Figure 1.
A–D: Fragment of skin of a patient with LCL Caratinga, MG, Brazil.
(A) Changes observed in the epidermis were intense acanthosis (AC) and papillomatosis (PL). Pearl corneas can also be seen (black arrow). Finger-like projections of epidermis into the dermis layer, papillomatosis (PL) Bar = 32 µm, (B) Higher magnification shows thickening of the spinous (acanthosis) layer due to proliferation of epidermal cells (arrowhead) leading to papillomatosis (PL). Bar = 16 µm, (C) Higher magnification showing the inflammatory infiltrate of mononuclear cells (plasma cells, macrophages and lymphocytes) in the dermis. Note Langhans-type giant cell formation, but without a typical granuloma formation (arrowhead). Bar = 16 µm. (D) Eosinophilic necrotic area in the dermis with fragmented collagen fibers resembling fibrinoid necrosis (arrowheads) Bar = 64 µm. Hematoxylin-eosin staining. Epithelium (Ep), Dermis (De), Papillomatosis (PL).
Table 1.
Comparison among paired test HE, IHC (dog serum), IHC (LPG) and IHC (biotin-free polymer) according to result obtained by PCR in the diagnosis of ATL.
Figure 2.
A–E: Fragment of skin of a patient with LCL, Caratinga, MG, Brazil.
(A, B) Immunohistochemical labeling of amastigotes of Leishmania with an aliquot of a commercial monoclonal anti-Leishmania antibody and the streptavidin-biotin peroxidase method. (A) Low magnification showing a brown background evidenced by the cytoplasm of the epithelial layer cells (arrowheads). Bar = 32 µm. (B) Higher magnification showing intense non-specific staining visible as dark brown cytoplasmic staining of epithelial (arrowheads) and inflammatory mononuclear cells (macrophages) with intracellular amastigotes of Leishmania in the dermis (arrows) Bar = 16 µm. (C,D) Immunohistochemical labeling of amastigotes of Leishmania using dog hyperimmune serum as the primary antibody with the streptavidin-biotin peroxidase method (C) Low magnification showing light-blue stained background. Bar = 32 µm. (D) Higher magnification showing dark-brown-stained intracellular amastigotes of Leishmania within macrophages in the dermis (arrows) and light-blue-stained background. Bar = 16 µm; (A–D) Immunohistochemistry with the streptavidin peroxidase method counter-stained with Harris’s hematoxylin. (E) Observe immunolabeled amastigotes inside macrophages associated areas of tissue debris (arrow) Epithelium (Ep), Dermis (De).
Figure 3.
Parasite load of 73 skin fragments of a sample subjected to the immunohistochemical methods of streptavidin peroxidase, using hyperimmune serum from a dog naturally infected by Leishmania infantum chagasi (dilution 1∶100) and monoclonal antibody anti-Leishmania lipophosphoglycan (LPG) (Mo-anti LPG) (dilution 1∶100).
Mann-Whitney p = 0.0001.