The effect of topical corticosteroids in combination with alefacept on circulating T‐cell subsets in psoriasis

The Expression of Activation Markers CD25 and CD69 Increases during Biologic Treatment of Psoriasis

CD (cluster of differentiation) 69 and CD25 are considered early and late markers of the activation of lymphocytes, respectively. CD25 is a part of the IL-2 receptor and is present on the surface of immune and non-immune cells, with high amounts on activated lymphocytes and regulatory T cells. CD69 is expressed on various types of white blood cells, including newly activated lymphocytes, lymphocytes infiltrating tissues isolated from subjects with chronic auto-inflammatory diseases, several subtypes of memory T cells and regulatory T cells. Primarily, CD69 was considered to be an early marker of the activation of lymphocytes, but, right now, data derived from in vitro and in vivo studies have revealed the immunomodulatory role of this surface antigen. In 84 patients with psoriasis, of whom 28 were treated with different biologic drugs, as well as in 29 healthy control subjects, the expression of CD25 and CD69 on different subtypes of peripheral blood mononuclear cells (PBMCs) was studied with the use of flow cytometry. Significantly higher levels of CD3/CD69-, CD8/CD69- and CD19/CD69-positive PBMCs as well as within CD3+ cells were present in subjects suffering from psoriasis when compared to healthy controls. In patients with psoriasis who were treated with biologic drugs, the levels of CD3/CD69-, CD4/CD69- and CD19/CD69-positive PBMCs, and CD3/CD69 within CD3+ cells, CD4/CD69 within CD4+ cells, CD4/CD25 within CD4+ cells and CD19/CD69 within CD19+ cells were significantly higher than before therapy. Our results support a role for activation markers, especially CD69, in psoriasis. Further research is warranted to fully clarify their significance in this common dermatosis, especially during biologic treatment.

An LC-MS Method for Determination of Betamethasone in Tissue Engineering Skin and Application to Dermatopharmacokinetic Study

Background and Objectives:

Tissue engineering skin is a three-dimensional skin substitute cultured in the gas-liquid interface using the immortalized keratinocytes (HaCaT cells). In this study, the preliminary metabolism of betamethasone dipropionate by tissue engineering skin was studied and the pharmacokinetics methodology was established using betamethasone dipropionate gel as the target drug.

Methods:

The betamethasone dipropionate gel was applied on the tissue engineering skin after the skin was cultured. Then the medium (receiving liquid) and skin were taken on 0.25, 0.75, 1.75, 3, 5, 8, 12, 24, 36, 48 h time points. The betamethasone concentration in the medium and skin was determinated by the LC-MS method. Chromatographic analysis was conducted using isocratic elution on a C18 column (150 mm × 2.0 mm, 5 µm) in mobile phase consisting of methanol and water (70 : 30, v/v). The mobile phase was pumped at a flow rate of 0.2 mL/min.

Results:

This method exhibited linearity within the concentration range of 0. 1 to 50 µg /mL of betamethasone. The LLOQ was 0. 1 µg /mL. The intra- and inter-day precisions of betamethasone in the blank medium were all less than 10.69 % (RSD, %), while in the blank, skin homogenates were all less than 13.96 % (RSD, %). As a result, the betamethasone concentration in the medium and skin could both be detected, which suggested that betamethasone dipropionate could be metabolized to betamethasone through the tissue engineering skin.

Conclusion:

It was feasible to use tissue engineering skin as a model to study the dermatopharmacokinetics of topical betamethasone dipropionate gel. The research could build a foundation for the dermato-pharmacokinetic study approach.

Development of a simple method for simultaneous determination of tazarotene and betamethasone dipropionate and their metabolites using LC-MS method and its application to dermatopharmacokinetic study

In our study, a method for the determination for tazarotene and betamethasone dipropionate in human tissue-engineered skin was established. Tazarotene gel, betamethasone dipropionate cream or a combination cream was administered to the skin. Then the skin was taken off at 0.25, 0.75, 1.75, 3, 5, 8, 12, 24, 36, 48 h time points after the residual drug was removed. The concentrations of tazarotene, betamethasone dipropionate and their major metabolites in skin were determined by LC-MS. Tazarotene and tazarotenic acid were detected in the concentration range of 2-200 μg/mL with an LLOQ of 2 μg/mL. Betamethasone dipropionate was detected in the concentration range 0.5-300 μg/mL with an LLOQ of 0.5 μg/mL, and betamethasone was detected at 2-200 μg/mL with an LLOQ of 2 μg/mL. The intra- and inter-day precisions of the four analytes in the skin homogenate were all <15% (RSD, %). The results showed that tazarotene could be metabolized to tazarotenic acid and betamethasone dipropionate could be metabolized to betamethasone in tissue-engineered skin. The results also revealed that this method was suitable for the simultaneous determination of tazarotene, betamethasone dipropionate and their metabolites in tissue-engineered skin.

