Cognitive function continues to improve up
to one year after starting antiretroviral therapy, according to the results of
a small international study published in HIV
The investigators monitored changes in
cognitive function six and twelve months after patients started therapy.
Significant overall improvements were observed at both time points.
Changes in cognitive function varied
according to treatment regimen and improvements were less pronounced in
patients taking a regimen based on efavirenz (Sustiva, also in Atripla)
than those seen in people taking alternative regimens.
“Overall, and of clinical relevance, we
observed improvements in neuro-cognitive function in neuro-asymptomatic
HIV-infected subjects commencing antiretroviral therapy for the first time,”
write the authors. “The majority of improvements were present within 24 weeks
of commencing therapy and continued improvements were observed until 48 weeks
after starting therapy.”
It is well recognised that starting HIV
treatment can lead to improvements in neuro-cognitive function. However, few
studies have explored the timing or dynamics of cognitive changes in people starting antiretroviral treatment.
Investigators from the ALTAIR study therefore
designed a sub-study involving 28 patients. All these people were starting
HIV therapy for the first time and none had symptomatic cognitive dysfunction.
All the patients
received FTC/tenofovir (Truvada). They were randomly allocated a third drug:
efavirenz; ritonavir-boosted atazanavir (Reyataz);
or AZT + abacavir (Ziagen).
was assessed at baseline using a battery of computerised tests. These measured
detection, identification, speed, working memory and executive function. The
tests were repeated 24 and again 48 weeks after treatment was started.
None of the
patients were taking antidepressants or anti-psychotic therapy, and
people with drug or alcohol problems, as well as those with hepatitis
C-co-infection, were excluded from participation.
Median CD4 cell
count increased from 218 cells/mm3 at baseline to 342 cells/mm3
at week 48, at which point all but one patient had an undetectable viral load.
neuro-cognitive function were observed at week 24 and these continued through
to week 48. The overall increases in neuro-cognitive scores were 0.16 at week
24 and 0.18 at week 48. Improvements in speed scores were also observed at both
time points (week 24: - 0.09; week 48: - 0.14, a negative score indicating
increased speed and improved response).
scores improved by week 24 but were unchanged at week 48 (0.24, 0.24). Executive
functioning also improved, but this was not apparent until week 48.
performance varied between the study arms. Most notably, speed scores
deteriorated slightly for patients in the efavirenz arm while improving for
patients taking the other study medications. By week 48, the difference between
the efavirenz and the AZT/abacavir arms was significant (p = 0.04).
suggest this finding could be due to “a specific effect of efavirenz…acute
neuropsychiatric disorders are well described with efavirenz use and may
persist with extended therapy.”
improvements in executive function were not seen until week 48, and then only
in the AZT/abacavir-treated patients (p = 0.02).
neuro-cognitive function in individuals commencing combination antiretroviral
therapy for the first time may be related to control of HIV viraemia and/or
recovery of cerebral synaptodendritic injury,” comment the authors.
their findings “may assist in the design and development of future treatment
and research programmes assessing changes in cerebral function over time in HIV