Cryopyrin-Associated Periodic Syndromes (CAPS) comprise three related conditions: Familial Cold Autoinflammatory Syndrome Type 1 (FCAS1), Muckle-Wells Syndrome, and Neonatal-Onset Multisystem Inflammatory Disorder (NOMID). These disorders were previously considered distinct but are now recognized as a spectrum with varying severity levels. CAPS involves recurring skin rash, fever, and joint pain triggered by cold exposure, stress, or spontaneously.
- FCAS1:Cold-triggered rash, pain, chills, fever, muscle aches, drowsiness, eye redness, headache, and nausea.
- MWS: Rash, fever, joint pain, hearing loss, skin lesions, and kidney damage (amyloidosis).
- NOMID: Skin rash, fever, joint inflammation, cognitive impairments, chronic meningitis, eye problems, and organ damage.
Due to mutations in the NLRP3 gene, CAPS is caused, which encodes the cryopyrin protein. Cryopyrin plays a role in the immune system’s inflammatory response by assembling an inflammasome, a molecular complex. Mutations in NLRP3 lead to an overactive cryopyrin, triggering excessive and inappropriate inflammation, which results in the characteristic CAPS symptoms.
Diagnosing CAPS involves:
Clinical Evaluation: Assessing recurring symptoms of rash, fever, and joint pain, along with their triggers.
Genetic Testing: Identifying mutations in the NLRP3 gene through genetic analysis.
Inflammatory Markers: Inflammation is confirmed by elevated inflammatory markers such as serum amyloid A (SAA) and C-reactive protein (CRP).
- Managing CAPS focuses on reducing symptoms and inflammation. Treatment options include:
- IL-1 Antagonists: Drugs like Kineret (anakinra) block IL-1 signaling, effectively managing symptoms.
- Other Biologics: Medications like canakinumab and rilonacept also target inflammation and show promise.
- Symptom Relief: Pain relievers, antihistamines, and supportive care alleviate discomfort.
- Early Intervention: Timely treatment minimizes complications like amyloidosis and improves quality of life.