CD79a in cases of acute leukemia

ABSTRACT

Immunoglobulins IgM and IgD on the plasma membrane of B lymphocytes lack a cytoplasmic region of sufficient size to react with other molecules in order to transmit a signal through these cells. It has been demonstrated that a dimeric molecule with a substantial intra-cytoplasmic region named CD79 is physically associated with membrane Igs and helps to initiate intracellular signaling. The two component polypeptide chains of this dimeric molecule have been designated CD79 alpha C [mb-1] and CD79 beta 3 [B29]. The aim of the present work was to study the value of CD79alpha as a diagnostic marker in cases of acute leukemia. Our patients were classified into 2 groups, group I included 20 patients with ALL and group II included 20 patients with AML. Immunophenotyping of the leukemic blasts was carried out using flow cytometry and CD79 alpha was studied. We found that 91.7% of our B-lineage ALL cases were positive for CD79 alpha. Also, CD19 was positive in 100% and CD22 in 75%. All of our T-ALL cases were negative for CD79 alpha and only one case of AML showed positive CD79 alpha expression [5%]. The sensitivity of CD 79 alpha in the diagnosis of B-ALL among all of our ALL patients was 91.7%, the specificity was 100%, the positive predictive value [PPV] was 100% and the negative predictive value [NPV] was 88.9%. The sensitivity of CD79 alpha in the diagnosis of B-lineage ALL among all of our acute leukemia patients was 91.7%, the specificity was 96.4%, the PPV was 91.7% and the NPV was 96.4%