Nitrotyrosine localization to dermal nerves in borderline leprosy.
BACKGROUND
Nerve damage is a common and disabling feature of leprosy, with unclear aetiology. It has been reported that the peroxidizing agents of myelin lipids-nitric oxide (NO) and peroxynitrite-are produced in leprosy skin lesions.


OBJECTIVE
To investigate the localization of nitrotyrosine (NT)-a local end-product of peroxynitrite-in leprosy lesions where dermal nerves are affected by a granulomatous reaction.


METHODS
We investigated by immunohistochemistry and immunoelectron microscopy the localization of the inducible NO synthase (iNOS) and NT in biopsies exhibiting dermal nerves from patients with untreated leprosy.


RESULTS
There were abundant NT-positive and iNOS-positive macrophages in the borderline leprosy granulomas infiltrating peripheral nerves identified by light microscopy, S-100 and neurofilament immunostaining. Immunoelectron microscopy showed NT reactivity in neurofilament aggregates and in the cell wall of Mycobacterium leprae.


CONCLUSIONS
Our results suggest that NO and peroxynitrite could be involved in the nerve damage following borderline leprosy.
Schön
T
T
Department of Medical Microbiology, Faculty of Health Sciences, 581 85 Linköping, Sweden. t.schon@telia.com
Hernández-Pando
R
R
Baquera-Heredia
J
J
Negesse
Y
Y
Becerril-Villanueva
L E
LE
Eon-Contreras
J C L
JC
Sundqvist
T
T
Britton
S
S
D006099:Granuloma / Q000201:enzymology / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D007918:Leprosy / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D008264:Macrophages / Q000378:metabolism; D016253:Microscopy, Immunoelectron / Q000379:methods; D009166:Mycobacterium leprae / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000032:analysis; D010525:Peripheral Nerves / Q000378:metabolism / Q000473:pathology; D009418:S100 Proteins; D012867:Skin / Q000294:innervation* / Q000378:metabolism / Q000473:pathology; D017192:Skin Diseases, Bacterial / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000032:analysis*
D009418:S100 Proteins; C002744:3-nitrotyrosine; D014443:Tyrosine; D019001:Nitric Oxide Synthase