Summary about Disease
Interleukin-1 Receptor-Associated Periodic Syndrome (CAPS) is a group of rare, inherited autoinflammatory diseases. These diseases are characterized by recurrent episodes of fever, rash, joint pain, and other inflammatory symptoms. The severity of CAPS varies widely, ranging from mild (Familial Cold Autoinflammatory Syndrome, FCAS) to severe (Chronic Infantile Neurological Cutaneous and Articular syndrome, CINCA/NOMID). The underlying cause is a genetic mutation affecting the NLRP3 gene, which leads to overproduction of interleukin-1 beta (IL-1β), a powerful inflammatory protein.
Symptoms
Symptoms of CAPS can vary in severity and combination, but common ones include:
Fever: Recurrent episodes of fever.
Rash: Urticaria-like rash (hives), often non-itchy.
Joint Pain: Arthralgia (joint pain) or arthritis (joint swelling and inflammation).
Fatigue: Extreme tiredness and lack of energy.
Eye Inflammation: Conjunctivitis (redness and irritation of the eyes).
Headaches: Frequent or severe headaches.
Neurological Issues (especially in severe forms): Meningitis (inflammation of the membranes surrounding the brain and spinal cord), hearing loss, cognitive impairment, developmental delays.
Other: Muscle pain, abdominal pain, swollen lymph nodes.
Cold-Triggered Symptoms (in FCAS): Symptoms exacerbated by cold exposure.
Causes
CAPS is caused by mutations in the NLRP3 gene (also known as CIAS1). This gene provides instructions for making a protein called cryopyrin, which is part of the inflammasome. The inflammasome is a complex that activates interleukin-1 beta (IL-1β). Mutations in NLRP3 cause the inflammasome to become overactive, leading to excessive production of IL-1β, which triggers inflammation throughout the body. The disease is usually inherited in an autosomal dominant pattern, meaning only one copy of the mutated gene is needed to cause the condition. However, some cases occur due to spontaneous (de novo) mutations.
Medicine Used
The primary treatment for CAPS involves medications that block the action of interleukin-1 beta (IL-1β). These include:
Anakinra (Kineret): A daily injection that blocks IL-1β.
Canakinumab (Ilaris): A subcutaneous injection given less frequently (typically every 8 weeks) that neutralizes IL-1β.
Rilonacept (Arcalyst): A weekly subcutaneous injection that also blocks IL-1β. These medications are highly effective in controlling the symptoms of CAPS and preventing long-term complications.
Is Communicable
No, CAPS is not communicable. It is a genetic disorder and cannot be spread from person to person.
Precautions
For individuals with CAPS:
Adherence to Medication: Strict adherence to prescribed medication is crucial for managing symptoms and preventing complications.
Avoidance of Triggers: Identifying and avoiding triggers, such as cold exposure (especially for FCAS), can help minimize symptom flares.
Regular Medical Follow-up: Regular visits to a rheumatologist or other specialist experienced in managing CAPS are essential for monitoring the disease and adjusting treatment as needed.
Genetic Counseling: Genetic counseling is recommended for individuals with CAPS and their families to understand the inheritance pattern and the risk of passing the condition on to future generations.
Vaccinations: Following recommended vaccination schedules is important, but consulting with a doctor about specific vaccines is advised, as some vaccines may trigger flares in some individuals.
How long does an outbreak last?
The duration of an outbreak can vary depending on the specific type of CAPS and the individual.
FCAS (Familial Cold Autoinflammatory Syndrome): Episodes often last for 12-24 hours after cold exposure.
MWS (Muckle-Wells Syndrome): Episodes may last for several days to weeks.
CINCA/NOMID (Chronic Infantile Neurological Cutaneous and Articular syndrome): This is the most severe form, and symptoms are often chronic and persistent, with less distinct "outbreaks." The length and severity of outbreaks are significantly reduced with effective treatment.
How is it diagnosed?
Diagnosis of CAPS typically involves:
Clinical Evaluation: Assessment of symptoms, medical history, and family history.
Blood Tests: Elevated inflammatory markers (e.g., ESR, CRP) are often present.
Genetic Testing: Confirmation of a mutation in the NLRP3 gene.
Imaging Studies: May be used to assess joint damage or other organ involvement.
Timeline of Symptoms
The onset of symptoms varies depending on the specific CAPS subtype:
FCAS: Symptoms typically begin in infancy or early childhood, often triggered by cold exposure.
MWS: Symptoms usually appear in childhood or adolescence.
CINCA/NOMID: Symptoms are often present from birth or early infancy. The course of the disease is generally chronic, with recurrent episodes of inflammation throughout life if untreated. With appropriate treatment, symptoms can be well-controlled, and the risk of long-term complications can be reduced.
Important Considerations
Early Diagnosis and Treatment: Early diagnosis and initiation of treatment are crucial for preventing long-term complications, such as hearing loss, amyloidosis (abnormal protein deposits in organs), and joint damage.
Multidisciplinary Care: Management of CAPS often requires a multidisciplinary approach involving rheumatologists, geneticists, ophthalmologists, neurologists, and other specialists.
Disease Monitoring: Regular monitoring for complications, such as hearing loss and kidney problems, is essential.
Personalized Treatment: Treatment plans should be individualized based on the severity of the disease and the individual's response to therapy.
Quality of Life: Effective management of CAPS can significantly improve the quality of life for affected individuals.