Search PubMed⌕ Search

Biomedical subjects

J D Bos

Publications and source records attributed to J D Bos.

At least 19 recordsLinked to original sources

Lichen planus is associated with human herpesvirus type 7 replication and infiltration of plasmacytoid dendritic cells.

BACKGROUND: Lichen planus (LP) is a common inflammatory skin disease of unknown aetiology. Viral causes have been suggested. OBJECTIVES: To find candidate viruses associated with LP. METHODS: Lesional and nonlesional skin samples, peripheral blood mononuclear cells and serum were obtained from patients with LP. Ultrastructural, viral DNA, immunohistochemical and serological analyses were performed, and comparisons were made with psoriatic and normal skin. RESULTS: Electron microscopy revealed typical 120-200-nm enveloped particles with a 100-nm nucleus resembling human herpesvirus (HHV) virions both in dermis and in epidermis of lesional LP tissue. HHV-7 DNA was found in 11 of 18 lesional LP samples, as opposed to only one of 11 nonlesional LP samples (P =0.06), two of 11 lesional psoriasis samples (P = 0.05) and none of four normal skin samples. No relation was found between LP skin and DNA of other known HHVs (HHV-1-6 and 8). With immunohistochemistry, significantly more HHV-7+ cells were found in lesional LP epidermis than in normal epidermis. Lesional LP dermis contained significantly more HHV-7+ cells than nonlesional LP, psoriatic or normal dermis. Moreover, LP skin contained overwhelmingly and consistently more plasmacytoid dendritic cells (upregulated in virally induced conditions) than nonlesional LP samples. CONCLUSIONS: We conclude that HHV-7 replicates in LP lesions, but not in psoriasis, another inflammatory skin condition. HHV-7 is possibly involved in the pathogenesis of LP. These preliminary data make further research on this topic of interest.

Adult↗

Percutaneous penetration of sodium lauryl sulphate is increased in uninvolved skin of patients with atopic dermatitis compared with control subjects.

BACKGROUND: Involved regions of the skin in patients with atopic dermatitis (AD) have been shown to have higher transepidermal water loss (TEWL), indicating a compromised skin barrier. Whether uninvolved skin also has diminished barrier characteristics is controversial. OBJECTIVES: To study the penetration of sodium lauryl sulphate (SLS) into uninvolved skin of patients with AD compared with the skin of control subjects. METHODS: Percutaneous penetration was assessed using the tape stripping technique on the stratum corneum (SC). Twenty patients with AD and 20 healthy subjects were exposed to 1% SLS for 4 h on the mid-volar forearm. After the end of exposure the SC was removed by adhesive tape. The amount of SLS was determined in each consecutive strip. Fick's second law of diffusion was used to deduce the diffusivity and the partition coefficient of SLS between water and the SC. RESULTS: The SC thickness was similar in both groups; however, the TEWL was higher in patients with AD compared with that of the control group (mean+/-SD 8.4+/-4.3 and 6.3+/-2.0 g m-2 h-1, respectively). There was a correlation between SC thickness and TEWL in control subjects but no correlation was found in patients with AD. The diffusivity of SLS through uninvolved AD skin was higher compared with normal skin (mean+/-SD 12.7+/-5.8x10(-9) and 6.2+/-3.0x10(-9) cm-2 h-1, respectively), while the partition coefficient between SC and water was lower (mean+/-SD 137+/-64 and 196+/-107, respectively). CONCLUSIONS: The results show a different penetration profile of SLS into the SC of patients with AD compared with control subjects. This indicates that even noninvolved skin in patients with AD has altered barrier characteristics, emphasizing the importance of skin protection and prevention of skin contact with chemicals.

Adolescent↗

CLinical experience acquired with the efalizumab (Raptiva) (CLEAR) trial in patients with moderate-to-severe plaque psoriasis: results from a phase III international randomized, placebo-controlled trial.

