Risk factors for recurrent positive results of the nucleic acid amplification test for COVID-19 patients: a retrospective study

Clinical Characteristics in Patients with Redetected Positive RNA Test After Recovery from Foreign-Imported COVID-19 Cases in Xi’an, China

Purpose

At present, it has been found that managing patients with a redetected positive RNA test after recovery from foreign-imported coronavirus disease 2019 (COVID-19) cases in China is challenging. The purpose of the current study was to describe the clinical characteristics of these patients.

Methods

This retrospective cohort study included 137 COVID-19 patients who were discharged from the Xi’an Public Health Center from 28 July 2020 to 31 December 2021. We compared the clinical characteristics between positive retest patients and non-positive retest patients.

Results

137 COVID-19 patients entered our study, 27 (19.7%) cases of COVID-19 with a redetected positive RNA test by the end of the follow-up period. Fever [(n = 31 (22.6%)], cough [n = 26 (18.9%)] and sore throat [n = 20 (14.5%)] were the most common initial symptoms among the foreign-imported COVID-19 patients, and there were almost no significant differences in initial symptoms between positive retest patients and non-positive retest patients. The positive retest patients had a higher lymphocyte count (p = 0.031) and lymphocyte percentage (p = 0.007) during readmission. There were generally no significant differences in other routine blood test findings, IgG and IgM antibody responses, between positive retest patients and non-positive retest patients, or in positive retest patients over time (before, during, or after positive patient detection). After readmission, positive retest patients displayed fewer symptoms or no obvious disease progression and more sustained remission by CT imaging.

Conclusion

Our findings revealed that the clinical characteristics at the time of initial diagnosis were not closely related to redetected positive RNA tests after recovery from foreign-imported COVID-19 cases. Positive retest patients had virtually no symptoms and displayed no obvious disease progression during readmission. These findings provide important information and clinical evidence for the effective management of foreign-imported COVID-19 patients during their convalescent phase.

Long non-coding RNA CCAT2 drives the growth of laryngeal squamous cell carcinoma via regulating YAP activity

Emerging evidence suggests that long non-coding RNA (lncRNA) is closely associated with numerous human diseases, including cancer. However, the functional relevance of lncRNA in human laryngeal squamous cell carcinoma (LSCC) is largely unknown. In the current study, we described CCAT2, a previously unappreciated oncogenic lncRNA in LSCC. CCAT2 was significantly upregulated in human LSCC tissue and serum samples, associated with larger tumor volume, higher clinical stage, and poorer differentiation status. Lentivirus-mediated CCAT2 knockdown notably repressed the cell viability, colony formation, and DNA synthesis rate of LSCC. Screening of transcription factors revealed that YAP/TEAD activity was affected by CCAT2 in LSCC cells. Further, CCAT2 directly binds to YAP protein and blocks the phosphorylation of YAP induced by LATS1, resulting in the nuclear translocation of YAP and the activation of YAP oncogenic targets, such as CTGF, CYR61 and AMOTL2. Importantly, we also confirmed the regulation of CCAT2 on YAP activity in vivo based on nude mice model. Altogether, we identified a novel lncRNA that controls YAP nucleocytoplasmic shuttling and promotes LSCC cell proliferation. Given the importance of YAP in tumorigenesis and progression, our results provide insights to intervene LSCC by targeting the CCAT2/YAP axis.