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Notes: Oral cyclosporin A (CyA) is highly effective in the treatment of psoriasis. The long-term use is limited by dose-dependent side-effects, and the local concentration of CyA is a determining factor in treatment. The concentration of CyA in suction-blister fluid (SBF) and in whole blood was assessed using a polyclonal radioimmunoassay (RIA). This was carried out in patients with psoriasis following a single dose of CyA and while on adequate oral treatment with the drug. Peak blister fluid levels ranged from 32 to 170 ng/ml, and whole blood levels from 1250 to 2540 ng/ml. CyA trough levels (12 h following taking the drug) in the blister fluid ranged from 22 to 113 ng/ml, and in whole blood from 148 to 935 ng/ml. The trough concentrations in SBF were approximately 10% of whole blood trough levels.

Notes: The current understanding of the function of natural killer (NK) T cells in innate immunity and their potential to control acquired specific immunity, as well as the remarkable efficacy of antitumour necrosis factor-α biological treatments in psoriasis, forces us to refine the current T-cell hypothesis of psoriasis pathogenesis, and to give credit to the role of innate immunity. Psoriasis might be envisioned to be a genetically determined triggered state of otherwise dormant innate immunity. This aggravated state of innate immunity is represented by the activity of NK T cells, dendritic cells, neutrophils and keratinocytes, leading to the recruitment and activation of preferentially type 1 T cells, possibly in an antigen-independent way. Keratinocytes in psoriasis then are sensitive to the effects of T-cell activation and cytokine production, interferon (IFN)-γ, by responding with psoriasiform hyperplasia. The chronic inflammation of psoriatic lesions suggests that this might be due to a deficiency in downregulation processes (e.g. a defect in the regulatory T-cell repertoire) and/or the persistence of an unknown trigger resulting in an exaggerated innate immune response.

Notes: An open, randomized trial was performed to determine the optimal dosage schedule with regard to the efficacy and safety of cyclosporin in severe atopic dermatitis. The study also provided clinical experience with regard to the efficacy and safety of long-term cyclosporin treatment. During a 2-month dose-finding period. 78 patients with severe, long-standing atopic dermatitis received cyclosporin at a dose of either 5 mg/kg per day, decreasing to 3 mg/kg per day (Group A), or 3 mg/kg per day, increasing to 5 mg/kg per day (Group B). Patients were maintained on their optimal dose for a further 10 months. Patients in Group A showed a significantly greater improvement in efficacy parameters over the first 2 weeks than with patients in Group B, but as the dose was decreased in Group A and increased in Group B, these differences were minimized. After 1 year, cyclosporin showed an efficacy of 59.8% in Group A and 51.7% in Group B, assessed by a severity score. Assessed in terms of an area score, these figures were 48.7% and 40%, respectively. Cyclosporin demonstrated a good safety profile during long-term treatment and was generally well tolerated. The lower starting dosage was not associated with higher dropout rates. This study showed no differences in efficacy or adverse events between the two dosage schedules in long-term treatment.

Notes: Summary Topical photochemotherapy with psoralen and its derivatives 4.5′,8-trimethylpsoralen (TMP) and 8-methoxypsoralen (8-MOP), with UVA irradiation, was evaluated with regard to minimum phototoxic dose, concentration, timing of UVA irradiation and systemic and local side-effects, in healthy volunteers. Psoralen (0.005%) in aqueous gel was found to be superior to TMP and 8-MOP in aqueous gel. No hyperpigmentation was seen after topical PUVA treatment with psoralen in aqueous gel. Patients with plaque-type psoriasis (n = 7), palmoplantar psoriasis (n = 7) and hyperkeratotic eczema (n = 2) were treated. Topical PUVA therapy was effective in most psoriasis patients, without the occurrence of local or systemic side-effects. Moreover, hyperkeratotic eczema patients who did not respond to conventional therapy showed partial remission. These results indicate that topical PUVA therapy with psoralen in aqueous gel is a useful therapeutic modality for treatment of psoriasis patients, and patients with recalcitrant dermatoses such as palmoplantar psoriasis and hyperkeratotic eczema.

