The Diagnostic Value Of Plasma α-synuclein,Plasma α-synuclein Oligomer And Iron Deposition In The Brain Substantia Nigra In Parkinson’s Disease At The Early Stage

BackgroundThe pathological characteristics of Parkinson’s disease(PD)are the loss and degeneration of dopaminergic neuron in the substantia nigra and the formation of LB.The main components of the LB is depositional alpha synuclein,which has a toxic effect on neurons.The major clinical manifestations of PD patients includ not only static tremor,rigidity,bradykinesia and posture balance disturbances such as motor symptoms,but also cognitive impairment,mental disorder,language barrier,autonomic nerve dysfunction and other NMS.At present,the diagnosis of PD relies mainly on the clinical history and physical examination.When it is diagnosed PD according to the clinical symptoms,50% of dopaminergic neuron has deathed in the substantia nigra,and more than 80% DA has fallen in the corpus striatum.It is difficult to identify PD patients on the early stage.The annual progress rate of PD on the early stage is greater than the advanced stage,or more than 70% of PD patients can survive only 15 years after diagnosis.Therefore,more and more researchers try to through various means of screening for PD markers for early diagnosis,to provide effective help to diagnose the early stage of PD,monitor the condition of PD and evaluate the curative effect of PD.ObjectiveTo eliminate the disturbance of severe cognitive impairment,mental disorder,and the interference of drugs,objectively reflect the change of clinical symptoms in the progression of disease,the study elected the untreated at early stage PD patients as the research object.The main porpose of this study is to explore the character and correlation of the plasma α-synuclein,plasma α-synuclein oligomer and iron deposition in the brain substantia nigra in PD at the early stage,ultimately,to improve the sensitivity and specificity of diagnosis of PD in early stage.Research object and methodThe research object: a total of 44 PD patients were included from October 1,2014 to December 31,2016 in Henan provincial people’s hospital,who was outpatient and inpatient clinical at first diagnosis,and healthy check-up of 42 cases as control group was collected matched with the PD group on the gender,age and culture level.Method:1.Choosing UPDRS and NMSQuest evaluate the clinical symptoms of PD patients.2.Taking the ELISA method respectively tests the peripheral blood plasma ɑ-Syn and ɑ-Syn oligomers in the PD group and control group.Apply the Curve Expert software to draw the standard curve,and according to the OD value of plasma samples to calculate the concentration on the standard Curve.3.Applying magnetic resonance SWI phase diagram to detect the iron deposition in the brain substantia nigra.4.Using SPSS 21.0 statistical software,the normal distribution of continuous measurement data was discribed with?x±s,and compared using t test.Count data was discribed with percentage,compared with x2 test.measurement data was analysed by Pearson correlation analysis.ROC curve analysis of plasma concentration of alpha syn and quantity of iron deposition in the brain substantia nigra as the sensitivity and specificity of diagnosis of PD disease,and find the best threshold.When the value of P is lower than 0.05,the difference was statistically significant.ResultsFirstly,compared with control group,plasma alpha-syn,the level of iron deposition in the brain substantia nigra were higher in the PD group,and the difference was statistically significant(P < 0.05).Secondly,when the correlation was analysed by Pearson correlation analysis on alpha-syn and the level of iron deposition in the brain substantia nigra with the PD patients’ age,duration,H-Y grading,UPDRS score,NMS score,the results showed that it were positively correlated between plasma alpha syn and the duration of the disease,NMS score,the level of iron deposition in the brain substantia nigra(r=0.546,0.540,0.634,P<0.01),and,the level of iron deposition in the brain substantia nigra and the duration of the disease,UPDRS-III scores were positively correlated(r=0.533、0.492,P<0.05).Thirdly,ROC curve analysis results show that when plasma alpha syn was as PD a marker in the diagnosis of PD,the area under the ROC curve was 0.880(P = 0.000),the best threshold is 127.01 ng/ml with sensitivity of 77.3%,specificity of 92.1%.Lastly,when the level of iron deposition in the brain substantia nigra was as a marker in the diagnosis of PD,the area under the ROC curve was 0.747(P = 0.004),the best threshold is 91.31 with sensitivity of 81.5%,specificity of 70%.ConclusionThe plusma alpha syn and the iron in the brain substantia nigra can be used as markers for early diagnosis of PD and were positively correlated with the duration of the disease.The concentration of plusma alpha syn can assess the severity of NMS and the level of iron deposition in the brain substantia nigra can be used to evaluate the severity of MS.