标题: Decreasing Levels of HBsAg Predict HBsAg Seroclearance in Patients with Inactive [打印本页] 作者: StephenW 时间: 2011-10-1 19:57 标题: Decreasing Levels of HBsAg Predict HBsAg Seroclearance in Patients with Inactive
Clin Gastroenterol Hepatol. 2011 Sep 2. [Epub ahead of print]
Decreasing Levels of HBsAg Predict HBsAg Seroclearance in Patients with Inactive Chronic Hepatitis B Virus Infection.
Chen YC, Jeng WJ, Chu CM, Liaw YF.
Source
Liver Research Unit, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taipei, Taiwan.
Abstract
BACKGROUND & AIMS:
Serum levels of hepatitis B surface antigen (HBsAg) decrease gradually during chronic hepatitis B virus (HBV) infection. We investigated the association between levels of HBsAg and HBsAg seroclearance.
METHODS:
We studied data from 46 patients who underwent spontaneous seroclearance of HBsAg (median age at seroclearance, 48 years; 87% male; 76% infected with genotype B). Controls were 46 patients matched for age, sex, and HBV genotype, with persistently normal levels of alanine aminotransferase and were seropositive for HBsAg. Levels of HBsAg were assessed in serum specimens collected 5 years, 3 years, and 1 year before HBsAg seroclearance (or at the last examination, for controls).
RESULTS:
The decrease in level of HBsAg was significant and accelerated within the 3 years before HBsAg seroclearance; there was no significant decrease in serum level of HBsAg among controls (P<.0001). The positive predictive value (PPV) for HBsAg seroclearance within 1 year was 36% among patients with HBsAg levels of 200 IU/mL, increasing to 44%, 54%, and 67% among those with 100 IU/mL, 50 IU/mL, or 10 IU/mL respectively; the negative predictive value (NPV) for these levels was ≥96%. The combination of HBsAg level <200 IU/mL and a decrease of ≥1 log10 IU/mL in a preceding 2-year period had PPVs of 97% and 100% for HBsAg seroclearance at 1 and 3 years, respectively; the NPVs were 100% and 92%, respectively.
CONCLUSIONS:
The decrease in the level of HBsAg accelerates during the 3 years before HBsAg seroclearance. Levels of HBsAg ≤200 IU/mL have high NPVs for HBsAg seroclearance; PPVs increase to 97%-100% when combined with a ≥1 log IU/mL decrease in level of HBsAg over a 2-year period.
1. there was no significant decrease in serum level of HBsAg among controls (P<.0001)
这句话不明白,意思是“血清样本的HBsAg没有显著下降”吗?目的是说明样本质量控制没问题?
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这里的“controls(控制)”是指“在对照组的病人”
"there was no significant decrease in serum level of HBsAg among patients in the control group"
In statistics and diagnostic testing, the negative predictive value (NPV) is a summary statistic used to describe the performance of a diagnostic testing procedure. It is defined as the proportion of subjects with a negative test result who are correctly diagnosed. A high NPV means that when the test yields a negative result, it is uncommon that the result should have been positive. In the familiar context of medical testing, a high NPV means that the test only rarely misclassifies a sick person as being healthy. Note that this says nothing about the tendency of the test to mistakenly classify a healthy person as being sick.
The Negative Predictive Value is defined as:
NPV = 100% 意味预测是准确.
作者: 把握当下 时间: 2011-10-2 11:25
StephenW 发表于 2011-10-2 10:56
回复 把握当下 的帖子
1. there was no significant decrease in serum level of HBsAg among controls (P ...
我觉得这句话比较容易理解:
The combination of HBsAg level <200 IU/mL and a decrease of ≥1 log10 IU/mL in a preceding 2-year period had PPVs of 97% and 100% for HBsAg seroclearance at 1 and 3 years, respectively.