A PUTATIVE MARKER FOR B-CELL PROLIFERATIONS - STAINING PROFILE OF 426 PARAFFIN-EMBEDDED TISSUES

Anti-BLA.36 is a monoclonal antibody that recognizes a 36-kilodalton glycoprotein designated B lymphocyte antigen. In this study, the sensitivity and specificity of staining for BLA.36, a putative B cell marker, was evaluated for a total of 426 paraffin-embedded specimens, including 228 lymphoid tissues involved by B or T cell lymphomas, 52 specimens involved by Hodgkin's disease, 61 bone marrow biopsies with a variety of hematopoietic disorders, 72 nonhematopoietic neoplasms, and 13 reactive or nonlymphomatous processes. Immunoreactivity for BLA.36 was detected in tissues fixed in B5 solution, formalin, or Zenker's-acetic acid solution. For B cell neoplasms, reactivity for BLA.36 was detected in 167/184 (91%) lymphoid tissues and in 25/40 (63%) bone marrow biopsies. All 17 anaplastic large cell lymphomas (CD30(+)) of T cell phenotype evaluated for BLA.36 were reactive. Only 4/31 (13%) other T cell neoplasms were positive. In all 52 cases of Hodgkin's disease of various histologic types, Reed-Sternberg cells and variants were reactive for BLA.36. Some bone marrow biopsies involved by myeloproliferative disorders (7/12 cases; 58%) were also positive for BLA.36, as were 20 of 72 (28%) nonlymphoid neoplasms, including carcinomas and occasional sarcomas. Comparison of reactivity for BLA.36 with that observed for the pan B cell antibody L26 (CD20) in lymphoid tissues of 88 B cell neoplasms revealed overall similar percentages (91% BLA.36(+), 96% L26(+)). However, when small and large neoplastic lymphoid cells were evaluated separately, the sensitivity of staining for L26 was greater than for BLA.36 in small lymphocytic neoplasms (p < 0.05). BLA.36 is a sensitive marker for detection of B cell neoplasms. However, since its staining profile is not absolutely specific, it must be used appropriately as part of an antibody panel.