Juvenile rheumatoid arthritis with IgA deficiency and appearance with febrile episode

A 24-year-old female had juvenile rheumatoid arthritis since the age of 3, with systemic manifestations such as fever, polyarthralgia, micrognathia, splenomegaly, hepatomegaly, lymphadenopathy, subcutaneous nodules, hidden rheumatoid factor of IgG type. Particularly noteworthy is selective IgA deficiency in this patient, with increases in concentration up to 50 mg/dl in the serum concurrently with the repeated febrile attacks in the clinical course.