Q and A


Why do guidelines differ in some countries?

I am very concerned about the discordant guidelines that have been recently updated in the UK and the USA regarding when to start treatment in treatment-naive individuals, like myself.

The UK still recommends to start treatment when CD4<350.

However the USA guidelines have decided that EVERYONE with HIV should start treatment as soon as possible, with special emphasis on those patients with CD4 <500.

My CD4 is about 700 and Viral Load about 1000.

Reading these news has made me very concerned and I feel very uneasy as to what guidelines to follow. I dont understand why would both countries differ so much on their recommendations, unless it is a case where the UK is aiming to save money since HIV Treatment is free on the NHS.

Please help me ease my worries, as I feel like every day that passes I should be on treatment rather than wait till my immune system is irreversibly damaged.


Note: Please see this link for an updated answer to this question.

Thank-you for your question.

The different guidelines in the US and UK are due to different interpretations of study findings and different approaches to healthcare. This can be difficult to understand and it is not surprising that this concerns you.

In the UK treatment is provided on the basis of risk of progression. There is a lot of evidence that starting treatment with a CD4 count of 350 or under reduces the likelihood of becoming ill and developing infections. This has been shown through randomised trials- considered to be the most accurate type of medical trial. The potential for added benefit of starting treatment with a CD4 of 350-500 has not been conclusively shown in this type of trial. Therefore UK HIV experts have decided that the proven benefits of starting treatment earlier do not outweigh the costs and potential negative effects.

In the USA they have a different approach to treatment. the USA guidelines have always been to start treatment at a higher CD4, even when the toxicity of drugs was much higher and potentially more damaging than the virus itself. The current guidelines in the USA are based on observational data from cohort studies. These look at databases of information stored about people taking HIV treatment. These have shown some potential benefit of starting treatment earlier. The data isn’t conclusive however, which is why the UK guidelines remain the same.

A second reason why the USA guidelines contain this higher recommended starting CD4 is because of the healthcare system in the USA. Because health insurance providers would not give treatment to people who were not recommended it by the guidelines there is this higher threshold- meaning that those wishing to start earlier would be given that possibility.

This is obviously something you are concerned about. If you really want to start treatment now, but your clinic has refused to do this, you have two options. The new UK guidelines state that treatment can be given to people with higher CD4 counts in order to reduce the possibility of transmission. This is because of new evidence which shows that having an undetectable viral load (under 50) are much less infectious. Therefore if you were to tell your clinic that you are very concerned about transmitting HIV to a sexual partner, and that this worry was affecting your quality of life in a major way, then they would be able to give you treatment in line with the guidelines.

A second way which you may be able to access treatment is through a medical trial. There is a study currently underway which is looking to answer the question of whether starting treatment at a higher CD4 count will have long term health benefits. This is called the START trial. For more information about the trial please take a look at this link.

As your CD4 count is so strong (well above 500) and your viral load is low there is no strong evidence that you should be worried about not being on treatment. The UK guidelines are based on an interpretation of data that may or may not prove to be right. In the past, guidelines have often got this question wrong. If, having looked at the advantages and disadvantages your decide that you want to start, then in the UK you should be able to do this. Please get in touch with us if your clinic does not give you this option in case we can help.

This answer was updated in January 2016 from an answer first posted in April 2012.


  1. Rebecca McDowall

    Hi Rick,

    There is nothing about you test results that a doctor would be worried about. CD4 % is different for everybody, and there’s a huge variation between people. For HIV negative people the normal range is 24%-68%. Your results are nothing to be concerned by.

    You also don’t need to be worried about the difference between your two readings. It’s possible that your next reading could be higher again. Or it might be very similar to the most recent one. Your doctor wouldn’t see these two test results as significantly different. That’s why he isn’t worried.

    Treatment guidelines in the UK recommend starting treatment when your CD4 count is around 350. This is the reading doctors will use to decide when it’s most important to start treatment. Your CD4 % is generally used to tell whether any big changes in CD4 count are significant or not.

  2. Rick

    I am the same person that posted the original question. I have now received my second results after three months and my CD4 count dropped to 500 (from 680), Viral Load stayed within 1000. CD% Percentage was around 25% in both cases. This is worrying me of course. I have been very stressed these few months and also had a chest infection and a constant cold, which may have affected the CD4 count, although the symptoms have now dissipated. Also, the CD4% seems to be lower than what the CD4 count reveals, since CD4 500 should be around 30%. Why is this? and which is the accurate figure that I should follow in order to start treatment before <500?

    Thank you very much for your advice.

  3. Simon Collins

    Hi Andrew,

    It is not that you have your facts wrong, but there are risk and benefits or early treatment and it is close to a jump of faith to say that because HIV is bad, treatment is always better. This might be proven in the future or it might not. If we knew the answer, the START trial would not be needed.

    There is enough uncertainty for this to be a decision that HIV positive people should also be able to make. Some people want treatment straight away and feel better for it. Others defer until their CD4 count is noticeably being knocked but the virus.

    A recent web blog by Joseph Sonnabend on poz.com discusses the limited evidence for treatment at CD4 counts higher than 500 and the weight and interpretation in the US guidelines.


    Joe is a distinguished British doctor who was both a doctor in New York through the 80’s and 90s when HIV and ADIS first was discovered and an early HIV researcher (he cofounded what later became amFar and ACRIA amongst other things).

    Although I’m less convinced by his comments on conflict of interest – I think the HHS panel are likely to believe they are recommending their patients best interests – his analysis of evidence base and the process is a helpful and sobering read.

  4. Andrew

    We have been informed that after succesful antiretroviral treatment our CD4 count never returns to the original values that existed before becoming positive and usualy remain much lower.
    I would have thought with this in mind that while the above fellow positive who is lucky enought to have been diagnosed before not much damage has been done and therefore has a brilliant strong count of 700 he/she would be better off to immediately start taking treatment to get to undetectable and stop the virus reducing their high count.
    If the treatment is delayed and started at 350 then that is the count they could stay at forever afterwards.
    Have I got all my facts wrong?
    Look forward to being corrected.

  5. Andrew

    We are constantly being told that our cd4 counts very seldom return to their original values that existed before becoming positive.

  6. Chris

    Guidelines are not absolutes, perhaps you need to explain in detail the concerns you have to your consultant. It is important that your HIV team take a wider overview of your wellbeing, and not just focus on blood results.

    If you are still not happy change your consultant / clinic. Hope you get things sorted out.


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