Background Whether persistent low-level viremia (pLLV) predicts virologic failure (VF) is unclear. We used data from the US Military HIV Natural History Study (NHS), to examine the association of pLLV and VF. Methods NHS subjects who initiated combination antiretroviral therapy (ART) after 1996 were included if they had 2 or more VLs measured with a lower limit of detection of ≤50 copies/mL. VF was defined as a confirmed VL ≥200 copies/mL or any VL >1000 copies/mL. Participants were categorized into mutually exclusive virologic categories: intermittent LLV (iLLV) (VL of 50–199 copies/mL on <25% of measurements), pLLV (VL of 50–199 copies/mL on ≥25% of measurements), high-level viremia (hLV) (VL of 200–1000 copies/mL), and continuous suppression (all VL <50 copies/mL). Cox proportional hazards models were used to evaluate the association between VF and LLV; hazard ratios and 95% confidence interval (CI) are presented. Results Two thousand six subjects (median age 29.2 years, 93% male, 41% black) were included; 383 subjects (19%) experienced VF. After adjusting for demographics, VL, CD4 counts, ART regimen, prior use of mono or dual antiretrovirals, and time to ART start, pLLV (3.46 [2.42–4.93]), and hLV (2.29 [1.78–2.96]) were associated with VF. Other factors associated with VF include black ethnicity (1.33 [1.06–1.68]) and antiretroviral use prior to ART (1.79 [1.34–2.38]). Older age at ART initiation (0.71 [0.61–0.82]) and non-nucleoside reverse transcriptase inhibitor (0.68 [0.51–0.90]) or integrase strand transfer inhibitor use (0.26 [0.13–0.53]) were protective. Conclusion Our data add to the body of evidence that suggests persistent LLV is associated with deleterious virologic consequences.

BackgroundInfluenza causes significant morbidity and mortality; the pandemic in 2009–2010 was a reminder of the potential for novel strains and antigenic changes. Studies have shown that vitamin D deficiency may be associated with poor vaccine immunogenicity, therefore we sought to determine if there was a correlation between 25-hydroxyvitamin D [25(OH)D] and influenza vaccine response.MethodsA retrospective observational study was conducted among young, healthy military members to evaluate the association between total 25(OH)D levels with post influenza vaccination antibody titers and healthcare encounters during the 2009–10 influenza season. Univariate analyses were performed to evaluate whether 25(OH)D levels are associated with baseline characteristics and post-vaccination antibody responses. Multivariable logistic regression models were utilized to determine the associations between antibody responses and 25(OH)D levels adjusting for possible confounders.ResultsA total of 437 subjects were studied. Most participants were young adults (91% were 18–39 years of age), 50% were male, and 56% resided in the southern U.S. Overall, 152 (34.8%) were vitamin D deficient, 167 (38.2%) insufficient, and 118 (27.0%) with normal 25(OH)D levels. There were no demographic differences by 25(OH)D category. Only 224 (51.3%) demonstrated a seroprotective anti-influenza post-vaccination titer, which did not vary by categorical 25(OH)D levels [vitamin D deficient vs. normal: OR 1.10 (0.68–1.78) and insufficient vs. normal: OR 1.25 (0.78–2.01)] or continuous vitamin D levels [OR 0.98 (0.84–1.15)]. There were also no associations with increased influenza like illnesses, respiratory diagnoses and healthcare encounters between the vitamin D groups.ConclusionVitamin D insufficiency and deficiency were highly prevalent despite evaluating a young, healthy adult population. There were no significant associations between 25(OH)D levels and post-vaccination antibody titers to influenza vaccine. Further studies are required to discover strategies to improve vaccine efficacy as well as to determine the role of 25(OH)D in vaccine immunity.

BackgroundThe principal goal of HAART is sustained viral load (VL) suppression resulting in immune reconstitution and improved HIV outcomes. We studied the factors associated with 10 years of continuous VL suppression on HAART in the US Military HIV Natural History Study.MethodsParticipants with continuous VL suppression (CS, n = 149) were compared to those who did not have continuous viral load suppression (NCS, n = 127) for ≥10 years on HAART. Factors associated with >10 years of VL suppression were evaluated by multivariate logistic regression. Additionally, association between CS and CD4 reconstitution was analyzed with a mixed effects model.ResultsCompared to NCS participants, a lower proportion of CS participants started HAART in the early HAART era (66 vs 90 %, for years 1996–1999; p < 0.001) and had less antiretroviral use prior to HAART (37 vs 83 %; p < 0.001). At initial HAART, the median CD4 cell count was higher and VL was lower for CS compared to NCS participants (375 cells/uL [256, 499] vs 261 cells/uL [146, 400]; p < 0.001 and 4.4 log10 copies/mL [3.5, 4.9] vs 4.5 log10 copies/mL [3.8, 5.0]; p = 0.048, respectively). New AIDS events were lower during HAART (5 vs 13 %; p = 0.032) and post-HAART CD4 trajectories were greater for the CS compared to NCS group. Factors negatively associated with ≥10 years of VL suppression included log10 VL at first HAART (OR 0.61, 95 % CI 0.4, 0.92; p = 0.020) and antiretroviral use prior to HAART (OR 0.16, 95 % CI 0.06, 0.38; p < .001).ConclusionsSustained VL suppression is a key to long-term health in HIV-infected patients, as demonstrated by the lower proportion of AIDS events observed 10 years after HAART initiation. The current use of more potent and well-tolerated regimens may mitigate the negative factors of pre-HAART VL and prior ARV use encountered by treatment initiated in the early HAART era.