Clinical value of serum interleukin-3 and bone marrow iron stores in chronic myeloid leukaemia : correlation with disease status

Abstract EN

Background : Chronic myeloid leukaemia (CML) represents a paradigm of a stepwise increment in disease aggressiveness, resistance to conventional therapy and transformation into an ultimate dramatic end.

Many prognostic models and staging systems have been advocated in order to categorize patients who will run a chronic disease and those who will enter into the accelerated and final blastic phase.

Aim : The present study aimed at estimating serum levels of Interleukin-3 (IL-3) and bone marrow iron stores in relation to disease status in patients with CML.

Subjects and Methods: Forty consecutive patients were enrolled in the study : 20 in the chronic phase (Group I) and 20 in the advanced stage (accelerated and blastic phases) (Group II).

Clinical examination and complete blood counts were done for all patients as well as Sokal staging and Euro scoring.

By Sokal staging, 18 patients were in stage 1, 2 in stage 2 and 20 in stage 3.

By Euro scoring, 7 patients were at low risk, 13 at intermediate risk and 20 at high risk.

Patients were subjected to bone marrow examination, iron staining of bone marrow smears by Prussian blue stain for quantitation of sideroblast percent, demonstration of the BCR-ABL fusion gene by RT-PCR and estimation of serum level of IL-3 by enzyme linked immunosorbent assay (ELISA).

Ten healthy individuals’ age and sex matched were included as a control for IL-3 asssay.

Results : A statistically significant higher mean sideroblast percent was found in group II versus group I (t = 6.196, p = 0.000).

Similarly, the highest statistically significant mean sideroblast percents was found in Sokal stage 3 (F = 21.09, p = .000) and in high risk patients by Euro score (F = 14.94, p = 0.000).The median serum Il-3 was increased in group I with statistically significant value when compared to group II and the control (U = 32.82, p = 0.000).

Patients at Sokal stage 2 had the highest statistically significant value (x 2 = 14.397, p = 0.001).

By Euro score, the intermediate risk group had the highest median IL-3 level, and it was statistically significant (x2 = 10.141, p= 0.006).

Serum IL-3 levels were positively correlated with blast percentage in peripheral blood in group I(r = 0.534, p = 0.01).

However, in group II a statistically significant negative correlation was observed between serum IL- 3 and blast percentages both in peripheral blood and bone marrow r=- 0.824, p = 0.044 and r =-0.895, p = 0.016, respectively).

Conclusion : Assessing iron stores on bone marrow smears together with estimation of serum levels of IL-3 are valuable prognostic markers for predicting early disease progression in patients with CML.