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Biomedical subjects

K Kragballe

Publications and source records attributed to K Kragballe.

At least 37 records · Page 2Linked to original sources

Recent developments in vitamin D analogs.

Within the past decade it has been shown that psoriasis can be treated topically with analogs of vitamin-D3. Impaired differentiation and increased proliferation of keratinocytes are key features in psoriatic lesions together with a local activation of T lymphocytes. Evidence has accumulated showing that analogs of vitamin D3 increase differentiation and inhibit proliferation of keratinocytes. Therefore, analogs of vitamin D3 have been investigated in a number of trials showing improvement of psoriasis. It has been shown that vitamin D analogs are better than their vehicle and show the same potency as potent topical steroids. However, vitamin D analogs have been proven efficacious and without side effects also when used on long term basis. Vitamin D analogs can be used both as monotherapy and in combination topical steroids, UVB, PUVA, retinoids and cysclosporine. The vitamin D3 analog calcipotriol has been investigated in most detail and is available as an ointment, a creme and as a scalp solutation. From clinical studies involving thousands of patients, it can be concluded that calcipotriol is efficacious, safe, well tolerated and can be used on a long term basis. Other analogs are available, however, these analogs have not been studied in greater details yet.

Calcitriol↗

Effect of intradermal injection of methionine-enkephalin on human skin.

Methionine-enkephalin (met-enk) detected in monocytes in psoriatic skin can modulate inflammatory processes and keratinocyte differentiation/proliferation in vitro. The purpose of the present study was to determine the effect of intradermal injection of met-enk on normal human skin and on the development of a delayed type skin hypersensitivity reaction. In 6 healthy volunteers, 50 microl of met-enk (16, 30, and 45 nmol) was injected once in the forearm and the reaction was evaluated clinically and by video-optical recording for 120 min. Compared to vehicle (0.9% saline), met-enk induced a time- and dose-dependent flare reaction, but no significant stimulation of a weal reaction. The flare reaction was maximal after 1 min and disappeared within 45 min. Pre-treatment with the antihistamine cetirizine reduced the flare reaction. Furthermore, the effect of met-enk on lymphocyte/monocyte infiltration and epidermal proliferation in normal skin and on a delayed type skin hypersensitivity reaction was assessed. Met-enk (45 nmol/ 50 microl) was injected at 0, 24 and 48 h. In normal skin, met-enk increased the number of dermal lymphocytes/monocytes (CD3/CD68 positive cells) and the degree of epidermal proliferation (MIBI-Ki67). In a delayed type hypersensitivity reaction induced by tuberculin (PPD), the degree of epidermal proliferation and the number of infiltrating lymphocytes/monocytes were reduced compared to PPD alone. Our study suggests that intradermal injection of met-enk in normal human skin induces an inflammatory reaction that may involve the release of histamine. In contrast, met-enk seems to down-regulate the development of a delayed type skin hypersensitivity reaction. These results may indicate that the direction of the effect of the opioid peptide met-enk on human skin depends on the rate of epidermal proliferation and the activity of immunocompetent cells.

Adult↗

Decrease in enkephalin levels in psoriatic lesions after calcipotriol and mometasone furoate treatment.

