Background A pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been spreading over the world. However, the viral dynamics, host serologic responses, and their associations with clinical manifestations, have not been well described in prospective cohort. Methods We conducted a prospective cohort and enrolled 67 COVID-19 patients admitting between Jan 26 and Feb 5, 2020. Clinical specimens including nasopharyngeal swab, sputum, blood, urine and stool were tested periodically according to standardized case report form with final follow-up on February 27. The routes and duration of viral shedding, antibody response, and their associations with disease severity and clinical manifestations were systematically evaluated. Coronaviral particles in clinical specimens were observed by transmission electron microscopy (TEM). Results The median duration of SARS-CoV-2 RNA shedding were 12 (3-38), 19 (5-37), and 18 (7-26) days in nasopharyngeal swabs, sputum and stools, respectively. Only 13 urines (5.6%) and 12 plasmas (5.7%) were viral positive. Prolonged viral shedding was observed in severe patients than that of non-severe patients. Cough but not fever, aligned with viral shedding in clinical respiratory specimens, meanwhile the positive stool-RNA appeared to align with the proportion who concurrently had cough and sputum production, but not diarrhea. Typical coronaviral particles could be found directly in sputum by TEM. The anti-nucleocapsid-protein IgM started on day 7 and positive rate peaked on day 28, while that of IgG was on day 10 and day 49 after illness onset. IgM and IgG appear earlier, and their titers are significantly higher in severe patients than non-severe patients (p<0.05). The weak responders for IgG had a significantly higher viral clearance rate than that of strong responders (p= 0.011). Conclusions Nasopharyngeal, sputum and stools rather than blood and urine, were the major shedding routes for SARS-CoV-2, and meanwhile sputum had a prolonged viral shedding. Symptom cough seems to be aligned with viral shedding in clinical respiratory and fecal specimens. Stronger antibody response was associated with delayed viral clearance and disease severity.

BACKGROUND Nucleic acid test and antibody assay have been employed in the diagnosis for SARS-CoV-2 infection, but the use of viral antigen for diagnosis has not been successfully developed. Theoretically, viral antigen is the specific marker of the virus and precedes antibody appearance within the infected population. There is a clear need of detection of viral antigen for rapid and early diagnosis.METHODS We included a cohort of 239 participants with suspected SARS-CoV-2 infection from 7 centers for the study. We measured nucleocapsid protein in nasopharyngeal swab samples in parallel with the nucleic acid test. Nucleic acid test was taken as the reference standard, and statistical evaluation was taken in blind. We detected nucleocapsid protein in 20 urine samples in another center, employing nasopharyngeal swab nucleic acid test as reference standard. RESULTSWe developed a fluorescence immunochromatographic assay for detecting nucleocapsid protein of SARS-CoV-2 in nasopharyngeal swab sample and urine within 10 minutes. 100% of nucleocapsid protein positive and negative participants accord with nucleic acid test for same samples. Further, earliest participant after 3 days of fever can be identified by the method. In an additional preliminary study, we detected nucleocapsid protein in urine in 73.6% of diagnosed COVID-19 patients.CONCLUSIONS Those findings indicate that nucleocapsid protein assay is an accurate, rapid, early and simple method for diagnosis of COVID-19. Appearance of nucleocapsid protein in urine coincides our finding of the SARS-CoV-2 invading kidney and might be of diagnostic value.

BackgroundProtein Induced by Vitamin K Absence or Antagonist-II (PIVKA-II) is an efficient biomarker specific for hepatocellular carcinoma (HCC). Some researchers have proved that levels of PIVKA-II reflect HCC oncogenesis and progression. However, the effectiveness of PIVKA-II based on real-world clnical data has barely been studied.MethodsA total of 14,861 samples were tested in Southwest Hospital in over 2 years’ time. Among them, 4073 samples were PIVKA-II positive. Finally, a total of 2070 patients with at least two image examinations were enrolled in this study. Levels of AFP and PIVKA-II were measured by chemiluminescence enzyme immunoassay (CLEIA) and chemiluminescent microparticle Immunoassay (CMIA), respectively.ResultsA total of 1016 patients with HCC were detected by PIVKA-II in a real-world application. In all these cases, 88.7% cases primarily occurred and patients with advanced HCC covered 61.3%. Levels of PIVKA-II were significantly higher in advanced group (4650.0 mAU/ml, 667.0–33,438.0 mAU/ml) than early-stage group (104.5 mAU/ml, 61.0–348.8 mAU/ml; P < 0.001). Levels of PIVKA-II elevated significantly in recurrence and residual group than recovery group (P < 0.001). A total of 1054 PIVKA-II positive patients were non-HCC cases. Among them, cirrhosis took the largest part (46.3%), followed by hepatitis (20.6%) and benign nodules (15.3%). High-levels of PIVKA-II in at-risk patients is an indicator of HCC development in two-year time.ConclusionsOur data showed that PIVKA-II effectively increases the detection rate of HCC was a valid complement to AFP and image examination in HCC surveillance.

RNA virus population in a host does not consist of a consensus single haplotype but rather an ensemble of related sequences termed quasispecies. The dynamics of quasispecies afford SARS-CoV-2 a great ability on genetic fitness during intrahost evolution.

Recent genome-wide associated studies (GWASs) have revealed several common loci associated with the risk of hepatitis B virus (HBV)- or hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC). We selected 15 single nucleotide polymorphisms (SNPs) identified through GWASs on HBV- or HCV-related HCC, and genotyped them in two independent Chinese cohorts of chronic HBV carriers, including 712 LC cases and 2601 controls. The association of each SNP with the risk of HBV-related LC was assessed by meta-analysis of the two cohorts. Of the 12 SNPs reported in HBV-related HCC GWASs, five SNPs (rs7574865 in STAT4, rs9267673 near C2, rs2647073 and rs3997872 near HLA-DRB1 and rs9275319 near HLA-DQ), were found to be significantly associated with the risk of HBV-related LC (rs7574865: P = 1.79 × 10−2, OR = 1.17, 95% CI = 1.03–1.34; rs9267673: P = 4.91 × 10−4, OR = 1.37, 95% CI = 1.15–1.63; rs2647073: P = 3.53 × 10−5, OR = 1.63, 95% CI = 1.29–2.06; rs3997872: P = 4.22 × 10−4, OR = 1.86, 95% CI = 1.32–2.62; rs9275319: P = 1.30 × 10−2, OR = 1.32, 95% CI = 1.06–1.64). However, among the three SNPs associated with the risk of HCV-related HCC in previous GWASs, none of them showed significant association with the risk of HBV-related LC. Our results suggested that genetic variants associated with HBV-related hepatocarcinogenesis may already play an important role in the progression from CHB to LC.