What is the typical CD4+ T-lymphocyte count in a healthy adult_______________?
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Answer: C. 1000
Explanation
A typical healthy human adult possesses a circulating CD4+ T-lymphocyte count averaging around 1000 cells per microliter. Normal reference ranges for CD4 counts generally span from 500 to 1500 cells per microliter of blood. Clinical immunology relies on these baseline numbers to evaluate overall cell-mediated immune system health status. CD4+ T-lymphocytes are helper T cells that coordinate adaptive immune responses by activating other white blood cells. Human immunodeficiency virus specifically targets and destroys cells expressing CD4 surface receptors over time. Flow cytometry is the standard laboratory technique used to quantify absolute CD4+ T-lymphocyte counts accurately.
500 cells per microliter often marks a clinical threshold indicating moderate immune system decline in infected individuals. 200 cells per microliter represents the critical threshold defining severe acquired immunodeficiency syndrome in clinical practice. 300 cells per microliter falls below normal baseline values and suggests ongoing immune cell depletion from infection.
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