Abstract Antiretroviral therapy (ART) generally suppresses HIV replication to undetectable levels in peripheral blood, but immune activation associated with increased morbidity and mortality is sustained during ART, and infection rebounds when treatment is interrupted. To identify drivers of immune activation and potential sources of viral rebound, we modified RNAscope in situ hybridization to visualize HIV-virus producing cells as a standard to compare the following assays of potential sources of immune activation and virus rebound following treatment interruption: 1) EDITS (envelope detection by induced transcription-based sequencing) assay; 2) HIV-Flow; and 3) Flow-FISH assays that can scan tissues and cell suspensions to detect rare cells expressing env mRNA, gag mRNA/Gag protein and p24 respectively; and 4) an ultrasensitive immunoassay that detects p24 in cell/tissue lysates at subfemtomolar levels. We show that the sensitivity of these assays is sufficient to detect a rare HIV-producing/env mRNA+/p24+ cell in a million uninfected cells. These high-throughput technologies thus provide contemporary tools to detect and characterize rare cells producing virus and viral antigens as potential sources of immune activation and viral rebound. Importance Anti-retroviral therapy (ART) has greatly improved the quality and length of life for people living with HIV, but immune activation does not normalize during ART, and persistent immune activation has been linked to increased morbidity and mortality. We report a comparison of assays of two potential sources of immune activation during ART: rare cells producing HIV virus or the virus’ major viral protein, p24, benchmarked on a cell model of active and latent infections and a method to visualize HIV-producing cells. We show that assays of HIV Envelope mRNA (EDITS assay) and gag mRNA and p24 (Flow-FISH, HIV-Flow and ultrasensitive p24 immunoassay) detect HIV-producing cells and p24 at sensitivities of one infected cell in a million uninfected cells, thus providing validated tools to explore sources of immune activation during ART in the lymphoid and other tissue reservoirs.
Abstract Background Human Immunodeficiency Virus (HIV) outcomes have significantly improved at the expense of other age-related diseases including chronic kidney disease. Early reports of people living with HIV (PLWH) undergoing deceased-donor kidney transplantation (DDKT) showed poor outcomes, but these have notably improved after introduction of antiretrovirals. Despite years of experience, the optimal induction immunosuppression (IIS) in PLWH remains subject of debate. Large-scale studies describing the current ISS practices in PLWH undergoing DDKT are lacking. Here, we describe the U.S. national trends of IIS used in PLWH undergoing DDKT from 2000 to 2018 using the United Network of Organ Sharing (UNOS) database. Methods We analyzed the UNOS database to determine the selection of IIS in PLWH undergoing first-time DDKT between 1/1/2000 and 12/31/2018. Cases with unknown HIV status at the time of transplant were excluded. Age, sex and demographics were analyzed. The regimen used for IIS was compared based on HIV serostatus and the change in induction regimen was trended over time. Results A total of 139,650 cases underwent DDKT during the study period. Among these, 1,384 were identified as HIV-positive. PLWH were significantly younger than HIV-negative (49±10 years vs. 51.6 ± 15.3 years; p< 0.001) (Table 1). A greater proportion of men was seen in the PLWH group compared to HIV-negative persons (76.2% vs. 60.4%; p< 0.0001). In the HIV-negative group, 12.1% undergoing DDKT did not receive IIS compared to 16.4% in PLWH (p< 0.0001). Medications that have significantly increased in use with years in PLWH included rabbit anti-thymocyte globulin (rATG), steroids, and basiliximab (3.54, 3.25, 2.28, respectively; p< 0.001). On our trend analysis (Figure 1), the percentage of PLWH receiving any IIS is increasing by 4.04% each year (p< 0.001). Table 1 Figure 1 Conclusion Our study suggests that IIS is an increasing practice in PLWH undergoing DDKT, predominantly using rATG, steroids, and basiliximab. Understanding the current practices might lead to further studies to determine the long-term outcomes after different induction regimens in PLWH. Disclosures All Authors: No reported disclosures
Abstract The epidemiology of infection after liver transplantation for hilar cholangiocarcinoma has not been systematically investigated. In this study of 124 patients, 255 infections occurred in 105 patients during the median follow‐up of 4.2 years. The median time to first infection was 15.1 weeks ( IQR 1.6‐62.6). The most common sites were the abdomen, bloodstream, and musculoskeletal system. Risk factors for any post‐transplant infection were pre‐transplant VRE colonization (Hazard Ratio [ HR ] 1.9, P =.002), living donor transplantation ( HR 6.6, P <.001), longer cold ischemia time ( HR 1.05 per 10 minutes, P <.001), donor CMV seropositivity ( HR 2.2, P <.001), hepatic artery thrombosis ( HR 2.6, P =.005), biliary stricture ( HR 3.8, P =.002), intra‐abdominal fluid collection ( HR 4.2, P <.001), and re‐operations within 1 month after transplantation ( HR 1.7, P =.020). Abdominal infections were independently associated with hemodialysis requirement within 1 month after transplantation ( HR 5.6, P =.006), hepatic artery thrombosis ( HR 3.3, P =.007), biliary stricture ( HR 5.2, P <.001), and abdominal fluid collection ( HR 3.7, P =.0002). Bloodstream infections were independently associated with allograft ischemia ( HR 17.8, P <.001), biliary stricture ( HR 6.5, P =.005), and recipient VRE colonization ( HR 4, P <.001). Abdominal infections ( HR 2.3, P =.02) and Clostridium difficile infections ( HR 4.6, P =.01) were independently associated with increased mortality.
HIV infection leads to activation of coagulation, which may increase the risk for atherosclerosis and venous thromboembolic disease. We hypothesized that HIV replication increases coagulation potentially through alterations in extrinsic pathway factors.Extrinsic pathway factors were measured among a subset of HIV participants from the Strategies for Management of Anti-Retroviral Therapy (SMART) trial. Thrombin generation was estimated using validated computational modeling based on factor composition. We characterized the effect of antiretroviral therapy (ART) treatment versus the untreated state (HIV replication) via 3 separate analyses: (1) a cross-sectional comparison of those on and off ART (n=717); (2) a randomized comparison of deferring versus starting ART (n=217); and (3) a randomized comparison of stopping versus continuing ART (n=500). Compared with viral suppression, HIV replication consistently showed short-term increases in some procoagulants (eg, 15% to 23% higher FVIII; P<0.001) and decreases in key anticoagulants (eg, 5% to 9% lower antithrombin [AT] and 6% to 10% lower protein C; P<0.01). The net effect of HIV replication was to increase coagulation potential (eg, 24% to 48% greater thrombin generation from computational models; P<0.01 for all). The pattern of changes from HIV replication was reversed with ART treatment and consistent across all 3 independent comparisons.HIV replication leads to complex changes in extrinsic pathway factors, with the net effect of increasing coagulation potential to a degree that may be clinically relevant. The key influence of changes in FVIII and AT suggests that HIV-related coagulation abnormalities may involve changes in hepatocyte function in the context of systemic inflammation.
