Abstract:

Objective To observe the expressions of antimicrobial peptides LL-37, human beta defensin-2 （HBD-2） and HBD-3 in the lesions of lupus vulgaris and tuberculosis verrucosa cutis, and to speculate the pathogenesis of cutaneous tuberculosis. Methods Tissue specimens were collected from the lesions of 18 patients with lupus vulgaris or tuberculosis verrucosa cutis and 15 patients with psoriasis, as well as from the normal skin of 10 healthy controls. The specimens were embedded by paraffin and subjected to an immunohistochemical analysis for the detection of antimicrobial peptides LL-37, HBD-2 and HBD-3. Statistical analysis was performed by using the SPSS 13.0 software package, and t test was carried out to compare the expressions of LL-37, HBD-2 and HBD-3 between these groups. Results LL-37 and HBD-2 were observed mainly in the upper and middle layer of the epidermis, appendages and vascular endothelial cells in cutaneous tuberculosis lesions. The expression levels of LL-37 and HBD-2 were significantly higher in tuberculosis lesions than in the normal skin （t = 2.632, 2.399, both P ＜ 0.05）. Psoriatic and tuberculosis lesions shared a similar expression pattern for LL-37 and HBD-2. HBD-3 was absent in the lesions of cutaneous tuberculosis, but present in both psoriatic lesions and normal skin. Conclusions Both LL-37 and HBD-2 may participate in the immune response in cutaneous tuberculosis, while the absence of HBD-3 may contribute to the pathogenesis of cutaneous tuberculosis.

Key words: Expression