The acute phase response in acute anterior uveitis.

The acute phase response is part of the body's systemic response to inflammation. It consists of the synthesis and release of proteins participating in the inflammatory process. The acute phase protein serum amyloid A (SAA) was studied by serial measurement of its concentration in 57 patients with acute anterior uveitis. Patients were divided into two big groups on the basis of their SAA concentrations. Thirty-eight patients showed a transient elevation of SAA and were designated responders. In 19 patients SAA levels remained normal throughout the study and these patients were designated non-responders. Responders and non-responders were of similar age and sex distributions. The severity of the uveitis was equal in the two groups, and did not correlate with the SAA concentrations at presentation. Responders tended to have had fewer previous attacks of uveitis than non-responders. HLA typing showed that HLA B27 was more frequent in patients with recurrent disease than in those suffering their first attack. The majority of HLA B27 positive patients were responders. SAA concentration does not predict the severity of an attack of uveitis, but absence of an acute phase response may be associated with a greater tendency to recurrence.