# Chronic inflammatory arthritis in 22q11.2 deletion (DiGeorge) syndrome: a multicentric study

## TL;DR

This study explores chronic arthritis in patients with 22q11.2 deletion syndrome, finding it to be a distinct and severe condition differing from typical juvenile arthritis.

## Contribution

The study identifies unique clinical features of arthritis in 22q11.2 deletion syndrome, suggesting it is a distinct entity.

## Key findings

- Arthritis in 22q11DS is aggressive, with a severe and prolonged course.
- It lacks typical markers like CCP and RF antibodies and rarely involves uveitis.
- Most patients required ongoing treatment, with half still active at last follow-up.

## Abstract

22q11 deletion syndrome (22q11DS) is a genetic disorder caused by a deletion at chromosome 22q11.2. Chronic arthritis may be occasionally observed in these, if this manifestion represents a concomitant association of two diseases or a rare complication of Di George syndrome is still a debate. This study aims to describe a retrospective, multicenter analysis of patients with 22q11DS, who developed chronic inflammatory arthritis, focusing on clinical presentation, diagnosis, and management.

An e-mail survey was distributed to pediatric centers, identifying patients diagnoses with both 22q11DS and chronic arthritis from 1992 to 2024. The clinical course was documented through medical record review.

A total of 30 patients were identified with a female predominance (20 cases). The median age at 22q11DS diagnosis was 12 months, and 3 years at arthritis onset. Polyarticular involvement was observed in 50.0% of patients, and the median number of affected joints at onset among all patients was 4.5 (range 1–25). Only one child developed uveitis. Erythrocyte sedimentation rate was elevated in 72.0% of tested patients, and C-reactive protein in 83.3%. Antinuclear antibodies was negative in 23.3% of patients, while rheumatoid factor (RF) and cyclic citrullinated peptide (CCP) antibodies were consistently negative. Treatment included systemic glucocorticoids (53.3%), methotrexate (66.6%), and biologic agents (56.7%). Infections were generally mild, primarily affecting the respiratory tract. At last follow-up, arthritis persisted active in 53.3% of cases, with 78.6% of those in remission still on medication.

Arthritis in 22q11DS appears to be a distinct clinical entity characterized by an aggressive phenotype and a severe, prolonged course, typically lacking CCP and RF antibodies and rarely associated with uveitis. These features suggest a distinct clinical entity, diverging from classical juvenile idiopathic arthritis.