Final answer:
Low counts of lymphocytes may suggest that a person is suffering from a prolonged illness, is immunocompromised, or has an HIV infection, which can lead to AIDS when CD4 T-cell levels fall critically low.
Step-by-step explanation:
Low counts of lymphocytes may indicate prolonged illness, HIV infection, or immunosuppression. Lymphocytes are a type of white blood cell and are crucial components of the immune system. They are instrumental in fighting off infections and are involved in the body’s immune responses. A healthy individual typically has lymphocyte counts of around 1,000 to 4,800 lymphocytes per microliter of blood.Abnormally low lymphocyte counts are characteristic of chronic illnesses, immunosuppression due to medication therapies, such as those involving steroids, and infectious diseases like HIV. When HIV progresses, it severely impairs the immune system, most notably through the reduction of CD4 helper T cells. A significant decline in these cells can lead to immunodeficiency, making an individual susceptible to opportunistic infections and potentially resulting in the development of acquired immunodeficiency syndrome (AIDS).During the various stages of HIV infection, medical professionals monitor the patient's CD4 T-cell count using sensitive tests like flow cytometry to adjust treatment as needed. For instance, AIDS is diagnosed when the CD4 T-cell count falls below 200 cells/μL or when the patient starts developing opportunistic diseases.