Prediction of interferon therapy efficacy in chronic myeloid leukemia according to histomorphological evidence

Aim. To investigate factors determining prognosis and efficacy of induction therapy including interferon-alpha-2b (intron-A, Schehng Plough) in patients at an early chronic stage of Ph-positive chronic myeloid leukemia (CML) as shown by histomorphological examination. Material and methods. The analysis covered 52 CML patients treated at an early chronic phase with intron-A in a standard daily dose 5 IU/m2 in combination with low-dose cytosinearabinoside (10 mg/m2, s.c. , daily for 10 days of each month). The treatment efficacy was assessed by the international criteria of complete and partial hematological remission and cytogenetic response. The cytogenetic study employed the direct method, even and G-differential staining, fluorescent hybridization in situ (FISH). The sections were stained with hematoxilin-eosine by Gomori, van Gieson. Histological samples were examined with histomorphometry. Immunohistochemical examination was made on paraffin sections using a panel of monoclonal antibodies CD3, CD4, CDS, CD20, NK, PCNA, Ki-67 (Dako, Denmark). Results. Repeated assessment of histomorphological parameters such as erythroid lineage, degree of myelofibrosis and reduction of leukemic population indicate the treatment efficacy. Estimation of the level of leukemic population proliferation in trephine biopsies from CML patients with monoclonal antibodies PCNA and Ki-67 before the treatment is prognostically significant as it further correlates with the cytogenetic response (r = 0.821, p = 0.000000). Conclusion. It is valid to study histomorphological picture of CML to prognosticate and assess treatment efficacy with standard doses of interferon-alpha with high probability.