The Effect of Coenzyme Q10 Supplementation on the Clinical Outcome of Juvenile Idiopathic Arthritis Patients

Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatological disorder in childhood of unknown etiology and a major cause of functional disability. It has a prevalence rate of about 1/1000 worldwide. The American College of Rheumatology (ACR) defines JIA as inflammation in one or more joints of unknown etiology with onset prior to age 16 years and a minimum of 6 weeks duration, following the exclusion of other known causes of synovitis. The International League of Associations for Rheumatology criteria classifies JIA into several different subgroups depending on the number of joints affected, presence of extra-articular manifestations such as uveitis or glomerulonephritis, systemic symptoms, serology and genetic factors. Peripheral arthritis is the common predominant clinical presentation among the various types. The three main types of JIA are polyarticular, oligoarticular, and systemic JIA. Therefore, diagnosis of JIA depends on physical findings, medical history, and the exclusion of other diagnoses.

The main hallmark of JIA is joint inflammation with bone resorption and tissue destruction.

This chronic inflammation limits the daily activities and productivity of patients. Interleukin-1 (IL-1), IL-6, IL-17, and tumor necrosis factor-α (TNF-α) are inflammatory cytokines that play an important role in the pathogenesis, prognosis, disease activity, and systemic features of JIA. Additionally, abnormal activation of T-cells, B-cells, natural killer (NK) cells, dendritic cells (DC), macrophages and neutrophils contribute to the pathogenesis of JIA.

All medications used to treat JIA including nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids, methotrexate, and biological agents have considerable adverse effects in addition to the high cost of the biologics. Also, despite the success of these treatment approaches, patients may still have active disease with other sequelae from chronic inflammation and considerable morbidity that may negatively impact patients' quality of life. Therefore, evaluating the potential benefit of alternative add-on anti-inflammatories and antioxidants might be a promising area for further research.

Coenzyme Q10 (CoQ10) is a mitochondrial electron carrier and a powerful lipophilic antioxidant located in almost all cell membranes and plasma lipoproteins. It can be found naturally and acquired from the diet or synthesized in-vivo by all cells of the body. Various in-vitro and animal studies have demonstrated the antioxidant and anti-inflammatory effect of CoQ10.7 This has raised interest in its therapeutic potential against pathologies related to mitochondrial dysfunction and enhanced oxidative stress such as systemic autoimmune diseases.