Comparative study of histopathological and immunohistochemical findings in skin biopsies from patients with psoriasis before and after treatment with acitretin

Relationship between histomorphological findings and platelet activation in psoriasis

BACKGROUND

Elevated platelet count (PC), mean platelet volume (MPV), and Platelet Mass Index (PMI) are reported in patients with psoriasis, while platelet activation is associated with psoriasis severity. Available studies examining the relationship between platelet activation markers and psoriasis have mostly focused on psoriasis area severity index. To the best of our knowledge, there is no study examining the relationship between histopathological features of a single psoriatic plaque and platelet activation. The present study examined the relationship between histomorphological findings obtained by morphometric analysis and psoriasis patients' PC, MPV, and PMI values.

MATERIALS AND METHODS

Morphometric analysis was performed on hematoxylin and eosin-stained preparations of skin biopsies to measure minimum suprapapillary epidermis thickness (SPET_min ) and maximum epidermal thickness (ET_max ), maximum suprapapillary keratosis thickness (SPKT_max ), and maximum keratosis thickness (KT_max ). The relationship between PC, MPV, PMI, and morphometric skin biopsy outcomes was evaluated.

RESULTS

While an inverse correlation was found between SPETmin and PC and PMI in cases with psoriasis (p values = 0.015 and 0.005, r values = -0.238 and -0.271, respectively), no significant correlation was found between SPETmin and MPV (p value = 0.600, r value = -. 052). On the contrary, no significant correlation was found between SPKTmax, ETmax, and KTmax values and platelet parameters.

CONCLUSION

We assume that an increased risk of platelet activation-related diseases is expected in psoriasis patients displaying histopathological findings of suprapapillary thinning due to increased platelet activation; therefore, it may be beneficial to monitor these patients in terms of such risks.

Oral Alitretinoin for Patients with Refractory Prurigo

Background: prurigo is a chronic skin disorder associated with a history of chronic pruritus. The pathogenesis of prurigo is largely unknown and the treatment of prurigo is unsatisfactory and challenging. Conventional systemic treatments may be beneficial; however, their possible side effects and possible transient efficacy is still a problem. We aimed to present the clinical course and effect of treatment with alitretinoin on patients with prurigo nodularis initially treated with conventional treatments like oral antihistamine, cyclosporine, and phototherapy. Methods: all the patients had prurigo nodularis refractory to conventional treatment. Their medical records included demographic features, past medical history, duration of disease, and treatment modalities; and the clinical courses of the patients were reviewed for this retrospective study. We evaluated patient pruritus and skin lesions for the duration. Results: we present reports involving 10 patients with refractory prurigo. All the patients in our cases were treated with oral alitretinoin after previous treatments and reported the improvement of skin lesions and pruritus within 2 weeks to 3 months. Conclusions: we suggest that oral alitretinoin may be an effective and well tolerated treatment option for patients with intractable prurigo. Further clinical studies are warranted to confirm the long-lasting efficacy and safety of alitretinoin for treating patients with prurigo.

Histopathologic findings characteristic of CARD14-associated papulosquamous eruption

BACKGROUND

Pathogenic mutations in caspase recruitment domain-containing protein 14 (CARD14) lead to CARD14-associated papulosquamous eruption, which shares clinicopathologic findings with psoriasis and pityriasis rubra pilaris. We aimed to describe distinguishing histopathologic features of CARD14-associated papulosquamous eruption.

METHODS

This retrospective study examined the histopathologic features of specimens from patients with confirmed CARD14-associated papulosquamous eruption and adult patients with plaque psoriasis and pityriasis rubra pilaris.

RESULTS

Lesional skin biopsies from patients with CARD14-associated papulosquamous eruption consistently showed alternating checkerboard parakeratosis and orthokeratosis, acanthosis without acantholysis, and dilated vessels in the dermal papillae, with some cases also showing follicular plugging.

CONCLUSION

CARD14-associated papulosquamous eruption has a range of findings, with a predominance of features typically associated with pityriasis rubra pilaris.

