Correlation Between Serum Inflammatory Cytokines And The Incidence Of Dry Eye In Systemic Lupus Erythematosus Patients Without Secondary Sj?gren's Syndrome

Purpose: To investigate the incidence,severity,and influencing factors of dry eye in systemic lupus erythematosus(SLE)patients without secondary Sj?gren's syndrome(sSS)and to explore if some serum inflammatory cytokines influence the incidence of dry eye in this group of subjects.Methods: a total of 78 patients who were diagnosed as systemic lupus erythematosus and met inclusion criteria was selected as the study subjects.Tear meniscus height(TMH),noninvasive tear film break-up time(NIBUT)including first NIBUT(NIBUT-Fir)and average NIBUT(NIBUT-Ave)of the subjects were measured using the Keratograph 5M,an ocular surface analyzer,and subjective symptoms were assessed using the ocular surface disease index(OSDI).The disease activity of SLE patients was evaluated though Systemic Lupus Erythematosus Disease Activity Index(SLEDAI).The results of the examination of 13 serum antibodies were collected from their medical record.Meanwhile,the peripheral blood of 54 patients who were informed consent was get into a tube which contain EDTA-K2,after centrifugation,the upper serum and the lower blood cells were separated and stored in a-80 degree refrigerator.According to the result of their dry eye indexes,they were divided into dry eye group(n=11),dry eye tendency group(n=25)and control group(n=18).The levels of MMP-2 and KLK13 in the serum of the patients were measured by western blot,and the concentrations of IL-1,IL-6 and TNF? in the serum were assessed by enzyme-linked immunosorbent assay(ELISA).Real-time quantitative polymerase chain reaction(RT-PCR)was used to detect the mRNA levels of MMP-2,IL-1 and TNF? in peripheral blood mononuclear cells.The correlation between SLEDAI and ocular surface parameters was analyzed and multiple-factor binary logistic regression analysis was performed.Protein levels of MMP-2,KLK13,IL-1,IL-6,TNF-? in serum of the three group were compared and the mRNA levels of MMP-2,IL-1,TNF-? were also compared,and the correlation between clinical dry eye index and cytokines was analyzed.Results: The average TMH of the 78 patients was 0.22 mm,and mean NIBUT-Fir was 9.12 s.The subjects whose NIBUT-Ave <10s and OSDI?13 accounted for 24.36%.SLEDAI showed a statistically significant correlation with tear meniscus height(r=-0.233,p=0.040),NIBUT-Fir(r=-0.254,p=0.025),NIBUT-Ave(r=-0.343,p=0.002)and OSDI(r=0.256,p=0.024).According to the multiple-factor binary logistic regression analysis,SLEDAI could be considered to be a risk factor of the incidence of dry eye in SLE patients without sSS.According to the results of serum inflammatory cytokines,MMP-2,IL-1 and TNF? showed significant difference in the three groups at protein level and mRNA level.The protein levels of KLK13 and IL-6 were not different in the three groups.MMP-2 correlated with OSDI(r=0.328,p=0.001),IL-1 correlated with TMH(r=-0.358,p<0.001),NIBUT-Fir(r=-0.424,p <0.001),NIBUT-Ave(r=-0.472,p<0.001),TNF? showed significant correlation with TMH(r=-0.221,p=0.037),NIBUT-Ave(r=-0.278,p=0.006)and OSDI(r=0.238,p=0.018).Conclusion:24.36% of those systemic lupus erythematosus patients without sSS suffered from different degrees of dry eye,and the severity of dry eye was directly related to the activity of SLE.MMP-2,IL-1,and TNF? affected the ocular surface condition of SLE patients without sSS,and TNF? might be an effective serological indicator to reflect ocular surface conditions.