HIV DNA Is Frequently Present within Pathologic Tissues Evaluated at Autopsy from Combined Antiretroviral Therapy-Treated Patients with Undetectable Viral Loads

Abstract

HIV infection treatment strategies have historically defined effectiveness through measuring patient plasma HIV RNA. While combined antiretroviral therapy (cART) can reduce plasma viral load (pVL) to undetectable levels, the degree that HIV is eliminated from other anatomical sites remains unclear. We investigated the HIV DNA levels in 229 varied autopsy tissues from 20 HIV-positive (HIV ؉ ) cART-treated study participants with low or undetectable plasma VL and cerebrospinal fluid (CSF) VL prior to death who were enrolled in the National Neurological AIDS Bank (NNAB) longitudinal study and autopsy cohort. Extensive medical histories were obtained for each participant. Autopsy specimens, including at least six brain and nonbrain tissues per participant, were reviewed by study pathologists. HIV DNA, measured in tissues by quantitative and droplet digital PCR, was identified in 48/87 brain tissues and 82/142 nonbrain tissues at levels >200 HIV copies/million cell equivalents. No participant was found to be completely free of tissue HIV. Parallel sequencing studies from some tissues recovered intact HIV DNA and RNA. Abnormal histological findings were identified in all participants, especially in brain, spleen, lung, lymph node, liver, aorta, and kidney. All brain tissues demonstrated some degree of pathology. Ninety-five percent of participants had some degree of atherosclerosis, and 75% of participants died with cancer. This study assists in characterizing the anatomical locations of HIV, in particular, macrophage-rich tissues, such as the central nervous system (CNS) and testis. Additional studies are needed to determine if the HIV recovered from tissues promotes the pathogenesis of inflammatory diseases, such as HIV-associated neurocognitive disorders, cancer, and atherosclerosis. IMPORTANCEIt is well-known that combined antiretroviral therapy (cART) can reduce plasma HIV to undetectable levels; however, cART cannot completely clear HIV infection. An ongoing question is, "Where is HIV hiding?" A well-studied HIV reservoir is "resting" T cells, which can be isolated from blood products and succumb to cART once activated. Less-studied reservoirs are anatomical tissue samples, which have unknown cART penetration, contain a comparably diverse spectrum of potentially HIV-infected immune cells, and are important since <2% of body lymphocytes actually reside in blood. We examined 229 varied autopsy specimens from 20 HIV ؉ participants who died while on cART and identified that >50% of tissues were HIV infected. Additionally, we identified considerable pathology in participants' tissues, especially in brain, spleen, lung, lymph node, liver, aorta, and kidney. This study substantiates that tissueassociated HIV is present despite cART and can inform future studies into HIV persistence.

HIV Maintains an Evolving and Dispersed Population in Multiple Tissues during Suppressive Combined Antiretroviral Therapy in Individuals with Cancer

“…Although the medical information reported here is complete to the best of our ability, some clinical variables are unknown. The precise location of tissue sampling could clearly impact HIV recovery; for example, Lamers et al (16) found high variability in the amount and detection of HIV in tissues could within an individual. We used a sequencing technique (singlegenome sequencing) and multiple extractions and amplifications in order to ensure that we sampled the broadest variability possible, but deep-sequencing studies could provide even more resolution.…”

“…Most participants are recruited premortem; however, the remains of very recently deceased individuals may be donated by legal heirs, in which case information is obtained from guardians and/or by authorized release of medical records. Extensive details concerning NNAB guidelines, questionnaires and medical assessments are available in reference 16.…”

“…These patients were chosen because they had substantial cancer pathology at death and an undetectable (Ͻ40 HIV copies/mm of fluid) VL at autopsy from the CSF and/or the blood (as measured from the cardiac aspirate). Extensive medical histories were available and are described in detail elsewhere (16). All tissues used in this study were histologically examined by ACSR pathologists and classified based on the pathology that was present in tissues extracted for the HIV DNA studies.…”

“…Tissues were chosen for sequence analysis from the NNAB cohort participants if they were HIV DNA positive using digital droplet PCR (ddPCR; details for ddPCR experiments are presented in reference 16). An additional two tissues were included (lung from patient C02 and aorta from patient C05) that were ddPCR negative.…”

“…HIV DNA was detected in 12 different anatomical locations, including tumor sites. Complete clinical details of the study are reported elsewhere (16).…”