CORRELATION OF PROGNOSIS OF COVID POSITIVE PATIENTS BETWEEN REAL TIME RT-PCR AND CT-VALUES OF E. GENE, N.GENE, RDRP GENE

Abstract

INTRODUCTION: COVID-19 – Corona virus disease-19 – A respiratory illness caused by severe acute respiratory syndrome corona virus 2 (SARS-CoV-2), colloquially referred to as coronavirus. Real-time PCR is conducted to quantify the absolute amount of target sequence or to compare relative amount of a target sequence among samples. This technique monitors amplication of the target in real time via a target specic uorescent signal emitted during amplication. During most real times PCR, a considerable amount of background uorescence occurs. Inspite of this fact PCR uorescent dyes and probes should be sequence specic. This CT value or cycle threshold value in a real time RT- PCR is dened as the number of cycles required for the uorescent signal to cross the threshold i.e., exceeds background level). This is inversely proportional to the amount of target nuclei in the sample. i.e., lower the CTlevel the greater the amount of target nuclei in the sample. AIM: To explore the association of the mutation pattern of covid-19 genetic variation with the severity and fatality of patients with covid-19 viral illness. Factors considered are Age, Sex, and Duration of hospital stay and outcome of patient. MATERIALS AND METHODS: The study was a comparative, correlation, retrospective, lab values based study. All covid+ve patients tested at Peerless hospital, Kolkata by RT-PCR on admission. It is imperative to choose reference genes whose expression levels are not expected to change during our experiment. Common housekeeping genes include actin, alpha-tubuliun, gapdh and ubiquitin. it is wise to use at least two reference gene for one study may not be suitable for another. Total 370 participants were present in this study. RESULT: In our study, 114(30.8%) COVID positive patients were in E GENE GR 11-20, 147(39.7%) COVID positive patients were in E GENE GR 21-30 and 109(29.5%) COVID positive patients were in E GENE GR 31-40. 163(44.1%) COVID positive patients were in N GENE GR 11-20, 132(35.7%) COVID positive patients were in N GENE GR 21-30 and 75(20.3%) COVID positive patients were in N GENE GR 31-40. 228(61.6%) COVID positive patients were in RdRp GENE GR 11-20, 112(30.3%) COVID positive patients were in RdRp GENE GR 21-30 and 30(8.1%) COVID positive patients were in RdRp GENE GR 31-40. We found that, 30(8.1%) COVID positive patients died and 340 (91.9%) patients have survived. CONCLUSION: The patients who died had signicantly lower RT-PCR CT-values OF E. GENE, N.GENE, RdRp GENE than patients who survived. We concluded that the time of onset of symptoms were earlier for patients with lower CTvalue, than the other group who survived. So we concluded after correlating CT-values of real time RT-PCR and E. GENE, N.GENE, RdRp GENE, that the patients with lower CTvalues had more severity and had poor prognosis than the other group with higher RT-PCR CT-values of E.GENE, N, GENE, RdRp GENE