Significance Of Detection Of Aβ42 And P-tau Levels In CSF Of Patients With Mild Cognitive Impairment

Objective:To investigate β-amyloid 1-42(Aβ42) and phosphorylated tau protein(P-tau) levels in cerebrospinal fluid(CSF) of patients with mild cognitive impairment(MCI) and analyze the relationship between neuropsychological scale and the levels of Aβ42 and P-tau in CSF with MCI. Aβ42 and P-tau levels in CSF may provide a better basis for the early diagnosis of MCI and be able to assessment of the cognitive impairment of MCI patients effectively. At last, get the purpose of delaying or prevention of dementia.Methods:Cerebrospinal fluid(CSF) of 25 cases of MCI(male 12, female 13) and 14(male 9, female 5) cases of cognitively normal(CN) from January 2013 to December 2013 were collected. The age of MCI group ranged from 34 to 78, with an average age of 53.76±13.58 years. The time of education ranged from 6 to 12 years, with an average time of 9.60±2.45 years. And age of CN group ranged from 38 to 65, with an average age of 49.86±6.56 years. The time of education ranged from 5 to 12 years, with an average time of 10.79±2.58 years. All the CSF specimens were collected by lumbar puncture. All the subjects were tested by Clinical Dementia Rating Scale(CDR), Mini Mental State Examination(MMSE), activity of daily living scale(ADL), the Montreal cognitive assessment scale(Mo CA), the HAMD and other mental scale tests. The CSF levels of Aβ42 and P-tau were detected by ELISA method. The difference of Aβ42 and P-tau level between MCI and CN were conpared. The relationship between MMSE score and the CSF level of Aβ42 and P-tau were analyzed.Results:1. The MMSE score of MCI was 24.60±1.44 and the Mo CA score of MCI was 22.00±2.78. The MMSE score of CN was 29.64±0.63 and the Mo CA score of CN was 28.64±1.65. The MMSE and Mo CA scores were reduced in MCI compared with CN(P<0.05). The Aβ42 level in CSF of MCI was 36.94±6.73μg/L and the Aβ42 level in CSF of CN was 41.79±4.79μg/L. The P-tau level in CSF of MCI was 57.81±10.45 ng/L and the P-tau level in CSF of CN was 49.08±9.18 ng/L.The CSF level of Aβ 42 was reduced and P-tau was elevated in MCI compared with CN(P<0.05).2. Compared with the CN group, the MMSE score of attention, calculation, memory in MCI group reduced and the Mo CA score of visual spatial and executive ability, attention, abstract reasoning and memory in MCI group decreased(P<0.05).3. Simple correlation analysis shows that P-tau level in MCI was negatively correlated with MMSE score(r=-0.427,P<0.05). After correcting education level, partial correlation analysis shows that P-tau level in MCI was also negatively correlated with MMSE score(r=-0.499,P<0.05). The relationship between MMSE score and Aβ42 in MCI group did not be found.Conclusion:Aβ42 and P-tau levels in CSF may be valuable biological markers in the diagnosis of MCI and have a predictive value in Alzheimer’s disease(AD). P-tau level in CSF P-tau may be related to the severity of cognitive impairment. MCI patients may have cognitive impairment in memory and calculation. Aβ42 and P-tau levels in CSF have a certain value in diagnosing MCI early and treating MCI effectively. and be able to assessment of the cognitive impairment of MCI patients effectively. At last, get the purpose of delaying or prevention of dementia. The P-tau levels in CSF may provide a basis for judging the severity of cognitive impairment in MCI.