Anti-cyclic Citrullinated Peptide Antibody-positive Girl with Chronic Polyarthritis Later Diagnosed with Juvenile Systemic Lupus Erythematosus: A Case Report.

BACKGROUND

Arthritis is one of the earliest symptoms of juvenile systemic lupus erythematosus (SLE) but is unusual in cases presenting with chronic arthritis or deforming/erosive arthritis. Overlap of juvenile idiopathic arthritis (JIA) and juvenile SLE is a rare clinical condition known as "rhupus" syndrome. The clinical and serological characteristics of rhupus syndrome in children remain to be established. In addition, no studies regarding anti-cyclic citrullinated peptide (CCP) antibody in juvenile SLE or juvenile rhupus syndrome have been reported.

CASE REPORT: A 12-year-old girl suffered from polyarthralgia lasting for one week. She was tentatively diagnosed with polyarticular JIA because of her symptom of chronic arthritis and a positive result for anti-CCP antibody. After six months of follow-up for JIA, she presented with a fever, malar rash, and worsening of arthralgia. Laboratory examinations revealed hypocomplementemia and a positive result for anti-double-stranded DNA antibody. She was diagnosed with juvenile SLE.

CONCLUSIONS

It is important to note that patients with chronic arthritis, as well as those with anti-CCP antibody-positive polyarthritis, should be carefully followed for their clinical and serological condition, considering the possibility of them developing juvenile SLE.