Significance of number of HLA determinants in HLA capping in childhood acute lymphoblastic leukemia.

The density of HLA determinants on the cell surface was studied in relation to HLA capping in childhood acute lymphoblastic leukemia (ALL). Analysis was performed with flow cytometry (FACS) and a subjective labeling score. These two methods gave comparable results. In T-ALL high percentages of capped cells were related to low numbers of HLA determinants. In c-ALL we found the opposite. This study shows that capping capacity and number of HLA determinants in childhood ALL are inversely related.