BACKGROUND: Efalizumab (anti-CD11a), a humanized monoclonal antibody, blocks multiple T-cell-dependent functions implicated in the pathogenesis of psoriasis, including T-cell activation, migration to the skin, reactivation in psoriatic skin and interactions with keratinocytes. OBJECTIVES: This multinational, randomized, double-blind, placebo-controlled, parallel-group trial was designed to evaluate the safety and efficacy of subcutaneous efalizumab 1.0 mg kg-1 once weekly for 12 weeks compared with placebo in a population that included high-need patients, defined as those for whom at least two systemic therapies were unsuitable because of lack of efficacy, intolerance or contraindication. PATIENTS/METHODS: Patients with moderate-to-severe plaque psoriasis [involvement of >or=10% of total body surface area and Psoriasis Area and Severity Index (PASI)>or=12.0 at screening] were randomized in a 2:1 ratio to receive efalizumab or placebo. The primary efficacy endpoint was the proportion of patients achieving >or=75% PASI improvement (PASI-75 response) at week 12 in the intention-to-treat population; secondary endpoints included changes in PASI, static Physician's Global Assessment, Physician's Global Assessment of change from baseline and percentage of body surface area affected. Results We enrolled 793 patients (529 received efalizumab and 264 placebo), including 526 high-need patients (342 received efalizumab and 184 placebo). Week 12 PASI-75 rates were 29.5% for efalizumab compared with 2.7% for placebo among high-need patients (P<0.0001) and 31.4% for efalizumab compared with 4.2% for placebo in the full study population (P<0.0001). RESULTS: for all secondary efficacy endpoints showed superiority of efalizumab over placebo in both the high-need and the full populations. Efalizumab demonstrated a favourable safety profile, without evidence of systemic toxicity, in both the high-need group and the overall study population. CONCLUSIONS: The efficacy and safety of efalizumab therapy were comparable between high-need patients and the more general moderate-to-severe psoriasis patient population. In view of its demonstrated efficacy and safety profile, efalizumab represents a valuable option for the treatment of adult patients with moderate-to-severe plaque psoriasis, including high-need patients.

Adult↗

Initial experience with routine administration of etanercept in psoriasis.

BACKGROUND: Etanercept and efalizumab recently became available and reimbursed for routine use in severe psoriasis in the Netherlands. The criteria for reimbursement are Psoriasis Area and Severity Index (PASI) > or = 10 (or Skindex-29 > or = 35 if PASI > or = 8 and < 10) and ineffectiveness of ultraviolet (UV) B/psoralen plus UVA, methotrexate and ciclosporin, or a contraindication to or serious side-effect(s) during these treatments. OBJECTIVES: We hypothesized: (i) that efficacy would be lower than that obtained in published phase II and III studies because (a) resistance to all conventional therapies as a reimbursement condition would select for more resistant cases and (b) inclusion would be more restricted to severe cases (higher PASI), and (ii) that efficacy would be lower in obese patients due to the possible role of adipose tissue in tumour necrosis factor (TNF)-alpha homeostasis. METHODS: We treated 50 patients (38 men, 12 women; mean PASI 15.8) with etanercept 25 mg or 50 mg twice weekly and evaluated in a retrospective analysis the efficacy and safety in comparison with data from published trials. Additionally, we related the clinical effect to the body mass index (BMI), for adipose tissue is thought to have a possible role in TNF-alpha homeostasis. RESULTS: Based on the literature, 30% and 49% of the patients treated with etanercept 25 mg and 50 mg twice weekly, respectively, should have achieved 75% or more improvement in PASI compared with baseline (PASI 75), and 10% and 21%, respectively, should have achieved 90% or more improvement (PASI 90). Our data showed that 21% in the 2 x 25 mg group and 23% in the 2 x 50 mg group achieved PASI 75. PASI 90 was only attained in 7% of patients treated with 2 x 25 mg and 6% of those treated with 2 x 50 mg. Contrary to our hypothesis, the mean initial PASI was comparable with the mean PASI mentioned in the phase II and III clinical trials. Although fatigue is not identified as a side-effect of etanercept, 10% of our patients reported fatigue as an adverse event during etanercept treatment. High BMI, indicating overweight or obesity, was found both in patients with little efficacy and in patients achieving PASI 75 or better. CONCLUSIONS: Use of etanercept in real practice gives impressive results, but these are generally less favourable than those published in clinical trial reports. This is probably due to the stringent conditions for reimbursement, which select for more treatment-resistant patients. Fatigue as a possible side-effect of etanercept should also be an issue for further investigation. Finally, the BMI does not seem to influence the patients' response to etanercept, although further investigations would be needed to confirm this.