BACKGROUND: Enkephalins are opioid peptides that can modulate immune responses and inflammatory processes. Furthermore, they inhibit keratinocyte proliferation/differentiation in vitro. Previously, we have shown that enkephalins are present in increased amounts in lesional psoriasis. OBJECTIVE: To determine the effect of topical treatment with the vitamin D analogue calcipotriol and the corticosteroid mometasone furoate on the level of methionine-enkephalin (enk) in psoriatic lesions. METHODS: Twelve psoriatic patients were treated with calcipotriol and mometasone furoate for 14 days without or with hydrocolloid occlusion. Keratome biopsies were obtained from treated and untreated skin, and the extracted enk was quantified by radioimmunoassay. Furthermore, punch biopsies were obtained for immunohistochemical analysis. RESULTS: Clinically, both calcipotriol and mometasone furoate improved psoriasis to the same degree, the effects being more pronounced after occlusion. Histologically, treatment with mometasone furoate without occlusion decreased both the epidermal thickness/parakeratosis and the number of dermal immunocompetent cells (CD3- and CD68-positive cells). In contrast, treatment with calcipotriol without occlusion reduced the epidermal thickness and the degree of parakeratosis but decreased the number of CD3- and CD68-positive cells only slightly. The mean enk level was decreased by 26 and 86% by calcipotriol without and with occlusion and by 16 and 63% by mometasone furoate without and with occlusion, respectively. The decreases in the enk levels corresponded to the degree of clinical improvement but not to the histological changes. CONCLUSION: The increased levels of enk in psoriatic lesions are reduced in parallel with the clinical improvement induced by a topical vitamin D analogue and a corticosteroid. Because enkephalins can modulate epidermal differentiation and inflammatory processes, the findings indicate that enkephalins may play a role in the pathogenesis of psoriasis.

Administration, Topical↗

[Renal biopsy in connection with long-term treatment of psoriasis with cyclosporine].

Renal biopsies were performed in 30 psoriatics during long-term low-dose cyclosporin (CSA) therapy (range 2.5-6 mg/kg/day) of from six months to eight years. The study included pretreatment biopsies in 25 of the patients. After two years all biopsies shared features consistent with CSA nephropathy despite completely normal pretreatment morphology in 18 of the 25 patients. The severity of the findings, which consisted of arteriolar hyalinosis, focal interstitial fibrosis and sclerotic glomeruli, increased with length of therapy. Mild renal lesions were seen during the first two years. After four years all but one had arteriolar hyalinosis, with interstitial fibrosis pronounced in five and moderate in six of 11 patients. At the same time glomerular sclerosis had become significant. A decrease in glomerular filtration rate (GFR) correlated with the severity of the fibrosis. GFR studied in 14 patients six months to seven years after discontinuation of CSA was still significantly decreased in relation to baseline prior to therapy. The data from our study together with experiences from cardiac-transplanted patients indicate that patients with psoriasis, after two years therapy with CSA, should be rotated to other treatments or be followed carefully by GFR and sequential renal biopsies.

Adult↗

Inhibition of the 1,25-dihydroxyvitamin D3-induced increase in vitamin D receptor (VDR) levels and binding of VDR-retinoid X receptor (RXR) to a direct repeat (DR)-3 type response element by an RXR-specific ligand in human keratinocyte cultures.

The biological active form of vitamin D, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), mediates most of its actions through the intracellular vitamin D receptor (VDR). VDR binds to vitamin D responsive elements (VDREs) in the promoter region of responsive genes and regulates transcription. Usually the VDREs consist of a direct repeat of two hexanucleotides spaced by three nucleotides (DR-3), to which VDR preferentially binds as a heterodimer with the retinoid X receptor (RXR). In the present study, we examined the effect of 1,25(OH)2D3 and a specific ligand for RXR, CD2809, on VDR and RXR levels in cultured human keratinocytes and on the binding of RXR-VDR to a DR-3 type response element. Incubation with 1,25(OH)2D3 increased VDR levels as determined by Western blotting, increased VDR-RXR binding to a DR-3 type response element as determined by the electromobility shift assay (EMSA), and induced the 25-OH-D3 24-hydroxylase (24-hydroxylase) gene, containing a DR-3 type response element. CD2809 caused a slight decrease in RXRalpha levels, but had no effect on VDR levels. Addition of both CD2809 and 1,25(OH)2D3 decreased VDR levels as well as the VDR-RXR binding levels to the DR-3 type response element, compared to 1,25(OH)2D3 alone. In conclusion, an RXR-specific ligand interferes with the 1,25(OH)2D3-induced stimulation of VDR levels and VDR-RXR binding to DNA in keratinocyte cultures. It is therefore possible that RXR-specific ligands may counteract certain biological actions of vitamin D3.

