Molluscum contagiosum:  immunomorphological aspects  of keratinocytes markers  of differentiation and adhesion.
BACKGROUND
Molluscum contagiosum (MC) is a Molluscipox virus infection of keratinocytes with hyperplasia and intracytoplasmic inclusions - the molluscum bodies (MBs). Few papers address cytokeratins (K) profile in MC, mainly focusing terminal keratinization process.


METHODS
Forty-one MC lesions were subjected to immunohistochemical technique to verify K1, K10, K14, K16, involucrin, filaggrin, E-cadherin and p63 expression. MC immunolabeling pattern was compared to adjacent normal appearing epidermis (ANAE).


RESULTS
In MC and ANAE, K1/K10 were expressed in suprabasal layers, K14 was expressed in basal and suprabasal layers and K16 was expressed through all spinous layer. Involucrin and filaggrin were observed in granular, spinous and in basal layer of ANAE and MC. E-cadherin was present up to the first layers of MC while ANAE exhibited E-cadherin labeling at basal and spinous layers. Basal and spinous layers keratinocytes nuclei, in both MC and ANAE, express p63.


CONCLUSIONS
Infection by Molluscipox virus alters keratinocyte differentiation status. The presence of K14 and p63 in spinous layer, as well as early expression of involucrin and filaggrin, associated to a hyperproliferative state disclosed by K16 expression, may be a result of disruption in keratinocytes maturation process. The changes observed at ANAE may represent early events in keratinization disturbance.
Callegaro
Clarissa Freitas
CF
Department of Dermatology, Faculdade de Medicina da Universidade de São Paulo, São Paulo - SP, Brazil.
Sotto
Mirian N
MN
D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000032:analysis; D015820:Cadherins / Q000096:biosynthesis; D002448:Cell Adhesion / Q000502:physiology; D002454:Cell Differentiation / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D000091344:Filaggrin Proteins; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D007381:Intermediate Filament Proteins / Q000096:biosynthesis; D015603:Keratinocytes / Q000378:metabolism* / Q000473:pathology; D007633:Keratins / Q000096:biosynthesis; D008565:Membrane Proteins / Q000096:biosynthesis; D008875:Middle Aged; D008976:Molluscum Contagiosum / Q000378:metabolism* / Q000473:pathology; D011498:Protein Precursors / Q000096:biosynthesis; D055815:Young Adult
D015415:Biomarkers; C081876:CKAP4 protein, human; D015820:Cadherins; C000717249:FLG protein, human; D000091344:Filaggrin Proteins; D007381:Intermediate Filament Proteins; D008565:Membrane Proteins; D011498:Protein Precursors; C032253:involucrin; D007633:Keratins