had a positive concordance rate of 94.3% and a negative concordance rate of 97.1%. TRC Ready® SARS-CoV-2 i can be utilized in a wide range of medical sites such as clinics and community hospitals due to its ease of operability, and is expected to be useful in infection control.

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.

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.

Sustained coronavirus disease 2019-related organizing pneumonia successfully treated with corticosteroid.

A 70-year-old Japanese man contracted severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and required oxygen to maintain oxygen saturation (>90%), 5 weeks after onset of coronavirus disease 2019 (COVID-19) symptoms. Transbronchial lung cryobiopsy revealed pathological features of organizing pneumonia with alveolar epithelial injury, and prednisolone administration led to alleviation of respiratory symptoms and recovery of respiratory function. This case report is the first to demonstrate the use of corticosteroids to successfully treat post-COVID-19 respiratory failure in a patient with biopsy-proven organizing pneumonia. We propose that steroid treatment be considered for patients with persistent respiratory dysfunction as COVID-19 pneumonia sequelae.