Adult↗

Leukocyte extravasation as a target for anti-inflammatory therapy - Which molecule to choose?

In view of the central pathogenic importance of leukocyte extravasation in inflammatory skin diseases, therapeutic interference with this - surprisingly complex - process is clearly a promising new approach for treating these dermatoses. Despite some disappointments during the clinical use of these agents and despite their crippling price tag, the recent incorporation of biologicals that target defined molecular controls of leukocyte extravasation into dermatological and rheumatological practise, consequently, has greatly enriched our therapeutic options for battling major, chronic, inflammatory dermatoses such as psoriasis. However, the - as yet unresolved and still rather controversially discussed - critical question is: Which of the multiple steps that control leukocyte extravasation in the human system really offer the most promising, most pragmatic, and safest molecular targets for therapeutic intervention for which disease entity? The current debate intends to stimulate public and rational debate of this crucial issue, beyond the evident commercial interests that are touched by whatever stand one takes.

Anti-Inflammatory Agents↗

A multicentre, randomized, double-blind, controlled study of long-term treatment with 0.1% tacrolimus ointment in adults with moderate to severe atopic dermatitis.

BACKGROUND: Atopic dermatis (AD) is a chronic disease that often requires long-term treatment. Topical corticosteroids are the usual therapy for patients with AD, but prolonged usage can result in skin atrophy and other side-effects. OBJECTIVES: In a randomized, double-blind, comparative study, to compare the efficacy and safety of a 6-month treatment period with 0.1% tacrolimus ointment vs. a corticosteroid ointment regimen in adults with moderate to severe AD. METHODS: Treatment was applied twice daily for a maximum of 6 months. Patients in the tacrolimus treatment group (n = 487) applied 0.1% tacrolimus ointment to all affected areas over the whole body. The patients treated with the corticosteroid regimen (n = 485) applied 0.1% hydrocortisone butyrate ointment to affected areas on the trunk and extremities and 1% hydrocortisone acetate ointment to affected areas on the face and neck. The study primary endpoint was the response rate, i.e. the proportion of patients with at least 60% improvement in the modified Eczema Area and Severity Index (mEASI) between baseline and month 3. RESULTS: By month 3, more patients in the 0.1% tacrolimus group responded to treatment (72.6% vs. 52.3% in the corticosteroid group, P < 0.001). The patients treated with 0.1% tacrolimus also showed greater improvement in mEASI, EASI, affected body surface area and physician and patient assessments of global response. Patients applying 0.1% tacrolimus ointment experienced more skin burning (52.4% vs. 13.8% in the corticosteroid group; P < 0.001). In most patients, skin burning was mild to moderate in severity and decreased rapidly after the first week of treatment. There was no increase in the incidence of infections or malignancies over time in either treatment group. CONCLUSIONS: Long-term treatment with 0.1% tacrolimus ointment is significantly more efficacious than a corticosteroid ointment regimen in adults with moderate to severe AD.

Adult↗

Psoriasis: dysregulation of innate immunity.

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-alpha 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)-gamma, 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.

Antigens↗

Quality of care in patients with psoriasis: an initial clinical study of an international disease management programme.

BACKGROUND: Patients with psoriasis have to cope with their disease for many years or even throughout their entire life. To provide optimal care, a disease management programme was developed. This programme consisted of disease education, disease management training, and psychological support, together with topical treatment. OBJECTIVE: To test a disease management programme in dermatological practice, to assess patients' satisfaction with this programme, and adherence to topical treatment. Additionally, disease severity and quality of life were assessed. METHODS: An initial clinical investigation was conducted in 10 European treatment centres. A total of 330 patients were included. Patient satisfaction, adherence, disease severity and quality of life were measured with study-specific and standardized self-report questionnaires. RESULTS: Patients reported a high degree of satisfaction with the programme, and a high degree of adherence to topical treatment. Disease severity and quality of life significantly improved. The programme was well received by the participating professionals. CONCLUSIONS: The disease management programme was found to be a useful tool in the management of psoriasis, providing patients with relief from the burden of psoriasis in everyday life. A full-scale evaluation is recommended.

