Background Adult onset Still’s disease (AOSD) is a rare systemic inflammatory syndrome characterized by high daily spiking fever, arthritis/arthralgias and salmon colour rash. Beyond the famous triad of symptoms it is also characterized by: sore throat, lymphoadenopathy, serositis, myalgia, hepato-splenomegaly and liver disfunction. Typical laboratory findings are neutrophilic leucocytosis, hyperferritinemia, and often increased liver enzimes. Three patterns of disease have been identified: monocyclic, polycyclic systemic and chronic articular. Prognosis is usually good, but life-threatening complication, such as diffused intravascular coagulation (DIC), may occur. Disease activity can be evaluated with Pouchot criteria which score 12 items. This score has been recently modified by Rau who replaced abdominal pain and splenomegaly with arthritis and serum ferritin >3000 ng/ml.

Objectives To describe a cohort of Italian patients with AOSD evaluated in our Rheumatology Division along the last 10 years.

Methods Patients diagnosed with AOSD (according to Yamaguchy criteria) were retrospectively evaluated. Clinical and laboratory data were collected. Disease activity was evaluated with Pouchot’s and Rau’s criteria and patients were defined “active” if they had ≥4 criteria at the moment of drawing.

Results In a cohort of fourty-nine patients (F 26, M 23; mean age at onset 34 years; 26 hospitalized, 23 outpatients) the most frequent symptoms were: fever (49/49; 100%), rash (38/49; 77.5%), arthralgia (37/49; 75.5%), sore throat (29/49; 59.1%;), lymphoadenopathy (28/49; 57.1%), arthritis (23/49; 46.9%), hepato-splenomegaly (19/49; 38.7%), myalgia (14/49; 28.5%), pleuritis (3/49; 6.1%;), pericarditis (2/49; 4%) and abdominal pain (1/49; 2%;). The most frequently involved joint was the knee (18/23; 78.2%). ESR and CRP mean value were respectively 74.84 mm/h (range 20 – 124) and 84.79 mg/dl (range 3 - 354). The mean WBC count was 19004.71/μl (range 8600 – 35900; [mean neutrophil count 83.9%, mean lymphocyte count 10.4%]), while mean serum ferritin value was 5582.14 ng/ml (range 69 – 32800). Nineteen out of 49 patients (38.7%) had increased transaminases [mean AST 67.39 UI/l (range 8-404), ALT 91.59 UI/l (range 4-535)]. Considering Pouchot’s criteria, 18/49 (36.7%) patients were “active''. A significant difference in mean serum ferritin levels was observed between “active” and “non active” groups (P=0.001). Using Rau’s criteria, the number of “active” patients increased from 18 to 21 out of 49 (42.8%). We could evaluate disease pattern in 37 patients, of which 43.2% had polycyclic systemic disease, 32.4% monocyclic and 24.3% chronic articular. Disease course was good in all patients except two who experienced DIC, with fatal outcome in one of these.

Conclusions Our clinical and laboratory findings are in agreement with those reported in the literature. We found that disease activity is associated with a key serum markers which is ferritin, thus suggesting that the new criteria proposed by Rau, which include ferritin evaluation, could result more accurate in defining disease activity. AOSD prognosis is usually favourable, however, severe life-threatening complications may occur.

Disclosure of Interest None Declared