Abstract

Zinc alpha-2-glycoprotien (ZAG) binding peptide is a multi-functional protein, which is structurally similar to a major histocompatibility complex class I. It has been discovered as a novel adipokine enhancing lipolysis and influencing other physiological processes such as sperm mobility and melanin production. Furthermore, ZAG level has been correlated to a variety of diseases such as atherosclerosis and diabetes type II with a potential use as a tumor biomarker in future. In this study, we aim to investigate the prevalence of ZAG among healthy blood donors attending to the Sultan Qaboos University Hospital blood bank and correlate it with their age and sex. The ZAG levels analysis of the sera from 106 (49 females and 57 males) apparently healthy donors from different regions was carried out using a competitive type of enzyme-linked immunosorbent assay (ELISA) (Abnova GmbH-Germany). Analysis was mainly based on two parameters; age and sex. Out of the 106 subjects, 78% of blood donors have high ZAG levels (>35 ng/ml), 13% have a normal level (20 to 35 ng/ml) while 9% have a level lower than 20 ng/ml. A significant association was found between ZAG level and sex (P = 0.012) with males showing low levels. Although high ZAG level was correlated between age and ZAG levels in the female group, higher levels were also found in donors below and above 22 years old (P = 0.0099). The prevalence of ZAG levels in blood donors was found to be high, especially in those between 20 to 30 years old. This emphasizes the measurement of ZAG level prior to blood transfusion to patient(s) who are clinical under weight. Gender and age significantly influences the plasma level of ZAG.

Key words: Zinc alpha-2-glycoprotien (ZAG), Oman, Sultan Qaboos University Hospital (SQUH), blood donation.