Genetics of Patients with HIV May Impact Disease Progression

Genetic differences in both humans and HIV itself influence the course of infection, a new study finds.

Scientists know that the rate of disease progression differs among patients with HIV. Individuals living with HIV who have a higher viral load tend to see their disease progress faster.

Prior studies have shown that an individual’s genetics and the genetics of the HIV strain, together, influence viral load. In a study published in PLOS Computational Biology, investigators were the first to examine the relative impacts of human and viral genetics on viral load with the same group of patients.

For the study, the authors obtained patient and viral genetic data from 541 individuals living with HIV. To determine how human and viral genetics may explain the differences in viral loads between the patients, the investigators used the computational modeling method called linear mixed modeling.

The results of the study showed that genetic differences between HIV strains explained 29% of differences in viral load among the patients, whereas, human genetic variation explained 8.4%.

Together, these differences explain 30% of viral load variation. According to the investigators, the findings suggest that patient genetics exert a majority of its influences by inducing genetic mutations in HIV as it multiples within the patient.

“Our patient demonstrates that the genetic make-up of both the patient and the infecting virus contribute to the clinical course of HIV infection,” said study director Jacques Fellay.

The authors noted that more research needs to be done using a larger patient population to confirm their findings. Additionally, because the investigators used a combination of host and pathogen data to provide new insight into the genetic determinants of HIV control, a similar strategy could be used to better understand other chronic infectious diseases.