Autoimmunity and retinitis pigmentosa

Linear streaks associated with retinitis pigmentosa

PURPOSE

To describe a phenotypical manifestation characterized by the identification of peripheral linear streaks associated with retinitis pigmentosa (RP).

METHODS

Study design is a prospective observational case series. All consecutive patients affected by RP underwent a complete ophthalmological examination. The diagnosis of peripheral linear streaks was based on the identification of curvilinear atrophic streaks in the periphery of the retina.

RESULTS

Overall, six out of 140 patients (4.2%) were affected by peripheral linear streaks associated with RP. A single patient showed also punched out chorioretinal lesions at the posterior pole, with macular neovascularization development over the follow-up, treated with ranibizumab injections.

CONCLUSIONS

RP phenotypical manifestation characterized by peripheral linear streaks is infrequent and may provide additional evidence to support the contribution of inflammation in the pathogenesis of RP.

A review of the immunologic findings observed in retinitis pigmentosa

Most patients suffering from retinitis pigmentosa (RP) inherit the disorder; however, the immune-pathologic features associated with this disease have yet to be extensively studied. Six reports correlate antiretinal immune activity with vision deterioration in RP patients. Some of these patients have sporadic RP that occurs in excess of expected gene segregation during inheritance. The hypothesis that a primary immune-mediated disease process occurs in this sporadic group is supported by significant associations of RP with autoimmune endocrinopathies and other immune-related conditions or factors; however, no immunologic difference regarding RP family history is reported in the peripheral blood studies of RP patients. Twenty-one percent to 51% of RP patients display antiretinal antibodies, whereas 19-58% have antiretinal lymphocyte reactivity to retinal extract, and 60-85% have activated T cells. Mutations in animal models of RP have been shown to cause endoplasmic reticulum stress that may initiate immunopathology for genetic RP, but oxidative stress also encourages immune cytotoxicity. In addition, necrotic cell death is evident, which promotes inflammatory conditions. We review mechanisms and evidence for an occult inflammation in genetic RP and examine reports of efficacy in retarding RP progression with anti-inflammatory agents in clinical trials.