Presence of Cytokeratins in Human Eccrine Sweat Gland Epithelia

AbstractThe distribution of various cytokeratins in human eccrine sweat gland epithelia was studied using the antikeratin monoclonal antibodies KL1, CK 8.12, CK 8.60, PKK2, CK 8.13, CK 4.62 and RPN 1160. Immunocytochemical techniques were performed according to a standard alkaline phosphatase and monoclonal anti‐alkaline phosphatase (APAAP) method.Specific patterns of cytokeratins were found in each of the cell types that constitute the three anatomical areas of the gland. Luminal cells in the intradermal duct displayed the same labeling patterns as inner cells in the acrosyringium. Moreover, identical labeling patterns were found in the outer cells in the acrosyringium and the prickle cells in the interfollicular epidermis. Characteristically, CK 8.60, which expresses cytokeratin 10/11, labeled only in the upper ductal portion of the eccrine sweat gland, and cytokeratin 18, which is specifically recognized by RPN 1160, was present only in the secretory cells in the secretory portion. In addition, cytokeratin 19, recognized by CK 4.62, was present in the cells of the secretory portion, luminal cells, and inner cells. Distinctive cytokeratin antigenicity was also found in the inner cells of the interfollicular epidermis.Our results showed that 1) distinct cell types of the human sweat gland express different cytokeratin contents; 2) some of these cells present common cytokeratin types, most probably a cytogenetic expression reflecting related origin; 3) the application of various antikeratin monoclonal antibodies may be useful in determining the origin of tumors derived from the eccrine sweat gland.