Predictors of the long-term outcome of early synovitis: a 5-year follow-up study

One hundred patients who presented to an Early Synovitis Clinic in 1979-81 were called for review after a minimum of 5 years. Sufficient data for analysis were obtained in 88 cases, of whom 36 had a final diagnosis of rheumatoid arthritis (19 seropositive, 17 seronegative) and 16 human parvovirus B19 arthropathy. Outcome was assessed by persistence of symptoms greater than 24 months and functional disability by Health Assessment Questionnaire. Sixty-two patients had persistent disease, with 26 showing some functional impairment (positive HAQ FDI). A number of presenting features were assessed for their ability to predict outcome at 5 years. Polyarticular onset of disease was associated with a poor prognosis but lacked both specificity and sensitivity. Certain laboratory tests at presentation, including positive rheumatoid factor and low serum sulphydryl levels, also indicated a poor outcome. Combining these serological abnormalities gave 100% specificity for detecting persistent, disabling disease but with rather low sensitivity. Thus, other test systems are required to increase further the successful prediction of clinical outcome in patients with early synovitis.