Effects of Using E-Cigarettes on Lungs in People With HIV (HBS Ancillary)

This project is an ancillary study to the HBS Study. Inclusion Criteria for that IRB approved study are: * documented HIV-infection * in care at an HIV specialty clinic * age ≥ 18 years. Exclusion criteria for the HBS Study are: * a pacemaker or other implanted electronic device * pregnant women, prisoners, cognitively-impaired subjects. For this ancillary, the experimental group must actively use at least one of the following: e-cigarettes, e-liquid vapes, burning leaf tobacco cigarettes, or inhaled burning leaf marijuana (cannabis). The control group will have no use of e-cigarettes or vape or active smoking in the past year. Participants must be willing to archive data and biological samples for future use. Exclusion from the ancillary are: * overt respiratory or oral cavity disease * acute illness in the past 4 weeks * active cancer * active weight loss program * any other medical, psychiatric or behavioral factors that, in the judgment of the PI may interfere with study participation or ability to follow the protocol