CD79a detected by ZL7.4 separates chronic lymphocytic leukemia from mantle cell lymphoma in the leukemic phase

Cytometry. 1999 Jun 15;38(3):102-5.


Both B-cell chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL) are characterized by a lymphoproliferation of neoplastic CD5+ B-cells, but an accurate differential diagnosis between these two malignancies is vitally important for guiding treatment options. Because CD79a has been identified as a pan-B marker, we intended to use it in place of CD19 to identify B-cells and to use CD23 to distinguish between CLL and MCL in the leukemic phase. Anti-CD79a (clone ZL7.4) was used to detect the Igalpha/mb1 protein in fresh CD5+ B-lymphocytes by dual-channel flow cytometry. Expression of CD19 and CD23 were similarly assessed. As expected, CD19 was expressed in all specimens, whereas CD23 expression was zero in 3/4 MCLs, weak in 1/4 MCLs, and 2/8 CLLs (10-19%) and stronger in 6/8 CLLs (> or =45%). However, although all the CD19+/CD5+ cells of MCL expressed high CD79a levels, CD79a expression was negligible or absent in 8/8 CLL specimens (mean positivity for CD79a = 2.41 +/- 2.71%). CD79a (ZL7.4) levels may provide a more reliable distinction than CD23 levels between CLL and MCL. If these results hold up in a larger series, we recommend that the ZL7.4 antibody should be considered in routine marker panels for CLL and low-grade lymphoma.

MeSH terms

  • Aged
  • Antibodies, Monoclonal / immunology
  • Antigens, CD / analysis*
  • Antigens, CD / biosynthesis
  • Antigens, CD / immunology
  • CD79 Antigens
  • Diagnosis, Differential
  • Humans
  • Leukemia, Lymphocytic, Chronic, B-Cell / diagnosis*
  • Leukemia, Lymphocytic, Chronic, B-Cell / immunology
  • Lymphoma, Non-Hodgkin / diagnosis*
  • Lymphoma, Non-Hodgkin / immunology
  • Middle Aged
  • Receptors, Antigen, B-Cell / analysis*
  • Receptors, Antigen, B-Cell / biosynthesis
  • Receptors, Antigen, B-Cell / immunology


  • Antibodies, Monoclonal
  • Antigens, CD
  • CD79 Antigens
  • CD79A protein, human
  • Receptors, Antigen, B-Cell