Dermatologic Agents↗

0.03% Tacrolimus ointment applied once or twice daily is more efficacious than 1% hydrocortisone acetate in children with moderate to severe atopic dermatitis: results of a randomized double-blind controlled trial.

BACKGROUND: Topical corticosteroids are the usual treatment for atopic dermatitis (AD) in children but can have side-effects. OBJECTIVES: This study compared the efficacy and safety of 0.03% tacrolimus ointment applied once or twice daily over a 3-week period with the twice daily application of 1% hydrocortisone acetate (HA) ointment in children with moderate to severe AD. PATIENTS AND METHODS: Patients applied ointment daily to all affected body surface areas. The primary study endpoint was the percentage change in the modified Eczema Area and Severity Index (mEASI) between baseline and treatment end. RESULTS: Six hundred and twenty-four patients, aged 2-15 years, applied 0.03% tacrolimus ointment once daily (n = 207), twice daily (n = 210) or 1% HA twice daily (n = 207). By the end of treatment, application of 0.03% tacrolimus ointment both once or twice daily resulted in significantly greater median percentage decreases in mEASI (66.7% and 76.7%, respectively) compared with 1% HA (47.6%; P < 0.001). Furthermore, the median percentage decrease in mEASI was significantly greater for patients applying 0.03% tacrolimus twice daily compared with once daily (P = 0.007). Patients with severe AD benefited especially from twice daily application of 0.03% tacrolimus ointment compared with once daily application (P = 0.001). Transient mild to moderate skin burning occurred significantly more often in the 0.03% tacrolimus groups (P = 0.028) but resolved in most cases within 3-4 days. Laboratory parameters showed no clinically relevant changes. CONCLUSIONS: 0.03% tacrolimus ointment applied once or twice daily is significantly more efficacious than 1% HA in treating moderate-severe AD in children. Twice daily application of 0.03% tacrolimus ointment results in the greatest improvement in mEASI, and is especially effective in patients with severe baseline disease.

Administration, Topical↗

Long-term safety and tolerability of pimecrolimus cream 1% and topical corticosteroids in adults with moderate to severe atopic dermatitis.

OBJECTIVE: This randomized, double-blind, multi-centre study compared the long-term safety and tolerability of pimecrolimus cream 1% and topical corticosteroids (TCS) in 658 adults with moderate-severe atopic dermatitis (AD). METHODS: Patients applied either pimecrolimus or TCS (i.e. 0.1% triamcinolone acetonide cream and/or 1% hydrocortisone acetate cream) twice daily to all affected areas until complete clearance or for up to 1 year. The study was approved by the institutional review board or ethics committee at each centre. RESULTS: A majority of patients treated with either pimecrolimus or TCS used the drug on a continuous basis over 1 year. In patients who had >30% of the body surface involved by AD, the incidence rate of all skin infections was significantly lower in the pimecrolimus group than in the TCS group (95% CI of the treatment difference: -25.3% to -3.4%). The most frequent application site reaction was burning (25.9% of patients on pimecrolimus and 10.9% on TCS), which was transient and mild-moderate in most cases. Three TCS-treated patients reported skin striae. There were no treatment-related serious or clinically significant systemic adverse events. Efficacy was better in patients on continuous TCS therapy, although patients completing the study were similarly well-controlled in both groups. About 42% of the pimecrolimus-treated patients were maintained for 1 year without TCS. CONCLUSION: Pimecrolimus demonstrated a favourable safety profile when used to treat adult patients with moderate-severe AD for up to 1 year. A significant proportion of patients could be maintained without TCS for a year.

Administration, Cutaneous↗

Clinical improvement in chronic plaque-type psoriasis lesions after narrow-band UVB therapy is accompanied by a decrease in the expression of IFN-gamma inducers -- IL-12, IL-18 and IL-23.

