Observations of the rapid development from HIV to AIDS by clinicians in Cuba have led to the identification of a rapidly progressing strain of HIV. While there are over 60 strains of HIV due to mutations, this newly identified mutation is associated with progression to AIDS within 3 years of infection.
When Cuban health officials noticed a disturbing trend in AIDS infections, they alerted Dr. Anne-Mieke Vandamme of the University of Leuvan in Belgium.
“We have a collaborative project with Cuba and the Cuban clinicians had noticed that they recently had more and more patients who were progressing much faster to AIDS than they were used to [seeing]. In this case, most of these patients had AIDS even at diagnosis already,” Vandamme told Voice of America.
Typically, HIV will progress to AIDS in five to 10 years without treatment. Officials in Cuba were noticing that patients who had been HIV positive for less than three years were developing AIDS. Such a rapid progression of HIV could be caused by several factors including an individual’s genetic makeup and immune response.
To investigate the rise of patients with rapid progression to AIDS (AIDS-RP), Vandamme and an international team of researchers recruited patients at various stages of infection who had not previously received treatment.
Adult patients with HIV-1 seeking treatment from the Institute for Tropical Medicine “Pedro Kourí” (IPK) were recruited for the study.
Two groups of recently diagnosed (within three years) HIV-1 patients were recruited – one group who had progressed to AIDS (n= 52) and another (n=21) which was AIDS-free at three years.
Another group of chronically infected individuals who had developed AIDS after an average of 9.82 years (n=22) was also retrospectively assessed.
In comparison to the other two groups, those with AIDS-RP were more likely to be heterosexual, and more likely to engage in unprotected sex. Additionally, those with AIDS-RP were more likely to be infected with a new form of HIV – CRF19-cpx.
The new form is a combination of three sub-types (A, D, and G), and all CRF19-cpx infected patients were found to have AIDS-RP.
“Here we had a variant of HIV that we found only in the group that was progressing fast. Not in the other two groups. We focused in on this variant [and] tried to find out what was different. And we saw it was a recombinant of three different subtypes,” explained Vandamme.
The team found that in this aggressive strain of HIV, the virus switched co-receptors (points at which HIV attaches to a cell) very quickly.
As Vandamme explains, “[t]here are two types of co-receptors that HIV can use: CCR5 or CXCR4. And in the normal progression of the HIV to AIDS it often happens that the virus switches co-receptor. It almost always starts with using CCR5 and then it switches to CXCR4 after many years. And once it switches the progression to AIDS goes very fast.”
Yet the new variant switches co-receptors very quickly, leading to the rapid onset of AIDS. According to Vandamme, the sub-type D could be contributing to the early switch. “Several studies have reported the association of HIV subtype D with faster and subtype A with slower disease progression,” the authors write.
While the new strain responds to most antiretroviral drugs, its rapid progression narrows the time frame for people to get diagnosed. According to the CDC, approximately 20 percent (or one in five) people with HIV don’t know they are infected. These latest findings underscore the need for people to get tested often.
The quick disease progression of this new strain of HIV means that by the time a person knows they’ve been infected with HIV, they may already have AIDS.
Vivian Kouri, Ricardo Khouri, Yoan Alemán, Yeissel Abrahantes, Jurgen Vercauteren, Andrea-Clemencia Pineda-Peña, Kristof Theys, Sarah Megens, Michel Moutschen, Nico Pfeifer, Johan Van Weyenbergh, Ana B. Pérez, Jorge Pérez, Lissette Pérez, Kristel Van Laethem, Anne-Mieke Vandamme. CRF19_cpx is an evolutionary fit HIV-1 variant strongly associated with rapid progression to AIDS in Cuba. EBioMedicine, 2015; DOI: 10.1016/j.ebiom.2015.01.015
KU Luven, Press Release