Abstract: 【Abstract】 Objective To investigate the expression of solute carrier family 35 member E1 （SLC35E1） and SLC35E2B in skin lesions of patients with Mycobacterium infections. Methods Paraffin-embedded skin tissues of 31 patients confirmedly diagnosed with Mycobacterium infections were collected from Dermatology Hospital of Southern Medical University from 2014 to 2018, including 10 cases of multibacillary leprosy, 9 of nontuberculous mycobacterial infection, 7 of cutaneous tuberculosis, and 5 of erythema induratum. Meanwhile, paraffin-embedded skin tissues of 10 healthy individuals were collected, and served as normal control group. Immunohistochemical staining was performed to determine the expression of SLC35E1 and SLC35E2B in the lesional and normal control skin specimens, and immunofluorescence staining to observe the co-expression of CD68 and S100 with SLC35E1 and SLC35E2B in the skin lesions. Results Neither SLC35E1 nor SLC35E2B was expressed in the normal control group, but high expression of SLC35E1 and SLC35E2B was observed in the dermis of skin lesions from the patients with leprosy, nontuberculous mycobacterial infection, cutaneous tuberculosis or erythema induratum. Immunohistochemical staining showed that the expression of SLC35E1 and SLC35E2B （expressed as average optical density） was significantly higher in the multibacillary leprosy group （0.143 ± 0.010, 0.169 ± 0.004, respectively）, nontuberculous mycobacterial infection group （0.278 ± 0.015, 0.229 ± 0.088, respectively）, cutaneous tuberculosis group （0.171 ± 0.010, 0.103 ± 0.016, respectively） and erythema induratum group （0.200 ± 0.015, 0.118 ± 0.021, respectively） than in the normal control group （both 0, all P < 0.05）. Immunofluorescence staining showed co-expression of SLC35E1 and SLC35E2B with CD68 in skin lesions of the patients with leprosy, nontuberculous mycobacterial infection, cutaneous tuberculosis. Conclusion Both SLC35E1 and SLCE2B were markedly highly expressed in skin lesions of patients with Mycobacterium infections.

Key words: Mycobacterium, Tuberculosis, Leprosy, Nontuberculous mycobacteria, Solute carrier family 35, member E1, Solute carrier family 35, member E2B