The role of interleukin-12 in the pathogenesis of psoriasis.
OBJECTIVE
To verify the role of IL-12 in the pathogenesis of psoriasis and determine its relation to IFNgamma.


METHODS
Skin biopsies from lesional and non-lesional skin of 30 patients and 10 healthy controls were obtained for quantitative PCR examination of IL-12 (P40) and IFNgamma mRNA as well as in situ PCR of IL-12 (P40) and IFNgamma mRNA.


RESULTS
IL-12 and IFNgamma levels were higher in lesional skin than in non-lesional and control skin. A significant correlation between IL-12 and IFNgamma was found. By in situ PCR hybridization, IL-12 expression was only found in the dermis, while IFNgamma was invariably expressed in the dermis and/or epidermis.


CONCLUSIONS
We suggest that IL-12 independently and through IFNgamma induction may have a crucial role in the development of the active psoriatic lesion itself, where it is probably produced locally in the dermis as a step in the evolution of the psoriatic lesion.
Shaker
Olfat G
OG
Department of Biochemistry, Faculty of Medicine, Cairo University, Egypt. olfatshaker@yahoo.com
Moustafa
Wedad
W
Essmat
Samia
S
Abdel-Halim
Mona
M
El-Komy
Mohamed
M
D000199:Actins / Q000235:genetics / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D005260:Female; D015870:Gene Expression; D006801:Humans; D007371:Interferon-gamma / Q000235:genetics / Q000378:metabolism*; D018664:Interleukin-12 / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011565:Psoriasis / Q000209:etiology / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D012867:Skin / Q000378:metabolism
D000199:Actins; D012333:RNA, Messenger; D018664:Interleukin-12; D007371:Interferon-gamma