The Multicenter AIDS Cohort Study (MACS) is a 30-year study of the HIV-1 infection in homosexual and bisexual men.

Carlton, Study Participant
When I was told I had HIV, there was no counseling, testing, or referral. I was told straight out I had 5–6 months to live. MACS was a way to put a face to HIV—a way to build community.
Study Participant

The MACS study is conducted by sites located in Baltimore, Chicago, Pittsburgh and Los Angeles, and includes over 7000 men with and without HIV infection. Biological and behavioral data are collected every six months from study participants.

Study visits include detailed questions covering HIV-related symptoms and utilization of health services, demographic and psychosocial characteristics, a quality of life survey, a physical examination, a detailed form on medications used as prophylaxis and/or treatment, a neuropsychological screening and examination, blood samples to measure hematologic variables including enumeration of T-cell subsets and HIV viral load, and the allocation of samples to be sent to the National Repository. These specimens are invaluable for helping to understand the pathogenesis of HIV-1 infection and the development of disease in HIV-infected people.


MACS Timeline


As a consortium of four clinical research sites and a data coordinating center, the MACS recruits and retains participants, collects and stores clinical specimens, and conceptualizes, designs, and implements a multidisciplinary, interdependent scientific agenda and research plan. Our ability to respond rapidly to a changing epidemic, whether it be the advent of effective combination antiretroviral therapy (cART) or a shifting demographic, allows the MACS to address the key questions facing HIV research today, including the effects of HIV, cART, and age on HIV-induced inflammation and immune dysfunction and on non-AIDS-defining outcomes including cancer, cardiovascular, liver, metabolic, neurologic, psychologic, and renal disease.