Why do you start HIV therapy when CD4 count is <200,000/mL?

[sgv]

Okay, so I'm a dental student and in my pharmacology class, the professor said that HIV/AIDS patients are to initiate drug therapy when CD4 count is below 200,000/mL.

Is this correct? Why wouldn't you start drug therapy as soon as possible? How is it advantageous to wait until a patient's CD4 is down to 200,000/mL or less?

So I just googled for the normal CD4 count and it's 500-1,500/uL.

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[NickNaylor]

I'm assuming that's a typo and your professor meant <200. It also sounds like your professor has an out-of-date understanding of HIV therapeutics. Delayed treatment used to be the mainstay because 1) patients with lower CD4 counts demonstrated a clear benefit to therapy while it was unclear whether patients with higher CD4 counts actually benefited from therapy and 2) the drugs were expensive and concerns about serious side effects were common. As a result, treatment was delayed until patients would be more likely to have a benefit from therapy.

That's no longer the case. Studies have shown that delayed treatment is associated with less than optimal responses (i.e., quicker immunological decline, more risk of complications of HIV infection, etc.). I'm no infectious diseases expert, but with some exceptions I think the standard of care is now to start ART as soon as possible.

 

[Jabbed]

CD4 count are commonly measured in cell/microliter or cells/mm^3. 200,000 cells/mL = 200 cells/mm^3 = 200 cells/microL

The historic rationale for delaying therapy when CD4 counts are greater than 200 cells/microL were related to a cost/benefit analysis of drug toxicity/resistance vs efficacy as well as lack of trial data. These reasons no longer apply. Within the last decade or so the improvements in retroviral therapies have changed the protocols and guidelines for treatment such that all HIV patients are started on therapies regardless of CD4 counts.

Your professor sucks btw.

 

[joker2400]

CD4 count are commonly measured in cell/microliter or cells/mm^3. 200,000 cells/mL = 200 cells/mm^3 = 200 cells/microL

The historic rationale for delaying therapy when CD4 counts are greater than 200 cells/microL were related to a cost/benefit analysis of drug toxicity/resistance vs efficacy as well as lack of trial data. These reasons no longer apply. Within the last decade or so the improvements in retroviral therapies have changed the protocols and guidelines for treatment such that all HIV patients are started on therapies regardless of CD4 counts.

Your professor sucks btw.

My understanding via our ID block is that its recommended but ultimately a clinical decision as your patients need to be compliant with the therapy to prevent the development of resistance. So we were taught that levels <250 generally get treated regardless of possible compliance issues

 

[Jabbed]

I'm assuming that's a typo and your professor meant <200. It also sounds like your professor has an out-of-date understanding of HIV therapeutics. Delayed treatment used to be the mainstay because 1) patients with lower CD4 counts demonstrated a clear benefit to therapy while it was unclear whether patients with higher CD4 counts actually benefited from therapy and 2) the drugs were expensive and concerns about serious side effects were common. As a result, treatment was delayed until patients would be more likely to have a benefit from therapy.

That's no longer the case. Studies have shown that delayed treatment is associated with less than optimal responses (i.e., quicker immunological decline, more risk of complications of HIV infection, etc.). I'm no infectious diseases expert, but with some exceptions I think the standard of care is now to start ART as soon as possible.

You beat me to it

Interesting blog post. Have you taken a look at the lobbying spending database on OpenSecrets by any chance?

 

[Jabbed]

My understanding via our ID block is that its recommended but ultimately a clinical decision as your patients need to be compliant with the therapy to prevent the development of resistance. So we were taught that levels <250 generally get treated regardless of possible compliance issues

http://jama.jamanetwork.com/article.aspx?articleid=1889146

 

[Kahreek]

guidelines distinguish HIV+ from AIDS by the cd4 count, lower in the later. (although some authors prefer to classify both as the same)
Therapy is usually started with the serological diagnoisis.