AIDSdefining

AIDSdefining, more commonly referred to as AIDS-defining, is a medical term used in HIV care to describe illnesses that signal the progression from HIV infection to Acquired Immunodeficiency Syndrome (AIDS). In many guidelines, AIDS is diagnosed if an HIV-positive person develops one of these defining conditions, or if the individual's CD4 T-cell count falls below 200 cells per microliter, indicating advanced immune suppression. The list of defining conditions is established by health authorities and can be updated as medical knowledge evolves.

The AIDS-defining illnesses include a range of opportunistic infections, certain cancers, and other severe clinical manifestations. Common examples of opportunistic infections are Pneumocystis jirovecii pneumonia, esophageal candidiasis, toxoplasma encephalitis, cryptococcal meningitis, and disseminated infections such as Mycobacterium avium complex or Histoplasma. Cancers that are considered AIDS-defining include Kaposi's sarcoma, invasive cervical cancer, and certain non-Hodgkin lymphomas. Other conditions historically included in the defining list are wasting syndrome and specific HIV-related neurologic diseases.

Diagnosis and management rely on a combination of HIV care, infection treatment, and immune restoration through antiretroviral therapy (ART). The appearance of an AIDS-defining illness generally prompts urgent, targeted treatment of the infection or cancer, along with optimization of ART to restore immune function and reduce the risk of further opportunistic diseases. Guidelines for definitions and prophylaxis are periodically updated by public health authorities to reflect new evidence and therapies.