Sitagliptin Reduces Inflammation and Chronic Immune Cell Activation in HIV+ Adults With Impaired Glucose Tolerance.

CONTEXT: HIV infection is associated with a greater risk for fasting hyperinsulinemia, impaired glucose tolerance, and higher incidence rates for vascular disease, myocardial infarction, or stroke despite effective combination antiretroviral therapy (cART). The underlying mechanism(s) may involve chronic low-grade systemic inflammation and immune cell activation. Dipeptidyl peptidase-4 inhibitors (sitagliptin) improve glucose tolerance and may possess immunomodulatory effects because leukocyte CD26 cell surface receptors express dipeptidyl peptidase-4 activity. OBJECTIVE: Sitagliptin will reduce inflammatory and immune cell activation markers known to be elevated in cART-treated HIV-infected (HIV+) adults with impaired glucose tolerance. DESIGN: This was designed as a prospective, randomized, placebo-controlled, double-blind trial of sitagliptin in HIV+ adults. SETTING: The setting was an academic medical center. PATIENTS: Patients were cART-treated HIV+ men and women (n = 36) with stable HIV disease and impaired glucose tolerance. INTERVENTIONS: Interventions included sitagliptin 100 mg/d or placebo for 8 weeks. MAIN OUTCOME MEASURES: At baseline and week 8, plasma high-sensitivity C-reactive protein and C-X-C motif chemokine 10 concentrations (ELISA), oral glucose tolerance, and abdominal sc adipose mRNA expression for M1 macrophage markers (monocyte chemotactic protein-1, EGF-like module-containing, mucin-like hormone receptor 1). RESULTS: Sitagliptin reduced glucose area under the curve (P = .002) and improved oral glucose insulin sensitivity index (P = .04) more than placebo. Sitagliptin reduced plasma high-sensitivity C-reactive protein and C-X-C motif chemokine 10 levels more than placebo (P < .009). Adipose tissue monocyte chemotactic protein-1 mRNA abundance declined significantly more (P = .01), and adipose EGF-like module-containing, mucin-like hormone receptor 1 mRNA expression tended to decline more (P = .19) in sitagliptin than placebo. CONCLUSION: Sitagliptin had beneficial systemic and adipose anti-inflammatory effects in cART-treated HIV+ adults with impaired glucose tolerance. Large-scale, long-term studies should determine whether sitagliptin reduces cardiovascular risk and events in HIV+ adults.

Dipeptidyl peptidase IV inhibition does not adversely affect immune or virological status in HIV infected men and women: a pilot safety study.

CONTEXT: People infected with HIV have a higher risk for developing insulin resistance, diabetes, and cardiovascular disease than the general population. Dipeptidyl peptidase IV (DPP4) inhibitors are glucose-lowering medications with pleiotropic actions that may particularly benefit people with HIV, but the immune and virological safety of DPP4 inhibition in HIV is unknown. OBJECTIVE: DPP4 inhibition will not reduce CD4+ T lymphocyte number or increase HIV viremia in HIV-positive adults. DESIGN: This was a randomized, placebo-controlled, double-blind safety trial of sitagliptin in HIV-positive adults. SETTING: The study was conducted at an academic medical center. PARTICIPANTS: Twenty nondiabetic HIV-positive men and women (9.8 ± 5.5 years of known HIV) taking antiretroviral therapy and with stable immune (625 ± 134 CD4+ T cells per microliter) and virological (<48 copies HIV RNA per milliliter) status. INTERVENTION: The intervention included sitagliptin (100 mg/d) vs matching placebo for up to 24 weeks. MAIN OUTCOME MEASURES: CD4+ T cell number and plasma HIV RNA were measured every 4 weeks; fasting serum regulated upon activation normal T-cell expressed and secreted (RANTES), stromal derived factor (SDF)-1α, Soluble TNF receptor II, and oral glucose tolerance were measured at baseline, week 8, and the end of study. ANOVA was used for between-group comparisons; P < .05 was considered significant. RESULTS: Compared with placebo, sitagliptin did not reduce CD4+ T cell count, plasma HIV RNA remained less than 48 copies/mL, RANTES and soluble TNF receptor II concentrations did not increase. SDF1α concentrations declined (P < .0002) in the sitagliptin group. The oral glucose tolerance levels improved in the sitagliptin group at week 8. CONCLUSIONS: Despite lowering SDF1α levels, sitagliptin did not adversely affect immune or virological status, or increase immune activation, but did improve glycemia in healthy, nondiabetic HIV-positive adults. These safety data allow future efficacy studies of sitagliptin in HIV-positive people with cardiometabolic complications.

