AIDS (Acquired Immunodeficiency Syndrome)

Pagana: Mosby’s Manual of Diagnostic and Laboratory Tests, 5th Edition

Case Studies

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/L)

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

Diagnostic Analysis

The detection of Pneumocystis jiroveci pneumonia (PCP) supports the diagnosis of AIDS.

PCP is an opportunistic infection occurring only in immunocompromised patients and is the

most common infection in persons with AIDS. The patient’s diarrhea was caused by

Cryptosporidium muris, an enteric pathogen, which occurs frequently with AIDS and can be

identified on a stool culture. The AIDS serology tests made the diagnoses. His viral load is

significant, and his prognosis is poor.

The patient was hospitalized for a short time for treatment of PCP. Several months after he

was discharged, he developed Kaposi sarcoma. He developed psychoneurologic problems

eventually and died 18 months after the AIDS diagnosis.

Case Studies 2

Critical Thinking Questions

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?