[Thrombocytosis in juvenile rheumatoid arthritis].

To find out the possible relationship between thrombocytosis and JRA, 2 to 11 platelet counts (every 1 to 6 months) were performed in each of 26 patients with active JRA, and were compared with figures for hemoglobin, WBC, sedimentation rate and articular index. Thrombocytosis was found in 88% of the cases. There was positive correlation, with statistical significance, among thrombocytosis, anemia, and sedimentation rate. Significant relationship was also found among thrombocytosis, the presence of articular inflammation and leukocytosis. There was no parallelism between platelets types of the disease. We conclude that in active JRA, thrombocytosis is a frequent finding in relation with anemia and the inflammatory activity of the disease.