Evaluating patients with arthritis of recent onset: studies in pathogenesis and prognosis.

Inflammatory synovitis of recent onset poses a diagnostic and prognostic challenge to primary care physicians and rheumatologists. A lack of understanding of the underlying etiologic and pathogenic processes limits the ability to distinguish forms of arthritis that follow a benign, self-limiting course from forms that proceed to an aggressive, erosive disease requiring intensive immunosuppressive therapy. It is estimated that between 30% and 40% of patients presenting with early synovitis have disease that remains unclassified. Using data from a cohort of patients with early synovitis and reviewing current literature, we discuss investigational approaches toward a new classification of patients with early synovitis. Although a lack of understanding of this heterogeneous clinical syndrome has led clinicians to take a largely empirical approach to treatment thus far, the evolving awareness of disease predisposition at a genetic level and the expanding ability to specifically manipulate biological pathways may ultimately change the approach to this clinical problem. JAMA. 2000;284:2368-2373.