OBJECTIVETo determine the circulating matrilin-1 levels in adolescent idiopathic scoliosis (AIS), and to investigate its potential role in etiopathogenisis of AIS.

METHODSThis study population consisted of 25 patients with AIS from June 2006 to March 2007 and 25 age-matched normal controls. All subjects of the study met the following criteria: no evidence of bone diseases, metabolic diseases or growth disturbances; no evidence of systemic illness or other condition known to affect bone metabolism; and no history of recent steroid intake and surgery of congenital cardiopathy. The maximum Cobb angle and curve pattern of AIS group were recorded. All AIS patients were categorized by progressive and non-progressive groups. Progression to a severe curve was defined per usual clinical criteria (progression to a > 40 degrees curve in an individual still growing or progression to a > 50 degrees curve in an adult). Measurements of genotype by PCR-RFLP methods and circulating matrilin-1 by ELISA assay were performed in both AIS and control groups. The circulating matrilin-1 levels were compared between AIS and control groups, and also among different genotype individuals. The relationship between matrilin-1 levels and cure progression were also analyzed.

RESULTSCompared with control group, a marked decrease of plasma matrilin-1 levels was found in AIS groups (P = 0.0002). Matrilin-1 levels of both AIS and control groups with GG genotype tended to be lower than with AA and AG genotypes, and this trend was stronger in AIS groups. Compared with non-progressive AIS group, plasma matrilin-1 levels in progressive AIS group were significantly lower.

CONCLUSIONSThere is an association between matrilin-1 levels and curve progression. Measurement of circulating matrilin-1 levels is helpful for early screening and diagnosis of AIS, and it may be considered as an independent index to predict curve progression.