The effect of alefacept on T-cell subsets and cells expressing NK receptors in lesional psoriatic skin: the effects of monotherapy and combination treatment with calcipotriol.

OBJECTIVES: To investigate the effect of weekly alefacept monotherapy 15 mg i.m. on epidermal hyperproliferation, keratinization, T-cell subsets and cells expressing NK receptors during 12 weeks of treatment. Furthermore, the addition of calcipotriol cream to alefacept treatment was studied and compared with alefacept monotherapy. METHODS: Five patients participated in this study, and used weekly alefacept 15 mg i.m. combined with calcipotriol cream up to a maximum of 100 g per week. Biopsies from two lesions (one treated and another lesion not treated with calcipotriol cream) were taken at week 0 and week 12. We investigated the number of T-cell subsets (CD4, CD8, CD45RO, CD45RA, CD2, CD25), cells expressing NK receptors (CD94 and CD161), the proliferation marker Ki-67 and the keratinization marker keratin-10. RESULTS: Alefacept monotherapy induced a statistically significant reduction of CD4+, CD45RO+ and CD2+ cells in dermis and epidermis and CD8+ cells in epidermis at week 12. Furthermore, the keratin-10 positive epidermal surface was significantly increased at week 12. The combination of alefacept and calcipotriol cream induced a statistically significant reduction of only CD4+ and CD45RO+ cells at week 12. CONCLUSIONS: The number of memory effector T-cells in the psoriatic lesion is significantly decreased by alefacept, and calcipotriol cream does not seem to have an additional effect on this reduction. Cells expressing NK receptors are virtually not targeted by alefacept monotherapy or the combination.

Topical treatment of mild to moderate plaque psoriasis with 0.3% tacrolimus gel and 0.5% tacrolimus cream: the effect on SUM score, epidermal proliferation, keratinization, T-cell subsets and HLA-DR expression.

BACKGROUND: Tacrolimus gel 0.3% and tacrolimus cream 0.5% were studied and compared with calcipotriol ointment 0.005%, as topical treatment for mild to moderate plaque psoriasis. Tacrolimus is able to inhibit several cellular processes thought to be important in the pathogenesis of psoriasis, e.g. the transcription of proinflammatory cytokines, keratinocyte hyperproliferation and the expression of HLA-DR in lesional psoriatic skin. METHOD: In the present study we investigated the effects of preparations of tacrolimus and calcipotriol ointment on SUM score, hyperproliferation (Ki67-positive keratinocytes), keratinization (percentage keratin 10 (K10)-positive epidermal surface), T-cell subsets (CD4, CD8, CD45RO, CD45RA, CD2, CD25), cells expressing natural killer receptors and HLA-DR expression. The following three topical treatments were studied in chronic plaque psoriasis over a 12-week treatment period: calcipotriol ointment 0.005% twice daily, tacrolimus gel 0.3% twice daily and tacrolimus cream 0.5% twice daily. RESULTS: The mean reductions in SUM score between day 0 and week 12 for calcipotriol ointment, tacrolimus gel and cream were significant. Calcipotriol ointment, and tacrolimus gel and cream had a comparable effect on epidermal proliferation (Ki67-positive cells), but calcipotriol is significantly more effective in normalizing differentiation (K10-positive epidermal surface). Calcipotriol and tacrolimus gel both reduced several lesional T-cell subsets significantly, whereas the effect induced by tacrolimus cream was modest. CONCLUSIONS: Calcipotriol and tacrolimus gel are comparable in reducing the SUM score, the number of Ki67-positive cells and T-cell subsets and HLA-DR expression, although calcipotriol induces a more substantial improvement of keratinization.

A double-blind, randomized quantitative comparison of calcitriol ointment and calcipotriol ointment on epidermal cell populations, proliferation and differentiation.

