On 29 August at 14:00 Liisa Kuhi will defend her doctoral thesis “A contribution of biomarker collagen type II neoepitope C2C in urine to the diagnosis and prognosis of knee osteoarthritis”.
Supervisors:
Professor Kalle Kisand, University of Tartu
Professor emeritus Agu Tamm, University of Tartu
Opponent:
Professor Stefan Lohmander, Lund University (Sweden)
Summary
Osteoarthritis (OA) is the most common joint disease, affecting about half a billion people worldwide. The knee is one of the main sites of impairment. According to the new approach to the disease, the alterations develop from the molecular level to structural changes in tissues (cartilage, bone, synovium, meniscus, ligaments). OA is a disease with an alternating course, with no signs of disease at an early stage. Therefore, molecular markers that reflect changes in tissue metabolism provide an early warning of tissue damage, an opportunity to assess the course of the disease, and a response to future treatment. Because type II collagen (Col2) is a major structural component of cartilage, several tests have been developed to measure Col2 degradation. In the current study, we evaluated the potential use of a new OA biomarker, C2C, in knee OA (kOA). uC2C is a Col2 cleavage neoepitope in urine. We compared uC2C values with X-ray findings, direct visual assessment of cartilage, and clinical status using different statistical models. uC2C is a good candidate for the development of an early diagnostic test for kOA. The level of uC2C is increased in the early stages of kOA and is related to several main processes of kOA: the cartilage lesions and the osteophytes in distinct knee compartments. uC2C is a good marker of progression in women–a higher baseline uC2C is an excellent predictor (> 90%) of the initiation or worsening of kOA over the next 3 years. uC2C is higher in higher X-ray grades, so uC2C levels are associated with the severity of kOA. uC2C values are highest in patients with end-stage kOA who reach joint replacement at a relatively young age (50-70 years). After knee replacement, urinary excretion of C2C may decrease, increase, or remain unchanged. Thus, in many cases, joint replacement does not stop the breakdown of Col2 in the body, and OA is a more systemic disease than previously thought. uC2C appears to be a better biomarker of pOA in women than in men.