CD1a and Factor XIIIa Immunohistochemistry in Leprosy: A Possible Role of Dendritic Cells in the Pathogenesis of Mycobacterium leprae Infection

Abstract

Leprosy is a curable chronic granulomatous infectious disease caused by the bacillus Mycobacterium leprae. This organism has a high affinity for skin and peripheral nerve cells. In the evolution of infections, the immune status of patients determines the disease expression. Dendritic cells are antigen-presenting cells that phagocytose particles and microorganisms. In skin, dendritic cells are represented by epidermal Langerhans cells and dermal dendrocytes, which can be identified by expression of CD1a and factor XIIIa (FXIIIa). In the present study, 29 skin samples from patients with tuberculoid (13 biopsies) and lepromatous (16 biopsies) leprosy were analyzed by immunohistochemistry using antibodies to CD1a and FXIIIa. Quantitative analysis of labeling pattern showed a clear predominance of dendritic cells in tuberculoid leprosy. Difference between the number of positive cells of immunohistochemistry for the CD1a and FXIIIa staining observed in this study indicates a role for dendritic cells in the cutaneous response to leprosy. Dendritic cells may be a determinant of the course and clinical expression of the disease.

Transepidermal elimination of Mycobacterium leprae in histoid leprosy: A case report suggesting possible participation of skin in leprosy transmission

“…They have a role in the cutaneous response to leprosy, which may be a determinant of the course and clinical expression of the disease. [9] Future studies on their contribution, if any, in the carriage and response to the presence of epidermal bacilli might help unravel a few unexplored aspects of leprosy.…”

Dermal Dendrocytes FXIIIa+ Are Essential Antigen-Presenting Cells in Indeterminate Leprosy

“…33 With respect to LCs in the indeterminate phase of Hansen disease, there are scarce articles about it, dating back over 20 years. 4,[14][15][16][17] This result however needs to be interpreted with caution. Alvarenga et al 19 found no correlation between the clinical forms and the amount of LCs but evaluated only 3 cases of IL, without a control group of normal skin.…”

“…This initial interaction between host and bacillus is seldom investigated, with few studies regarding the immune response in this phase. 4 LCs are located mainly at the epidermis and stimulate a wide range of T-cell immune responses. 3 In the skin, major APCs are represented by Langerhans cells (LCs) and some dermal dendrocytes.…”

“…4,[14][15][16][17][18][19] To our knowledge, there is no previous research on DDFXIIIa and PDC in IL. 4,[14][15][16][17][18][19] To our knowledge, there is no previous research on DDFXIIIa and PDC in IL.…”

Epidermotropism of lepra bacilli in a patient with histoid Hansen′s disease

“…They have a role in the cutaneous response to leprosy, which may be a determinant of the course and clinical expression of the disease. [10] Future studies on their contribution, if any, to the carriage of and response to the epidermal bacilli might help unravel a few unexplored aspects of leprosy.…”