Switched Memory B Cells Are Increased in Oligoarticular and Polyarticular Juvenile Idiopathic Arthritis and Their Change Over Time Is Related to Response to Tumor Necrosis Factor Inhibitors

Emiliano Marasco, Angela Aquilani, Simona Cascioli, Gian Marco Moneta, Ivan Caiello, Chiara Farroni, Ezio Giorda, Valentina D'Oria, Denise Pires Marafon, Silvia Magni-Manzoni, Rita Carsetti, Fabrizio De Benedetti

Research output: Contribution to journalArticle

Abstract

OBJECTIVE: To investigate whether abnormalities in B cell subsets in patients with juvenile idiopathic arthritis (JIA) correlate with clinical features and response to treatment.

METHODS: A total of 109 patients diagnosed as having oligoarticular JIA or polyarticular JIA were enrolled in the study. B cell subsets in peripheral blood and synovial fluid were analyzed by flow cytometry.

RESULTS: Switched memory B cells were significantly increased in patients compared to age-matched healthy controls (P < 0.0001). When patients were divided according to age at onset of JIA, in patients with early-onset disease (presenting before age 6 years) the expansion in switched memory B cells was more pronounced than that in patients with late-onset disease and persisted throughout the disease course. In longitudinal studies, during methotrexate (MTX) treatment, regardless of the presence or absence of active disease, the number of switched memory B cells increased significantly (median change from baseline 36% [interquartile range {IQR} 15, 66]). During treatment with MTX plus tumor necrosis factor inhibitors (TNFi), in patients maintaining disease remission, the increase in switched memory B cells was significantly lower than that in patients who experienced active disease (median change from baseline 4% [IQR -6, 32] versus 41% [IQR 11, 73]; P = 0.004). The yearly rate of increases in switched memory B cells was 1.5% in healthy controls, 1.2% in patients who maintained remission during treatment with MTX plus TNFi, 4.7% in patients who experienced active disease during treatment with MTX plus TNFi, and ~4% in patients treated with MTX alone.

CONCLUSION: Switched memory B cells expand during the disease course at a faster rate in JIA patients than in healthy children. This increase is more evident in patients with early-onset JIA. TNFi treatment inhibits this increase in patients who achieve and maintain remission, but not in those with active disease.

Original languageEnglish
Pages (from-to)606-615
Number of pages10
JournalArthritis and Rheumatology
Volume70
Issue number4
DOIs
Publication statusPublished - Apr 2018

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