Calcitriol↗

The vitamin D3 receptor and retinoid X receptors in psoriatic skin: the receptor levels correlate with the receptor binding to DNA.

It is unknown whether vitamin D3 analogues improve psoriasis by overcoming an intrinsic abnormality of the vitamin D3 signalling pathway in psoriatic skin. The effects of vitamin D3 are mediated through the vitamin D3 receptor (VDR). The VDR heterodimerizes with another transcriptional regulator, preferentially the retinoid X receptor (RXR). In the present study the levels of VDR and RXR in involved and uninvolved psoriatic skin were determined by immunoblotting, and the binding of the VDR-RXR complex to a vitamin D3 response element (VDRE) consisting of two hexanucleotides spaced by three nucleotides (DR-3) by the electrophoretic mobility shift assay. The levels of VDR were similar in involved and uninvolved skin. RXR alpha, but neither RXR beta nor RXR gamma, was detectable. The RXR alpha levels were slightly lower in involved psoriatic skin than in uninvolved psoriatic skin, but this difference was statistically insignificant. The binding of VDR-RXR to the DR-3 VDRE was similar in uninvolved and involved psoriatic skin. Furthermore, there was a strong linear correlation between the levels of both VDR and RXR alpha and their binding to DNA. In conclusion, the initial part of the vitamin D3 signalling pathway involving receptor levels and receptor binding to DNA is normal in involved psoriatic skin.

Carrier Proteins↗

Calcipotriol cream with or without concurrent topical corticosteroid in psoriasis: tolerability and efficacy.

The objectives of the study were to determine whether concurrent treatment with calcipotriol (50 microg/g) and either clobetasone 17-butyrate cream (0.5 mg/g) (moderate potency) or betamethasone 17-valerate cream (1 mg/g) (potent) or placebo (vehicle of calcipotriol) was more effective and/or caused less skin irritation than calcipotriol cream (50 microg/g) used twice daily. It was a multicentre, double-blind, parallel group study. Patients applied calcipotriol cream in the morning and either vehicle (n = 174), calcipotriol (n = 174), clobetasone (n = 175) or betamethasone creams (n = 176) in the evening for up to 8 weeks. Adverse events led to withdrawal in 20 patients (2.9%). The mean percentage change in PASI (psoriasis area and severity index) was -40.6 in the calcipotriol/vehicle group, -48.3 in the calcipotriol/calcipotriol group, -53.7 in the calcipotriol/clobetasone 17-butyrate group and -57.5 in the calcipotriol/betamethasone 17-valerate group. A statistically significant difference was seen between the four treatment groups (P = 0.006) with calcipotriol/vehicle being less effective than the other treatments. A statistically significant difference in favour of calcipotriol/betamethasone 17-valerate was seen between the calcipotriol/calcipotriol group and the calcipotriol/betamethasone 17-valerate group. The majority of adverse events were skin irritations, which were reported for 31.2% of patients treated with calcipotriol/vehicle, 34.3% of patients treated with calcipotriol twice daily and 23.8% vs. 17.1% of patients treated with calcipotriol/clobetasone 17-butyrate and calcipotriol/betamethasone 17-valerate, respectively. Skin irritation was seen statistically significantly less frequently in patients treated with calcipotriol/ clobetasone 17-butyrate or calcipotriol/betamethasone 17-valerate (P = 0.001), whereas no difference was seen between the other groups. In conclusion, calcipotriol applied twice daily was as effective as calcipotriol/clobetasone 17-butyrate, but slightly less effective than calcipotriol/betamethasone 17-valerate. The incidence of skin irritation was less for patients using concurrent corticosteroids, whereas treatment with calcipotriol/vehicle did not reduce the incidence of skin irritation when compared with calcipotriol twice daily.

Adult↗

Increased levels of enkephalin following natural sunlight (combined with salt water bathing at the Dead Sea) and ultraviolet A irradiation.

