Human immunodeficiency virus status and delayed-type hypersensitivity skin testing in Ugandan children

Area of Science:

• Immunology
• Infectious Diseases
• Pediatrics

Background:

• Delayed-type hypersensitivity (DTH) skin testing is influenced by nutritional status, infections, immune status, and prior antigen exposure.
• Human immunodeficiency virus type 1 (HIV-1) infection can impact immune responses, including DTH skin testing.

Purpose of the Study:

• To evaluate the effect of HIV-1 status on DTH skin testing in Ugandan children.
• To assess DTH responses to Candida and purified protein derivative (PPD) in HIV-1-infected versus non-infected children.

Main Methods:

• A nested case-control study was conducted in Ugandan children.
• Thirty HIV-1-infected and 30 age-matched, HIV-1-noninfected children underwent Mantoux skin testing with Candida and PPD.
• Skin test results were read at 48-72 hours, and CD4 lymphocyte counts were obtained for HIV-1-infected children.

Main Results:

• HIV-1-infected children showed significantly smaller PPD reaction sizes compared to non-infected children.
• Candida responses did not differ between the groups, but larger Candida reactions were observed in HIV-1-infected children who received recent chloroquine treatment.
• Lack of PPD reaction correlated with lower CD4 counts and progressive HIV-1 disease; active tuberculosis was associated with lower CD4 counts.

Conclusions:

• DTH skin testing in HIV-1-infected Ugandan children is affected by the antigen used and HIV-1 status.
• Recent chloroquine treatment may influence Candida responses in HIV-1-infected children, warranting further investigation.
• DTH skin testing has limitations as an adjunct for diagnosing active tuberculosis in HIV-infected children.