Background: In autoimmune diseases that onset during childhood, the gender disparity is typically less pronounced compared to adulthood, likely due to distinct hormonal environments, with estrogen playing a significant role in autoimmunity development. However, juvenile idiopathic arthritis (JIA) exhibits a notable predilection for girls [1].

Objectives: To understand the potential impact of gender on disease outcomes in JIA, we aimed to investigate the relationship between sex and disease activity and severity in JIA patients.

Methods: We conducted a retrospective study involving JIA patients diagnosed according to the International League of Associations for Rheumatology (ILAR) 2010 diagnosis criteria and followed in our rheumatology department.

For each patient we collected the following data: JIA subtype, age, age at the onset of the disease, disease duration, tender joint count, swollen joint count, clinical enthesitis count, patient and physician Visual Analogue Scale (VAS), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) level, antinuclear antibodies (ANA), human leukocyte antigen B27 (HLA-B27), the presence of uveitis, and the presence of structural damage on imagery.

Disease activity was assessed using the juvenile arthritis disease activity score 10 using normalized ESR (JADAS-10-ESR) for all JIA subtypes and the Juvenile Spondyloarthritis Disease Activity Index (JSpDA) for related-enthesitis arthritis (ERA) and psoriatic arthritis subtypes.

The patients were divided into 2 groups: males (M) and females (F).

Statistical analysis was performed using SPSS software.

Results: In total, 72 patients were included, comprising 37 boys and 34 girls, with a mean age of 13.73±5.06 years. The mean age at the onset of the disease and the mean disease duration of JIA were 9.19±4 years and 4.34±3.6 years, respectively.

Various JIA forms were observed, with systemic JIA in 4 (6%) patients, oligoarthritis form in 15 (21%), polyarthritis with positive rheumatoid factor in 3 (4%), polyarthritis with negative rheumatoid factor in 5 (7%), enthesitis-related arthritis in 33 (46%) patients, psoriatic arthritis in 8 (11%) patients, and undifferentiated juvenile arthritis in 4 (6%).

The mean patient VAS and physician VAS were 4.1±2.48 and 3.6±2.02, respectively.

The mean tender joint count and swollen joint count were 2.7±3.2 and 0.8±1.26, respectively.

Clinical enthesitis was noted in 20 of the cases (28%) with a mean enthesitis count of 1.55.

The mean ESR and CRP levels were 30.16±26.61 mm and 19.92±26.16 mg/L, respectively.

ANA and HLA-B27 were present in 16 (22%) and 9 (13%) patients, respectively.

The mean JADAS-10-ESR and JSpDA were 9.1±5.4 and 2.8±1.6, respectively.

Uveitis was noted in 5 patients (7%).

Radiographic sacroilitiis was noted in 16 patients (22%).

The ERA form was more prevalent among males (M: 24 (63%) vs F: 9 (27%), p=0.015). Similarly, clinical enthesitis was more prevalent in males (M: 15 (41%) vs F: 5 (16%), p=0.023).

Physician VAS (M: 4.5±1.4 vs F: 3.1±2.1, p=0.046) and JspDA (M: 3.21±1.5 vs F: 2.07±1.77, p=0.037) exhibited significant male gender association.

As for biological features, the mean ESR was higher in the male group (M: 37.28 + 30.58mm vs F: 22.2±18.7mm, p=0.015), as was CRP level (M: 27.7±30.2 mg/L vs F: 11.1±17.18mg/L, p=0.006).

Moreover, the presence of radiographic sacroilitiis was more prevalent among boys (M: 13 (67%) vs F: 3 (18%), p=0.002)

The was no association between gender and the following parameters: age at the onset of the disease, patient global assessment, tender joint count, swollen joint count, JADAS-10-ESR, uveitis, the presence of ANA, nor the presence of HLA-B27.

Conclusion: Our study highlights a notable disparity in the severity and activity of JIA between males and females, with males exhibiting more severe disease activity and structural damage. These results underscore the necessity for a gender-specific approach in addressing JIA, offering insights for the development of tailored care strategies in pediatric rheumatology.

REFERENCES: [1] Cattalini M, Soliani M, Caparello MC, Cimaz R. Sex Differences in Pediatric Rheumatology. Clin Rev Allergy Immunol. 2019 Jun;56(3):293-307.

Acknowledgements: NIL.

Disclosure of Interests: None declared.