Juvenile Idiopathic Arthritis With Associated Inflammatory Bowel Disease and CARD8 Mutation

Area of Science:

• Pediatric rheumatology
• Gastroenterology
• Genetics

Background:

• Juvenile idiopathic arthritis (JIA) affects approximately 1 in 1000 children and can be linked to other inflammatory conditions like inflammatory bowel disease (IBD).
• Genetic factors, including mutations in CARD8, are implicated in IBD pathogenesis, with CARD8 regulating the NLRP3 inflammasome and potentially influencing gastrointestinal inflammation.
• Previous studies on the association between CARD8 mutations and IBD are limited in scope and patient numbers.

Observation:

• A 7-year-old female presented with symptoms of JIA, including arthritis and rash, initially showing limited response to methotrexate.
• Further investigations revealed sacroiliitis, elevated inflammatory markers, and a CARD8 variant of unknown significance.
• The patient's condition progressed to severe gastrointestinal symptoms, including diarrhea and hematochezia, with markedly elevated fecal calprotectin levels, leading to a diagnosis of IBD consistent with Crohn's disease.

Findings:

• The pediatric patient diagnosed with IBD-associated arthritis was found to have a CARD8 mutation.
• The patient responded well to treatment with Adalimumab, indicating the effectiveness of biologic therapy in managing this condition.
• This case underscores the potential association between CARD8 mutations and the development of IBD, particularly when presenting with arthritis.

Implications:

• This case highlights the importance of considering IBD in pediatric patients with arthritis, especially when genetic predispositions like CARD8 mutations are present.
• The findings suggest that genetic screening for CARD8 mutations may be beneficial in diagnosing and managing pediatric IBD-associated arthritis.
• Further research into the role of CARD8 in IBD pathogenesis is warranted to improve diagnostic and therapeutic strategies for affected children.