Determinación de la actividad de la óxido nítrico sintetasa endotelial y del factor NF-kB, en la piel del paciente con pseudoangiomatosis eruptiva
Eruptive pseudoangiomatosis (EPA) is a dermatosis characterized by sparse erythematous papules, with vascular appearance and surrounded by a blanching halo. It has acute onset and spontaneous resolution. Histopathology shows vascular affection. Though it has been related to viral infection and in...
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| Publicado en: | Revista Médica Universitaria |
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| Autores principales: | , , , , |
| Materias: | |
| Acceso en línea: | https://bdigital.uncu.edu.ar/fichas.php?idobjeto=2737 |
| Sumario: | Eruptive pseudoangiomatosis (EPA) is a dermatosis characterized by sparse
erythematous papules, with vascular appearance and surrounded by a blanching halo.
It has acute onset and spontaneous resolution. Histopathology shows vascular
affection. Though it has been related to viral infection and insects bites its aetiology
and pathogenesis remains unclear. Based on clinical and histological findings, related
to vascular affection, the main objective was to observe changes in endothelial nitric
oxide synthase (eNOS) activity and nuclear factor-ĸ B (NF-kB) expression related to
inflammatory pathogenesis.
Materials and methods: Samples from ten patients with clinical diagnosis of EPA were
fixed for light microscopy in formalin solution, embedded in paraffin and stained with
haematoxylin and eosin and Masson´s trichrome stain.
In three patients serological testing for echovirus, enterovirus, cytomegalovirus,
parvovirus A and B, hepatitis C and hepatitis B virus were performed.
eNOS activity: in five patients snap-frozen tissue was obtained and homogenized in a
buffer containing 250 mM sucrose, 50 mM tris-HCl pH 7.4 and added protease
inhibitors: SBTI, aprotinin, PMSF, leupeptin, DTT and EDTA. The activity was
evaluated in the supernatant measuring the conversion of L-[3H]-arginine in L-[3H]-
citruline and subsequent liquid scintillation counting. 4. Expression of NF-ĸB, a
promoter of inflammatory processes activated by redox status was determined by
immunohistochemistry.
Results: The patients, 5 women and 5 men, had 3 to 6 mm, red papules surrounded by
a 2 to 5 mm blanching halo, especially located on the lower extremities, around knees,
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forearms and arms. In two patients the lesions were also on the trunk and face.
Histological findings show dilated dermal blood vessels with plump endothelial cells
and perivascular lymphohistiocytic infiltrate. All serological tests for virus were
negative. eNOS activity in lesions was significant lower when compared with normal
skin (p= 0,002). NF-ĸB expression was strongly positive in dermal vessels of the
papillary and reticular dermis.
Conclusions: As all our patients were affected in summer, mosquito bites must be
considered as etiologic factor. eNOS lower expression suggests that probably it has no
role in this inflammatory process, but linked to blood stasis. The increased expression
of NF-ĸB confirms that the inflammatory process is related to the developing process.
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