Elevated levels of anti‐endotoxin antibodies in patients with bilateral idiopathic acute anterior uveitis

Purpose: Endotoxins have been proved to be responsible for acute anterior uveitis (AAU) in animals in a well‐established experimental model of endotoxin‐induced uveitis (EIU). The purpose of our study was the detection of antibodies against endotoxins of selected enterobacteria in the serum of patients with idiopathic AAU and searching for correlations between the levels of these antibodies and the presence of HLA‐B27 antigen as well as characteristic signs of EIU such as bilaterality and the absence of spontaneous recurrences of the disease. Methods: Reactions of serum IgG antibodies with lipopolysaccharides (LPSs) of Escherichia coli O1, E. coli O10, E. coli O111, E. coli J5, and Klebsiella pneumoniae O3 were determined for 60 patients with idiopathic AAU and 40 healthy volunteers. The presence of HLA‐B27 antigen in patients was determined. Documentation of the frequency of recurrences of AAU during a follow‐up period of 8 years was collected. Results: We have observed that the sera of patients with a first attack of AAU reacted stronger with the LPS of K. pneumoniae O3 than the sera of patients with relapse of the disease. Patients with bilateral AAU had markedly higher levels of antibodies against four of the five used LPSs than patients with one eye involved. A multiply comparison showed higher levels of IgG reacting with LPS of E. coli O111 in patients with bilateral eye inflammation admitted with the first attack of AAU comparing to controls. The incidence of recurrent form of AAU was significantly increased in HLA‐B27‐positive patients compared to HLA‐B27‐negative patients. However, we found in HLA‐B27 carriers that those with the bilateral form of AAU had over three times smaller risk of recurrence and showed stronger immunization by endotoxins than patients with unilateral inflammation. Conclusion: Our results suggest a potential role of endotoxins in the aetiology of the nonrecurrent bilateral form of AAU. We suggest that not only HLA‐B27 status but also determination of number of involved eyes may be useful to assess the risk of recurrence of the idiopathic AAU.