GM-CSF Fails to Improve Immune Responses to Booster Hepatitis B Vaccination in HIV-Infected Individuals.

BACKGROUND: Hepatitis B (HBV) vaccination is an important preventive intervention for HIV-infected population. Data regarding booster HBV vaccine for persons with low HBV surface antibody (sAb) titers after vaccination in this immunocompromised population is lacking. METHODS: We randomized 60 HIV-infected subjects lacking HBV protection after completion of 3 doses of HBV vaccine to receive a booster dose of HBV vaccine with 250mcg GM-CSF as an adjuvant or booster vaccine alone. RESULTS: GM-CSF was safe with expected side effects. However, only 35% of persons receiving GM-CSF developed protective sAb while 50% in vaccine only arm developed protection (P = 0.47). Overall, only 28% of subjects maintained protective sAb 1 year after vaccination. CONCLUSIONS: GM-CSF failed to improve responses to the booster HBV vaccination. Overall, response was poor with only 42% of persons responding at one month post-vaccination confirming booster vaccination with the current HBV vaccine has poor immunogenicity among HIV-infected persons. Further research is needed to develop optimal vaccination strategies in HIV-infected persons.

Selenium supplementation in HIV-infected patients: is there any potential clinical benefit?

In HIV-infected patients undergoing antiretroviral therapy, the question of whether selenium supplementation has any therapeutic benefit is still open. With recent popular coverage of this issue, many patients have considered using selenium. Clinicians have a duty to ensure that the recommendations they make to their patients are evidence based. The literature search reported here showed that evidence to support standard selenium supplementation in patients with HIV is both limited and insufficient. To definitively answer this clinical question, the overall effect of selenium supplementation would need to be evaluated in a large randomized, controlled trial with solid methodology and strong internal validity. Although the available evidence for selenium supplementation is weak, its low toxicity and side effect profile seem to pose minimal risks, especially at low doses. For patients who want to add selenium to their regimen, discussing the potential risks and benefits as well as close follow-up is warranted.

Alendronate, vitamin D, and calcium for the treatment of osteopenia/osteoporosis associated with HIV infection.

BACKGROUND: Osteopenia and osteoporosis are frequent complications of HIV infection and/or its treatment. Alendronate is the only bisphosphonate approved for the treatment of osteoporosis in men and women. We conducted a 48-week prospective, randomized, open-label study to evaluate the effects of alendronate, vitamin D, and calcium supplementation on bone mineral density (BMD) in patients with HIV infection. METHODS: Thirty-one HIV-infected subjects with lumbar spine BMD t-scores less than -1.0 on antiretroviral therapy for a minimum of 6 months were randomized to receive (n = 15) or not to receive (n = 16) 70 mg of alendronate weekly for 48 weeks. All subjects received calcium (1000 mg daily as calcium carbonate) and vitamin D supplementation (400 IU daily). The study was powered to detect 3% changes in BMD in the lumbar spine within arms at 48 weeks. RESULTS: Thirty-one patients were enrolled; most were male, with an average length of HIV infection of 8 years. Eighty-four percent had an HIV RNA load below 400 copies/mL, with a current median CD4+ T-cell count of 561 cells/mm3 (median nadir CD4 cell count of 167 cells/mm). At baseline, the median t-score in the lumbar spine was -1.52 and the median t-score in the hip was -1.02. Alendronate in combination with vitamin D and calcium increased lumbar spine BMD by 5.2% (95% confidence interval [CI]: 1.3-6.4) at 48 weeks compared with an increase of 1.3% (95% CI: -2.4 to 4.0) in subjects receiving vitamin D and calcium alone. One subject discontinued treatment in each arm. There were no serious adverse events. CONCLUSIONS: Alendronate, vitamin D, and calcium are safe and potentially useful in the treatment of osteopenia/osteoporosis associated with HIV infection.