Notes: Summary Ultraviolet (UV) irradiation of trans-urocanic acid (UCA), a major UV absorbing component of the epidermis, leads to the formation of cis-UCA, which mediates immunosuppressive effects. In this study, the net yield of cis-UCA was measured after the photoisomerization of urocanic acid by narrow UV wavebands (spectral range 295–405 nm), with the irradiation doses related to solar irradiance at sea level. The formation of cis-UCA in Caucasian skin (in vivo), as well as in aqueous solution (in vitro), was determined by HPLC analysis. The same irradiation conditions were met in both components of the study. The in vivo experiments showed high efficiency of cis-UCA formation in the spectral region of 305–341 nm, whereas high efficiency in vitro was found at 305 and 326 nm. At 350 and 363 nm, cis-UCA was formed in vivo, but not in vitro. At longer test wavelengths up to 405 nm. no significant formation of cis-UCA was detectable. The established partition between UVB and UVA at 320 nm is not relevant for the isomerization pattern of UCA. Additional studies revealed substantial cis-UCA formation in human skin by UVA phototherapy lamps. Furthermore, raised levels of 295 nm irradiation doses, a possible effect of stratospheric ozone depletion, were found to increase the cis-UCA yield. Our results demonstrate that the formation of cis-UCA in the skin with common exposures takes place over a broad spectrum range of UVB and UVA, up to at least 363 nm. These findings emphasize the potency of UVA to isomerize UCA, and they may contribute to further elucidation of the effects of phototherapy and sunbathing.

Notes: The side-effects of long-term cyclosporin A (CyA) treatment in 26 patients with severe psoriasis were evaluated. These patients had a mean PASI score of 30.2 and were treated with CyA for between 7 and 37 months (mean 19.5 months). There were three groups according to the dose of CyA, 〈 2 mg/kg per day, 2–3 mg/kg per day and 〉 3 mg/kg per day. In all three groups, CyA was found to be equally effective. Treatment with CyA was discontinued in 12 of the 26 patients because of nephrotoxicity and/or development of hypertension. One was in the 〈 2 mg/kg per day group, three were in the 2–3 mg/kg per day group and eight in the 〉 3 mg/kg per day group. There was no hepatotoxicity with CyA treatment. One patient developed two squamous cell carcinomas of the skin.

Notes: Summary Background Cyclosporin is an effective treatment for severe plaque psoriasis. Unfortunately, its use may be limited by time- and dose-related nephrotoxicity. Serum trough levels may be useful for monitoring the risk of nephrotoxicity. Objectives To determine whether monitoring of trough levels is necessary in psoriasis patients undergoing short-term treatment with cyclosporin. Methods A computerized and manual literature search identified studies on adults with plaque-type psoriasis treated with cyclosporin ≤ 5 mg kg−1 daily, in which trough levels were measured in whole blood. Number of patients, treatment duration, formulation and dosage, renal function tests and trough levels were extracted. The association between renal function and trough levels was investigated. Additionally, in a randomized controlled trial on cyclosporin vs. methotrexate in moderate to severe psoriasis, cyclosporin trough levels were measured frequently in 20 patients during 12 weeks of treatment. The Pearson correlation coefficient between serum creatinine and cyclosporin trough levels was calculated. Results Fifty-six articles were found concerning cyclosporin trough level measurements in psoriasis patients, of which eight were analysed. Many studies were excluded due to inappropriate cyclosporin dosages used. As data were heterogeneous and lacked various key parameters, a correlation study and a meta-analysis could not be performed. Instead, a quantitative description of the literature was given. No high mean trough levels or elevations of serum creatinine were described. In our clinical study, all the mean trough levels in 17 patients treated with cyclosporin 3 mg kg−1 daily were within the therapeutic range (〈 200 ng mL−1). Elevated trough levels were found in two of three patients treated with cyclosporin 3–5 mg kg−1 daily. No signs of renal dysfunction were seen. Conclusions The literature does not provide a definitive answer on whether monitoring cyclosporin trough levels in patients with psoriasis should be standard practice. Our own data show no need for cyclosporin trough level monitoring during short-term treatment with cyclosporin 3 mg kg−1 daily. However, when cyclosporin doses are 〉 3 mg kg−1 daily, monitoring may be indicated.

