RESUMO
BACKGROUND: Pro-inflammatory cytokines play an important role in diabetic retinopathy. There is conflicting evidence about their serum elevation in this condition and that they also may be possible serum inflammatory biomarkers of diabetic retinopathy. OBJECTIVE: To evaluate the presence of serum pro-inflammatory cytokines and acute phase reactants in the serum of patients with and without diabetic retinopathy. MATERIAL AND METHODS: Comparative case series with 36 patients divided into three groups were included: 12 patients with diabetes mellitus and diabetic retinopathy (group 1), 12 diabetic patients without diabetic retinopathy (group 2), and 12 healthy patients as a control group. Serum levels of the following pro-inflammatory cytokines were measured in all patients: TNF-α, IL-1ß and IL-6. Pro-inflammatory biomarkers measurements were also performed, such as erythrocyte sedimentation rate and C-reactive protein. RESULTS: The levels of TNF-α and IL-6 were higher in group 1 (TNF-α: 19.4 ± 10.9 pg/ml, IL-6: 5.75 ± 7 pg/ml) compared to the other two groups, although the difference was statistically significant only in the case of TNF-α (group 1: 19.4 ± 10.9 pg/ml, group 2: 14 ± 4.3 pg/ml and control: 8.49 ± 3.69 pg/ml, p = 0.001). There were no differences among pro-inflammatory biomarkers such as erythrocyte sedimentation rate and C reactive protein. among the three groups (p > 0.05). CONCLUSIONS: Pro-- inflammatory serum cytokine levels were higher in the diabetes mellitus with diabetic retinopathy group. Larger studies are warranted to establish the real impact of this finding.
