Growth hormone binding protein and acid labile subunit levels in the assessment of acromegaly treatment

Abstract

Post-treatment monitoring of acromegalic patients is a matter of controversy, as discrepancies between GH and IGF-I levels have been reported. The aim of our study was to evaluate the role of acid-labile subunit (ALS), a component of the 150 kD IGF-I/IGFBP-3/ALS complex, and the growth hormone binding protein (GHBP) in the follow-up of patients with acromegaly after therapeutic intervention. Forty-one patients with acromegaly, 10 at the time of diagnosis and 31 post therapeutic intervention, were studied. Patients were evaluated by the determination of baseline (fasting) IGF-I, ALS and GHBP and of glucose and GH during OGTT. Significantly lower ALS and higher GHBP levels were detected in successfully treated acromegalics compared to patients before treatment (34.1+/-1.6 vs. 52.8+/-2 mg/L and 0.9+/-0.08 vs 0.4+/-0.1 ìg/L, respectively P<0.05). Furthermore, no difference was noted in ALS and GHBP values between patients successfully treated with either somatostatin analogues or another type of treatment. a) Successfully treated acromegalic patients demonstrate lower ALS and higher GHBP levels than patients before treatment, and b) somatostatin analogue treatment does not have a direct effect on GHBP and ALS concentration in acromegaly. Studies in larger groups of patients are needed to disclose whether these alterations will be useful in the post-treatment assessment of acromegalic patients.