NAPLEX practice question 23 of 25

A CD4 count of 180 cells per cubic meter may be evaluated as which of these?

Full set: 154 questions

Domain Ensure Safe and Effective Pharmacotherapy and Health Outcomes

Answer options
A: Very low Correct answer
B: Low
C: High
D: Severely high
Correct Answer:
A. Very low
Explanation

A normal CD4+ T-lymphocyte (CD4) count in a healthy adult typically ranges from 500 to 1,500 cells/mm³. A CD4 count that falls below 200 cells/mm³ is a laboratory marker for severe immunodeficiency. In an individual with Human Immunodeficiency Virus (HIV), this value is a defining criterion for a diagnosis of Acquired Immunodeficiency Syndrome (AIDS). Therefore, a count of 180 cells/mm³ is considered very low, indicating a severely compromised immune system and a high risk of developing opportunistic infections.

Why Incorrect

B. Low: This term is not specific enough; it understates the clinical severity of an AIDS-defining CD4 count, which signifies a critical level of immunosuppression.
C. High: This is incorrect. A count of 180 cells/mm³ is significantly below the normal physiological range for CD4 cells.
D. Severely high: This is incorrect. This term describes the opposite condition and is not clinically relevant to CD4 count interpretation in this context.

References

1. Centers for Disease Control and Prevention (CDC). (2014). Revised Surveillance Case Definition for HIV Infection — United States

2014. Morbidity and Mortality Weekly Report (MMWR)

63(RR03)

1-10. In Table 1

"Staging of HIV Infection

" Stage 3 (AIDS) is defined by a CD4+ T-lymphocyte count of <200 cells/µL.

2. Panel on Guidelines for the Prevention and Treatment of Opportunistic Infections in Adults and Adolescents with HIV. (2023). Guidelines for the Prevention and Treatment of Opportunistic Infections in Adults and Adolescents with HIV. National Institutes of Health. The introduction and various sections (e.g.

"Pneumocystis Pneumonia") consistently refer to the <200 cells/mm³ threshold as the point of severe immunosuppression requiring prophylaxis.

3. Thompson

M. A.

Horberg

M. A.

Agwu

A. L.

et al. (2020). Primary Care Guidance for Persons With Human Immunodeficiency Virus: 2020 Update by the HIV Medicine Association of the Infectious Diseases Society of America. Clinical Infectious Diseases

73(11)

e3572–e3605. https://doi.org/10.1093/cid/ciaa1391. The section on "Initial Evaluation and Immediate Follow-up for Persons with HIV" specifies that a CD4 count <200 cells/µL indicates severe immunosuppression.

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