HLA (class 1 antigen) status and cell-mediated immunity in multiple sclerosis.

In vitro lymphocyte proliferation in response to allogeneic pooled cells, phytohaemaglutinin (PHA), and pokeweed mitogen (PWM), was measured in relation to HLA A, B and C status in 67 patients with clinically definite multiple sclerosis and in 67 age- and sex-matched controls. Analysis of covariance taking age into account showed significant effects only for A9 and B12 in controls and B27 and Cw3 in patients, fewer than would be expected by chance. It is concluded that HLA Class 1 status is not an important factor in regulating mitogen responsiveness.