Analysis of ocular fluids for local antibody production in uveitis.

Uveitis or intraocular inflammation is a potentially blinding disorder that is initiated by a diverse group of diseases. Concepts of uveitis have evolved rapidly over the past few years, but many questions about the aetiology still remain unanswered. Uveitis is associated with several systemic diseases but the frequency of systemic diseases among uveitis patients is dependent on age of onset and type of uveitis.1 2 In a white population the most common systemic disorders associated with uveitis are seronegative spondylarthropathy and sarcoidosis.1 3 Several types of uveitis are associated with histocompatibility leucocyte antigens (HIA) for instance, acute anterior uveitis with HIA B27 and birdshot chorioretinopathy with HLA A29.4 The reason why these HLA types increase the relative risk for uveitis is unclear but in the case ofHLA B27 infections with Gram negative bacteria might be an influence.5 Autoimmune mechanisms are also thought to participate in the pathogenesis of uveitis since the eye harbours autoimmune inducing or uveitogenic material such as retinal S-antigen and interphotoreceptor retinoid binding protein.4 After immunisation with adjuvants these antigens induce ocular inflammation in several species. Infectious diseases might indirectly play a role in autoimmune uveitis by triggering the immune response against autoantigens.4 Furthermore, infectious diseases are able to induce directly intraocular inflammation.6 The retina consists of neural tissue, making it particularly prone to infection with neurotropic organisms such as Toxoplasma gondii and herpesviruses. Other infectious diseases that can induce uveitis are tuberculosis, syphilis, and Lyme borreliosis. In some forms of infectious uveitis for example, ocular toxoplasmosis, autoimmune mechanisms are thought to participate in the ocular manifestations of the disease.7-9 Discrimination between the infectious or non-infectious aetiology of uveitis is important since the treatment is different. Immunosuppressive therapy is often essential but it might be deleterious in direct infectious uveitis entities without specific antimicrobial treatment. In various infectious ocular diseases, such as ocular toxoplasmosis or acute retinal necrosis, there are no signs of a systemic infection. Investigation of serum antibody titres therefore gives little if any information about the aetiology of the uveitis. 10 Instead of looking in the general circulation, it might be