Migratory and intermittent polyarthritis as an atypical presentation of carnitine palmitoyltransferase II deficiency with positive response to treatment with Interleukin-1 receptor antagonist: a case presentation and case-based review

Carnitine palmitoyltransferase 2 (CPT2) deficiency is an autosomal recessive disorder affecting fatty-acid metabolism that manifests in three phenotypes: lethal neonatal, infantile and adult. In the adult population, CPT2 deficiency is characterized as the commonest cause of recurrent episodes of rhabdomyolysis. Although inflammatory arthritis has not been previously associated with CPT2 deficiency, existing literature suggests a potential mechanism involving synovial inflammation secondary to the accumulation of fatty acids and acylcarnitine. Attacks are most commonly triggered by infections, strenuous exercise, fasting and consumption of a fat-rich meal. Management in typically conservative, involving dietary modification (high-carbohydrate, low-fat diet) and personalized exercise regimens. The following article describes the case of 43-year old male patient with chronic, intermittent arthritis who was diagnosed with CPT2 deficiency and is currently receiving treatment with interleukin 1 receptor antagonist (IL-1Ra). In addition, a case-based review was conducted to evaluate the possible, underlying mechanisms of inflammatory arthritis in patients with CPT2 deficiency, along with any nuances in the treatment strategy. The presented case, along with the associated case-based literature review, highlight the inflammatory changes taking place in the synovial cells upon accumulation of fatty acids and acylcarnitine molecules that release IL-1β. Finally, the report explores potential future therapeutic strategies.