AIDS (Acquired Immunodeficiency Syndrome)
The patient, a 30-year-old homosexual man, complained of unexplained weight loss, chronic diarrhea, and respiratory congestion during the past 6 months. Physical examination revealed right-sided pneumonitis. The following studies were performed:
Studies
Results
Complete blood cell count (CBC), p. 174
Hemoglobin (Hgb), p. 259
12 g/dL (normal: 14-18 g/dL)
Hematocrit (Hct), p. 256
36% (normal: 42%-52%)
Chest X-ray, p. 1014
Right-sided consolidation affecting the posterior lower lung
Bronchoscopy, p. 587
No tumor seen
Lung biopsy, p. 738
Pneumocystis jiroveci pneumonia (PCP)
Stool culture, p. 855
Cryptosporidium muris
Acquired immunodeficiency syndrome (AIDS) serology, p. 297
p24 antigen
Positive
Enzyme-linked immunosorbent assay (ELISA)
Positive
Western blot
Positive
Lymphocyte immunophenotyping, p. 306
Total CD4
280 (normal: 600-1500 cells/mL)
CD4%
18% (normal: 60%-75%)
CD4/CD8 ratio
0.58 (normal: >1.0)
Human immune deficiency virus (HIV) viral load, p. 297
75,000 copies/mL
1. What is the relationship between levels of CD4 lymphocytes and the likelihood of clinical complications from AIDS?
2. Why does the United States Public Health Service recommend monitoring CD4 counts every 3 to 6 months in patients infected with HIV?
