Evolution of recurrent herpes simplex lesions. An immunohistologic study.

Area of Science:

• Immunology
• Virology
• Dermatology

Background:

• Recurrent peripheral herpes simplex lesions involve complex inflammatory processes.
• Understanding the cellular infiltrate and cytokine production is key to characterizing lesion pathogenesis.

Purpose of the Study:

• To phenotype the inflammatory infiltrate in herpes simplex lesions.
• To detect cells producing interferons (IFNs) alpha and gamma.
• To locate herpes simplex virus (HSV) antigen-containing cells.

Main Methods:

• Immunoperoxidase staining of skin biopsies from nine patients with recurrent HSV lesions.
• Analysis of biopsies collected 12 hours to 6 days post-symptom onset.
• Phenotyping inflammatory cells, detecting IFN-producing cells, and locating HSV antigens.

Main Results:

• HSV glycoprotein antigen was found in necrotic epidermal cells between days 1-3.
• Predominant inflammatory cells were T lymphocytes and histiocytes; B cells and NK cells were rare.
• Early lesions showed a predominance of helper T lymphocytes, with ratios shifting towards blood levels in later stages.
• DR antigen expression was noted on T lymphocytes and epidermal cells.
• Interferon-gamma-producing cells were identified within lesions and circulation.

Conclusions:

• The inflammatory infiltrate in herpes simplex lesions is dynamic, with a shift in T lymphocyte subsets over time.
• Interferon-gamma may play a significant role in lesion pathogenesis, potentially by activating macrophages and cytotoxic T lymphocytes.
• The presence of HSV antigens in necrotic epidermal cells highlights viral replication and cell damage.