This Week in HIV Research: What's in a Blip?
Attempting to read clinical tea leaves is often a big part of an HIV care provider's job. How likely is it that a patient's risk factors for virologic failure will actually manifest in a loss of viral suppression, and how can one know whether a brief loss of suppression will result in actual treatment failure? Teasing apart fear from reality is a constant struggle -- and it's a primary focus of our study selection this week.
Our latest featured set of four recently published HIV-related research manuscripts features the following:
- New insight into the relationship between viral load blips, low-level viremia, and eventual virologic failure.
- Clues that non-adherence is often the cause of HIV treatment failure even when a patient feels it's not.
- Signs that HIV care costs vary widely not only by disease state and patient demographics, but also by region.
- A better understanding of how Kaposi sarcoma incidence is evolving in the U.S. in the modern HIV treatment era.
Join us as we begin to interpret these new medical scryings. To beat HIV, you have to follow the science!
Low-Level Viremia Associated With Virologic Failure
The risks associated with low-level viremia vary depending on a person's HIV treatment experience, a U.S. study published in AIDS found. The results attempt to shed new light on a much-debated issue over the clinical relevance of viral load test results that are slightly above 50 copies/mL.
Researchers analyzed data on 2,795 participants (75% male, 50% African American) who were not currently on treatment at baseline and subsequently achieved viral suppression (VL < 50 copies/mL) after initiating or resuming antiretroviral therapy. Low-level viremia (LLV) was defined as > 51 c/mL during 2 subsequent measurements after viral suppression. Blips were defined as > 51 c/mL in a single test.
Overall, half of the study population achieved and maintained an undetectable viral load, while 10% experienced virologic failure (defined as two or more viral load test results over 500 c/mL). At least one blip or LLV was experienced by 29% of participants, with 3% of patients experiencing both:
- 20% had a blip between 51-200 c/mL
- 4% had a blip between 201-500 c/mL
- 5% had LLV between 51-200 c/mL
- 4% had LLV between 201-500 c/mL
Blips were not associated with virologic failure in the study. LLV between 51-200 c/mL roughly doubled the risk of virologic failure, while LLV between 201-500 c/mL increased failure risk approximately fourfold. Antiretroviral experience was correlated with sensitivity to LLV: In treatment-naive people, only the higher level of LLV was associated with virologic failure, while in antiretroviral-experienced people, even the lower level was linked to virologic failure.
The more often viral loads were measured, the less likely virologic failure was to occur among the study population. "This finding suggests that the patient-physician relationship and close clinical monitoring are important to successfully achieving virologic control," study authors concluded.
Virologic Failure May Not Be What It Seems in Some Treatment-Experienced Patients
A novel pilot approach to directly observed therapy (DOT) for people experiencing HIV treatment failure revealed that non-adherence -- despite a patient's self-report to the contrary -- was a common characteristic of virologic failure, according to a report published in Clinical Infectious Diseases.
Twenty treatment-experienced people who had failed their current drug regimen were provided their current medications in a DOT protocol while they were hospitalized. Participants were told to request their HIV drugs, but if they failed to do so, they were given the medication anyway. Adherence counseling and psychosocial support were also provided.
Under these conditions, 45% percent of participants showed a > 0.5 log copies/mL viral load decline on the regimen they were supposedly failing. However, viral load rebounded in most during outpatient follow-up.
Study authors suggested that outpatient DOT, which could be delivered virtually, may be appropriate in some cases. They also noted that participants with adherence-related treatment failure had greater socioeconomic barriers than those with regimen-related failure. Early adherence interventions for people living with HIV (PLWH) who experience food insecurity, housing instability, or similar socioeconomic challenges may help forestall treatment failure and thereby preserve future treatment options, study authors suggested.
Medical Care Costs for PLWH Differ Across U.S.
Among PLWH, mean quarterly health care costs were mostly driven by disease progression, but also varied with geographic region, a retrospective U.S. cohort study published in AIDS showed.
Researchers analyzed administrative data on 40,022 PLWH at 17 U.S. sites. Unsurprisingly, costs were highest for those who inject drugs and people on HIV treatment. Costs also tended to be slightly higher among women than men, as well as among heterosexual men than men who have sex with men. Geographic differences also emerged, including, that the average quarterly cost of health care for PLWH tended to be lower in northeastern states than in southern or western states.
Further analysis showed that the higher cost differences in the South compared to the Northeast may be due to barriers to care among certain groups. The size of effects among those not on antiretroviral treatment also likely reflect usage patterns: little preventive care (small effects at lower quantiles), but later complications from untreated HIV (large effects at higher quantiles).
Study authors noted that due to limited data, "cost differences likely understate variation in prices across geographic regions and should be interpreted as differences in costs from health resource use intensity, rather than differences in prices for the same services across regions or by different payers." Findings show the need for more differentiated input in cost-effectiveness models, they concluded.
Kaposi Sarcoma Incidence Decline Not Evenly Distributed
While Kaposi sarcoma rates have fallen overall in the U.S. since 2000, the decline was not distributed evenly across geographical areas, ages, or racial categories, a study published in Journal of Acquired Immune Deficiency Syndromes found.
KS trends decreased in most states with high incidence rates in the beginning of the study period (2000-2014) but increased by 1.82% annually in Georgia. The drop in KS was also not matched among younger (20-29 years old) or African-American men; in fact, it may be on the rise in younger African-American men, particularly in the U.S. South.
Geographic differences are likely due to a variety of factors, including population size in urban areas (where KS is more common), seroconversion rates, access to antiretroviral treatment, and HHV-8 virus prevalence (HHV-8 is necessary for the development of KS), study authors noted. They called for further research into the cause of these disparities in KS prevalence, as well as the development of targeted interventions to prevent it.