Prognostic Value of Serum MICA Levels as a Marker of Severity in COVID-19 Patients

Abstract Purpose: The global pandemic of COVID-19 and high mortality rates, necessitate the development of diagnostic and prognostic tools and expansion of testing capacity. The existing approaches to identification and characterization of SARS-COV-II infection are usually based on viral genome detection or measuring COVID-19-specific antibody levels. Despite being valuable, these methods are unable to anticipate disease outcomes in patients. Given the point that the innate immune cells, particularly NK cells, ‌contribute significantly to anti-viral defense, this research aimed to determine the prognostic value of serum secretory MHC class I polypeptide–related sequence A (sMICA) levels as an important ligand for NKG2D receptor, the master regulator of NK cell development and responsiveness.Methods: Serum levels of MICA were measured by ELISA assay. Sera (n = 60) were collected from SARS-CoV-2 positive patients and disease severity was assessed by clinical criteria. The patient group consisted of 30 cases with mild disease and 30 severely ill patients examined versus 30 controls. Results: Our data revealed that serum levels of MICA were considerably higher in patients compared with controls, particularly in cases with severe complications (P<0.0001). Conclusion: Higher serum levels of MICA may be associated with respiratory failure in COVID-19 and can serve as a marker of clinical severity for patients with SARS-CoV-2 infection in particular whenever the clinical manifestations are not sufficient to make a confident prediction.