The Correlation Of YKL40 With Alzheimer's Disease And Mild Cognitive Impairment

Objective:Alzheimer's Disease(AD)is a nervous system degenerative disease with insidious onset and gradual progress.Clinical manifestation mainly includes a series of neural mental symptoms,such as progressive memory disorders,cognitive decline,language function degradation and personality changes.The pathological characteristics of AD are senile plaques(SP)composed of aggregated amyloid-?(A?)and nerve fiber tangles(NFTs)with excessive phosphorylated tau protein.The pathological process of AD is not only related to neurons apoptosis but glial cells hyperplasia or inflammatory reaction.The neural inflammatory reaction in AD involves stellate cells,macrophages,neutrophils composition,numerous cytokines and other inflammatory regulation substances.Mild cognitive dysfunction(MCI)is a cognitive disorder with mild memory impaired which does not yet damage the activities of daily living.According to the clinical symptoms of MCI,it can be divided into amnestic mild cognitive impairment(aMCI)and not aMCI.Individuals with aMCI have significantly increased risk for progressing into Alzheimer's disease(AD).YKL 40 is a 40-kDa glycoprotein belonging to the human chitinase family,which mainly comes from microglial cells.So far,it is found that the YKL 40 concentration of cerebrospinal fluid could have changed in a variety of diseases of the nervous system.Methods:This study includes AD group of 38 patients,MCI group of 18 patients and normal control of 39 healthy people.The age,gender and education conditionamong three groups are matched each other.AD and MCI patients are inpatients from the first affiliated hospital of Dalian medical university,and normal control group is composed by healthy people from physical examination center at the same time.Diagnosis of AD is according to the IWG-2 criteria and MDS criteria,and the diagnosis of MCI is according to the DSM-4 criteria and Peterson diagnostic criteria of MCI.AD and MCI patients accept the detailed medical history collection,physical examination,laboratory and imaging examination,and the evaluation of Mini-Mental State Examination(MMSE),Montreal Cognitive Assessment(MOCA),Clock Drawing Test(CDT).The concentration of serum YKL40 is measured by Enzyme-linked Immunosorbent Assay(ELISA).The statistical analysis software of this experiment is SPSS 13.0,P < 0.05 is statistical standards significantly.Results:(1)Serum concentration of YKL40 in AD group is 32.70(13.80)ng/ml,in MCI group is 53.67(14.42)ng/ml,in normal control group is 44.38±11.47 ng/ml.(2)Serum YKL40 concentration of AD group is lower than healthy people group(P= 0.003),AD group is lower than MCI group(P < 0.001).Serum YKL40 concentration of MCI group is higher than healthy people group(P = 0.014).(3)There are no correlation relationship between serum YKL40 concentration and age(P = 0.112),MMSE score(P = 0.345),MOCA score(P = 0.458),CDT score(P =0.583)in AD group.However,in AD group,the concentration of serum YKL40 is significantly negative correlated with the course of AD(P = 0.010).(4)There are no correlation relationship between serum YKL40 concentration and age(P = 0.790),MMSE score(P = 0.256),MOCA score(P = 0.795),CDT score(P = 0.220)in MCI group.(5)To healthy controls,there is no difference of serum YKL40 level in different age(P =0.659)and gender(P=0.651).(6)The ROC curve analysis shows that the concentration of serum YKL40 has no definite diagnosis value between AD and healthy people(A = 0.090,P = 0.002).However,serum YKL40 level is of diagnostic efficacy in MCI and healthy people(A = 0.751,P = 0.003).Conclusion:1.Concentration of serum YKL40 in AD patients is lower than the healthy people.There is no obvious correlation between serum YKL40 level and age,MMSE score,MOCA score and CDT score in AD patients.However,the concentration of serum YKL40 is of significantly negative correlation with the clinical course of AD patients.2.Concentration of serum YKL40 in MCI patients is higher than the healthy people.There is no obvious correlation between serum YKL40 level and age,MMSE score,MOCA score and CDT score in MCI patients.3.There is no obvious correlation between serum YKL40 level and age,gender in healthy people.4.The concentration of serum YKL40 has no definite diagnosis value between AD patients and healthy people.However,serum YKL40 level is of diagnostic efficacy in MCI patients and healthy people.