AS2762900-00, a potent anti-human IL-23 receptor monoclonal antibody, prevents epidermal hyperplasia in a psoriatic human skin xenograft model

Interleukin (IL)-23 is thought to be critical in the pathogenesis of psoriasis, and anti-IL-23 monoclonal antibodies (mAbs) have been approved for the treatment of psoriasis. We speculated that an anti-IL-23 receptor mAb might have greater efficacy than an anti-IL-23 mAb in the treatment of local inflamed lesions with high IL-23 levels. We previously generated an anti-human IL-23 receptor mAb, AS2762900-00, which potently blocked IL-23-induced cell proliferation, regardless of the concentration of IL-23. Here, we evaluated the therapeutic potential of AS2762900-00 in the treatment of psoriasis. Compared with untreated control, AS2762900-00 significantly reduced the epidermal thickness of lesions in a clinically relevant psoriatic human skin xenograft model. The expression of inflammatory genes including genes downstream of IL-23 signaling in the lesion tended to be lower in the AS2762900-00 group than the untreated group, suggesting that the inhibitory effects of AS2762900-00 in the psoriatic human skin xenograft model might occur via blockade of IL-23 signaling pathways. Further, AS2762900-00 showed an inhibitory effect on signal transducer and activator of transcription 3 (STAT3) phosphorylation as a downstream signal of IL-23 receptor activation in whole blood from patients with psoriasis. We also confirmed that AS2762900-00 inhibited IL-23-induced STAT3 phosphorylation in a concentration-dependent manner using whole blood from healthy donors. These data suggest that AS2762900-00 is a promising drug candidate for the treatment of psoriasis. In addition, STAT3 phosphorylation in whole blood may be a useful biomarker for the evaluation of the pharmacodynamic effects of AS2762900-00 in healthy volunteers in clinical development.

Pivotal role of Acitretin nanovesicular gel for effective treatment of psoriasis: ex vivo-in vivo evaluation study

The goal of the current study was to explore the potential benefits of Acitretin (Act) nanovesicular gel as a prospective antipsoriatic topical delivery system counteracting the drug challenges in terms of its extremely low aqueous solubility, instability, skin irritation, and serious systemic adverse effects. Act-loaded niosomes were successfully developed, entirely characterized, and optimized. Further evaluation of the optimized formula was conducted regarding its stability and ex vivo cytotoxicity on different cell lines. The optimized niosomal vesicles were then incorporated in gel base matrix and investigated by sequential ex vivo (skin permeation and deposition) and in vivo (skin irritation and antipsoriatic activity using mouse tail model) experiments. The optimized Act-loaded niosomes (span 60:cholesterol molar ratio 1:1) were spherical in shape and exhibited the highest entrapment efficiency (90.32±3.80%) with appropriate nanosize and zeta potential of 369.73±45.45 nm and -36.33±1.80 mV, respectively. Encapsulation of the drug in the nanovesicles was further emphasized by differential scanning calorimetric and powder X-ray diffraction studies. After 3 months storage at 4±1°C, the optimized formula preserved its stability. Act nano niosomal gel produced a remarkable enhanced ex vivo permeation profile up to 30 h and significant drug deposition in the viable epidermal-dermal layers compared with those of Act gel. The pronounced antipsoriatic activity of the medicated nano niosomes was proved ex vivo in HaCaT cells (a keratinocyte cell line). Topical application of Act nano niosomal gel to mouse tail model further established its distinct in vivo antipsoriatic superiority in terms of significantly higher orthokeratosis, drug activity, and reduction in epidermal thickness compared with the control and other gel formulations. Also, negligible skin irritation and better skin tolerability of Act nanovesicular gel were revealed by primary irritation index and histopathologic examination.

Methotrexate treatment provokes apoptosis of proliferating keratinocyte in psoriasis patients

