Serum anti‐recoverin antibodies is found in elderly patients with retinitis pigmentosa and cancer

PURPOSE: To screen for anti-recoverin antibodies in elderly patients with retinitis pigmentosa (RP) with or without cancer and cross-sectionally characterize the seropositive patients clinically. METHODS: Serum from 75 RP patients who had been tested for mutations in a panel of 83 RP genes and 73 normal controls, all aged 50-80 years, were screened for anti-recoverin antibodies by Western blot using recombinant recoverin, retinal lysate from a marmoset and commercial anti-recoverin antibodies as a control. RESULTS: Three RP patients with typical pigmentary degeneration of the 75 (4.0%) were seropositive for anti-recoverin antibody. Pathogenic mutations were identified in two seropositive RP patients. All three patients had visual impairment since childhood and were diagnosed as RP by the age of 30. The severity of the retinopathy varied greatly among these three patients, ranging in visual acuity from light perception OU to 20/30 OU. Retinitis pigmentosa (RP) patients with a history of cancer were more likely to have anti-recoverin antibodies (3/14; 21.4%) than those without (0/61; 0%; p = 0.005, Fischer exact test). All 73 healthy controls with no history of cancer were also seronegative. CONCLUSION: Our results show that serum anti-recoverin antibodies can be detected in typical RP patients with identified pathogenic mutations and that a history of cancer may increase the risk of developing anti-recoverin antibodies.