Fc-rosette inhibition by pregnant women's sera and by rabbit anti-beta2-microglobulin.

Some anti-HLA sera showed Fc-rosette inhibitory activity, which had little correlation with type-specific anti-HLA activity. Cytotoxic titers did not correlate with Fc-rosette inhibition rate and these antisera showed considerable inhibition of rosette formation even after absorption of anti-HLA activity with T lymphocytes. These results suggest that some anti-HLA sera contain B-cell-specific inhibitory activity against Fc-receptor like anti-Ia antibody in mice. Rabbit antiserum against human beta2-microglobulin showed specific inhibition of Fc-rosette formation. It was suggested that Fc-receptor or Ia-like antigen in human has a close relation with beta2-microglobulin.