Clues to the hepatitis mystery
Thirteen centuries ago, Pope Zacharias quarantined jaundiced patients to stop liver sickness from spreading through Rome. But despite the fact that researchers (and a pope) have long thought some forms of liver disease -- namely hepatitis -- to be contagious, it took centuries of investigation before a team of scientists discovered the cause of infection. Even then, it was largely by chance.
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In combing Australian aboriginal blood for cholesterol-carrying proteins in the early 1960s, physician and researcher Baruch S. Blumberg and his colleagues stumbled across a protein far rarer than the one they were seeking. They dubbed the protein the Australia antigen and began looking for it elsewhere in their stores of patients’ blood.
The antigen was rare in the United States but common among Asians, Africans and some Europeans. Attempting to make sense of the patterns, they looked for the protein in populations around the globe. It often turned up in people with leukemia and those who had blood transfusions. Down syndrome patients were highly likely to have it in their blood, as were Japanese who had lived in wartime Hiroshima.
But the first clue linking Australia antigen to liver disease came from Claxton, Ga., where a local family doctor let the researchers test the blood of several hundred of his patients. They found just one Claxton patient with Australia antigen -- and the patient happened to have hepatitis.
Blumberg’s team continued screening populations for the antigen, now with a new link in mind.
The most important clue tying the antigen to hepatitis came in 1966, from a mentally ill patient in New Jersey named James Bair. The patient had no Australia antigen in early blood tests. But on a subsequent test the antigen appeared. Bair, the researchers concluded, had been recently infected.
When they tested to see if Bair’s liver function had changed, they found it had. Since acquiring the Australia antigen, Bair had acquired the symptoms of a mild case of hepatitis.
Over the course of the following year, Blumberg and colleagues continued testing scores of hepatitis patients for the Australia antigen. In 1967, they published their results: the Australia antigen, they concluded, appeared to be the agent that caused one form of infectious hepatitis.
In time, Australia antigen was identified as part of the virus that causes hepatitis B, which has infected nearly a third of the world’s population and still causes more than 350 million cases of chronic liver disease each year. In a domino effect, Blumberg’s 1967 discovery led to some of the greatest advances in medicine in the last century. Hepatitis B’s blood-borne transmission route was revealed. Donor blood is now routinely screened for the disease, at least in the United States. The discovery helped pave the way for the identification, by researchers in the 1970s and ‘80s, of the viruses that cause hepatitis A, C, D and E. In 1982, the first vaccine to prevent a major form of cancer, the hepatitis B vaccine, was approved. And just a few years before, Blumberg received the Nobel Prize for the research that uncovered a long evasive virus.
Elena Conis
