Detection of myeloperoxidase activity in primary leukemic cells by an enhanced chemiluminescent assay for differentiation between acute lymphoblastic and non-lymphoblastic leukemia

Abstract

Background Myeloperoxidase (MPO) plays a crucial role in the differentiation of acute lymphoblastic leukemia (ALL) and acute non-lymphoblastic leukemia (ANLL). In this report, we proposed the application of the enhanced chemiluminescent (ECL) technique to the determination of MPO activity in blasts of acute leukemia (AL). Methods Bone-marrow samples were obtained from 23 patients with AL (ALL, 5 cases; ANLL, 13 cases; AUL, 1 cases; mixed-lineage AL, 4 cases). Cells were incubated with a standard reaction mixture and chemiluminescence was measured. The mean peak light emission (PLE) was assessed. Results When the cut-off point of PLE was settled at 2483, which was set for the discrimination between ANLL and ALL (mean + 3 × SD of ALL samples, n = 5), all cases of ALL were MPO-negative, and ten of the thirteen ANLL patients were MPO-positive, which was concordant with cytochemical staining. In addition, this technique was able to demonstrate MPO activity in 4 mixed-lineage AL cases which did not stain for MPO in cytochemistry preparations. Conclusions Our ECL technique is simple, inexpensive, and easier to perform compared to other procedures used to measure MPO activity in AL.