The Clinical Significance Of Platelet APP Isoform Ratio And Hippocampal Volume In The Diagnosis Of Early Alzheimer's Disease

BackgroundAlzheimer's disease?AD?is a chronic progressive neurodegenerative disease,one of the most common types of dementia.With the aging of population in China,the incidence rate is increasing year by year.The medical expense and care problem has become a heavy burden of the society and family,and has also become the main problem that public health is facing in China.Today,however,there is no effective treatment for reversing or terminating the progression of the disease.But,early active intervention in AD may delay further progress in cognitive impairment.Therefore,to explore effective and feasible biological markers at the early stage of AD has always been a hot spot in the research of AD diagnosis.Abnormal metabolism of brain amyloid precursor protein?APP?plays an important role in the pathogenesis of Alzheimer's disease.Because the peripheral blood platelets contain a lot of APP isoforms and the related proteases needed for the APP metabolism,the platelets have been used as a good carrier for the study of APP isoforms.It is also found that platelet ratio of amyloid precursor protein?APP?isoforms has a certain correlation with hippocampal atrophy.Based on the above,this study is to explore the clinical significance of platelet APP isoform ratio and hippocampus volume in the diagnosis of early Alzheimer's disease.PurposeTo explore the diagnostic value of platelet APP isoform ratio and hippocampal volume among early Alzheimer's disease patients.Methods59 patients with Alzheimer's disease were randomly selected from the outpatient and ward of the the 1st Affiliated Hospital of Zhengzhou University,and 61 healthy controls were selected as well.The subjects were tested based on the neuropsychological scale?including MMSE,MoCA,ADL,and HIS?.Besides,we detected their platelet APP isoform ratio(APP_130kDa/APP_110kDa),the left and right lateral and total hippocampal volumes after standardization.Results1.The differences of MMSE,MoCA and ADL scores between the case group and the control group were statistically significant?P<0.05?.The MMSE and MoCA scores in case group were lower than those in control group,and ADL scores in case group were higher than that in control group.2.The platelet APP isoform ratio(APP_130kDa/APP_110kDa)in the case group was significantly lower than that of the control group?P<0.01?.3.There were correlations between platelet APP isoform ratio(APP_130kDa/APP110kDa)and the neuropsychological scale?including MMSE,MoCA and ADL scores?.Among these correlations,there were positive correlations between platelet APP isoform ratio(APP_130kDa/APP_110kDa)and MMSE,MoCA?the correlation coefficients separately were 0.731 and 0.761;P values were all less than 0.05?;there was negative correlation between platelet APP isoform ratio(APP_130kDa/APP_110kDa)and ADL?the correlation coefficient was-0.668 and P value was less than 0.05?.4.The right hippocampus volume was larger than the left side in case group?P<0.05?.There was no difference between the left hippocampus volume and the right side in control group?P=0.266?.The left and right sides and the total hippocampus volume in case group were all smaller than those in control group?P<0.05?.5.There were correlations between the neuropsychological scale?including MMSE,MoCA and ADL scores?and the left and right sides and the total hippocampus volume.Among these correlations,there were positive correlations between MMSE,MoCA scores and the left and right sides and the total hippocampus volume?the correlation coefficients were 0.724 and 0.746;0.631 and 0.669;0.703 and0.733.P values were all less than 0.05?;there were negative correlations between ADL scores and the left and right sides and the total hippocampus volume?the correlation coefficients were-0.626,-0.559 and-0.614 repectively.P values were all less than 0.05?.6.There were positive correlations between platelet APP isoform ratio(APP_130kDa/APP_110kDa)and the left and right sides and the total hippocampus volume?the correlation coefficients were 0.582,0.533 and 0.577.P values were all less than 0.05?.7.The APP isoform ratio(APP_{130k Da}/APP_110kDa),the left and right sides and total hippocampal volume were analyzed by ROC curve.All above indicators had significant diagnostic value for AD,and P values were all less than 0.05.When using APP isoform ratio?the numerical value is less than or equal to 6.84?as a standard for the diagnosis of AD,the accuracy rate can be up to 88.7%;When using the left hippocampal volume?the numerical value is less than or equal to 3.158cm³?as a standard for the diagnosis of AD,the accuracy rate can be up to 94.1%;The accuracy rate can be up to 88%if using the right hippocampal volume?the numerical value is less than or equal to 3.284cm³?as a standard for the diagnosis of AD.And the accuracy rate can be up to 92.4%by using the total hippocampal volume?the numerical value is less than or equal to 6.44cm³?as a standard for the diagnosis of AD.ConclusionThe platelet APP isoform ratio(APP_130kDa/APP_110kDa)and hippocampal volume combining the neuropsychological scale?including MMSE,MoCA and ADL scores?have important clinical significance in the diagnosis of early Alzheimer's disease.