Evaluation of the diagnostic kits for hepatitis E and establishment of a quantification method for de-tecting anti-HEY IgG / 中华微生物学和免疫学杂志

ABSTRACT

Objective To evaluate anti-HEV IgG and IgM diagnostic kits with sera from convalescent hepatitis E patients and to establish the quantification method of detecting anti-HEV lgG.Methods Detect 42 convalescent serum samples of over 6 months after onset of hepatitis E patients from Jiangsu province with anti-HEV IgM and IgG diagnostic kits. Select and mix the anti-HEV IgG positive sera which were confirmed by Western blot with ORF2 and ORF3 antigen. The mixed serum was calibrated with a WHO anti-HEV Ig standard. A series quantitative linear standard was made for quantitative detection of anti-HEV IgG in hepatitis E vaccine clinical trials phase Ⅲ. Results The positive rates of the anti-HEV IgG di-agnose kits of G, K, MP, Wantai were 71.4%, 78.6%, 92.9% and 100% respectively. The positive rates of G was lower than that of MP (χ~2 = 5.19, P<0.05) and obviously lower than Wantai (χ~2 = 11.76,P<0.01). The positive rates of K was also obviously lower than that of Wantai (χ~2 =7.96, P <0.01).The positive rates of the anti-HEV IgM diagnose kits of MP, G, X, Wantai, K were 21.4%, 7.1%,21.4%, 64.3%, 78.6% respectively. The positive rate of both K and Wantai were obviously higher than that of MP(χ~2 = 15.75 ,P<0.01 ; X2 = 27.43 ,P< 0.01). With the Western blot confirmation test, 30 and 18 sera were reactive to ORF2 and ORF3 antigen separately. The anti-HEV IgG concentration of HEV-D01 mixed by 13 samples was 57.94 U/ml by the calibration. Prepare seven 1.5-fold dilution series of quantita-tive linear standard for HEV vaccine clinical trials phase Ⅲ, concentration range from 0.077 to 0.877 U/ml. The quantitive values of high, medium and low concentrations quality control samples lay in the range of average ± 2s, and the CV of quantitative values were 16%, 16%, 12% respectively. Conclusion The quality of different anti-HEY IgM and IgG diagnose kits were different. This study had set up a set of anti-HEV IgG linear quantitative standard, which fit for detecting anti-HEV IgG antibodies quantitatively in HEVvaccine clinical trial phase Ⅲ.