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Updated: Aug 6, 2026
Mouse Model of Alloimmune-induced Vascular Rejection and Transplant Arteriosclerosis
Published on: May 17, 2015
The predictive value of soluble major histocompatibility complex class I chain-related molecule A (MICA) levels on
Beatriz Suárez-Alvarez1, Antonio López-Vázquez, Beatriz Díaz-Molina
1Department of Immunology, Hospital Universitario Central de Asturias, Oviedo, Spain.
Background:
Recently the presence of a soluble form of major histocompatibility complex class I chain-related molecule A (sMICA) has been detected in the sera of patients with tumors. Shedding of sMICA by tumor cells downregulates NKG2D-mediated antitumor immunity. The aim of this investigation was to study the possible involvement of sMICA in the allograft acceptance after heart transplantation (HTX).
Methods:
We monitored the levels of sMICA by specific enzyme-linked immunosorbent assay (ELISA) in a total of 146 serum samples obtained from 34 heart transplantation patients followed up during the first year post-HTX.
Results:
The persistence of sMICA expression was correlated with the clinical evolution of these patients. sMICA was detected in the serum of 21 of 34 patients (61.70%) between 15 and 20 days after implantation and was practically absent in pretransplant serum samples. Twenty of these 21 patients (95.24%) with sMICA did not experience episodes of severe rejection during this period (P = 0.0001), whereas sMICA was practically absent in patients with manifestations of severe acute rejection. The longitudinal study of these patients revealed that the presence of sMICA was consistently maintained in 75% of the patients with good graft status during the period of observation.
Conclusion:
This has led us to believe that the presence of levels of sMICA during the first year post-HTX may contribute to allograft acceptance. Additionally, functional studies indicate that sMICA downregulates NKG2D surface expression, which may lead to a functional impairment of cell-mediated cytolysis. These data suggest a significant correlation between the presence of sMICA and a lower incidence of rejection.
