Detectable viral load may be associated with increased pain sensitivity in persons living with HIV: Preliminary findings

Objective. Animal models have previously shown that HIV is associated with hyperalgesia, or heightened sensitivity to painful stimuli. Efforts to determine whether this finding translates to humans are presently lacking. Among persons living with HIV (PLWH), those with detectable viral loads may be at greatest risk for heightened pain sensitivity. It was hypothesized that PLWH with detectable viral loads would be more sensitive to painful stimuli compared with PLWH without detectable viral loads and healthy controls without HIV. Design. A total of 47 PLWH and 50 communitydwelling, healthy adults without HIV (controls) were recruited. Participants completed a quantitative sensory testing protocol to assess threshold, tolerance, and temporal summation in response to painful mechanical and heat stimuli. Most recent viral load was collected from medical records, and viral load was considered detectable if the count was greater than 50 copies/mL of blood. Of the 47 PLWH, 11 (23.4%) had detectable viral loads, the median viral load count was 10,200 copies/mL. Results. PLWH with detectable viral loads demonstrated significantly lower pain thresholds for mechanical stimuli (F_2,89 53.15, P50.049), significantly lower heat pain tolerances (F_2,89 53.38, P50.039), and significantly greater temporal summation of heat pain at 48 °C (F_2,89 510.66, P < 0.001) and 50 °C (F_2,89 53.82, P50.026), compared with PLWH without detectable viral loads and healthy controls. Conclusions. These preliminary results tentatively suggest that the detectable presence of the virus may sensitize PLWH to painful mechanical and heat stimuli.