Hepatitis B -- retest

Following up on my postings from last month -- when I discussed how
I had tested positive (reactive) on the hepatitis B core antibody
test, but negative on several other hepatitis B tests:

My local blood bank offered to retest me, using a new and improved
hepatitis B screening test (the PRISM test) which they had recently
started using. The results just came in, and this time I tested
"non-reactive" for the hepatitis B core antibody (combined IgG + IgM).

The people at the blood bank believe this means my earlier, reactive
anti-HBc results (from the blood bank in 2001, and from my doctor in
2003) most likely represented false positives -- i.e., that I had in
fact never been exposed to hepatitis B after all, and that my blood
most likely was (and is) safe for transfusion to others.

Now, it might be worth noting that my score on the new test, though
definitely in the non-reactive domain, was slightly iffy. On a scale
where the dividing line is 24,000, and figures higher than 24,000 are
considered non-reactive, my measurement was 30,000. According to the
blood bank expert who discussed the test with me, most of the old
"false positives" retested using the new test have been measured at
around 40,000. I was told it wasn't clear just what my "weakly non-
reactive" score means -- e.g., just what might be causing my blood
not to score as "high" on the test as others who were non-reactive
-- or, alternatively, if in fact I really have been exposed to HBV,
how long ago I would need to have been exposed for my immunity to be
as distant as it would have to be to explain all the other negative
test results.

In any case, I've been told that I'm welcome to donate blood again,
and that it's unlikely (not totally impossible, but unlikely) that
I'll test "reactive" in the future on the new hepatitis B screening
test.

Comments from anyone on the new PRISM screening test, the "false
positive" interpretation of the old results, my "slightly non-
reactive" score on the new test, whether my blood really is safe,
or anything else?

Rich Wales richw@xxxxxxxxx http://www.richw.org
*DISCLAIMER: I am not a doctor. My comments are for discussion pur-
poses only and are not intended to be relied upon as medical advice.

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