Hepatitis B virus flares common in postpartum period

By Reuters Staff

One-quarter of pregnant women with chronic hepatitis B virus (HBV) infection will develop increased liver inflammation after giving birth, although these flare-ups are typically asymptomatic and resolve within a year, according to a new prospective study.

Women who are positive for hepatitis B antigen (HBeAg) were more than twice as likely to have flares, Dr. Michelle Giles of Alfred Hospital and Monash University in Melbourne, Victoria, Australia and her colleagues found.

"Clinicians need to be aware of this phenomenon so women at the highest risk can be appropriately identified for close monitoring in the postnatal period," they conclude in their report, published online November 27 in Gut.

While some research has suggested that hepatic flares are more common postpartum, the studies were small and retrospective, Dr. Giles and her team point out. To investigate prospectively whether changes in the immune system during and after pregnancy might affect HBV activity, the researchers enrolled 126 pregnant women with HBV.

Twenty-seven of the 108 women (25%) with sufficient data to be evaluated had flares after giving birth, which the researchers defined as alanine aminotransferase (ALT) levels twice the upper limit of normal (ULN) or twice the upper limit of baseline ALT.

Thirty women were HBeAg-positive at baseline. On multivariate analysis, there was a trend toward a reduced risk of flare with greater parity (p=0.066), while the increased risk with baseline HBeAg positivity fell just short of significance (adjusted incidence risk ratio, 2.56; p=0.051).

Four of the women had ALT levels five times above the ULN but less than 10 times above the ULN, while four had ALT levels more than 10 times as high as the ULN.

The women who had flares with ALT peaks less than five times the ULN all had returned to normal ALT levels by nine to 12 months postpartum. Just two women in the study who had flares, both of whom had ALT levels greater than 10 times the ULN, did not return to normal by 12 months postpartum.

All women in the study had higher ALT levels in their first and second trimester compared to their third trimester, and higher ALT postpartum than during pregnancy.

"Taken together, these data support the hypothesis that the immune suppression during pregnancy reduces hepatic necroinflammatory activity and that these changes reverse postpartum in association with immune restitution," Dr. Giles and her colleagues write.

Six women in the study were on antiviral therapy, four of whom had flares. "Therefore, in addition to HBeAg positivity and parity, the use of antiviral therapy may be a third important factor to consider when developing guidelines identifying which women should be targeted for close follow-up postpartum," the researchers write.

SOURCE: http://bit.ly/1vWmJhc

Gut 2014.

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