Local defense systems in the prepuce

Urinary tract infection (UTI) is a common bacterial infection in children. Circumcision reduces the incidence of UTI, and prevents preputial colonization with uropathic bacteria in childhood. However, there is insufficient information about the reason(s) why such colonization tends to occur in prepucium skin.

We evaluated some of the humoral and cellular defense systems in the prepucium skins of 30 boys (age range 6 months to 5 years). We measured the expressions of Langerhans cells, mast cells, T lymphocytes, IgA, IgG and IgM in the prepuce and compared them with those in normal skin. Tissues obtained during circumcision were divided into two groups. In the first group, sections were stained with hematoxylin-eosin and toluidine blue. Immunohistochemical reactions were performed on paraffin-embedded tissue by means of the avidin-biotin-peroxidase complex method. The antibodies used were S-100 for Langerhans cells and CD8 and CD4 for T lymphocytes. In the second group, frozen sections were stained for IgA, IgG and IgM using an immunofluorescence method.

The distribution of mast cells and IgG positivity was similar to that of normal skin. Langerhans cells were increased in prepucium skin (p<0.05), whilst only a few CD4 T lymphocytes were observed around the perivascular area and no expression of CD8 was observed in the prepucium and normal skin.

The increase in Langerhans cells in prepucium skin may be the result of continuous stimulation of bacteria found in the periurethral area, and the absence of CD8 may help the colonization of uropathic bacteria.