Chlamydia Pneumonia and Proliferative Diabetic Retinopathy: Serologic Evidences in a Pilot Study

Purpose: chlamydia pneumonia is a known endothelial pathogen in several vascular diseases including atherosclerosis, age-related macular degeneration and non-arteritic anterior ischemic optic neuropathy. diabetic retinopathy is a retinal vascular disease that may similarly be affected. we serologically investigated the presence of c. pneumonia infection in patients with proliferative diabetic retinopathy. design: pilot case-control study. patients & methods: during a period of 12 months, we examined sera of 27 type i diabetic patients with different stages of diabetic retinopathy for anti-chlamydial igg and iga by enzyme-linked immunosorbent assay (elisa). results: the igg seropositivity was significantly different between different diabetic retinopathy groups (p=0.017). rate of seropositivity was higher among patients with pdr comparing to patients without pdr, with a marginal significance (p=0.062). although the titer of iga was negative in all patients (less than 0.357 u/ml), the iga titer was higher in patients with pdr than those without pdr, reaching the significance at p<0.06 level. conclusion: c. pneumonia may be an independent risk factor for proliferative diabetic retinopathy.