L1 is a major granulocyte and monocyte protein, released during activation and turnover of such cells. Blood and synovial fluid (SF) from 41 patients with rheumatoid arthritis (RA) and 6 patients with osteoarthritis (OA), were analyzed for L1 and the acute phase proteins C-reactive protein, orosomucoid, haptoglobin, alpha 1-antitrypsin and albumin as well as for differential leukocyte count. L1 levels in plasma and SF showed highly significant differences (p less than 0.0001), between the RA and OA patients. All the OA patients had normal plasma concentrations of L1 and low concentrations of L1 in SF. All the RA patients had elevated plasma levels of L1 and high L1 concentrations in SF. In the RA patients, the ratios between the protein concentrations in SF and blood were 3.29 for L1 and less than or equal to 0.64 for the acute phase proteins. In the SF, the L1 levels did not correlate with the monocyte count, while a low, positive correlation was found between L1 and the granulocyte count. The high L1 concentrations observed in SF from RA patients probably reflected an increased turnover of leukocytes in the inflamed joints. In SF from RA patients, high L1 concentrations were found in joints with a high amount of swelling. The present study suggests that L1 may represent a marker of both local and systemic inflammation.

Adult-onset Still's disease (AOSD) has often been regarded as the adult spectrum of systemic juvenile idiopathic arthritis (sJIA). The present study aims to compare the clinical and laboratory features, the disease course and the response to treatment in patients having AOSD with those having sJIA. Retrospective review of all available data that were filled out by adult and paediatric rheumatologists from six centers using a standard data extraction form was performed. A total of 95 patients with AOSD and 25 patients with sJIA were recruited for the study. The frequency of fever, rash, myalgia, weight loss and sore throat was higher in patients with AOSD. The pattern of joint involvement differed slightly. Laboratory findings were similar in both groups, except that liver dysfunction and neutrophilia were more common among adults. A multiphasic pattern dominated the childhood cases, whereas the most frequent course was a chronic one in adults. Corticosteroids and methotrexate were the most commonly employed therapy; however, chloroquine was another popular therapy in the adult group. We showed a difference in the rate of clinical and laboratory features between patients with AOSD and those with sJIA. AOSD and sJIA may still be the same disease, and children may simply be reacting differently as the result of the first encounter of the putative antigens with the immune system.

Our study illustrates the frequency and significance of vascular involvement in BD.

This preliminary study suggests that elevated serum homocysteine levels may play some role in the development of venous and arterial thromboses in BD.

We conclude that psoriasis is probably a genetically determined disease and suggest that HLA-Cw6 antigen seems to associate commonly with early onset of psoriasis in Turkish patients.