Abstract:

BACKGROUND: Current approaches for diagnosis of osteoarthritis include imaging and arthroscopy. However, both of them have some limitations. Therefore, a specific, sensitive, high diagnostic rate and operable method is needed.
OBJECTIVE: To explore the relationship between the level of EKGPDP peptide in urine and the severity of cartilage degradation in knee osteoarthritis patients. 
METHODS: A total of 60 patients with knee osteoarthritis (KOA), including 45 undergoing joint debridement and 15 undergoing knee replacement, were selected from Department of Orthopaedics, Fourth People’s Hospital of Shenzhen (Futian Hospital, Guangdong Medical University) between January 2006 and April 2008. In addition, 40 healthy volunteers were selected as controls. The EKGPDP peptide concentration in urine was measured with competitive enzyme-linked immunoassay (ELISA). The pathologies of the synovium and cartilage in knee osteoarthritis were observed with arthroscopy; the degree of synovitis and cartilage degradation under arthroscopy was graded with Ayral’s score system and Outbridge’s score system, respectively.
RESULTS AND CONCLUSION: EKGPDP peptide level in KOA was greater than control group (P < 0.001). The EKGPDP peptide level in KOA was correlated positively with Outbridge’s score and body mass index (P < 0.001), but had no correlation with accumulative Ayral’s score (P > 0.05). Half a year after total knee replacement, the level of EKGPDP peptide decreased significantly (P < 0.05); arthroscopic debridement remained unchanged (P > 0.05). The EKGPDP peptide level in urine can reflect the degree of cartilage degradation, and it is a sensitive marker for the diagnosis of KOA.