The evaluation of dot immunogold filtration method in detection of serum SAA and its clinical value of diagnosing the infectious diseases of children / 中华检验医学杂志

ABSTRACT

Objective The purpose of this study was to assess the analysis capabilities of the dot immunogold filtration method on detecting serum amyloid A ( SAA ) protein in blood.It also aimed to research the clinical value of SAA in diagnosing the infectious diseases of children .Methods ( 1 ) The performance evaluation including the accuracy , within-run precision, inter assay variations , the linear and the distraction-analysis of SAA-SPOT was estimated following the EP file; From March to July in 2014, children from five 3A Grade hospitals in Guangdong Province were enrolled into this observational study.Data including white blood WBC count , CRP and SAA were obtained.(2) From March to July in 2014, children from five 3A Grade hospitals in Guangdong Province were enrolled randomly into this observational study.This study used a cross-sectional survey research method , and 386 children with bacterial infection and 219 children with virus infection were as the research object.The general , clinical diagnosis , treatment information as well as the data of blood SAA , C-reactive protein ( CRP ) and white blood cell ( WBC ) of children were collected.Data were analyzed by variance , independent t test, ROC curve analysis and stepwise regression statistics method.Results ( 1 ) The average recovery rate is 103.74 %.Coefficient of variation (CV) for 10 mg/L,100 mg/L within-run assays were 8.77%, 3.61% and between-run assays were 9.01%, 3.74%;the inter-day CV were 9.07%, 4.03%respectively;the linear range was 5 mg/L-200 mg/L, hemoglobin(5 g/L),serum bilirubin(800 μmol/L),triglyceride(TG, 22 mmol/L), and had no interference in SAA detection.When compared to the BNPRO quantitate system of SIEMENS , the coefficient of association of detection of SAA by SAA-SPOT was R2 =0.96.( 2 ) Compared with control group , the serum SAA of infection group ( bacterial infection group , t =13.05, P=0.001;virus infection group t =7.68, P=0.001) and SAA/CRP ratio (bacterial infection group t=2.29, P=0.023;virus infection group t=3.32, P=0.01) were significantly increased.(3) The serum CRP and SAA rose similarly in bacterial infection, while in viral infection, only SAA increased significantly , CRP had no apparent change.In combination with CRP and WBC , SAA had the better diagnostic efficiency apparently.Conclusions As a POCT detection project , analysis capabilities of the SAA assayed by domestic SAA-SPOT can meet the requirements of clinical test.Combined with CRP , WBC and SAA can improve the efficiency in the diagnosing of infectious disease especially in the virus infection.As a new biomarker of infections , SAA is useful for the early auxiliary diagnosis and differential diagnosis of childhood infection.