AUTHOR=Wang Geng , Wang Qian , Wang Yeming , Liu Changzheng , Wang Linghang , Chen Hong , Jiao Tao , Hu Chaojun , Lei Xiaobo , Guo Li , Ren Lili , Li Mengtao , Zhao Yan , Zeng Xiaofeng , Zhang Dingyu , Cao Bin , Wang Jianwei 

TITLE=Presence of Anti-MDA5 Antibody and Its Value for the Clinical Assessment in Patients With COVID-19: A Retrospective Cohort Study

JOURNAL=Frontiers in Immunology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2021.791348

DOI=10.3389/fimmu.2021.791348

ISSN=1664-3224

ABSTRACT=<sec><title>Background</title><p>Striking similarities have been found between coronavirus disease 2019 (COVID-19) and anti-melanoma differentiation-associated gene 5 (MDA5) antibody (Ab)-related dermatomyositis, implying a shared autoinflammatory aberrance. Herein, we aim to investigate whether the anti-MDA5 Ab is present in COVID-19 and correlates with the severity and adverse outcome of COVID-19 patients.</p></sec><sec><title>Methods and Findings</title><p>We retrospectively recruited 274 adult inpatients with COVID-19 in this study, including 48, 164, and 62 cases of deaths, severe, and non-severe patients respectively. The anti-MDA5 Ab was determined by ELISA and verified by Western Blotting, which indicated that the positive rate of anti-MDA5 Ab in COVID-19 patients was 48.2% (132/274). The clinical and laboratory features, as well as outcomes between patients with positive and negative anti-MDA5 Ab were compared and we found that the anti-MDA5 Ab positive patients tended to represent severe disease (88.6% <italic>vs</italic> 66.9%, <italic>P</italic>&lt;0.0001). We also demonstrated that the titer of anti-MDA5 Ab was significantly elevated in the non-survivals (5.95 ± 5.16 <italic>vs</italic> 8.22 ± 6.64, <italic>P</italic>=0.030) and the positive rate was also higher than that in the survivals (23.5% <italic>vs</italic> 12.0%, <italic>P</italic>=0.012). Regarding severe COVID-19 patients, we found that high titer of anti-MDA5 Ab (≥10.0 U/mL) was more prevalent in the non-survivals (31.2% <italic>vs</italic> 14.0%, <italic>P</italic>=0.006). Moreover, a dynamic analysis of anti-MDA5 Ab was conducted at different time-points of COVID-19, which revealed that early profiling of anti-MDA5 Ab could distinguish severe patients from those with non-severe ones.</p></sec><sec><title>Conclusions</title><p>Anti-MDA5 Ab was prevalent in the COVID-19 patients and high titer of this antibody is correlated with severe disease and unfavorable outcomes.</p></sec>