Association of BCR/ABL transcript variants with different blood parameters and demographic features in Iraqi chronic...

Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm characterized by the presence of BCR-ABL fusion gene (GenBank accession NC_000022.11). In the vast majority of CML patients, the typical subtype of BCR-ABL transcript are b3a2, b2a2 or both. The aim of this study was to determine the different subtypes of BCR-ABL transcript and their impact on the demographic and hematological parameters in Iraqi patients with CML.

One hundred patients with chronic phase CML (11 newly diagnosed and 89 imatinib-resistant) were enrolled in this study. Ribonucleic acid (RNA) was extracted from leukocytes, and complementary DNA was created using reverse transcriptase polymerase chain reaction technique. A multiplex polymerase chain reaction with four specific primers was used to determine the BCR-ABL fusion subtypes in each patient.

Male to female ratio was 1.38:1. Fifty-nine patients expressed b3a2 transcript, whereas 39 of the remaining cases were positive for b2a2 variant. One case expressed b2a3 transcript, while the last case coexpressed the two subtypes of mRNA b3a2/b2a2. Male and female were significantly associated with b3a2 and b2a2 subtypes, respectively. The b3a2 subtype showed higher total leukocyte count than b2a2 subgroup, while b2a2 variant demonstrated significantly elevated platelet counts compared to those with b3a2 transcript. A significantly higher plateletcrit percentage (PCT%) was found in patients with b2a2 transcript whereas.

The testified Iraqi group expressed M-BCR-ABL type with preponderance of b3a2 over b2a2 subtype. There was a gender-skewed distribution in BCR-ABL transcript types with b3a2 transcript more prevalent in males. The type of BCR-ABL transcript is reflected by different leukocyte and platelet counts at diagnosis, which might represent a distinct phenotype and disease biology.