Late Diagnosis Gets Earlier
posted: 29/01/2010
Late HIV diagnosis will be sooner after infection, and a new stage of HIV infection, ‘advanced HIV disease’ is proposed for the UK.
‘Late diagnosis’ is fuzzy and confusing – it means different things depending on who you talk to. The boundary line of when diagnosis is late has also been shifting over time. UK experts are now saying we need to end the confusion and bring things up to date so we all talk about and mean the same thing. They looked at thousands of people diagnosed in the UK, their CD4 counts and what became of them.
Late diagnosis matters. Many people are diagnosed late and starting treatment late means you don’t get the full benefit of HIV treatment. People diagnosed late are more likely to get HIV illnesses and die sooner than people who start treatment at the best time. And people diagnoses late are more infectious and therefore more likely to pass on HIV without realising this.
The 'new late' : any CD4 below 350
A CD4 count of 350 is when most people in the UK should start treatment. The UK researchers now say that anyone diagnosed with HIV with a CD4 count below this 350 has a late diagnosis. In the USA, guidelines for treatment now say treatment should start when the CD4 count is between 500 and 350. It is likely that the UK treatment guidelines will soon say something similar. The benefits of starting treatment sooner are becoming clear.
‘Advanced HIV disease’
A new HIV disease stage is also proposed for the UK. If a person at diagnosis has any of the things that are associated with a higher risk of death within three months – such as a CD4 cell count below 200 or an AIDS-defining illness – they should be described as having ‘advanced HIV disease’.
Late diagnosis is a blight
Large numbers of people diagnosed in Europe and elsewhere are diagnosed late. Most of the HIV-related deaths in Europe are among people who were diagnosed late.
Diagnosing more people earlier would help cut the amount of HIV-related illness and death. Cutting late diagnosis would also reduce the spread of HIV - people who are diagnosed late have high viral loads and are more infectious.
What’s late?
Investigators from the UK Collaborative HIV Cohort (UK CHIC) looked at information on 15,774 people seen between 1996 and 2006 to find “a definition that can reliably identify a high proportion of individuals who will die shortly after their HIV diagnosis”.
Overall, 10% of people had a CD4 cell count below 50 cells/mm3 at the time of diagnosis, and another 17% had a CD4 cell count below 200 at diagnosis. But for 14% of the people in the study no CD4 figures at the time of diagnosis were available.
Just under 10% of people had an AIDS-defining illness at the time of their HIV diagnosis. For 2.4% of people this illness was moderate or severe and posed a significant risk of death.
Almost 4 out of 5 people with a CD4 cell count below 50 also had an AIDS-defining illness at diagnosis. Almost half the people with a more serious AIDS-defining illness had a CD4 below 200, but 4 out of 5 people who had a serious AIDS-defining illness at diagnosis had a CD4 count below 50.
206 (1.3%) people in the study died within three months of their HIV diagnosis.
More deaths with lower CD4, advanced illness signs
The death rates were highest for all the disease stages the researchers now propose.
If your CD4 cell count is below 200 at diagnosis the mortality rate within three months is 3%. If the CD4 count at diagnosis is below 5o, the mortality rate after three months reaches 5%.
If you have an AIDS-defining condition when HIV is diagnosed then there is a 6% chance of death within the next three months. If you have a potentially life-threatening AIDS-defining condition at diagnosis then the risk of death rises to 10% within three months.
But a lot of useful data is missing – for 45% of the people who died there was no CD4 count.
Combining CD4 cell counts and clinical characteristics proved a more reliable guide than just looking at CD4 counts, or just looking at clinical stages of HIV illness. Using both together accounted for over two-thirds of the people in the study who died.
Late and advanced disease recommendations
“We propose that any individual who presents with either a CD4 cell count below 200 cells/mm3 or a clinical AIDS event is defined as presenting with advanced HIV disease”, write the investigators.
In addition they suggest that patients diagnosed with a CD4 cell count below 350 cells/mm3, or who develop an AIDS-defining illness within a month of diagnosis should be classified as having their HIV diagnosed late.
The investigators caution that a reliance on CD4 cell counts alone would not identify a substantial number of patients who have advanced HIV disease and a high risk of death at the time of their diagnosis. They write, “these patients may present and die without having their CD4 cell count measured”.
They hope that their proposed definitions will facilitate cross-country comparisons and help identify patients with a high risk of advanced disease at the time of their HIV diagnosis.
Source and Journal reference
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