December 12, 2013
Patients infected with the HIV-1 recombinant form A3/02 saw a faster progression to AIDS-related death than those infected with HIV A3 sub-subtype, researchers reported in the Journal of Infectious Diseases.
“Our study indicates that there are some HIV variants that are more aggressive than others,” Angelica Palm, a PhD student at Lund University in Sweden, told Infectious Disease News. “It is important to be aware of the fact that different variants may vary in aggressiveness, and to try to understand the mechanisms behind these differences.”
Palm and colleagues evaluated a cohort of police officers from Guinea-Bissau in West Africa. The cohort formed in 1990 and the officers provided blood plasma samples every 12 to 18 months, with follow-up until February 2011. The researchers extracted viral RNA from the samples to perform sequencing and evaluate the HIV-1 subtype and circulating recombinant forms (CRFs). They identified sequences of sub-subtype A3 and the CRF02_AG as parental sequences and a recombinant sequence was A3/CRF02_AG (A3/02).
Among the 191 available samples, 147 were included in the analysis. The dominant sequence was CRF02_AG (n=78), followed by sub-subtype A3 (n=42). The A3/02 recombinant virus was identified in 22 individuals. Five had other subtypes and were excluded from the analysis.
The median time to AIDS-related death for the A3 group was 11.3 years compared with 9 years for the CRF02_AG group and 8 years for the A3/02 group. When comparing AIDS-related deaths, the adjusted HRs were 2.2 for CRF02_AG group vs. sub-subtype A3 group, and 2.9 for A3/02 group vs. the A3 group.
“The HIV pandemic is extremely dynamic and new variants are constantly formed,” Palm said. “With the knowledge we have today, we can only speculate on the effect of these findings in practice. However, it is important to point out that the medications we have today appear to be equally potent against all known HIV variants.”
Palm said HIV-1 used to be relatively geographically isolated, and variants were typically confined to specific regions.
“With an increased mobility of people, this is changing and the HIV pandemic is becoming more and more heterogeneous,” Palm said. “With this in mind, it would be interesting to study if new recombinant variants of HIV-1 are spontaneously arising in other parts of the world, and in the longer run, if they are also associated with faster disease progression.”
Angelica Palm can be reached at firstname.lastname@example.org.
Disclosure: Palm reports no financial disclosures.