Application of IV 99mTc-tilmanocept for Imaging of Macrophage-specific Inflammation

The purpose of this study is to evaluate uptake of intravenously administered 99mTc-tilmanocept using single photon emission computed tomography (SPECT/CT) scanning in individuals with HIV and individuals without HIV.

People living with HIV (PLWH) have an increased risk of cardiovascular disease (CVD) compared to individuals without HIV. Increased systemic immune activation and arterial inflammation are thought to contribute to this increased risk by affecting the highly inflammatory process of atherosclerotic plaque formation and progression. This study will evaluate whether intravenous administration of a macrophage-specific imaging agent, 99mTc-tilmanocept, followed by SPECT/CT scanning can permit quantification of aortic 99mTc-tilmanocept uptake, reflective of aortic macrophage-specific inflammation among participants with HIV. We will also compare aortic 99mTc-tilmanocept uptake in participants with HIV to participants without HIV. Immunology parameters such as markers of immune activation and traditional CVD parameters will be assessed in relation to imaging assessments.

Eligibility Criteria:
HIV-infected participants:

Inclusion Criteria:

* men and women, ages 18 to 80, with documented HIV infection
* current use of antiretroviral therapy (ART), with no changes to regimen within last 3 months

Exclusion Criteria:

* pregnancy or breastfeeding
* known active opportunistic infection requiring ongoing medical therapy (not including Hepatitis B/C)
* CD4 count \< 50 cells/mm3
* history of myocardial infarction,acute coronary syndrome, or coronary artery stenting or surgery
* stable or unstable angina
* recent and/or current treatment with prescription, systemic steroids or anti-inflammatory/immune suppressant medical therapies
* current use of statin or use of statin for \> 1 month within the last 6 months
* known allergy to dextrans and/or DTPA and/or radiometals
* eGFR \< 60 ml/min/1.73 m2 calculated by CKD-EPI
* known severe allergy to iodinated contrast media
* contraindication to nitroglycerin
* significant radiation exposure (\>2 CT angiograms) received within the past 12 months
* reported active illicit drug use
* concurrent enrollment in another research study judged by the study investigators to interfere with the current study

Non-HIV-infected participant:

Inclusion criteria:

-men and women, ages 18 to 80, without HIV infection

Exclusion Criteria:

* pregnancy or breastfeeding
* history of myocardial infarction, acute coronary syndrome, or coronary artery stenting or surgery
* stable or unstable angina
* recent and/or current treatment with prescription, systemic steroids or anti-inflammatory/immune suppressant medical therapies
* current use of statin or use of statin for \> 1 month within the last 6 months
* known allergy to dextrans and/or DTPA and/or radiometals
* eGFR \< 60 ml/min/1.73 m2 calculated by CKD-EPI
* known severe allergy to iodinated contrast media
* contraindication to nitroglycerin
* significant radiation exposure (\>2 CT angiograms) received within the past 12 months
* reported active illicit drug use
* concurrent enrollment in another research study judged by the study investigators to interfere with the current study