AN ASSOCIATION BETWEEN AN AGGRECAN POLYMORPHIC ALLELE AND BILATERAL HAND OSTEOARTHRITIS IN ELDERLY WHITE MEN - DATA FROM THE BALTIMORE LONGITUDINAL-STUDY OF AGING (BLSA)

Objective: The aggrecan proteoglycan is a major component of articular cartilage and supports the biomechanical function of this tissue. A v ariable number tandem repeat (VNTR) polymorphism has been discovered r ecently in a region of the human aggrecan gene that codes for the chon droitin sulfate attachment sites. We examined whether alleles of this polymorphism displayed a non-random association with bilateral hand or knee osteoarthritis (OA) in men from the Baltimore Longitudinal Study of Aging (BLSA). Design: DNA was obtained from 93 Caucasian men, aged 60 and above, who had bilateral hand and standing knee radiographs re ad for changes of OA. The DNA was analyzed by polymerase chain reactio n (PCR) and/or Southern blotting for the presence of the VNTR alleles. Results: Bilateral hand OA and knee OA were present in 46 and 30% of the men respectively. The following distribution of alleles was observ ed: allele 33 (0.5%), 29 (2.2%), 28 (31.7%), 27 (43.0%), 26 (16.7%), 2 5 (3.2%), 22 (2.2%) and 19 (0.5%). This distribution was similar to th at detected in a random population of individuals from a separate stud y. In multiple logistic regression analysis, adjusting for age and bod y mass index, the presence of allele 27 was associated with bilateral hand OA with an odds ratio (OR) = 3.23 (95% confidence intervals (CI): 1.24-8.41). No other alleles showed an association with bilateral han d OA and the association between allele 27 and bilateral knee OA was n ot statistically significant (OR = 1.14; 95% CI: 0.45-2.88). Conclusio ns: These data demonstrate the first association between a human aggre can gene polymorphic allele and hand OA. This finding supports the con cept that genetic factors may play a role in the development and/or pr ogression of some forms of age-onset OA.