Hematic levels of type I collagen C-telopeptide in erosive versus nonerosive osteoarthritis of the hands.

C-telopeptide of type I collagen (CTX I) is considered to be a specific marker sensitive to bone resorption; conversely, type II collagen C-telopeptide (CTX II) is considered to be a useful cartilage marker. CTX I assays in serum and urine samples of patients with various metabolic bone disorders, such as osteoporosis and Paget's disease, have been reported to show increased levels of this collagen fragment. In patients with knee osteoarthritis, a decrease in CTX I and an increase in CTX II were found. Osteoarthritis of the hands is one of the most common forms of osteoarthritis. Erosive osteoarthritis of the hands is a variant entity in which, as a consequence of rapid chondrolysis, bone involvement occurs very early in the process. The aim of this cross-sectional study was to compare CTX I assays in patients with erosive osteoarthritis of the hands versus those with nonerosive osteoarthritis of the hands. From a group of over 200 patients fulfilling the American College of Rheumatology's criteria for hand osteoarthritis, we considered the first 21 consecutive postmenopausal women with hand nodal osteoarthritis and disease duration of > or = 5 years and the first 21 consecutive postmenopausal women additionally presenting central joint erosions and disease duration of > or = 5 years. Our results show that in patients with erosive osteoarthritis, CTX I values are much higher than those in patients with nonerosive osteoarthritis.