BACKGROUND: Calcitriol and calcipotriol are widely used in the topical treatment of psoriasis. However, studies comparing both treatment modalities are scarce. Especially, there are almost no studies comparing the effects on epidermal cell populations in a quantitative manner. OBJECTIVES: The aim of this study was to quantitatively compare the effects of topical calcitriol and topical calcipotriol on clinical scores and epidermal subpopulations. PATIENTS AND METHODS: From five patients with stable plaque psoriasis, skin biopsies were taken from two symmetrical regions on the trunk or extremities before and after treatment with either calcitriol or calcipotriol. Frozen sections were labelled immunofluorescently using direct immunofluorescence for beta-1 integrin and the Zenon labelling technique for keratin (K) 6, K10 and K15. The digital photographs of the stained sections were quantitatively analysed and the results of both treatments were compared. RESULTS: The clinical SUM-score improved significantly for both the calcitriol- and the calcipotriol-treated lesions. In the calcipotriol-treated group the expression of K10 and K15 increased and the expression of K6 decreased significantly. No changes were seen for the marker beta-1 integrin. In the calcitriol-treated group none of the markers changed significantly. A tendency towards significance was seen for the changes in the expression of K6 and K15 in favour of calcipotriol. CONCLUSIONS: Both calcitriol and calcipotriol gave a significant improvement in clinical scores. However, treatment with calcipotriol resulted in a normalization of K6, K10 and K15, whereas treatment with calcitriol did not. Comparison of both treatments showed a tendency towards significance for the above-mentioned markers for calcipotriol only.

Effect of calcipotriol on epidermal cell populations in alefacept-treated psoriatic lesions.

BACKGROUND AND OBJECTIVES: The effect of the established antipsoriatic treatment with topical calcipotriol (with a maximum of 100 g per week) in addition to systemic treatment with alefacept, a new biological agent for psoriasis, on epidermal cell populations in the psoriatic lesion was investigated using a combination of the Zenon labelling technique and microscopic image analysis. Epidermal cell populations were measured quantitatively with this sensitive method. PATIENTS/METHODS: Frozen sections of non-treated psoriatic epidermis and psoriatic epidermis treated with either alefacept intramuscular or alefacept intramuscular in combination with topical calcipotriol for 12 weeks were compared immunohistochemically. Antibodies against keratin 6, 10 and 15 were labelled with the Zenon technique, whereas antibodies against the Ki-67 antigen and beta-1 integrin were covalently Fluorescein Isothiocyanate (FITC)-labelled. Using image analysis, these markers were measured in the epidermis in a standardized manner. RESULTS AND CONCLUSIONS: Treatment of psoriasis with alefacept resulted in a good clinical response in several patients and in a normalization of epidermal expression of the immunohistochemical parameters for differentiation and proliferation. The addition of topical calcipotriol resulted in a faster clinical improvement with a similar overall clinical response and a similar response of epidermal cell populations as compared to treatment with alefacept monotherapy after 12 weeks of treatment. This study also suggests that the appearance of keratin 15 has a predictive value for the duration of remission. It can be concluded that the addition of a low-dose calcipotriol treatment does not contribute to the clinical efficacy of alefacept, both at the clinical level and with respect to markers for epidermal proliferation and differentiation.

Flexural versus plaque lesions in psoriasis: an immunohistochemical differentiation.

Clinical presentation, therapeutic options, micro-environment and HLA-typing have been reported to be different in flexural psoriasis as compared to plaque psoriasis. We were interested in any difference concerning the pathogenesis of both conditions. By analysing T-cell subsets, NK-T cells and proliferation and differentiation markers, insight into the pathogenesis of both subtypes was obtained. Quantitative studies of T-cell subsets, cells expressing NK-receptors and markers of proliferation and differentiation in flexural and plaque psoriasis were investigated. Biopsies from 6 patients with both flexural and plaque lesions were obtained and processed for immunohistochemistry. Several T-cell subsets were stained: CD4+, CD8+, CD2+, CD25+, CD45RO+ and CD45RA+ T-cells. In addition cells expressing NK receptors were stained: CD94+ cells and CD161+ cells. T-cell subsets and cells expressing NK-receptors were analysed by immunohistochemical scoring. The proliferation marker Ki-67 and differentiation marker keratin-10 were revealed immunohistochemically by MIB-1 and RKSE60 respectively. Both markers were analysed using quantitative image analyses. The number of Ki-67 positive nuclei and the percentage of keratin-10 positive epidermal cells in flexural and plaque psoriasis were comparable. There is no difference between flexural and plaque psoriasis concerning other T-cell subsets. However a highly significant reduction is seen in flexural psoriasis with respect to CD161+ cells in the dermis. The similarity of chronic plaque psoriasis compared to flexural psoriasis with respect to T-cell subsets, epidermal proliferation and keratinization suggests that both conditions are pathogenetically identical. We propose the decreased quantity of lesional CD161+ cells in the dermis of flexural psoriatic lesions may result from chronic microbial challenge in flexural psoriasis.

Immunohistochemical differentiation between inflammatory linear verrucous epidermal nevus (ILVEN) and psoriasis.

