Table 1.
The demographics for each disease group are comparable to the control group, except for AD.
Fig 1.
JAK1, JAK2, JAK3 and TYK2 immunohistochemical localization in the epidermis.
Similar expression was seen in all studied diseases: JAK1, 2 and 3 were expressed in the cytoplasm of the keratinocytes and TYK2, besides cytoplasmic expression, had nuclear expression of TYK2 (arrow). Original magnification x 200. Pso = psoriasis, LP = lichen planus, CLE = cutaneous lupus erythemathosus, AD = atopic dermatitis, AA = alopecia areata, PG = pyoderma gangrenosum.
Fig 2.
PhosphoJAK1, pJAK2, pJAK3 and pTYK2 immunohistochemical localization in the epidermis.
Cytoplasmic expression of pJAK1, pJAK3 and pTYK2. Intranuclear expression of pJAK2 and pTYK2 (arrows). Similar expression was seen in all studied diseases. Original x 200. Pso = psoriasis, LP = lichen planus, CLE = cutaneous lupus erythemathosus, AD = atopic dermatitis, AA = alopecia areata, PG = pyoderma gangrenosum.
Fig 3.
Overview of JAK/STAT protein (by immunohistochemistry) expression in the studied inflammatory skin diseases as compared to healthy skin.
Pso = psoriasis, LP = lichen planus, CLE = cutaneous lupus erythemathosus, AD = atopic dermatitis, AA = alopecia areata, PG = pyoderma gangrenosum, epid ext = epidermal extent. NS = not statistically significant.
Fig 4.
SPSS statistical analysis of the keratinocyte staining compared with control (staining intensity for pJAK1 and pJAK3 and density of the positively stained cells for pJAK2, pTYK2, pSTAT1, pSTAT2 and pSTAT3).
Pso = psoriasis, LP = lichen planus, CLE = cutaneous lupus erythemathosus, AD = atopic dermatitis, AA = alopecia areata, PG = pyoderma gangrenosum, epid ext = epidermal extent. NS = not statistically significant. * p≤0.05 ** p≤0.001.
Table 2.
Percentage of JAK/STAT family positivity (in grey)/negativity in dermal inflammatory cells of ISDs comparing to controls.
Fig 5.
JAK/STAT mRNA levels in human skin biopsies from psoriasis compared to healthy controls illustrates JAK3, STAT1 and STAT3 overexpression.
* p≤0.05.
Fig 6.
Immunohistochemical staining of normal keratinocytes (KCs) and psoriasis induced keratinocytes (Pso KCs) with or without tofacitinib treatment.
The pJAKs expression in Pso KCs was similar and summarizes the one observed in the epidermis of the psoriasis skin biopsies. Strong pJAK3 expression and weak positive pJAK1 expression was induced by psoriasis stimulation and inhibited after treatment with tofacitinib. Phospho-JAK2 and pTYK2 expression did not change neither with psoriasis stimulation nor with the treatment. Note the cytoplasm localization of pJAK1 and pJAK3 and the nuclear localization of pTYK2 in the keratinocytes. As pJAK2 was negative in all conditions, the localization of the staining could not be analysed. Original magnification x200.