CD4 cell count monitoring more than once a year is
unnecessary for people doing well on HIV therapy, investigators from the
United States report in the online edition of Clinical Infectious Diseases. They found that there was a 99%
probability over five years that people whose viral load was suppressed and
who had a CD4 cell count above 300 cells/mm3 would maintain a CD4 level
adequate to protect them from opportunistic infections.
“Our data supports less frequent CD4
monitoring in clinically stable, virally suppressed patients and suggests that
routine CD4 monitoring for this population may be unnecessary,” write the
They believe that reducing the frequency of
CD4 cell testing would have benefits for both providers and patients, saving
substantial sums of money and reducing anxiety in people with HIV.
The author of an editorial accompanying the
study labelled the current frequency of CD4 cell monitoring in people undergoing successful HIV therapy a “wasteful addiction”.
CD4 cell counts are used to gauge the health
of the immune system and have long been a central component of HIV care.
Regular monitoring is important for people who are not taking antiretroviral
therapy, and a fall in CD4 cell count to around 350 cells/mm3 is the
threshold for starting antiretroviral therapy in the United Kingdom. (Other countries have begun to recommend earlier treatment, although expert opinion in the United States remains divided on when to start treatment in the absence of data from a large randomised study.)
Current United States treatment guidelines
recommend that people who are doing well on HIV treatment with an
undetectable viral load should have their CD4 cell count monitored every six to
Investigators from the Department of
Veterans Affairs in Washington DC wanted to see if this frequency of monitoring
was clinically justified. They especially wanted to establish the risk of the CD4
cell count falling to below 200 cells/mm3 – indicating vulnerability
to HIV-related opportunistic infections and the need for prophylaxis – for
people treated with anti-HIV drugs whose viral load was suppressed to below
A total of 832 treated people who
received care between 1998 and 2011 were included in the study. All had paired CD4 cell and viral load results. The median period of follow-up was 7.7
years and the median interval between CD4 and viral load monitoring was 113
Overall, 93% of participants maintained their
CD4 cell count above the 200 cell/mm3 threshold during periods of
virological suppression. In 61 participants CD4 cell count dipped below this level.
However, in 24 individuals the cause was unrelated to HIV.
The investigators calculated that people with CD4 cell counts between 300 and 349 cells/mm3 and virologic
suppression had a 95% probability over four years of maintaining a CD4 cell
count above the 200 cell/mm3 level. When baseline CD4 cell count was
above 350 cells/mm3, the probability was 97% and increased to 99%
when non-HIV-related causes of CD4 cell count decline were excluded.
The investigators believe their results
show that frequent, routine monitoring of CD4 cell count in people undergoing
successful HIV treatment is unnecessary, even harmful.
“Reduced CD4 monitoring would provide a
substantial cost saving,” they write. “For example, 55% of our patients had
both viral suppression < 200 and CD4 > 300...if these patients were
monitored only annually, over $41,000 would be saved.” Another benefit would be
“alleviating patient anxiety from fluctuations in serial CD4 due to laboratory
and physiologic variability”.
The author of an accompanying editorial
believes that frequent monitoring of CD4 cell count in stable, treated patients
with virologic suppression is unnecessary, with no impact on “clinical decision
He suggests that care guidelines should be
revised, removing the recommendation for regular CD4 cell count tests in
clinically stable patients. Instead, guidelines should stress the primacy of
viral load monitoring for individuals treated with antiretroviral drugs.
“We would need to continue educating our
patients about why we are changing our practice,” writes the author. “The
message should be simple – we no longer need this test to make decisions about
Note: these findings should be discussed with a medical professional familiar with your medical history before making individual decisions about the frequency of clinic visits.