The opioid peptides enkephalins have been shown to modulate inflammatory responses and keratinocyte proliferation and differentiation. Furthermore, increased levels of enkephalin are present in psoriatic lesions. The purpose of the present study was to determine the effect of natural sunlight combined with salt water bathing in the Dead Sea on the methionine-enkephalin (e.n.k.) level in psoriatic skin. Ten patients were treated at the Dead Sea for 4 weeks, and keratotome biopsies were obtained before and after treatment. The amount of enkephalin extracted from the biopsies was measured by radioimmunoassay. Treatment at the Dead Sea resulted in a complete clinical clearance of psoriasis, and immunohistochemical stainings of lesional skin showed that the treatment decreased both epidermal thickness/parakeratosis and the dermal infiltration of CD3- and CD68-positive cells, although the number of CD3- and CD68-positive cells became normal in only two of the 10 cases. However, there was only a slight decrease in the mean enk levels (21%). Furthermore, the level of enk was high in non-lesional psoriatic skin after treatment at the Dead Sea, and immunostaining showed that, in some patients, the treatment induced a mild epidermal hyperplasia and a dermal infiltration of CD3- and CD68-positive cells. Enkephalin-like immunoreactivity was detected in the cytoplasm of both epidermal keratinocytes and dermal infiltrating cells. To determine whether the relatively high skin enk levels after treatment at the Dead Sea was caused by ultraviolet (UV) radiation, normal volunteers were exposed to a single dose of UVA and UVB (2 minimal erythema doses). UVA, but not UVB, irradiation stimulated the mean enk level in the irradiated skin by about sixfold. Furthermore, multiple whole-body UVA irradiations not only resulted in increased skin levels of enk, but also in increased plasma levels. In conclusion, natural sunlight combined with salt water bathing cleared psoriasis without causing a significant decrease in lesional enk levels. Furthermore, non-lesional enk levels were increased. These findings may be the result of a direct stimulatory effect of UVA irradiation on enk formation in the skin. It is possible that the increased circulating levels of enk after UV exposure may contribute to the beneficial effects of UVA irradiation.

Adult↗

Enkephalin-like immunoreactivity in human skin is found selectively in a fraction of CD68-positive dermal cells: increase in enkephalin-positive cells in lesional psoriasis.

Opioid peptides are synthesized in neurons, endocrine cells, monocytes/macrophages and B and T lymphocytes. They interact with opioid receptors located on immune cells and nociceptive nerve terminals. Because opioid peptides might be of importance in inflammatory skin diseases, for example psoriasis, sections of skin from psoriatic patients were immunohistochemically stained with antisera against methionine and leucine enkephalin, CD68 (KP1, PG-M1), calprotectin (M747), M130 (Ber-MAC3), CD1a and CD3. Enkephalin-like activity was detected selectively in dermal CD68-positive macrophages/monocytes. The activity showed no association with the activation markers M747 and Ber-MAC3. There was a statistically significant increase in enkephalin-positive cells in involved psoriatic skin compared with uninvolved and normal skin. These results were confirmed by radioimmunoassay which showed elevated levels in extracts from involved psoriatic skin compared with uninvolved skin (81%) and normal skin (204%). Furthermore, preproenkephalin mRNA of an expected size was detected in involved psoriatic skin. If the increased levels of enkephalins present in monocytes/macrophages in psoriatic skin lesions reach the threshold for biological activity, they may play a role in the regulation of the inflammatory processes seen in this skin disease.

Adult↗

Upregulation of vitamin D receptor levels by 1,25(OH)2 vitamin D3 in cultured human keratinocytes.

