Evaluation of lipid oxidative stress status and inflammation in atopic ocular surface disease

[摘要] Background: Although the oxidativestress status in atopic skin disease has been reported to be elevated,there are still no studies related to the status of oxidative stress inatopic ocular surface disease. The purpose of this study was toevaluate the ocular surface lipid oxidative stress status andinflammation in atopic keratoconjunctivitis (AKC) patients and normalsubjects. Methods: Twenty eight eyes of 14patients (9 males, 5 females) with AKC and 18 eyes of 9 age and sexmatched (4 males and 5 females) normal healthy controls were examinedin this prospective study. The severity of atopic dermatitis (AD) wasscored by the SCORing Atopic Dermatitis (SCORAD) index. All subjectsunderwent Schirmer test, tear film break up time (BUT),fluorescein/Rose Bengal stainings, tear collection, and brush cytologyfrom the upper palpebral conjunctiva. The brush cytology samples werestained with Diff-Quik for differentiation of inflammatory cells andimmunohistochemistry (IHC) staining with HEL (hexanoyl-lysine) and4-HNE (4-hydroxy-2-nonenal) to study lipid oxidation. HEL and cytokine(interleukin-4 (IL-4), interleukin-5 (IL-5), interleukin-10 (IL-10),tumor necrosis factor-alpha (TNF-α), interferon-gamma (IFN-γ)) levelswere measured by enzyme-linked immunosorbent assay (ELISA) from tearsamples of AKC patients and control subjects. Toluidine Blue and IHCstaining with HEL, 4-HNE and cluster of differentiation 45 (CD45) wereperformed on papillary samples of AKC patients. This study wasconducted in compliance with the “Declaration of Helsinki.” Results: The tear stability and vitalstaining scores were significantly worse in eyes of AKC patients(p<0.05) compared to the controls. Inflammatory cells and positivelystained conjunctival epithelial cells for HEL and 4-HNE showed asignificant elevation in brush cytology samples of AKC patients.Significantly higher levels of HEL and cytokines were detected in tearsof AKC patients compared to controls. Papillary specimens also revealedmany CD45 inflammatory cells as well as many cells positively stainedwith HEL and 4-HNE in IHC. A strong significant linear positivecorrelation between conjunctival inflammation and epithelial lipidoxidative stress status was observed. Conjunctival lipid oxidativestress also correlated strongly with tear HEL levels and epithelialdamage scores. Conclusions: The ocular surface diseasein AKC was characterized by marked tear instability, ocular surfaceepithelial damage, increase in inflammatory infiltrates and presence ofincreased lipid oxidation.

[学科分类] 生物化学/生物物理