IL-12 concentrations in the aqueous humor and serum of diabetic retinopathy patients.
BACKGROUND
Previous studies suggest that inflammation plays an important part in the pathogenesis of diabetes. Cytokines may have a role in both positive and negative control of immunological reactions. Among many cytokines, interleukin 12 (IL-12) is known to be a strong pro-inflammatory cytokine.


METHODS
A total of 76 participants were enrolled in this study and classified into four groups: 23 diabetic patients with non-treated retinopathy, 17 diabetic patients with treated retinopathy, 12 diabetic patients without retinopathy, and 24 healthy control patients. Serum and aqueous humor samples were taken for the analysis of IL-12 concentration.


RESULTS
The aqueous humor IL-12 concentration was significantly elevated in the patients with non-treated diabetic retinopathy (χ(2)(3, n = 76) = 27.137; p < 0.001). No significant differences in IL-12 serum concentrations between the groups were found (F = 0.405, p = 0.750). Correlation analysis of IL-12 concentrations in the serum and aqueous humor showed a linear association between the two variables only in non-diabetic patients (p = 0.003).


CONCLUSIONS
This is the first study to show a significantly higher concentration of pro-inflammatory cytokine IL-12 in the aqueous humor of non-treated diabetic retinopathy patients in comparison with diabetic patients treated for retinopathy, without retinopathy, or with healthy individuals. Because the serum levels of IL-12 did not differ considerably between the studied groups, it is plausible that this is due to its local production and secretion.
Department of Ophthalmology, General Hospital Dubrovnik, Roka Mišetića bb, 20 000 Dubrovnik, Croatia. agantonela@net.hr
Antonela
A
Gverović Antunica
Ksenija
K
Karaman
Ljubo
L
Znaor
Ada
A
Sapunar
Vesna
V
Buško
Velibor
V
Puzović
D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal; D001082:Aqueous Humor / Q000378:metabolism*; D003124:Colorimetry; D003920:Diabetes Mellitus / Q000097:blood; D003930:Diabetic Retinopathy / Q000097:blood* / Q000601:surgery; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005451:Fluorescein Angiography; D006801:Humans; D018664:Interleukin-12 / Q000097:blood*; D017075:Laser Coagulation; D008297:Male; D008875:Middle Aged
D000911:Antibodies, Monoclonal; D018664:Interleukin-12