Comparative Analysis Of Characteristics Of Immunity And Clinical Features In Late-life Depression And Amnesic Mild Cognitive Impairment Patients

Objective Through the detection of pro-inflammatory cytokines and chemokines in late life depression(LLD),amnesic mild cognitive impairment(aMCI)patients and healthy elderly and compare the characteristic pattern of immunity and clinic among the three groups,then finding the high-specific biomarkers.Also,to investigate the predicative validity of pro-inflammatory cytokines and chemokines combining cognitive assessments to discriminate depression populations from aMCI population and healthy controlsMethods All participants were subjected to the diagnosis according to the DSM-IV diagnostic standard by clinicians,then they are enrolled into the group of LLD,aMCI patients and healthy elderly people.After entering the group,they need to complete the general information,cognitive and emotional scale evaluation including Chinese version of neuropsychological test battery(NTB),Montreal Cognitive Assessment(Mo CA),the Geriatric Depression Scale(GDS)and take blood routine examination,blood fat test,erythrocyte sedimentation rate test and pro inflammatory cytokines test.A total of 69 subjects comprising23 LLD,23 aMCI and 23 healthy subjects were included in the final analysis.The data of education levels,blood routine test results,pro-inflammatory cytokines and chemokines were analyzed by means of variance analysis,the sex,daily routine,past diseases and family history were used chi-square analysis across the three groups.Based on the differences of immune characteristics between LLD and aMCI patients,we try to screen the high-specific biomarkers.The logistic regression analysis were conducted to modeling differential diagnosis so as to differentiate LLD patients from both healthy control and aMCI population via pro-inflammatory cytokines and chemokines.Results 1.The results of this study show that in terms of general information,a trend significance on the years of education between the three groups,from high to low: healthy control,aMCI and LLD patients[(15.2±2.2)/Y VS(13.0±3.4)/Y VS(11.2±2.9)/Y,F=11.11,P<0.01];Among the three populations,the LLD patients show less tea drinking habits and exercise habits comparing to the other two groups,the difference was statistically significant(p<0.05).2.In terms of cognitive evaluation in Mo CA,compared with the healthy control,the LLD and aMCI patients displayed significantly worse in the total score in Mo CA cognitive test[(26.3±2.1)VS(20.8±2.6)VS(18.8±6.1),F=21.10,P<0.01].Similarly,the scores of the healthy control group were higher than the disease group in language ability,abstraction test and delayed recall test(P<0.05),there is no difference between aMCI and LLD groups.In the time and place orientation test,LLD group displayed significantly worse than HC and aMCI groups(P<0.05);The LLD group displayed significantly worse than the aMCI and HC group in attention score.Three groups showed a trend significance in the visual space and executive ability test,from low to high: LLD,aMCI patients and healthy control.3.In the Chinese version of neuropsychological test battery,comparing with the HC group,the LLD and aMCI groups displayed significantly worse in digital breadth and phonological fluency tests(P<0.05);The scores in semantic fluency test,from low to high: LLD,aMCI patients and healthy control(P<0.05).4.In terms of assessment in GDS,the LLD patients were significant higher than the aMCI and HC groups in the total score [(22.0±4.6)VS(7.0±6.2)VS(5.1±3.7)/分,F=80.82,p<0.01].5.For blood routine examination,comparing to the normal elderly and the aMCI patients,the LLD patients appeared highest proportion of neutrophils and lowest the proportion of lymphocytes among three groups(P <0.01).For the proportion of basophils,the aMCI patients were significant higher than the control and LLD population(P < 0.01).In terms of the proportion of eosinophilic granulocyte,the aMCI patients were significant higher than LLD population(P<0.05).In the aspect of ESR,the LLD patients showed significantly higher in ESR than the HC and aMCI group(P<0.01).6.For pro-inflammatory cytokines and chemokines examination,The plasma concentration of IL-6 in LLD group was higher than that in HC and aMCI group(P < 0.05),and the plasma concentration of IL-16、CXCL-6、CCL25 and CXCL15 in LLD group was significantly lower than that in HC group(P<0.05);The plasma concentration of CCL13 in aMCI group was higher than that of HC and LLD groups(P < 0.05),then the concentration of CCL2 、CXCL11 and CCL17 were higher than that in LLD group(P<0.05),CCL15 higher than that in HC group(P<0.05).7.In the correlation between clinical characteristics and inflammatory cytokines concentration,the total score of MOCA was positively correlated with the plasma concentrations of TNF-α,IL-16 and ccl25(P < 0.05),which also shows negatively correlation with the total score of GDS and ESR level(P > 0.05);the total score of GDS was positively correlated with the proportion of neutrophils,ESR speed and the plasma concentration of IL-6(P < 0.05),however negatively correlated with the proportion of lymphocytes in peripheral blood and the plasma concentration of ccl13(P < 0.05).8.Independent predictor analysis of geriatric depression.The independent variables were selected by two categories of non-conditional logistic regression analysis.Finally,three independent variables were selected as independent predictors of geriatric depression,including the proportion of neutrophils,ESR and IL-6 concentration.The accuracy of diagnosis of geriatric depression was 84.8%(39/46),the sensitivity was 83.3%(20/24),and the specificity was 86.4%(19/22),then the positive predictive value was 87.0%(20/23)and negative predictive value was 82.6%(19/23).Conclusions 1.Cognitive impairment exists both in LLD and aMCI patients,including visual spatial ability,memory and language ability,and cognitive impairment in depression patients is more serious.2.In terms of pro-inflammatory cytokines and chemokines,it is suggested that there is a abnormal immune response in both the late life depression patients and the amnesic mild cognitive impairment patients,however the expression of inflammatory factors are not the same.3.The selected target in blood routine test,pro-inflammatory cytokines and chemokines have a high accuracy in the diagnosis and differentiation of late life depression and amnesic mild cognitive impairment.The studies on immune system are of great value.