No abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), is a new virus that emerged in China and immediately spread around the world. Evidence has been documented that the immune system is impressively involved in the pathogenesis of this disease, especially in causing inflammation. One of the important components of the immune system is the complement system whose increased activity has been shown in inflammatory diseases and consequently damage caused by the activity of its components. In the present study, serum levels of C3 and C4 factors as well as the activity level of complement system in the classical pathway were measured by CH50 test in patients with SARS-CoV-2. Participants in the study consisted of 53 hospitalized patients whose real-time PCR test was positive for SARS-CoV-2. The mean age of these patients was 42.06 ± 18.7 years, including 40% women and 60% men. The most common symptoms in these patients were cough (70%), fever (59%), dyspnea (53%) and chills (53%), respectively. Analysis of biochemical and hematological test results revealed that 26 (49%) patients had lymphopenia, 34 (64%) patients were positive for C-reactive protein (CRP) and 26 (49%) patients had ESR and LDH levels significantly higher than normal. In addition, 27 patients (51%) had vitamin D deficiency. The mean CH50 activity level in COVID-19 patients was significantly reduced compared to healthy individuals (84.9 versus 169.9 U/ml, p = < 0.0001). Comparison of the mean CH50 activity levels between different subgroups of patients indicated that COVID-19 patients with decreased peripheral blood lymphocyte count and positive CRP had a significant increase in activity compared to the other groups ( p = 0.0002). The serum levels of C3 and C4 factors had no significant change between patients and healthy individuals. Conclusion: The activity level of complement system in the classical pathway decreases in COVID-19 patients compared to healthy individuals, due to increased activity of complement system factors in these patients.

Objectives: Coronavirus disease 2019 (COVID-19) associated by infection and high death rate. The unresolved questions about the fatality rate of COVID-19 is most probably related to cytokine storm syndrome. There is currently no specific medication. Understanding the pathogenic pathway of this disease will lead to production of treatment and decreases of death rate. The aim of this study is to investigate changes of peripheral blood parameters (Interleukin-6 and Ferritin) in COVID-19 patients, which may be beneficial in the management of patients.Methods: In this case-control study, we collected data of 270 subjects in two groups including 133 patients with severe type COVID-19 (case) and 137 patients with nonsevere (control) between March 20 and May 21, 2020, and the clinical symptoms and inflammatory indications of patients diagnosed by laboratory test in Shahid Jalil hospital of Yasuj University of medical Sciences were collected to explore potential markers for disease monitoring. The data were analyzed by SPSS software version 20. Descriptive statistics, T-test and bivariate correlation tests were used to analyze. Results: The enrolled COVID-19 patients consisted of 53.4% males and 46.6% females with the medium age of 45.56±18.55 years and there were 50.04% males and 49.6% females with the medium age of 45.59±17.0 years for non COVID-19 patients. There was no significant difference in the age and sex ratio between two population under study. The proportion interstitial abnormalities evidenced by CT imaging in COVID-19 patients was 91.0%, while, 4.4% abnormalities was found in non COVID-19 patients. The frequency of positive RT-PCR test for case and control groups were 88.0% and 3.6%, respectively. The mean IL-6 and Ferritin levels and hematological parameters in two groups of patients with COVID-19 and non- COVID-19, were significantly different across all comparisons.There was a direct positively correlated between serum level of IL-6, Ferritin levels and hematological parameters including WBC, Lymphocytes, Neutrophils and Hb, except for platelets (negatively correlate), with COVID-19. Conclusions: In conclusion, inflammatory markers specifically IL-6 and Ferritin and hematological parameters (WBC, Lymphocytes, Neutrophils, Platelet and Hb) were correlated with the severity of COVID-19. Measurement of IL-6, Ferritin and hematological indices might be workable tests to diagnosis and prognosis of patients with COVID-19.