The natural biologically active form of vitamin D3, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), possesses antiproliferative, prodifferentiating and immunomodulatory properties. The actions of 1,25(OH)2D3 are mediated through the intracellular vitamin D receptor (VDR), and the level of VDR is believed to determine the cellular responsiveness to vitamin D3. In the present study we examined the effects of 1,25(OH)2D3 on the expression of VDR and its message in cultured human keratinocytes. Western analysis showed the mean VDR content to be higher in undifferentiated cultures (175 pg/microgram protein) than in differentiated cultures (90 pg/microgram protein). Incubation with 1,25(OH)2D3 induced an increase in the VDR in both undifferentiated and differentiated keratinocytes. The VDR increase was detectable after 2 h and maximal (approximately two-fold stimulation) after 8 h. The 1,25(OH)2D3-induced stimulation of VDR levels was dose dependent with a maximum at 10(-7) M. The VDR mRNA levels as determined by the ribonuclease protection assay showed a peak (50% stimulation) after approximately 2 h. Although this increase in VDR mRNA was not statistically significant, the results indicate that the ligand-induced upregulation of VDR involves increased transcription. The upregulation of VDR levels may increase the responsiveness to 1,25(OH)2D3 and may, therefore, be an important mechanism for regulating the effects of 1,25(OH)2D3 on keratinocyte proliferation and differentiation.

Calcitriol↗

Enkephalins modulate differentiation of normal human keratinocytes in vitro.

Opioid peptides are a group of neuropeptides which include enkephalins, endorphins and dynorphins. In addition to their central and peripheral antinociceptive function, opioids can modulate immune activity and cell proliferation. Previously, we have shown that enkephalins are present in macrophages infiltrating the dermal papillae in involved psoriatic skin and that the amount of enkephalin is significantly increased in involved psoriatic skin. Because enkephalins were detected close to the epidermis, we examined the effects of opioid peptides on the differentiation (transglutaminase type 1 activity and cytokeratin 10 expression) and proliferation (MTT assay) of cultured human keratinocytes. Enkephalins (methionine-enkephalin, leucine-enkephalin and the synthetic DADL) inhibited cell differentiation dose-dependently, while beta-endorphin had no effect. The opioid receptor antagonist naltrexone completely antagonized the inhibitory effect of methionine-enkephalin and leucine-enkephalin, but not that of DADL. Furthermore, methionine-enkephalin had a slight inhibitory effect on the proliferation of keratinocytes. Enkephalin was detected in unstimulated keratinocyte cultures, and naltrexone alone stimulated keratinocyte differentiation. These results indicate that enkephalins may play a role in the differentiation of epidermal keratinocytes. It remains to be determined whether the enkephalin detected in psoriatic skin are sufficient to affect epidermal differentiation in vivo.

Cell Differentiation↗

Proliferation and differentiation of cultured human keratinocytes is modulated by 1,25(OH)2D3 and synthetic vitamin D3 analogues in a cell density-, calcium- and serum-dependent manner.

The natural form of vitamin D3, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) decreases proliferation and promotes terminal differentiation of cultured human epidermal keratinocytes. The purpose of this study was to find out to what extent the culture conditions determine the sensitivity of keratinocytes to 1,25(OH)2D3 and synthetic vitamin D analogues. Human keratinocytes were grown in microplates. Cell proliferation (MTT-assay) and differentiation (quantity of transglutaminase type I) were measured consecutively in the same monolayer. When vitamin D3 analogues were added to 50-60% confluent keratinocytes grown in serum-free keratinocyte growth medium with 0.09 mM Ca2+, stimulation of the proliferation was either minimal or non-existent, while differentiation was unaffected or slightly inhibited. There was no difference in the sensitivity to 1,25(OH)2D3 and the vitamin D3 analogues. When 1,25(OH)2D3 was added to less confluent keratinocytes (30%) a marked antiproliferative effect was observed. Addition of 3% charcoal stripped foetal calf serum further enhanced the antiproliferative effect of 1,25(OH)2D3, and a difference in the sensitivity of the vitamin D3 analogues was noted. If, finally, the Ca2+ concentration was raised to 0.3 mM, 1,25(OH)2D3 and the vitamin D3 analogues stimulated differentiation. Also, a biphasic effect on proliferation occurred: stimulation at low vitamin D concentrations and inhibition at higher concentrations. Furthermore, keratinocytes became more sensitive to the synthetic vitamin D3 analogues than to 1,25(OH)2D3: KH1060 > EB1089 > GS1500 > or = EB1213 > calcipotriol > 1,25(OH)2D3. For all compounds tested differentiation occurred at concentrations 10 to 30 times lower than for proliferation. These results indicate that the sensitivity to vitamin D3 analogues as well as the direction of the response to vitamin D3 analogues is dependent on the keratinocyte density, the availability of serum and Ca2+ concentrations.