Inflammatory linear verrucous epidermal nevus (ILVEN) is a rare skin disorder with a clinical and histological resemblance to psoriasis. In the past clinical and histological criteria have been defined. However, there remains a discussion as to whether ILVEN is a disease entity distinct from linear psoriasis. Our objective was to compare by quantitative immunohistochemistry the subsets of T-lymphocytes and markers for epidermal growth and keratinisation in biopsies taken from skin lesions of 4 patients with psoriasis and 3 patients with ILVEN: 1. patients with psoriasis (case 1-4) 2. patient with ILVEN cum psoriasis (case 5) 3. patients with ILVEN sine psoriasis (case 6 and 7). Our aim was to delineate ILVEN from psoriasis. Four patients with active psoriasis and three patients with signs and symptoms of ILVEN are described in this case report. Two patients of the ILVEN group had only linear verrucous lesions (ILVEN sine psoriasis), and one patient had linear lesions combined with widespread psoriasis outside the linear verrucous lesion (ILVEN cum psoriasis). The following markers were investigated in skin biopsies taken from the aforementioned patients by quantitative immunohistochemistry: CD2, CD4, CD8, CD25, CD161, CD94, CD45RO, CD45RA, HLA-DR, Keratin-10, Ki-67. In patients with ILVEN (cum and sine psoriasis) the number of Ki-67 positive nuclei, tended to be lower, the number of keratin-10 positive cells and HLA-DR expression higher as compared to psoriasis. In ILVEN sine psoriasis all T-cell subsets and cells expressing NK receptors were reduced as compared to psoriasis, except for CD45RA+ cells, whereas in the patient with ILVEN cum psoriasis the number of these T cell subsets had an intermediary position. In particular the density of CD8+, CD45RO+ and CD2+, CD94 and CD161 showed a marked difference between ILVEN sine psoriasis and psoriasis. In addition to the increased keratin 10 expression in ILVEN sine psoriasis, T cells relevant in the pathogenesis of psoriasis are markedly reduced in ILVEN sine psoriasis as compared to psoriasis. T-cell subsets in ILVEN cum psoriasis had an intermediary position.

Aggravation of psoriasis by infections: a constitutional trait or a variable expression?

Focal infections are a well known triggering factor in patients with psoriasis. A question which remains to be answered is whether relapsing of psoriasis after infections is a constitutional trait of a restricted population or whether it is a feature of all patients in some phase of their disease. A questionnaire was mailed to patients with psoriasis comprising general questions, psoriasis related questions and questions on the relationship between focal infections and aggravation of psoriasis. The questionnaire was mailed to 126 patients and 45 questionnaires which were returned, were evaluable. From the 45 questionnaires the following preliminary conclusion can be drawn. Aggravation of psoriasis following infections appeared to be a consistent trait throughout the duration of psoriasis in 18% of patients as opposed to 71% of the patients who did not experience this association at all and 11% who experienced the association sometimes. Patients who experienced aggravation of psoriasis by infections as a consistent feature have an age of onset 9 years earlier as opposed to patients without this association and express guttate psoriasis in the vast majority as first manifestation at initiation of psoriasis. These patients had an average of 4.6 relapses per year in contrast to 1.1 per year in the patients without an association between infection and aggravation of psoriasis. In these patients infections proved to be responsible for 67% of the exacerbations. Stress was indicated in this subpopulation as a triggering factor as well in 88% of the patients. Although this conclusion only can be very preliminary based on the small group of patients, we may conclude that patients with a strong association between aggravation of psoriasis and infections belong to a restricted population of patients tending to an unstable course of the disease.

Memory effector (CD45RO+) and cytotoxic (CD8+) T cells appear early in the margin zone of spreading psoriatic lesions in contrast to cells expressing natural killer receptors, which appear late.

