| A | B |
|---|
| Human immunodeficiency virus (HIV) | A retrovirus that is the etiologic agent of AIDS |
| Acquired immunodeficiency syndrome (AIDS) | A disease affecting the immune system caused by HIV. |
| Opportunistic illnesses | Infections or malignancies that primarily occur in individuals who are immunocompromised. |
| Seroconversion | Change of a serological test result from antibody negative to antibody positive from samples obtained during the course of an immune response. |
| Viremia | The presence of a virus circulating in the blood. |
| Viral load tests | Quantitative tests for nucleic acid from viruses such as HIV. These tests are used to predict disease progression and to monitor the effects of antiretroviral therapy. |
| p24 antigen | A structural core antigen that is part of HIV. |
| Western blot test | A confirmatory test that has been used for some infections (e.g., HIV, Lyme disease) based on separation of antigens from the pathogen by electrophoresis followed by transfer or blotting of the antigen pattern to a supporting medium for reaction with test serum. |
| Flow cytometry | An automated system for identifying cells based on the scattering of light as cells flow single file through a laser beam |
| CD4 T cells | Type of lymphocyte that provides help to B cells to initiate antibody production (T helper cell) or, less commonly, inhibits the immune response (T regulatory cell). |
| CD8 T cells | cytotoxic T lymphocytes (CTLs), play a crucial role in the immune system by directly killing infected or cancerous cells and producing cytokines that enhance the immune response. |
