Page 50 - AIDSBK23C

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the longitudinal observational EuroSIDA study showed that among 3,496 individuals (2,230
treatment-experienced and 266 treatment-naïve), all of whom started ART in 1997/1998, the
incidence of triple class failure was negligible shortly after initiation of ART, but 21.4% of
treatment-experienced patients and 11.2% of treatment-naive patients had triple class failure 6
years after starting treatment, reinforcing the importance of selecting first-line treatment
regimens that are as potent and tolerable as possible. The incidence of new resistance mutations
in patients remaining on stable antiretroviral therapy despite continued viremia is approximately
1.6/person-year (95% CI: 1.36 – 1.90). Failure to adhere to prescribed therapies threatens the
emergence of resistance. The development of resistance to all three main classes of drugs leads
to limited range of subsequent treatment options, higher rates of disease progression, poorer
clinical outcomes and increased risk of transmission of resistant virus to others.[280]
The use of antiretroviral therapy (ART) with combinations of antiretroviral agents forms
the basis for therapy of HIV infection and has similarities to cancer chemotherapy. Therapy for
adults is based upon CD4 cell count, with recommendations from the International AIDS Society
and from the World Health Organization as follows:[256,281]

CD4 cells (per µL) Recommendation for Treatment

Symptomatic HIV disease Recommend Therapy
≤200 Recommend Therapy
>200 but <350 Consider Therapy (IAS); Recommend Therapy (WHO)
≥350 but ≤500 Defer Therapy (unless viral load >100,000 copies/mL
or CD4 counts declining rapidly
>500 Defer Therapy

Recommendations for initiation of antiretroviral therapy in children and adolescents are
different. One problem in comparing adult to pediatric populations is the variability of CD4
lymphocyte counts in younger persons. Hence, a CD4 percentage of the total lymphocyte count
can be employed as follows:[282]

Age Recommendation for Treatment

Infants, <1 yr Treat all patients

Treatment deferral and intense monitoring may be
considered in asymptomatic infants with CD4 >30% and
uncertainty about the feasibility of adequate adherence

Children 1 to <3 yr Treat all children with CDC class B or C disease

Treat all children with CD4 <25% or <750/µL

Closer monitoring if HIV-1 RNA load >250,000 copies/mL