BACKGROUND: An influx of immunocytes, increased epidermal proliferation and abnormal keratinization are hallmarks of the psoriatic lesion. T-lymphocyte subsets in particular activated effector memory T cells and natural killer (NK) T cells have been suggested to play an important role in the pathogenesis of psoriasis. OBJECTIVES: In the present study we investigated the number of T-cell subsets (CD4, CD8, CD45RO, CD45RA, CD2, CD25), cells expressing NK receptors (CD94 and CD161), the proliferation marker Ki67 and the keratinization marker keratin (K10) across the margin of the spreading psoriatic plaque: distant uninvolved skin, the outer margin (immediately outside the clinical edge), the inner margin (immediately inside the clinical edge) and the central area. PATIENTS AND METHODS: Eight patients with active psoriasis vulgaris participated in this study. Biopsies were taken from the spreading psoriatic lesion from the distant uninvolved skin, the outer margin, the inner margin and the central area. Biopsies were processed for immunohistochemical staining. RESULTS: In the outer margin CD8+ (cytotoxic T cells) and CD45RO+ (memory effector T cells) T lymphocytes invade the epidermis and in this early stage the activation markers CD2 and CD25 also show a substantial increase. The next phase, from the outer to the inner margin, shows a statistically significant increase of these markers, and especially, the cells expressing NK receptors (CD94 and CD161) show a massive increase together with a significant increase of epidermal proliferation (Ki67) and a decrease of the K10+ epidermal surface. CONCLUSIONS: CD8+, CD45RO+, CD2+ and CD25+ T cells have a role in the early phase of the psoriatic process, whereas CD94- and CD161-expressing cells together with epidermal proliferation and keratinization are involved in a later phase.

The effect of the combination of calcipotriol and betamethasone dipropionate versus both monotherapies on epidermal proliferation, keratinization and T-cell subsets in chronic plaque psoriasis.

Several reports have indicated that the combination of calcipotriol ointment and potent or ultrapotent corticosteroids are more effective and better tolerated, as compared to the monotherapies. The aim of the present study was to find out the effect of combination of calcipotriol ointment once daily and betamethasone dipropionate ointment once daily vs. the effect of twice-daily applications of each of the two treatments as monotherapy during a four-week treatment period. Seven patients with chronic plaque psoriasis were included for treatment with the three treatment schedules. Biopsies were taken before treatment and after four weeks of treatment, and markers for epidermal proliferation (Ki-67) and epidermal differentiation (keratin-10) were studied using a quantitative image analysis, and T-cell subsets in epidermis and dermis (CD4, CD8, CD25, CD45RO, CD45RA, CD94, CD161, and CD2) were studied using immunohistochemical scoring. The most impressive clinical result was reached with the combination. Calcipotriol proved to have a major effect on the proliferation marker Ki-67 and differentiation marker keratin-10, whereas the effect on T-cell subsets was more selective with major reductions of CD45RO(+) and CD8(+) T cells. In contrast, the effect of betamethasone dipropionate on the epidermis was restricted to a normalization of differentiation with a highly significant increase of keratin-10 positive epidermal surface without a significant effect on Ki-67 positive nuclei, and the effect on T-cell subsets was restricted to a reduction of natural killer T-cell receptors designated by CD94 and CD161 in the epidermis. The combination of the two treatments did not affect the proliferation marker Ki-67 and keratinization marker keratin-10, beyond the effect of calcipotriol monotherapy. However, the combination had a profound effect on, virtually, all T-cell subsets, beyond the effect of the monotherapies. It is concluded that the action spectra of calcipotriol and betamethasone on the psoriatic plaque are different and that the combination has effects on T-cell subsets, beyond the addition of the effects of monotherapies.

The topical treatment of psoriasis.

According to the patients, improvement of efficacy, long-term safety and improvement of compliance are needed. The topical treatment has been innovated during the last decade. Most important are the introduction of two new classes of treatments: topical vitamin D(3) analogues and the retinoid tazarotene. To what extent, however, have we achieved developments which are in line with the needs as expressed by the patients? Improved efficacy has been realized by successful combinations of topical treatments. In particular, the combinations of dithranol, vitamin D(3) and tazarotene with a topical corticosteroid proved to be very effective with a reduced profile of side-effects. The efficacy of vitamin D(3) analogues and tazarotene is such that the efficacy of a potent corticosteroid (betamethasone-17-valerate) is approached; calcipotriol even showed an efficacy which is at least as good as this corticosteroid. The long-term safety of new compounds has been evaluated for at least 12 months in large studies. Remarkably for corticosteroids such information is available for only 12 weeks. However, intermittent applications of a topical corticosteroid in combination with another topical treatment provide an effective and safe long-term control of psoriasis. Compliance is a conditio sine qua non for an effective topical treatment. Important progress has been made to increase compliance. Short-contact dithranol has been popularized as an ambulatory treatment which is a highly effective approach as a care instruction programme. Formulations which are better from a cosmetical point of view have been developed for various topical treatments. Reduction of the frequency of applications proved to be possible for most treatments. Once daily applications for corticosteroids, vitamin D(3) analogues and retinoids have been developed, and intermittent applications, a few times per week, are possible for corticosteroids, which proved to be very effective with a reduced profile of side-effects, and are also developed for dithranol.