A new monoclonal anti-CD7 antibody reactive on paraffin sections.
CBC.37 monoclonal antibody (mAb) was generated using balb/c mice immunized with CEM T cell line. It was selected because of its strong reactivity on T lymphocytes on paraffin tissue sections. The anti-CD7 specificity of CBC.37 mAb was assessed by immunohistochemistry, cross-blocking, and cross-immunoprecipitation experiments using CBC.37 and the anti-CD7 mAb DK24. CBC.37 mAb immunoprecipitated a 40-kDa protein. Cross-blocking and cross-immunoprecipitation experiments demonstrated that the two antibodies recognized the same molecule. Immunostaining of a large number of reactive lymph nodes and B and T cell lymphomas confirms that CBC.37 mAb was directed against T cells. As expected, on reactive lymph nodes the staining pattern was comparable to that of CD3. Among the 110 T cell lymphomas examined, all T lymphoblastic lymphomas were positive (15+/15; 100%). As a result of the frequent loss of CD7 antigen, only 25+/95 (26%) of peripheral T cell neoplasms were found to be positive for CBC.37. A marked reduction in the number of CBC.37-positive T cells was observed in 7 of the 60 cases of benign inflammatory dermatoses studied (approximately 12%). CBC.37 was unreactive with all healthy and neoplastic non-lymphoid samples examined. Because the lack of CD7 expression in T cell lymphomas is of diagnostic value, CBC.37 mAb in association with other anti-T cell antibodies working on paraffin sections could be of particular value in asserting the diagnosis of T cell lymphomas in routine histopathology.
Al Saati
T
T
Department of Pathology and Unité de Physiopathologie Cellulaire et Moléculaire, CNRS-UPR 2163, CHU Purpan, Toulouse, France. alsaati@immgen.cnrs.fr
Alibaud
L
L
Lamant
L
L
Boyes
J
J
March
M
M
Delsol
G
G
D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis / Q000302:isolation & purification; D019011:Antigens, CD7 / Q000276:immunology*; D000951:Antigens, Neoplasm / Q000276:immunology; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006801:Humans; D007118:Immunoassay; D007150:Immunohistochemistry; D015458:Leukemia, T-Cell / Q000276:immunology / Q000473:pathology; D016399:Lymphoma, T-Cell / Q000276:immunology / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D016612:Paraffin Embedding / Q000379:methods*; D011233:Precipitin Tests
D000911:Antibodies, Monoclonal; D019011:Antigens, CD7; D000951:Antigens, Neoplasm