|LETTER TO THE EDITOR
|Year : 2015 | Volume
| Issue : 4 | Page : 300-301
Expression of p16 in psoriasis and chronic spongiotic dermatitis
Viktoryia Kazlouskaya1, Elina Shustef2, Elen Blochin1
1 Ackerman Academy of Dermatopathology, NY, USA
2 Department of Pathology, Montefiore Medical Center and Albert Einstein College of Medicine, NY, USA
|Date of Web Publication||8-Jul-2015|
Ackerman Academy of Dermatopathology, 145 E32 Street, 10th Floor, New York, NY 10016
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Kazlouskaya V, Shustef E, Blochin E. Expression of p16 in psoriasis and chronic spongiotic dermatitis. Indian Dermatol Online J 2015;6:300-1
|How to cite this URL:|
Kazlouskaya V, Shustef E, Blochin E. Expression of p16 in psoriasis and chronic spongiotic dermatitis. Indian Dermatol Online J [serial online] 2015 [cited 2020 Apr 6];6:300-1. Available from: http://www.idoj.in/text.asp?2015/6/4/300/160289
Several recent studies have addressed the pathogenesis of psoriasis and the interplay between keratinocyte proliferation and apoptosis. Nickoloff have shown that p16 protein is expressed in keratinocytes resistant to apoptosis, proposing that its overexpression may play a role in the development of psoriatic plaques. , p16 INK4a gene promoter methylation was found in approximately 30% of psoriasis patients and correlated with the Psoriasis Area Severity Index.  The definitive role of p16 protein in psoriasis has not yet been confirmed and much of the data are inconsistent. In contrast to Nickoloff's results, Mark et0 al. found no difference in p16 gene expression in lesional and perilesional psoriatic skin through experiments with real-time polymerase chain reaction (PCR).  Abou EL-Ela et al. reported that the concentration of p16 protein measured with PCR was lower in patients with psoriasis prior to phototherapy, but was increased after treatment. 
Histopathological criteria for psoriasis are well-established; however, the diagnosis is challenging in certain scenarios. When considering the differential diagnosis of chronic spongiotic dermatitis, particularly in acral sites, distinguishing between these entities may be challenging. We aimed to determine if p16 protein expression is unique for the psoriasis lesions and if its expression is helpful in the differentiation of psoriasis from chronic spongiotic dermatitis in acral and nonacral sites. A retrospective search was performed, and 13 biopsies from patients with psoriasis (5 from acral sites) and 11 biopsies from patients with subacute spongiotic dermatitis (6 from acral skin) were selected. The average age of patients with psoriasis was 57.7 ± 14.3 (4 men and 9 women) and spongiotic dermatitis - 64.5 ± 15.8 years (6 men and 5 women). Periodic acid-Schiff staining was performed on all lesions to exclude fungal infection. We intended to include only patients with a primary diagnosis of psoriasis or spongiotic dermatitis and no previous treatment.
The slides were stained with the p16 antibody (clone E6H4, Roche mtm laboratories AG, Heidelberg, Germany). Overall expression of p16 protein was seen in less than 25% of the total epidermis in lesions of both psoriasis and spongiotic dermatitis. Focal expression (presence of clustered positive cells) of p16 protein was observed in 7/13 lesions of psoriasis [Figure 1] and in 3/11 lesions of spongiotic dermatitis [Figure 2] (P = 0.4, Yates corrected Chi-square, Statistica ® 10, Tulsa, OK, USA).
|Figure 1: Psoriasis. (a) Inflammatory lymphocytic dermatitis with acanthosis. Parakeratosis and neutrophils in the stratum corneum, dilated blood vessels within the epidermis (H and E, stained slides, ×200). (b) Expression of p16 protein in psoriatic skin, p16 stained sections, ×200|
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|Figure 2: Spongiotic dermatitis. Inflammatory lymphocytic dermatitis with acanthosis and slight spongiosis with an overlying scale crust (H and E, stained slides, ×200). (b) Expression of p16 protein in spongiotic dermatitis, p16 stained sections, ×200|
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No difference was seen in the expression of p16 between acral and nonacral lesions of psoriasis and chronic spongiotic dermatitis (p16 was expressed in 3/6 lesions biopsied from acral skin of patients with spongiotic dermatitis and in 2/5 patients with psoriasis; P = 0.8, Yates corrected Chi-square. Review of both types of lesions revealed no differences in the pattern of p16 expression between acral and nonacral sites.
In summary, overexpression of p16 in psoriatic lesions is not a consistent finding and cannot be used in the assessment of the psoriasiform dermatitis. The presence of p16 expression in spongiotic dermatitis also suggests that it may play a role in its pathogenesis. Further investigation is necessary to evaluate the clinical significance and potential role of p16 protein in cutaneous inflammatory conditions.
| References|| |
Nickoloff BJ. Creation of psoriatic plaques: The ultimate tumor suppressor pathway. A new model for an ancient T-cell-mediated skin disease. Viewpoint. J Cutan Pathol 2001;28:57-64.
Elias AN, Barr RJ, Nanda VS. p16 expression in psoriatic lesions following therapy with propylthiouracil, an antithyroid thioureylene. Int J Dermatol 2004;43:889-92.
Chen M, Chen ZQ, Cui PG, Yao X, Li YM, Li AS, et al.
The methylation pattern of p16INK4a gene promoter in psoriatic epidermis and its clinical significance. Br J Dermatol 2008;158:987-93.
Mark EB, Jonsson M, Asp J, Wennberg AM, Mölne L, Lindahl A. Expression of genes involved in the regulation of p16 in psoriatic involved skin. Arch Dermatol Res 2006;297:459-67.
Abou EL-Ela M, Nagui N, Mahgoub D, El-Eishi N, Fawzy M, El-Tawdy A, et al.
Expression of cyclin D1 and p16 in psoriasis before and after phototherapy. Clin Exp Dermatol 2010;35:781-5.
[Figure 1], [Figure 2]