Blood samples now being stored

[NB: The text of this article has been updated since this newsletter was first published.]

In 1997 we started asking Vanguard participants to provide a small blood sample on an annual basis to be frozen and stored. These samples are being coded to match the questionnaires, and confidentiality is assured. As of March '99, over 550 participants have provided blood samples. [NB: This figure has been updated since this newsletter was first published.]
	Vanguard Nurse Mary Lou Miller

By storing blood, we will be able to:

• test the blood for other viruses such as hepatitis C;
• conduct future tests to look for diseases that have not yet been identified;
• compare genetic information of people who test HIV+ with those who don't;
• compare the immune systems of seroconverters before and after infection;
• and look for genetic resistance to new drugs such as protease inhibitors.

There are now three test sites able to store blood samples: Vanguard nurse Mary Lou Miller, Dr. Brian Woodfall and Dr. Phil Sestak. If you are willing to provide us with a blood sample and have not yet done so, please let us know, or contact one of these three test sites directly. If we receive both a completed questionnaire and a blood sample, you will receive an honorarium of $10.

Isn't HIV antibody testing enough?

As of March '99, over 800 Vanguard participants have been tested for HIV antibodies. [NB: This figure has been updated since this newsletter was first published.] The results of these tests have allowed us to calculate HIV infection rates in the community. But there is a lot of other information that can be gained from blood. Until now it has not been possible for us to gather any other information, as once the HIV tests are completed the labs have thrown the blood away.

Unforeseen benefits of storing blood samples:

Most of what we now know about HIV transmission and disease progression has been learned through studies such as the Vancouver Lymphadenopathy-AIDS Study (VLAS), which has been storing blood samples since the early '80s. Stored blood from VLAS participants has contributed greatly to our understanding of HIV disease progression. When the VLAS began in 1982, HIV hadn't even been identified. When tests for HIV antibodies became available in 1984, we were able to test the stored blood samples and to see how long some participants had been infected.

Similar benefits of storing blood samples were shown by a study of gay men in San Francisco, which began storing blood in the late 1970s with the original intention of studying infection rates for hepatitis B. When tests for HIV antibodies became available in the early 1980s, San Francisco researchers were able to test the stored blood samples to get a rapid estimate of HIV prevalence in that community.