Marker discrepancy as a diagnostic criterion for lymphoid neoplasms.

Multimarker studies were conducted on 195 lymph node, 59 bone marrow, 44 peripheral blood, eight body fluid, and eight internal organ specimens. The markers were identified by fluorochrome-labeled antibodies quantified with flow cytometry. T-cell receptor gene rearrangements were used for the determination of T-cell clonality. These studies confirmed that CD 19 (B4, Leu 12) is highly sensitive for B-lymphoblastic leukemia, CD 7 (Leu 9) is highly sensitive for T-lymphoblastic leukemia, and CD 5 (Leu 1) is highly sensitive for chronic lymphocytic leukemia. When these markers were compared to antigens of the same cell lineage (e.g., CD 19 to CD 20 [Leu 16] or to surface immunoglobulin, CD 7 to CD 3 [Leu 4], and CD 5 to CD 3), a marked discrepancy between them was diagnostic of the corresponding tumor. T-cell marker discrepancy (CD3 vs. CD 7) was demonstrated in T-cell lymphomas, but it was also shown occasionally in polyclonal T-cell populations. On the other hand, a marked discrepancy between the percentages of a B-lineage (CD 19 or CD 20)-positive and a surface-immunoglobulin-positive population is a reliable phenotype for the diagnosis of a surface-immunoglobulin-negative B-cell lymphoma.