Anti-HBc levels predict hepatic inflammation in patients with chronic HBV
medwireNews: Serum hepatitis B core antibody (anti-HBc) levels significantly predict hepatic inflammation in patients with chronic hepatitis B virus (HBV) infection, including those with normal alanine aminotransferase (ALT) levels, Chinese research shows.
“Thus, anti-HBc may be a strong indicator for assessing the hepatic inflammatory degree and used for antiviral treatment decisions in [chronic HBV] patients with normal ALT levels,” Ningshao Xia (Xiamen University) and colleagues write in Scientific Reports.
They explain: “Active significant hepatic inflammation is the main risk factor for developing cirrhosis and [hepatocellular carcinoma] in [chronic HBV] patients.”
Therefore, “accurate evaluation of the initial stage of liver inflammation and progression over time represents a high priority and growing medical need,” they add.
In their study of 655 treatment-naïve patients with chronic HBV infection, the researchers found that serum anti-HBc levels increased significantly with increasing histology activity index (HAI) score.
For example, among the 404 patients positive for hepatitis B e antigen (HBeAg), those with an HAI score of 0–4 had a mean anti-HBc level of 3.80 log10 IU/mL, compared with a mean level of 5.02 log10 IU/mL for those with an HAI score of 10–18 (p<0.001). The corresponding levels among the 251 HBeAg-negative patients were 4.21 and 5.06 log10 IU/mL (p<0.05).
And among 45 patients with liver biopsies before and after 78 weeks of antiviral treatment, the levels of anti-HBc decreased significantly in line with significant decreases in HAI (p<0.001 for both).
Xia and team report that 193 patients had a normal ALT level; of these, 70 (36.6%) had moderate-to-severe hepatic inflammation, defined as an HAI of at least 5.
Multivariate analysis showed that anti-HBc was independently associated with likelihood of moderate-to-severe hepatic inflammation in these patients, at odds ratios of 4.78 (p=0.009) for HBeAg-positive patients and 5.40 (p<0.001) for HBeAg-negative patients.
Furthermore, serum anti-HBc, at an optimal cutoff of 4.47 log10 IU/mL, showed a high diagnostic accuracy for predicting moderate-to-severe inflammation in both HBeAg-positive and HBeAg-negative patients with normal ALT levels, with areas under the receiver operating characteristic curve (AUC) of 0.87 and 0.75, respectively.
The researchers also point out that these values were higher than the AUCs achieved with aspartate aminotransferase (0.72 and 0.67, respectively) and gamma glutamyl transpeptidase (0.72 and 0.71, respectively), and were not improved with the addition of HBV DNA and total bilirubin to form a combination index.
Xia et al comment that the underlying mechanism for the function of anti-HBc in hepatic inflammation is still unknown.
But they suggest that it “could play an important role […] through the hepatocytotoxic effects of anti-HBc-secreting B-lymphocytes.”
“Anti-HBc may be a strong indicator for liver damage during a certain cellular immune response in [chronic HBV] patients, and further studies on the mechanism of anti-HBc involvement hepatocellular injury will be worthwhile,” the researchers conclude.
By Laura Cowen
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