Author(s)

Haq Nawaz¹, Masood Umer¹, Shahryar Noordin¹, Bo Christer Bertilson², Jian Li³, Aisha Siddiqah Ahmed⁴, Mahmood Ahmed²

¹Department of Surgery, Aga Khan University, Karachi, Pakistan.
²Karolinska Institute, Department of Neurobiology, Care Sciences and Society, Huddinge, Sweden.
³Karolinska Institute, Department of Molecular Medicine and Surgery, Karolinska University Hospital, Stockholm, Sweden.
⁴Karolinska Institute, Department of Clinical Neurosciences, Stockholm, Sweden.

Purpose: The purpose is to study whether pain and inflammation in knee joint osteoarthritis (OA) are associated with local synovial neuronal changes. Methods: Synovial biopsies were harvested from the medial and lateral knee compartments from OA patients undergoing total joint replacement surgery. All patients had predominant pain at the medial joint compartment. Pain and knee joint function were evaluated by knee society score (KSS). Synovial inflammation was analyzed by histopathological analysis and expression of growth associated protein-43 (GAP-43), sensory (SP, CGRP) and autonomic (NPY, VIP, TH) neuropeptides was studied by single and double immunohistochemistry techniques. Results: We observed reduced KSS and increased inflammatory score in synovial membrane of medial knee compartment. A significant increase in GAP-43 [P = 0.001], SP [P = 0.05], CGRP [P = 0.05] and TH [P = 0.05] expression was observed and SP, CGRP and NPY were found to be co-existed predominantly with GAP-43 in synovial membrane collected from medial compared to the lateral knee compartment. Conclusions: Regenerating nerve fibers containing sensory and autonomic neuropeptides are associated with pain and inflammation in knee joint OA.

Osteoarthritis, Knee Joint, Pain, Inflammation, Neuropeptides

Nawaz, H. , Umer, M. , Noordin, S. , Bertilson, B. , Li, J. , Ahmed, A. and Ahmed, M. (2016) Synovial Neuronal Changes in Knee Joint Osteoarthritis. Open Journal of Rheumatology and Autoimmune Diseases, 6, 26-33. doi: 10.4236/ojra.2016.62005.