Notes: Summary Background Necrobiosis lipoidica (NL) is a rare skin disease, mostly seen on the legs and often occurring in patients with diabetes mellitus. The disease belongs to the idiopathic cutaneous palisading granulomatous dermatitides associated with a degeneration of collagen, thus leading to skin atrophy. Application of topical corticosteroids is the most widely used treatment but the results are not always satisfactory and may worsen skin atrophy. Preliminary studies in patients with NL have shown a clinical response with psoralen plus ultraviolet (UV) A (PUVA). Objectives To study the effect of topical PUVA on NL in a multicentre prospective study. Methods Thirty patients (27 women and three men) including 13 with insulin-dependent diabetes mellitus, with a diagnosis of NL proven by histopathology, were included. All patients had been unsuccessfully treated with topical and/or intralesional corticosteroids. Patients were treated twice weekly with an aqueous gel containing 0·005% psoralen followed by irradiation with UVA. Clinical photographs were taken for evaluation. In addition, 20-MHz high-frequency ultrasound analysis was performed in 10 patients to evaluate the thickness and density of the dermis during topical PUVA therapy. Results Five patients (17%) showed complete clearing (healing of ulceration and disappearance of erythema) after a mean of 22 exposures (range 15–30). Eleven patients (37%) showed improvement, defined as healing of ulceration and/or reduction of erythema, after a mean of 23 exposures (range 11–42). Ten patients (33%) showed no effect and four patients (13%) worsened during topical PUVA therapy. The treatment results of the patients who suffered from diabetes mellitus were not different from those who did not have diabetes mellitus. No difference was seen in mean dermal thickness (1666 vs. 1706 µm) and density (17 vs. 16 units) before and after topical PUVA therapy. Side-effects were seen in 10 patients: hyperpigmentation (n = 4), blistering (n = 4) and bacterial infection (n = 2). Conclusions Topical PUVA may be a useful treatment modality for NL in patients not responding to topical or intralesional corticosteroids.

Notes: Activated T lymphocytes are thought to be involved in the pathogenesis of psoriasis. From studies with peripheral blood T lymphocytes it is known that T cells show a decrease in membrane expression of CD27 molecules during continuous antigenic stimulation. The T-cell activation molecule CD28 is thought to be involved in the transduction of an antigen-non-specific costimulatory signal. Therefore, in order to elucidate further the pathogenesis of psoriasis we studied the expression of CD27 and CD28, together with CD4, CD8 and CD45RA in this benign inflammatory dermatological disease. We used immunohistochemical techniques to determine absolute numbers of T lymphocytes and expression of these T-cell activation and T-subset-specific molecules in normal (n= 7), uninvolved perilesional (n= 7) and lesional psoriatic (n= 7) skin. We found that not only lesional but also clinically uninvolved perilesional skin showed an increased number of T cells. Further, immunohistochemical studies showed that CD27 is expressed by a minority of normal skin T cells, while in lesional psoriatic skin, expression was even lower, and almost absent in perilesional skin sections. In contrast to normal skin, both perilesional and lesional psoriatic skin contained no CD28 positive T cells. In lesional psoriatic skin, however, T cells showed predominantly the CD4 phenotype, while in perilesional skin CDS positive T cells were dominant. Two conclusions were reached: first, the absolute number of T cells, their CD27, CD28 and CD45RA expression, and the influx of CD8 positive T cells, indicate that perilesional psoriatic skin is different from normal and lesional psoriatic skin; and secondly, the data on CD27 and CD28 suggest that not only lesional but also perilesional psoriatic skin is subject to continuous antigenic stimulation, thus leading to decreased CD27 and CD28 expression on skin T cells.