Objective To reduce the screening positive rate (SPR) and improve clinical efficiency of maternal serum screening for Down's syndrome.Methods Nine thousand and thirty-three cases of second trimester maternal serum screening for Down's syndrome were included from Apr.2013 to Apr.2014 in the present study.The screening results,all basic data and equation curves were analyzed retrospectively.Based on the data from the authors' laboratory,the important adjustment parameters were simulated.Combined with postnatal follow-up results,the quality and clinical performance of second trimester serum screening for Down's syndrome were evaluated.Results The SPR of second trimester serum screening for Down's syndrome was 6.69％(604/9033),the detection rate (DR) was 75％(3/4),and FPR was 6.65％(601/9033).The median multiple of median (MOM) of alpha-fetoprotein (AFP) was low and SPR was high,and MOM of free human chorionic gonadotropin β subunit (free hCGβ) were high and SPR was high,while MOM of unconjugated estriol (uE3) were a little bit low,and SPR was slightly high.Considering these three factors,it is believed that the screening positive rate is high.By the simulation adjustments of MOM value equations (AFP and free hCGβ) and weight correction equation,the SPR reduced to 4.11％(371/9033) after recalculating the risk,FPR declined to 4.07％(368/9033),and no more Down's syndrome fetus were missed compared with postnatal follow-up results.Conclusion Based on a localized setting depending on the local laboratory data,we suggest that the MOM value distributions(AFP,free hCGβ and uE3) and maternal weight should be regularly adjusted since it is a useful way to reduce the false-positive rate and improve clinical efficiency of maternal serum screening for Down's syndrome.

Objective To investigate the efficacy of interferon α(IFNα)and adefovir dipivoxil (ADV)combination therapy in HBeAg positive chronic hepatitis B(CHB)patients and to explore the optimized strategy for individualized treatment.Methods A total of 156 HBeAg positive CHB patients were enrolled in the study from January 2005 to June 2009 in the Third Affiliated Hospital of Hebei Medical University.Fifty-six CHB patients with hepatitis B virus(HBV)DNA≥1 X 107copy/mLand/or liver fibrosis stage≥S3,or previous monotherapy failure(relapse)were treated with initial IFNα and ADV combination therapy.Fifty-two patients who didn't meet any of the above baseline characteristics received initial IFNα monotherapy.The remaining 48 patients treated with IFNα monotherapy for full treatment duration were considered as control.At week 24 of treatment,the treatment regimens were adjusted according to quantitative changes of HBV DNA,HBeAg and HBsAg:16 patients who achieved early response in group of initial IFNα and ADV combination therapy subsequently received IFNα monotherapy,the other patients in group of initial combination therapy together with patients who did not achieved early response in group of initial IFNα monotherapy subsequently received IFNα and ADV combination treatment.The HBV DNA levels,HBeAg and HBsAg titers were detected at the end of 48 weeks of treatment to determine the treatment duration.The treatment efficacy,safety,drug resistance and relapse rates were finally evaluated at week 72.All data were analyzed using chi square test.Results At week 24,the early response rate in group of initial combination therapy was 28.6%,and the HBV DNA negative rate and alanine aminotransferase(ALT)normalization rate were significantly higher than those in groups of initial IFNα monotherapy and control(53.6%vs 32.7%vs 27.1%and 62.5%vs 40.4%vs 37.5%,respectively,P<0.05);in addition,HBeAg loss rate was higher than control group(39.3%vs 18.8%,x2=7.48;P<0.05).At week 48,five of 16 patients who achieved early response developed HBeAg reversion and three cases accompanied with virological breakthrough in group of initial combination therapy after switching to IFNα monotherapy,while the rates of HBV DNA negative,HBeAg seroconversion and HBsAg clearance were 73.2%,41.1%and 12.5%,respectively.The HBV DNA negative rate,HBeAg seroconversion rate and HBsAg clearance rate in 96 patients Who had received different combination treatment regimens were 65.6%,33.3%and 8.3%,respectively.At week 72,the relapse rate in individualized treatment group was comparable to those in control group,while HBsAg clearance rate increased 2.7%in individualized treatment group.Conclusions IFNα and ADV combination treatment could improve early biochemical and virological responses.Individualized treatment strategy based on baseline characteristics and treatment responses may be helpful for optimizing antiviral treatment in CHB patients.