Rare Clinical Case of Cryopyrin-associated Periodic Syndrome Presented with Ankylosing Spondylitis: A Case Report.

Background: Cryopyrin-Associated Periodic Syndrome (CAPS) is a variety of clinical variants of autoinflammatory diseases. The pathology is based on a mutation in the NLRP3 gene encoding the cryopyrin protein, which leads to the uncontrolled production of interleukin-1β. Particular attention should be paid to the rarity of this disease and the lack of clinical knowledge about it in therapeutic and rheumatological practice, which leads to an erroneous diagnosis and the appointment of ineffective treatment for a long time, leading to the progression of the disease and disability of the patient.

Case Presentation: This article describes a clinical case of this disease. The first manifestations of the disease in a woman appeared from the age of 2 years, in the form of a rash and fever. Since school age, there have been signs of arthritis. By the age of 24, sensorineural hearing loss and pain in the spine were evident. The disease occurred under the clinical manifestations of spondyloarthritis. Its treatment with anti-inflammatory therapy did not give a stable result.

Conclusion: From the analysis, we can conclude that patient M. from early childhood suffers from a severe Neonatal-onset Multisystem Inflammatory Disease of a genetic nature. For a long time, the patient was diagnosed with ankylosing spondylitis, and appropriate treatment was carried out without significant success. The correct diagnosis of CAPS was made only in 2018. This patient has conditions of both CAPS and AS together, which is a very rare association in rheumatological practice. The only treatment method that could stop the manifestations of the disease and prevent life-threatening kidney damage (amyloidosis) is the use of genetically engineered biological drugs, i.e., IL-1β inhibitors. The only drug of this group registered in Russia is canakinumab (Ilaris®). From the moment of diagnosis to the present day, the patient is treated with the genetically engineered drug canakinumab (Ilaris®) at a dose of 150 mg once every 8 weeks. 6 months after taking the drug, the patient went into complete clinical and laboratory remission.