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

✍ Scribed by Philip B. Bell; Nicholas Rooney; Andrew G. Bosanquet

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 92 KB
• Volume: 38
• Category: Article
• ISSN: 0196-4763
• DOI: 10.1002/(sici)1097-0320(19990615)38:3<102::aid-cyto2>3.0.co;2-0

✦ Synopsis

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 Ig␣/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 (H45%). 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.