Why is mhc class 2 more important in renal transplant than mhc class 1?

Rejection Severity: Both are import ant and each can trigger rejection when the host is mismatched for any of these hla antigens. Recipients that develop antibodies to these phenotypes, in particular class ii dq--may have poorly responsive rejections. The antibody generated against class ii may derive from more resilient memory cells. Both are bad though.