Biologic therapy with or without topical treatment in psoriasis: what does the current evidence say?

Biologic therapy represents a relatively new class of drugs which have revolutionized the treatment of psoriasis and are used with increasing frequency in order to control this chronic, systemic inflammatory disease. However, it is unclear what role there is for combination therapy of biologics with traditional topical agents. The purpose of this article is to assess the literature on the role of topical agents as adjuvants to biological treatments in the treatment of psoriasis and identify areas for further research. A MEDLINE search was performed in order to identify English-language publications from 1996 to 2014 examining combination biologic therapy with topical medications in the treatment of psoriasis. Data from these clinical studies are summarized and the outcomes are discussed. In general, the addition of adjuvant topical therapy to systemic biologic therapy allowed for a reduction in dosage and side effects of both agents, maintenance of initial response to biologics, treatment of recalcitrant lesions in partial responders, and potential acceleration of response to biologic therapies. The current data, though limited, suggest that using topical therapies as adjunct treatment to biologics is a well tolerated and effective means of controlling psoriasis and improving quality of life for patients. However, the treating physician should remain attentive to signs of adverse events and seek opportunities to reduce the dose or treatment frequency during chronic use.

Humanized mouse model of skin inflammation is characterized by disturbed keratinocyte differentiation and influx of IL-17A producing T cells

Humanized mouse models offer a challenging possibility to study human cell function in vivo. In the huPBL-SCID-huSkin allograft model human skin is transplanted onto immunodeficient mice and allowed to heal. Thereafter allogeneic human peripheral blood mononuclear cells are infused intra peritoneally to induce T cell mediated inflammation and microvessel destruction of the human skin. This model has great potential for in vivo study of human immune cells in (skin) inflammatory processes and for preclinical screening of systemically administered immunomodulating agents. Here we studied the inflammatory skin response of human keratinocytes and human T cells and the concomitant systemic human T cell response.

As new findings in the inflamed human skin of the huPBL-SCID-huSkin model we here identified: 1. Parameters of dermal pathology that enable precise quantification of the local skin inflammatory response exemplified by acanthosis, increased expression of human β-defensin-2, Elafin, K16, Ki67 and reduced expression of K10 by microscopy and immunohistochemistry. 2. Induction of human cytokines and chemokines using quantitative real-time PCR. 3. Influx of inflammation associated IL-17A-producing human CD4+ and CD8+ T cells as well as immunoregulatory CD4+Foxp3+ cells using immunohistochemistry and -fluorescence, suggesting that active immune regulation is taking place locally in the inflamed skin. 4. Systemic responses that revealed activated and proliferating human CD4+ and CD8+ T cells that acquired homing marker expression of CD62L and CLA. Finally, we demonstrated the value of the newly identified parameters by showing significant changes upon systemic treatment with the T cell inhibitory agents cyclosporine-A and rapamycin.

In summary, here we equipped the huPBL-SCID-huSkin humanized mouse model with relevant tools not only to quantify the inflammatory dermal response, but also to monitor the peripheral immune status. This combined approach will gain our understanding of the dermal immunopathology in humans and benefit the development of novel therapeutics for controlling inflammatory skin diseases.

Biologics in the management of psoriasis

Psoriasis is a chronic inflammatory systemic disease for which there exist topical, ultraviolet, systemic, and biologic treatments. Biologic agents selectively interfere with the immune mechanisms responsible for psoriasis. Etanercept, infliximab, and adalimumab target tumor necrosis factor-alpha and have demonstrated efficacy in the treatment of psoriasis and psoriatic arthritis. Alefacept and efalizumab target T lymphocytes, are effective in the treatment of psoriasis, but are not approved for psoriatic arthritis. Finally, ustekinumab and ABT-874 target interleukin-12 and interleukin-23, and they have demonstrated efficacy in the treatment of psoriasis. The objective of this review is to present efficacy and safety data from randomized controlled trials of the biologic agents in the treatment of psoriasis.