Antibodies, Monoclonal↗

Effects of vitamin D3 on keratinocyte proliferation and differentiation in vitro: modulation by ligands for retinoic acid and retinoid X receptors.

Keratinocytes express receptors for 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], all-trans-retinoic acid (all-trans-RA), 9-cis-retinoic acid (9-cis-RA) and triiodothyronine (T3). The vitamin-D receptor (VDR) can act as a transcription factor by forming homodimers or heterodimers with the retinoic-acid receptor (RAR), the retinoid X receptor (RXR) or the triiodothyronine receptor (TR). This study investigated whether the antiproliferative and prodifferentiating effects of 1,25(OH)2D3 on normal human keratinocyte cultures is modified by all-trans-RA, a ligand for RAR, by CD2809, a ligand for RXR, by 9-cis-RA, a ligand for the RAR and RXR, and T3, a ligand for the TR. Submerged, second-passage normal human keratinocytes were grown to approximately 30% confluency before incubation for 4 days with ligands in keratinocyte growth medium supplemented with 3% charcoal-stripped fetal calf serum and 0.3 mM Ca2+. Proliferation was measured by the dimethylthiazolyl-diphenyl-tetrazolium-bromide assay. Then differentiation was determined in the same culture, performing a cell ELISA for transglutaminase type 1. All-trans-RA, 9-cis-RA and CD2809 had a slight stimulatory effect on proliferation. In combination with 1,25(OH)2D3, all retinoids partially counteracted the antiproliferative effect of 1,25(OH)2D3. The differentiation was dose-dependently inhibited by all-trans-RA, 9-cis-RA and CD2809 alone. In combination with 1,25(OH)2D3, all retinoids reversed the prodifferentiating effect of 1,25(OH)2D3, resulting in a net inhibition of differentiation. T3 had no effect on proliferation of differentiation, either alone or in combination with 1,25(OH)2D3. In conclusion, retinoids with different receptor selectivities had similar effects on keratinocyte proliferation and differentiation. The effects of 1,25(OH)2D3 on proliferation and differentiation were reversed by all retinoids. Therefore ligand-dependent heterodimer formation between the VDR and retinoid receptors may not be important for the combined effects of 1,25(OH)2D3 and retinoids on keratinocyte proliferation and differentiation in vitro.

Alitretinoin↗

Significance of leukotriene-A4 hydrolase in the pathogenesis of psoriasis.

The 5-lipoxygenase (5-LO) product of arachidonic acid, leukotriene (LT-)B4, is considered to play a significant role in the pathogenesis of psoriasis. In vitro LTB4 is a potent chemoattractant for leukocytes, and it increases DNA synthesis in human cultured keratinocytes. Intradermal injection of LTB4 into human skin in vivo results in a wheal and flare reaction, and topical application produces intraepidermal microabscesses and induces hyperproliferation. Furthermore, LTB4 has been determined in biologically active amounts in psoriatic skin lesions. Despite the importance of LTB4 in psoriasis, the capacity of the human epidermis to synthesize LTB4 has remained controversial. Recently, a very limited 5-LO activity was reported in human epidermis. Thus, it was shown that human epidermis can contribute significantly to LT formation by transcellular LT synthesis. By this mechanism, LTA4 released from activated leukocytes is further transformed into LTB4 in the keratinocytes by the LTA4 hydrolase. Transcellular metabolism may be of importance in psoriasis where neutrophils migrate into the epidermis, because in human neutrophils the LTA4 hydrolase has been shown as the rate-limiting step in LTB4 formation. The LTA4 hydrolase was localized in the epidermis by activity determination, by inhibition of enzyme activity with known LTA4 hydrolase inhibitors, by Western blotting and by immunohistochemical staining. Moreover the enzyme was purified and further characterized from human cultured keratinocytes and human epidermis. Because of these recent results it is concluded that LTB4 is of significance in the pathogenesis of psoriasis, and it is suggested that future work should focus on developing potent LTA4 hydrolase inhibitors for treatment of psoriasis.

