Endocrine Abstracts

Introduction: The number of cells in tissue is governed by two processes – the proliferation and ‘programmed cell death’ – apoptosis. Both processes in the body are controlled by enabling or inhibiting factors that are expressed on the surface of CD25+ and CD95+-lymphocytes. Somatotropin (GH) and insulin-like growth factor 1 (IGF1) stimulate proliferation, differentiation, and division of immune cells simultaneously inhibits their apoptosis and can cause tumor growth in acromegaly.

Aim: To study the expression of CD25+ and CD95+-lymphocytes level depending on the acromegaly stage.

Methods: The study population consist 47 acromegalic patients (38 with active acromegaly and 9 in disease remission, mean age 50.4±12.58, range 27–73 years, the latent period duration of acromegaly was 5.72±5.02 years) and 65 age-matched controls. The surface lymphocytes markers expression was assessed by indirect immunofluorescence method using the FITC-marked monoclonal antibodies to CD25 and CD95. The concentrations of GH and IGF-I were measured by ELISA.

Results: Compared to the control both acromegalics – with active phase and disease remission had significantly higher level of CD25+- (respectively; P<0.001 and P<0.01) and CD95+-lymphocytes (P<0.01 and P<0.05). However it was found that the expression of apoptotic activation markers was higher in patients with disease remission compared to active acromegaly group respectively: CD25+- (median 66.5 vs 37.0%; P<0.05) and CD95+-cells (43.5 vs 18.0%; P<0.05).

Conclusion: Stimulating and antiapoptotic effect of GR/IGF1 in acromegaly simultaneously promotes proliferation and expression of apoptotic activation markers of lymphocytes, but causes an accumulation in the body of acromegalics the long-lived immunoreactive cells. Long-term effects of IGF-I in acromegaly mediate the intensity of proliferation and apoptosis in patients with the disease remission. According to these, it can be suggested that increased oncological risk in active acromegaly patients ongoing even in remission period.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.