07 aug. 2008 PATOGENEZA PENFIGOIDULUI GESTATIONAL
C. SItaru*, P. Vârtej**
*Clinica de Dermatologie si Venerologie, Universitatea Lubeck, Germania
**Clinica de Obstetricã si Ginecologie, Spitalul Universitar UMF “Carol Davila”, Bucuresti
Rezumat
Pemfigoidul gestational, cunoscut si sub numele de herpes gestationis, este o boalã cutanatã autoimunã caracterizatã prin leziuni veziculo-buloase. Formarea de bule poate însã deseori lipsi; în aceste cazuri boala se manifestã sub formã de leziuni urticariene sau eczematoase, cel mai frecvent ca macule, papule sau plãci eritematoase associate cu prurit intens.
În pielea pacientelor cu pemfigoid gestational se pot evidential depuneri de complement (factorC3) la nivelul jonctiunii dermo-epidermale prin imunoflorescentã directã. În serul acestor bolnave circulã autoanticorpi care fixeazã complement la nivelul jonctiunii dermo-epidermale. Studiile moleculare recente au arãtat cã acesti autoanticorpi recunosc specific colagenul de tip XVII. Acest antigen, cunoscut si sub numele de antigenul pemfigoid bulos de 180kDa (BP 180), este o proteina hemidesomozomalã importantã pentru mentinerea adeziunii epidermului de dermul subiacent. Legarea autoanticorpilor de la pacientle cu pemfigoid gestational la nivelul jonctiunii dermo-epidermale declanseazã o cascadã inflamatorie care duce la formarea de bule subepidermale.
Folosind forme recombinate ale colagenului de tip XVII autoanticorpii în PG pot fi relativ usor detectati prin metode imunoenzimatice de tip imunoblot sau ELISA. Aceste metode sunt de asemenea utile si pentru monitorizarea evolutiei bolii si a rãspunsului la tratament.
Abstract
Pemphigoid gestationis, also refered to as herpes gestationis, is an autoimmune blistering skin disease characterized by vesiculo-bullous lesions. Howevere, blister formation may often occur; in these insances the disease is manifested as urticarial or eczematous lesions, usually erythematous macules, papules or plaques associated with intense itching.
In the skin of these patients deposition of complement (C3) at the dermal-epidermal junction can be detected by direct immunofluorescence microscopy. Autoantibodies circulating in serum of these patients fix complement at the dermal-epidermal junction. Recent molecular studies showed that these autoantibodies specifically recognize type XVII collagen. This antige, also known as bullous pemphigoid antigen of 180kDA, is a transmembrane hemidesmoisomal protein important for maintaining the adhesion of the epidermis on the underlying dermis. Binding of autoantibodies from pemphigoid gestationis patients to the dermal-epidermal junction triggers an inflammatory cascade resulting in subepidermal blisters.
Pemphigoid gestationis autoantibodies can be readily detected by immunoblot or ELISA immunoassays using recombinant forms of type XVII collagen. In addition, these molecular tests are also useful for monitoring disease activity during the course of the disease and the response to treatment.