The nondeleted allele of the CAR and EST70/Leu1 genes was expressed in B-CLL specimens, including those with monoallelic loss, whereas no expression of 1B4/Leu2 was detectable in B-CLL, regardless of the 13q14 status.
Since their putative involvement in B-CLL was controversial, our present study provide support for reconsidering the DLEU1 and DLEU2 genes as B-CLL candidate genes, with a new definition of their organisation and context.
The first exons of two genes, Leu1 and Leu2, mapped in a minimally deleted 13q14.3 region, are systematically lost in B-CLL sharing a 13q14.3 deletion.
Flow cytometric analysis of forward- and right-angle light scatters demonstrated the presence of two populations of cells, one lymphoid, bearing predominantly lambda light chain surface immunoglobulin and showing phenotypic characteristics of B cell chronic lymphocytic leukemia (HLA-DR-positive, BL-1-positive, BL-2-positive, BL-7-positive, Leu-1-positive, Leu-10-positive, BL-5-negative, BL-6-negative, and OKM1-negative), and another granulocytic population expressing phenotypic features compatible with myeloid lineage (HLA-DR-negative, Leu-1-negative, BL-1-negative, BL-2-negative, BL-7-negative, Leu-10-negative, BL-5-positive, BL-6-negative, OKM1-positive, and surface immunoglobulin-negative).