Aim: To investigate the frequency of HLA-B27 in patients with presumed Bartonella henselae associated uveitis and to describe the clinical characteristics of HLA-B27 positive patients with uveitis and presumed ocular bartonellosis (POB).
Methods: The diagnosis of POB was considered in 19 patients with unexplained uveitis (except for the HLA-B27 association) and high positive IgG (titre >/=1:900) and/or IgM (titre >/=1:250) antibodies against B henselae. In addition to B henselae serology and HLA-B27 typing, all patients underwent an extensive standard diagnostic screening procedure for uveitis and in all cases the results were within the normal limits. The control group consisted of 25 consecutive patients with panuveitis and negative B henselae serology.
Results: HLA-B27 was positive in six of the 19 patients (32%) with POB in contrast to the 4% frequency of HLA-B27 in the control group (p=0.03) and 8% prevalence of HLA-B27 in the Dutch population (p=0.003). At the time of positive Bartonella serological testing five of six HLA-B27 positive patients with POB had severe posterior segment involvement with papillitis, macular oedema, and vitreitis. The duration of intraocular inflammatory activity was more than 6 months in five HLA-B27 positive patients. Although four of the six HLA-B27 positive patients had previous recurrent attacks of acute anterior uveitis, the clinical presentation at the time of positive Bartonella serology differed, as illustrated by the involvement of the posterior segment and chronic course of the ocular disease.
Conclusions: The frequency of HLA-B27 in patients with uveitis and serological characteristics of acute infection with B henselae is higher than in the general Dutch population. The findings of this study also suggest a relation between infection with Bartonella species and HLA-B27.