February 22, 2008

Discordant Responders Have Faster Disease Progression

HIV-positive people who have discordant responses to antiretroviral therapy—for example, an undetectable viral load but a blunted CD4 immune response—may progress faster to AIDS or death than those who respond both virologically and immunologically to treatment, according to a new study to be published in an upcoming issue of the Journal of Acquired Immune Deficiency Syndromes.

Approximately 20 to 40 percent of HIV-positive people receiving antiretroviral treatment have discordant responses to treatment, whether it’s a positive immunologic response in the absence of a virologic response or vice versa. While some studies have shown patients with discordant treatment responses are more likely to develop an AIDS-defining illness or die than those who have concordant responses to treatment—positive immunologic and virologic responses—results have been inconsistent.

To better understand the clinical consequences of discordant treatment responses, Ruiman Tan, MD, MSPH, from the School of Public Health at the University of Alabama at Birmingham (UAB), and his colleagues reviewed the medical records of patients

who received their health care at the UAB outpatient HIV clinic. Their analysis included 404 patients who had initiated antiretroviral therapy after January 1, 1995, and who had at least one CD4 cell count and viral load test on record between three and nine months after starting treatment.

Tan’s team split the patients into four groups, based on whether the patients had an increase of at least 50 CD4 cells and achieved an undetectable viral load. One group, the concordant responders, had a good CD4 and viral load response. The second group, the discordant immunologic responders, had a good CD4 response but never achieved an undetectable viral load. The third group, the discordant virologic responders, had a poor CD4 response, but did achieve an undetectable viral load. The last group, the concordant non-responders, had poor CD4 and viral load responses to treatment.

The majority of the patients, 70 percent, were concordant responders. As expected, they faired the best were the least likely to die or develop a new AIDS-related illness. Five percent of the patients were concordant non-responders and, not surprisingly, had the fastest rates of disease progression.

As for discordant responders, 16 percent of the patients were immunologic responders and 9 percent were virologic responders. Both types of discordant responses were significantly associated with earlier development of an opportunistic infection or death. According to the study authors, the virologic responders did slightly better than the immunologic responders.

People who had the lowest CD4 counts before starting antiretroviral therapy, and African Americans, were most likely to experience disease progression regardless of their response to therapy.

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Dr. Abraham Calleros,GN,PA,DD, West Allis, 2008-03-03 13:50:04
I don't take medications,have beeb HIV/Hep-C positive since1986. CD4 went from 350 to 756 in the last year, viral load undetectable. Still trying to find out why, yet my clients are taking meds, not doing great at all. I still trying to find the best treatment for my clients. Yet, others seem to be doing okay after starting antiretroviral therapy.

joe, Montgomery, 2008-03-02 22:35:06
I worry because I am discordant. My vl is undetectable but my cd4s aren't going up as much as I thought.