Psoriasis is a chronic inflammatory skin disease characterized by hyper proliferation of keratinocytes. Recent data show that the epidermis thickening in psoriasis may be related to imbalance of homeostasis caused by abnormal apoptotic process. Maintenance of keratinocyte apoptotic process is very important in psoriasis. Methotrexate (MTX) has been used for many years to restore the normal skin in psoriasis condition. However, the exact mechanism of MTX in psoriasis condition is poorly understood. The aim of this study was to examine the role of MTX on keratinocyte apoptosis pathway in psoriasis patients. A total of 58 psoriasis vulgaris patients were recruited for this study. Nonlesional skin biopsies served as control. Skin biopsies of psoriatic patients were collected and analyzed for cytosolic, mitochondria and total cytochrome c by ELISA. Expression of caspase-9, NFκBp65, pAkt1 by western blot, real-time PCR and immunohistochemical analysis of c-FLIP protein was analyzed in nonlesional and lesional skin biopsies before (day 0) and after (at the end of 6 and 12 weeks) MTX treatment. After MTX treatment, a significant increase in cytochrome c was observed when compared with before MTX treatment in psoriasis patients (p < 0.001). Protein and gene expression of cleaved caspase-9 were significantly increased after MTX treatment, whereas the expression of Bcl-xL, c-FLIP, NFκBp65, pAkt1 significantly downregulated after MTX treatment. In conclusion, these results showed that intrinsic apoptotic pathway induced by MTX eventually adds the beneficial therapeutic role of MTX in psoriasis by controlling the acanthosis.

Alitretinoin in Dermatology-An Update

Alitretinoin is a pan retinoic acid agonist. It was initially used as 0.1% gel in the management of localized Kaposi's sarcoma. At present, the use of systemic alitretinoin has proved extremely efficacious in the management of recalcitrant chronic hand eczema. Furthermore, there have been other retinoid responsive dermatosis that have demonstrated remission post usage of systemic alitretinoin. With a better toxicity profile, compared to the other systemic retinoids, alitretinoin could be considered a valuable treatment option in the near future for the treatment of these dermatologic disorders.

Diagnostic utility of Ki-67 and Cyclin D1 immunostaining in differentiation of psoriasis vs. other psoriasiform dermatitis

Background:

Differentiation of psoriasis from non-psoriasis psoriasiform dermatitis (NPPD) may be difficult for dermatopathologists, as lack of distinctive histopathological features in a subset of cases may cause confusion in diagnosis.

Objective:

As the prototype of psoriasiform dermatitis, psoriasis is a hyperproliferative skin disorder with increased epidermal turnover compared with NPPD, we investigated the role of proliferation markers, Ki-67 and Cyclin D1 as diagnostic tools to differentiate psoriasis from other psoriasiform dermatitis.

Methods:

Histopathological specimens of psoriasis (n = 35) and NPPD (n = 36, 14 pityriasis rubra pilaris, 12 pityriasis rosea and 10 lichen simplex) cases were reviewed and immunohistochemically stained for Ki-67 and Cyclin D1. Ki-67 and Cyclin D1 positive cells were counted for suprabasal, and total epidermal immunostaining per mm².

Results:

Suprabasal and total epidermal cell counts for Ki-67 were found to be significantly higher in the psoriasis group compared with the NPPD group (p < 0.05). An important and interesting feature was the presence of a cut-off value for the suprabasal/total epidermal cell count ratio of 75% for Ki-67 immunostaining, which was higher in all patients having psoriasis (range, 77.1% – 92.4%) and lower in all NPPD cases (range, 21.0% – 73.3%). However, suprabasal Cyclin D1 cell counts were higher in the psoriasis group compared with the NPPD group (p < 0.05), total epidermal Cyclin D1 cell counts were not statistically significant in either group (p = 0.167), and a cut-off value for suprabasal/total epidermal cell count ratio to distinguish these two entities was not detected using this immunostain.

Conclusions:

We suggest that Ki-67 is a more sensitive marker than Cyclin D1 in terms of having a cutoff value of 75% for the suprabasal/total epidermal immunoreactive cell count ratio, which we believe could be useful for dermatopathologists in differentiating psoriasis from other psoriasiform dermatitis.

Serum concentrations of interleukin-2 and tumour necrosis factor-α under cyclosporine versus acitretin treatment in plaque-type psoriasis

Objective

A prospective, randomized clinical study to compare the short-term effects of cyclosporin and acitretin on psoriasis severity, and serum interleukin (IL)-2 and tumour necrosis factor (TNF)-α concentrations.

Methods

Patients with moderate-to-severe plaque-type psoriasis were randomly assigned to receive either 3 mg/kg per day cyclosporine or 0.3–0.5 mg/kg per day acitretin for 8 weeks. Disease severity (psoriasis area severity index [PASI] score) and serum IL-2 and TNF-α concentrations were determined before and after treatment.

