Accurate, Ancell, Biodesign (ALB1, ALB2), Coulter (J5), Cymbus Bioscience (Mem 78), Dako (SS2/36), GenTrak, Immunotech (ALB1, ALB2), Research Diagnostics (MEM 78, J-149), Sanbio (MEM 78, BFA.11), Seralab (B-E3) and Serotec.

Current antibodies are immunoreactive only in fresh-frozen tissue.

The common acute lymphoblastic leukemia antigen (CALLA) is a 100 kD single-chain glycoprotein whose sequence is virtually identical to that of neutral endopeptidase (NEP-24.11 enkephalinase). It is a metalloenzyme that requires zinc as a cofactor and is thought to inactivate regulatory peptides favoring cell differentiation. It was originally defined by hetero-antiserum raised in rabbits by immunization with cells of a ''non-B, non-T" cell acute lymphoblastic leukemia. CD 10 is present on the cell surface of stem cells in the bone marrow and fetal liver that are also TdT and HLADR antigen positive (Anderson et al, 1984; Letarte et al, 1988).

CD 10 was originally used as a specific marker for non-B, non-T cell ALL. It is expressed in approximately 75% of precursor B-cell ALL and more than 90% of cases of myelogenous leukemia in lymphoid blast crisis, but it is not a leukemia-specific antigen nor is it B- or T-cell lineage restricted (Carrel et al, 1983). The antigen is found on variable proportions of cells making up T-cell ALL/LBL, Burkitt's lymphoma, follicular lymphoma and multiple myeloma (Durie & Grogan, 1985; Ruiz-Arguelles & San Miguel, 1994). In addition, CD 10 is expressed on the renal glomerular and tubular cells, fibroblasts, bile canaliculi, melanoma cell lines and various other epithelial cells.

While CD 10 is neither lineage specific nor tumor restricted, it remains a useful marker, especially in the analysis of childhood ALL/LBL and follicular lymphomas (Greeves et al, 1975, 1983).

•Anderson KC, Bates MP, Slaughtenhoupt BL et al 1984. Expression of human B cell associated antigens on leukemias and lymphomas: a model of B cell differentiation. Blood 63: 1424-1433.

•Carrel S, Schmidt-Kessen A, Mach J-P et al 1983. Expression of common acute lymphoblastic leukemia (cALLa) by lymphomas of B cell and T cell lineage. Journal of Immunology 130: 2456-2460.

•Durie BGM, Grogan TM 1985 CALLA-positive myeloma: an aggressive subtype with poor survival. Blood 66: 229-232.

•Greeves MF, Brown G, Rapson NT, Lister TA 1975 Antisera to acute lymphoblastic leukemia cells. Clinical Immunology and Immunopathology 4: 67-84.

•Greeves MF, Hariri G, Newman RA, et al 1983. Selective expression of the common acute lymphoblastic leukemia (gp 100) antigen on immature lymphoid cells and their malignant counterparts. Blood 61: 628-639.

•Letarte M, Vera S, Tran R et al 1988. Common acute lymphocytic leukemia antigen is identical to neutral endopeptidase. Journal of Experimental Medicine 168: 1247-1253. neutral endopeptidase. Journal of Experimental Medicine 168: 1247-1253.

•Ruiz-Arguelles GJ, San Miguel JF 1994. Cell surface markers in multiple myeloma. Mayo Clinic Proceedings 69: 684-690.

Manual of diagnostic antibodies for immunohistology / Anthony S.-Y. Leong, Kumarasen Cooper, F. Joel W.-M. Leong.