Adult onset Still's disease: review of 50 cases and evaluation of diagnostic criteria
On the basis of clinical and laboratory data of 50 patients with adult onset Still's disease (AOSD), we strictly examined 4 diagnostic criteria adopted by different authors: criteria of Calabro, ARA, Medsger and Liu Gui-xin. Our result shows that Calabro's criteria has the best specificity (100%) and a higher diagnosis index (0.90) among the 4 criteria. Liu's criteria provides the best sensitivity (98%), but a lower specificity (86.9%) with a misdiagnosis rate of 14%. The rate of missed diagnosis with the ARA criteria is 35.7%. According to the present study, we recommend Liu's criteria for preliminary screen diagnosis, while Calabro's criteria for confirmation and differential diagnosis. Of special interest is that serum ferritin (SF) determination showed significantly higher level in 20 patients with AOSD (average 1194.5mg/L) than that in 19 patients with other rheumatic diseases (average 94mg/L, P < 0.001). AOSD patients with active disease have higher SF levels than patients with inactive disease (average 2742.9mg/L & 291.25mg/L, P < 0.001). So this test might be useful in diagnosis in AOSD and assessment of disease activity.