Results

PASI scores and serum IL-2 and TNF-α concentrations were significantly decreased after treatment with either cyclosporine ( n = 21) or acitretin ( n = 25). There were no statistically significant between-group differences in any parameter.

Conclusions

Acitretin and cyclosporine are equally effective in the treatment of moderate-to-severe plaque-type psoriasis.

Acitretin

Acitretin, a synthetic retinoid, is the pharmacologically active metabolite of etretinate. It is currently approved by the US Food and Drug Administration for the treatment of severe psoriasis in adults and has been established as a second-line therapy for the treatment of psoriasis resistant to the use of topical therapy. It is also an option for generalized pustular psoriasis, palmoplantar pustulosis, exfoliative erythrodermic psoriasis, and severe psoriasis in the setting of acitretin. It also has been shown to have chemo-preventative characteristics. Acitretin is limited by its teratogenicity and therefore considered inappropriate in most female patients of childbearing age. Common side effects include mucocutaneous dryness and elevated triglycerides.

Guidelines for the use of acitretin in psoriasis. Psoriasis Group of the Spanish Academy of Dermatology and Venereology

Phototherapy, classic systemic treatments (methotrexate, acitretin, and ciclosporin), and biologic agents (etanercept, infliximab, adalimumab, and ustekinumab) constitute a broad therapeutic arsenal that increases the likelihood of achieving control of severe and extensive disease in patients with psoriasis. Acitretin continues to be a very valuable tool in both monotherapy, in which it is combined with other systemic treatments (classic or biologic), and in sequential therapy. Thanks to its lack of a direct immunosuppressive effect and its ability to achieve a long-term response, acitretin has an important role in the treatment of psoriasis, although this has not always been acknowledged in relevant treatment guidelines. We present consensus guidelines for the use of acitretin in psoriasis drawn up by the Psoriasis Group of the Spanish Academy of Dermatology and Venereology. These guidelines provide a detailed account of acitretin, including pharmacological properties, indications and contraindications, adverse effects, and factors that should be taken into account to enhance the safe use of this drug. They also propose treatment strategies for use in routine clinical practice. The overall aim of these guidelines is to define the criteria for the use and management of acetretin in psoriasis.

About the cutaneous targets of bexarotene in CTCL patients

There are several approved therapies for cutaneous T-cell lymphoma (CTCL). The retinoids are one of the major biologic response modifiers used in CTCL, producing good response rates but few complete responses. Bexarotene has been demonstrated to act on malignant T-cells by inducing their apoptosis, but nothing is known about its role on keratinocytes and Langerhans cells. Immunohistochemical analysis using CD1a, HLA-DR, ICAM-1 (activation markers), CD95 and CD40 (apoptosis markers) was conducted on frozen sections of bexarotene-exposed cutaneous explants and skin biopsy specimens from patients treated with bexarotene. None of the studied markers was significantly modulated both on cutaneous explants and on skin biopsy specimens after treatment with bexarotene, compared to controls. Langerhans cells and keratinocytes do not appear to play a central role in the therapeutic control of CTCL by bexarotene therapy. The main bexarotene's target thus remains T-cells by inducing their apoptosis, a mechanism that is different from the other retinoids used in CTCL.

Syntheses and evaluation of the antioxidant activity of acitretin analogs with amide bond(s) in the polyene spacer

Ester analogs of the antipsoriatic drug acitretin were synthesized by coupling either anilines with N-protected indole-3-carboxylic acid, followed by deprotection and coupling with O-monoprotected dicarboxylic acids or Wittig reaction of indole-3-carboxaldehyde, 3-acetyl-1-tosylpyrrole and 4-amino-9-fluorenone with Ph3P=CHCO2tBu, followed by N-deprotection, where necessary, and finally coupling with cinnamoyl fluorides. Corresponding free acids were obtained through TFA-mediated carboxyl group deprotection. Although these analogs and acitretin showed very low reducing abilities, analogs 5, 6, 8 and 12 strongly inhibited LOX with IC50 values ranging from 35-65 microM. Acitretin and its analogs 5-7, 10, 11 and 15 inhibited lipid peroxidation more strongly than trolox whereas acitretin and analog 4 were in vivo more potent anti-inflammatory agents on rat paw oedema induced by Carrageenan than indomethacin.