Defective expression of MHC class I antigens is frequent in B-cell lymphomas of high-grade malignancy.
An unselected series of 66 immunohistologically proven B-cell lymphomas was examined for the expression of MHC class I antigens with monoclonal antibodies directed against non-polymorphic determinants of HLA-A,B,C heavy chain and beta 2-microglobulin. The tumors were classified according to the Kiel classification. No significant differences were observed in the reaction for HLA-A,B,C and beta 2m which may be indicative of a coordinate expression in our lymphoma series. In 37 cases (56%), all tumor cells exhibited strong staining for class I antigens as observed in normal B cells. The remaining 29 cases (44%) showed abnormally low or undetectable class I expression in varying tumor cell subsets; 13 cases were completely devoid of HLA-A,B,C. Twenty-two out of 30 lymphomas of high-grade malignancy but only 7/36 lymphomas of low-grade malignancy presented defective class I expression. This difference in proportion is highly significant (p less than 0.00002). Eleven of the 13 class I-negative lymphomas belonged to the group of high-grade malignancy. Centrocytic lymphoma, which has the poorest prognosis among the B-cell lymphomas of low-grade malignancy, was defective in 40% of the cases examined. The lymphoblastic type represented an exception within the lymphomas of high-grade malignancy as no defective expression was observed. In addition to the correlation between the high-grade malignancy and defective class I expression, defects occurred more frequently in lymphomas with an extra-nodal primary manifestation (p less than 0.05). The grade of malignancy, however, was not correlated with the primary site of the lymphoma.
Möller
P
P
Herrmann
B
B
Moldenhauer
G
G
Momburg
F
F
D000911:Antibodies, Monoclonal; D001402:B-Lymphocytes; D006680:HLA Antigens / Q000032:analysis; D006649:Histocompatibility Antigens; D006651:Histocytochemistry; D006801:Humans; D008223:Lymphoma / Q000276:immunology* / Q000473:pathology; D001613:beta 2-Microglobulin / Q000032:analysis
D000911:Antibodies, Monoclonal; D006680:HLA Antigens; D006649:Histocompatibility Antigens; D001613:beta 2-Microglobulin