Question

At what CD4 count should treatment be started?

26 April 2007. Related: All topics, CD4 and viral load, Newly diagnosed, Starting treatment.

At what CD4 count should treatment be started? if the normal CD4 count in HIV-negative people ranges from 500 to 1500, how can one know if a CD4 count of 500 is less or enough for any individual?

Answer

Answer: Simon Collins

Thank you for posting your question and allowing us to answer this online.

Anyone with symptoms relating to HIV is usually recommended to start treatment, whatever their CD4 count.

Otherwise, guidelines for when to start treatment are slightly different in different countries, and can change over time.

Without specific symptoms, in the UK, treatment is currently recommended before your CD4 count falls below 200 cells/mm3.

In practice this can be anywhere between 200 and 350 cells/mm3 and relates to how quickly the CD4 count has been falling over the previous year.

In the US, and some other countries, treatment is recommended before CD4 counts fall below 350 cells/mm3.

There probably isn’t much difference between these two approaches. The UK guidelines are likely to move towards starting a bit earlier, mainly because treatments are now more tolerable that they were a few years ago, so the balance of risk and benefit of treatment is in favour of earlier treatment.

Your question about knowing whether HIV has caused any immune damage given the wide range of CD4 counts in an HIV-negative person is a very good one. Some HIV negative people have a ‘normal’ count that is even lower than 500, and CD4 counts also drop in everyone age we get older and certainly once we are in our 50s and 60s.

Because it is very unusual to have had a CD4 count result from before someone was infected with HIV, we have to judge the damage caused by the virus using CD4 results over time. This includes the first result, and then looking for any trend from the results taken every 3-6 months afterwards.

If the trend is stable – at any CD4 count above 350 cells/mm3, then there is no urgency in starting treatment. If it started at 900 but is falling by 200 every 3 months then it is likely you would need to start treatment earlier. It is fairly rare for HIV to progress so quickly though. On average CD4 counts drop by around 50 cells/mm3 a year in people who are not on treatment.

Ongoing research is looking at whether there are any additional benefits for starting treatment at higher CD4 counts, including before CD4 counts drop below 500 cells/mm3. So far, there hasn’t been any clear benefit shown from starting treatment any earlier.