Recognition of Immune Response for the Early Diagnosis and Treatment of Osteoarthritis

Abstract

Osteoarthritis is a common and debilitating joint disease that affects up to 30 million Americans, leading to significant disability, reduction in quality of life, and costing the United States tens of billions of dollars annually. Classically, osteoarthritis has been characterized as a degenerative, wear-and-tear disease, but recent research has identified it as an immunopathological disease on a spectrum between healthy condition and rheumatoid arthritis. A systematic literature review demonstrates that the disease pathogenesis is driven by an early innate immune response which progressively catalyzes degenerative changes that ultimately lead to an altered joint microenvironment. It is feasible to detect this infiltration of cells in the early, and presumably asymptomatic, phase of the disease through noninvasive imaging techniques. This screening can serve to aid clinicians in potentially identifying high-risk patients, hopefully leading to early effective management, vast improvements in quality of life, and significant reductions in disability, morbidity, and cost related to osteoarthritis. Although the diagnosis and treatment of osteoarthritis routinely utilize both invasive and non-invasive strategies, imaging techniques specific to inflammatory cells are not commonly employed for these purposes. This review discusses this paradigm and aims to shift the focus of future osteoarthritis-related research towards early diagnosis of the disease process.

Monocyte activation is elevated in women with knee-osteoarthritis and associated with inflammation, BMI and pain

“…Many depletion studies additionally deplete monocytes, and thus likely reduce osteoclast numbers and bone resorption. Subchondral bone remodeling and innate immune infiltration are highest during early OA 17 . This body of data suggests that monocytes and their downstream progeny (i.e., osteoclasts and synovial macrophages) drive OA disease pathogenesis.…”

Ion channel expression and function in normal and osteoarthritic human synovial fluid progenitor cells

“…Early diagnosis may be able to predict the onset of OA before pain and macroscopic cartilage damage has occurred, allowing for better management of the disease and potentially even delayed progression. 3 Normally, the synovium plays a role in maintaining health of articular cartilage through nourishment and lubrication, however, the synovium and synovial fluid also contain resident synovial fluid mesenchymal progenitor cells (sfMPCs) that have the ability to differentiate into bone, fat, and cartilage. 4 In OA, our lab and others have shown that sfMPCs have increased proliferative but reduced chondrogenic capacities.…”

Targeting formyl peptide receptor 1 of activated macrophages to monitor inflammation of experimental osteoarthritis in rat

“…As a leading cause of hospitalization, clinical OA affects up to 30 million people in the United States, leading to significant disability, reduction in quality of life, and ultimate joint replacement . Although OA was originally considered a wear and tear, non‐inflammatory disease, recent research has revealed that synovial inflammation, immune cells, cytokines, chemokines, and complement are involved in the pathogenesis of this disease . It is therefore important to detect inflammatory events of OA for diagnosing and monitoring its progression.…”