Amino Acids↗

Oral terbinafine in toenail dermatophytosis. A double-blind, placebo-controlled multicenter study with 12 months' follow-up.

The treatment of onychomycosis has previously often been protracted and unsuccessful. Terbinafine has been shown to be effective in short-term regimens. In this double-blind, placebo-controlled study, 148 patients with toenail dermatophytosis were randomized to treatment with either 250 mg terbinafine daily or placebo for 3 months. An additional treatment was given for 3 months to patients whose infection had not responded. The patients were followed clinically and mycologically through 12 months. After 3 months 82% of the terbinafine-treated group, versus 5% of the placebo group, showed significant improvement, i.e. negative culture and growth of unaffected nail more than 2 mm (p = < 0.0001). After 12 months clinical and mycological cure was seen in 40% of the patients treated with terbinafine for 3 or 6 months, while 67-81% were clinically cured, but with positive microscopy. Side-effects occurred in 13.5% of the terbinafine group, versus 5.4% of the placebo group, and were mild. 250 mg terbinafine daily for 3 months was significantly more effective than placebo. The efficacy did not appear to improve with additional treatment for 3 months.

Administration, Oral↗

Topical application of a platelet-activating factor (PAF) antagonist in atopic dermatitis.

Platelet-activating factor (PAF acether) is a lipid mediator with a potent proinflammatory activity. Results derived both from in vitro and in vivo studies suggest a possible role of this substance in the pathophysiology of atopic dermatitis. A double-blind, randomized, multi-center, within-patient study was performed to evaluate the efficacy of a topically applied PAF antagonist (RO-24-0238) in 36 patients with atopic dermatitis. Over a period of 28 days, 0.25 ml of the PAF antagonist and the vehicle (placebo) were applied twice daily on opposite sites of symmetrical lesions (measuring 10 to 20 cm2 each). The overall assessment of the therapeutic efficacy did not demonstrate a superior effect of the PAF antagonist in comparison to placebo, and this was the same with the individual study parameters erythema, scaling, induration and exudation. For reducing pruritus, as assessed by the patient using a visual analogue scale, a statistically significant action was documented during the first 2 weeks of the study (p < 0.04; Wilcoxon rank sum test), with a continued, yet not statistically significant efficacy after weeks 3 and 4. The exact role of the pathological events of atopic dermatitis that might be influenced by a PAF antagonist remains to be determined, but the anti-pruritic component of this substance especially deserves further scientific interest.

Administration, Topical↗

Renal biopsy findings in long-term cyclosporin treatment of psoriasis.

Renal biopsies were performed in 30 psoriatics during long-term low-dose cyclosporin (CsA) therapy (range 2.5-6 mg/kg per day) of from 6 months to 8 years. The study included pretreatment biopsies in 25 of the patients. After 2 years all biopsies shared features consistent with CsA nephropathy despite completely normal pretreatment morphology in 17 of the 25 patients. The severity of the findings which consisted of arteriolar hyalinosis, focal interstitial fibrosis and sclerotic glomeruli increased with length of therapy. Mild renal lesions were seen during the first 2 years. After 4 years all but one had arteriolar hyalinosis, with interstitial fibrosis pronounced in five and moderate in six of 11 patients. At the same time glomerular sclerosis had become significant. A decrease in glomerular filtration rate (GFR) correlated with severity of structural lesions. The data from our study together with experiences from cardiac-transplanted patients treated with CsA indicate that patients with psoriasis after 2 years therapy with CsA should be rotated to other treatments or be followed carefully by GFR and sequential renal biopsies.

Adult↗