Serum Acid-Labile Subunit Is a Good Parameter for Diagnosis of GH Deficiency

Abstract

Acid-labile subunit (ALS) is one of the components of a ternary complex with insulin-like growth factor-I (IGF-I) and IGF binding protein-3 (IGFBP-3) in the circulation. The role of ALS in the circulation is not well known, but the levels of ALS are dependent on GH levels, suggesting that ALS plays an important biological role in the circulation. This study is to research whether serum ALS levels are suitable parameters for the diagnosis of GH deficiency (GHD). In this study, ALS levels were measured by Western immunoblotting in sera from patients with GHD and hypophysectomised (hypox) rats. ALS levels of the patients with GHD were less than 10% of ALS levels of control agematched children and adults. ALS levels of hypox rats were less than 10% of ALS levels of control (non-hypox) rats. The levels were partially reverted towards normal levels after rat GH treatment. Our data suggest that ALS levels are one of the best parameters for the diagnosis of GHD.