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5. What is the natural clearance rate of the surface and e-antigen?

Now what about if we do nothing? If we don’t have any therapy at all for hepatitis B, is there a natural clearance rate? Well there is, but it’s very low. And I have to say that I only rarely see this in my practice, but there are some very nice reports in the literature, particularly from Taiwan and China, showing that if you follow a large number of carriers, particularly older individuals, that they will actually lose the surface antigen. The surface antigen, that we abbreviate HBsAg, is really the marker of infection. When that goes away, the antibody of recovery is called the surface antibody, abbreviated Anti-HBs, occurs. But more importantly, as it relates to therapy, is there is an antigen called the “e-antigen”, which is a marker of activity of the virus. And so, it along with DNA indicates an active virus. This particularly applies to what is called the “Wild type” virus. Now the e-antigen will spontaneously convert in about 4%- 12% of carriers per year, even if we do nothing. That means the disease shuts down spontaneously. In over 5 years it’s 40%-50%, over 10 years it’s 70%-80%. These studies come from Asian countries, and also from Brian McMahon, who’s been very carefully studying Native Americans in Alaska and has published some very nice papers. This occurs more often in older individuals and those with elevated liver enzymes. The ALT, that patients sometimes called the “alt”, is the abbreviation for the alanine aminotransferase, it’s a liver enzyme. It’s simply a protein in the liver cell. When the liver is inflamed, that protein gets out of the liver cell into the blood stream, so it’s a marker of inflammation of the liver. The ALT tends to be higher in people who are converting. So some doctors, and you’ll see some guidelines that are conservative will say that if we see a new patient, and the ALT level is up to 200- 400, and the patient is e-antigen positive, that patient may be going into a spontaneous sero-conversion, they’re going to lose the e-antigen and develop the e-antibody, and they’re going to become quiet without therapy, so wait, don’t treat right away. My own philosophy, I would rather initiate therapy and accelerate sero-conversion because when the ALT is elevated, there is liver damage taking place. I would rather accelerate the process if I can. Now up to 20% who lose the e-antigen may revert back and become active, but that’s the high figure, it’s more like 5% over a lifetime. Now the one thing we’ve learned, for those of you who have hepatitis B, if you ever have a malignancy, and have to have chemotherapy, like breast cancer or colon cancer, you need to be protected with an oral agent, like lamivudine or adefovir, because while you’re having chemotherapy, there’s a high likelihood your hepatitis B will reactivate again. Now, oncologists are starting to get that message out, but it’s still not there across the community, so you should be aware of that, that’s one of the issues that will lead to the reactivation of hepatitis B.