Re: Aaverage Indian CD4 counts'

[Guest guest]

Marsrover_89 asks about 'average Indian CD4 counts'.

I think this comes from a concern that if 'normal' counts are lower in an

Indian population, then current guidelines for treatment of HIV might lead

to over-treatment or undue anxiety among people diagnosed with HIV who

become aware of their CD4 counts.

How realistic a concern this may be, given limited access to treatment and

the indisputably low CD4 counts (expressed as a number of cells per cubic

millimetre) reported in people who actually go on treatment, is for readers

to make up their own minds about. Western guidelines have changed, even in

the USA, from advocating treatment for adults when CD4 counts are below 500

to proposing treatment when they fall repeatedly below 350 - with the real

goal, at least here in the UK, being to make sure that treatment starts

before a threshold of 200 is crossed. WHO currently recommends treatment at

or below a level of 200. [CD4 values in young children are much higher, even

in the presence of disease, so different treatment criteria may be needed.]

I would not have thought there was any reason to do extensive surveys of

healthy populations, since CD4 count doesn't mean much outside of specific

contexts - such as monitoring HIV disease, where perhaps what matters most

is the trend over time. However, what information I've seen lately (see

below) doesn't suggest that Indian average CD4 counts in healthy HIV

negative adults are any different to those seen in Western Europe or North

America.

When reading any claims about CD4 counts in any population, especially in

the older literature, a question that needs to be asked is whether the

laboratory that carried out the tests takes part in a quality assurance

scheme, since there can otherwise be significant inter-laboratory variation.

Others may be able to say if such a scheme currently exists in India or how

extensive it might be. (Brazil, for example, has a substantial national CD4

quality assurance scheme which is also linked in to an international quality

assurance scheme, NEQAS, run from Sheffield in the UK.)

A small study from Chennai presented at the Paris IAS conference last month

claimed to show (but in fact did not show, because it was too small and did

not apply appropriate analytical methods) that total lymphocyte counts could

be substituted for CD4 counts. This was based on testing the blood of 11

people without HIV and 5 people with HIV/AIDS. Quoting the relevant sections

from the abstract:

" 2 ml of EDTA-treated whole blood was collected in a vacutainer tube from 11

normal healthy individuals and five HIV-infected patients who were

classified as symptomatic from Tambaram sanatorium hospital. These samples

were transported to the laboratory (DEM) and processed on the same day. Flow

cytometer (Beckman coulter-USA) [was used] for enumerating CD4 T cells " ...

" The CD4 T cell values ranged between 690-2420 per mm3 in case of the normal

individuals and 74-268 per mm3 CD4 T cells in HIV-infected persons. ... The

mean CD4 T cell counts in normals was 1177 per mm3 and 172 per mm3 in

HIV-infected persons. "

REFERENCE: Srihari BJ et al. Correlation of CD4 T cells with total

lymphocyte counts (TLC) - a marker for monitoring HIV/AIDS patients in

resource limited settings. Antiviral Therapy 8 (Suppl. 1): abstract 477.

2003.

Hope this is helpful - and perhaps it can prompt someone who has greater

expertise and knowledge to cite another larger and more relevant Indian

study.

n Meldrum, International Editor, www.aidsmap.com

NAM, Lincoln House, 1 Brixton Road, London, England SW9 6DE

E-mail: <julian@...>