Outcomes in patients with incipient undifferentiated arthritis

Objective. To determine outcomes in patients with onset within the last yea r of peripheral inflammatory arthritis that does not meet classification cr iteria for any specific disease. Methods. Symptoms and laboratory tests wer e evaluated at baseline and 14 to 60 months later in 43 patients, 32 women and 11 men, with a mean age of 50 years. Results. At baseline, a presumptiv e clinical diagnosis was made in 16 of the 43 patients. Diagnoses at last f ollow-up were undifferentiated inflammatory arthritis in seven cases, mild rheumatoid arthritis in 18, psoriatic arthritis in two, Sjogren's syndrome in two, lupus in one, and paraneoplastic syndrome in one. The remaining 12 patients were free of inflammatory joint symptoms; three had symptoms of os teoarthritis and nine were asymptomatic. Factors present at baseline and pr edictive of progression to definite rheumatoid arthritis were a positive te st for rheumatoid factor, presence of an HLA DRB1*04 allele, and a presumpt ive clinical diagnosis of rheumatoid arthritis. Conclusion, 55% of our pati ents developed a specific inflammatory joint disease, and 42% developed rhe umatoid arthritis, which was consistently mild. Resolution of all inflammat ory joint symptoms occurred in 28% of cases. A number of clinical, laborato ry, and genetic findings of use for predicting the outcome of undifferentia ted arthritis were identified. (C) 2000 Editions scientifiques et medicales Elsevier SAS.