Purpose To determine the levels of Th17-associated cytokines, particularly interleukin (IL)-17 and IL-22 in tears of patients with dry eye syndrome. Methods Tear samples were collected from 20 healthy volunteers, 20 dry eye (DE) patients with non-Sjö gren's syndrome (NSSDE) and 20 DE patients with Sjö gren's syndrome (SSDE). Symptom questionnaire was self-administered and multiple dry eye disease (DED)-related clinical tests were performed. The levels of IL-17 and IL-22 in tears were measured by enzyme-linked immunosorbent assay. Results The levels of IL-17 and IL-22 were significantly increased in tears of DE patients compared with those of controls and also higher in SSDE patients compared with those of NSSDE patients (Po0.05). Moreover, the levels of IL-17 and IL-22 were positively correlated with questionnaire score and keratopathy score but negatively correlated with tear film break-up time and Schirmer I test in both NSSDE and SSDE patients (Po0.05). Conclusions The levels of IL-17 and IL-22 in tears were significantly increased in DE patients, which were associated with the disease severity. Therefore, Th17 cellassociated cytokines, particularly IL-17 and IL-22, may have important roles in the immunopathogenesis of the DED.

Background: As a potential brain imaging biomarker, amplitude of low frequency fluc-tuation (ALFF) has been used as a feature to distinguish patients with Alzheimer’s disease (AD) and amnestic mild cognitive impairment (aMCI) from normal controls (NC). However, it remains unclear whether the frequency-dependent pattern of ALFF alterations can effectively distinguish the different phases of the disease. Methods: In the present study, 52 AD and 50 aMCI patients were enrolled together with 43 NC in total. The ALFF values were calculated in the following three frequency bands: classical (0.01-0.08 Hz), slow-4 (0.027-0.073 Hz) and slow-5 (0.01-0.027 Hz) for the three different groups. Subsequently, the local functional abnormalities were employed as features to examine the effect of classification among AD, aMCI and NC using a support vector machine (SVM). Results: We found that the among-group differences of ALFF in the different frequency bands were mainly located in the left hippocampus (HP), right HP, bilateral posterior cingulate cortex (PCC) and bilateral precuneus (PCu), left angular gyrus (AG) and left medial prefrontal cortex (mPFC). When the local functional abnormalities were employed as features, we identified that the ALFF in the slow-5 frequency band showed the highest accuracy to distinguish among the three groups. Conclusion: These findings may deepen our understanding of the pathogenesis of AD and suggest that slow-5 frequency band may be helpful to explore the pathogenesis and distinguish the phases of this disease.

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