cellular immune response in non-ulcerated skin lesions due to infection.

BACKGROUND

Skin lesions of patients affected by non-ulcerated cutaneous leishmaniasis (NUCL) caused by are characterized by lymphohistiocytic inflammatory infiltrate associated with epithelioid granuloma and scarce parasitism. However, the cellular immune response of these patients is unclear. Therefore, the aim of the present study was to characterize the cellular immune response in the skin lesions of patients affected by NUCL.

METHODS

Twenty biopsies were processed by immunohistochemistry using primary antibodies to T lymphocytes (CD4, CD8), NK cells, B lymphocytes, macrophages, nitric oxide synthase and interferon-gamma.

RESULTS

Immunohistochemistry revealed higher expression of all cellular types and molecules (IFN-γ, iNOS) in the dermis of diseased skin compared to the skin of healthy individuals (p < 0.05). Morphometric analysis performed in the skin lesions sections showed the predominance of CD8 T lymphocytes in the mononuclear infiltrate, followed by macrophages, mostly iNOS, a response that could be mediated by IFN-γ.

CONCLUSION

Our study improves knowledge of the cellular immune response in non-ulcerated or atypical cutaneous leishmaniasis caused by in Central America and pointed to the pivotal participation of CD8 T lymphocytes in the host defense mechanisms against the parasite in patients with NUCL.