HLA-B5701 and low viral load?


I am 4.5 months since infection. My viral load is 4,000 copies/ml and CD4 > 500. My doc said I am not yet at my set point. I tested positive for the HLA-B5701 allele. I found several papers that discuss a correlation between the presence of HLA-B5701 allele and Long Term Non-Progressor Status. But my doc did not mention this fact to me. Is it common practice to omit informing a patient that HLA-B5701 is predictive of low viral set point and LTNP status?


Thanks for your question.

We do not fully understand the factors that determine the height of the viral setpoint for any particular individual. We know that it is a complex interaction between the immune system and the particular virus with which a person has been infected. The genetic makeup of a person must be involved, because the same virus can infect 2 people and have very different outcomes. It was recognized fairly early on that most slow progressors were not infected with deficient (or weakened) virus, but that the interplay with the immune system and the genetic makeup of the host was important.

Several factors have been identified that are linked to progression including the lack in some people of co-receptors (called CCR5) on their CD4 cells that are needed for the virus to attach and enter the cell and HLAB5701. HLAB5701 is molecule expressed on the surface of our immune cells that is part of a system that enables the body to distinguish its own cells from foreign cells. While the presence of HLAB5701 is more common among people who are slow progressors with HIV infection, it is also found among normal progressors in the rate that might be expected in the general population. Since only about 1-2% of people with HIV are slow progressors, the majority of people with B5701 will be normal progressors. What that means is that knowing you are HLAB5701 by itself cannot predict that you will be a slow progressor (since many with it are normal progressors). This is the likely reason your doctor did not bring it up. There are other factors that might be linked with being B5701+ that might need to be in place to be a slow progressor. The usual reason we screen for HLA B5701 is to see if a person can take one of the anti-HIV meds called abacavir with lower risk of serious side effects (HLAB5701+ people should not use abacavir containing treatments).

I hope you are among the slow progressors, but either way you will do well if you monitor your HIV closely and treat it when the time comes.

Best, Joe