C3 and COVID-19: Also, increased plasma levels of sC5b-9 complexes have been found in COVID-19 patients, deposition of C4d and C3 has been detected in the lungs of diseased patients and binding of MBL and MBL associated serine protease (MASP)-2 of the LPW to virus proteins of the SARS CoV-2 virus has been reported (26, 30, 31).