Type-1 cytokine-producing T cells are important in the pathogenesis of psoriasis vulgaris, for which efficient therapy is provided by means of narrow-band ultraviolet-B (NB-UVB). The expression of the type-1 cytokine interferon-gamma (IFN-gamma) is regulated by interleukin-12 (IL-12), IL-15, IL-18 and IL-23; however, not much is known about the effect of this therapy on the levels of these cytokines in lesional psoriatic skin in situ. In this study, we investigated the effects of NB-UVB therapy on the expression of IFN-gamma-inducing cytokines. Ten patients with chronic plaque-type psoriasis selected to be treated with NB-UVB therapy were recruited for these experiments and the expression of cytokines IL-12, IL-15, IL-18, IL-23 and IFN-gamma in lesional psoriatic skin before, during and after therapy was determined with the help of immunohistochemistry. Double staining was performed in order to determine the cell types expressing these cytokines. The decrease in the psoriasis area and severity index was accompanied by a significant decrease in the expression of IFN-gamma, and concomitantly, significant reduction of IFN-gamma inducers -- IL-12, IL-18 and IL-23. Thus, we concluded that the decrease of IFN-gamma expression in psoriasis lesions after NB-UVB therapy could be a result of diminished expression of IL-12, IL-18 and IL-23 in lesional skin. Therapies targeting these three cytokines should, therefore, be considered in the treatment of psoriasis.

Adult↗

Biological therapies in the systemic management of psoriasis: International Consensus Conference.

Psoriasis is a chronic, immune-mediated disorder that usually requires long-term treatment for control. Approximately 25% of patients have moderate to severe disease and require phototherapy, systemic therapy or both. Despite the availability of numerous therapeutic options, the long-term management of psoriasis can be complicated by treatment-related limitations. With advances in molecular research and technology, several biological therapies are in various stages of development and approval for psoriasis. Biological therapies are designed to modulate key steps in the pathogenesis of psoriasis. Collectively, biologicals have been evaluated in thousands of patients with psoriasis and have demonstrated significant benefit with favourable safety and tolerability profiles. The limitations of current psoriasis therapies, the value of biological therapies for psoriasis, and guidance regarding the incorporation of biological therapies into clinical practice are discussed.

Age Factors↗

The role of topical calcineurin inhibitors in atopic dermatitis.

For more than five decades, topical corticosteroids and emollients have been the mainstay of therapy for atopic dermatitis. However, the potential for side-effects limits the clinical utility of corticosteroids in providing long-term disease control. With a unique mode of action that differs from that of corticosteroids, the steroid-free topical calcineurin inhibitors (TCIs), tacrolimus ointment and pimecrolimus cream, provide skin-selective treatment that targets key factors involved in the pathogenesis of this chronic disease. An extensive series of clinical trials involving more than 16,000 patients with predominantly moderate to severe atopic dermatitis in tacrolimus studies and over 2000 patients with primarily mild to moderate disease in pimecrolimus studies has shown that both TCIs provide effective and well-tolerated treatment for atopic dermatitis. Randomized controlled trials have demonstrated that tacrolimus is superior to conventional hydrocortisone-based regimens and does not cause skin atrophy or other steroidal side-effects. Both tacrolimus and pimecrolimus prevent disease flares and provide progressive and sustained disease improvement with long-term therapy. These and other clinical benefits of TCIs are discussed, together with the safety profiles of tacrolimus and pimecrolimus and their use in clinical practice. In addition, this review summarizes findings from the many trials carried out with these agents and outlines how TCIs can provide long-term treatment and control of a chronic skin disease that may persist for years.

Administration, Topical↗

Early effects of tumour necrosis factor alpha blockade on skin and synovial tissue in patients with active psoriasis and psoriatic arthritis.

BACKGROUND: Tumour necrosis factor alpha (TNFalpha) blockade using infliximab, a chimeric anti-TNFalpha antibody, is an effective treatment for both psoriasis and psoriatic arthritis (PsA). OBJECTIVE: To analyse the early effects of infliximab treatment on serial skin and synovial tissue biopsy samples. METHODS: Twelve patients with both active psoriasis and PsA received a single infusion of either infliximab (3 mg/kg) (n = 6) or placebo (n = 6) intravenously. Synovial tissue and lesional skin biopsy specimens were obtained at baseline and 48 hours after treatment. Immunohistochemical analysis was performed to analyse the inflammatory infiltrate. In situ detection of apoptotic cells was performed by TUNEL assay and by immunohistochemical staining with anti-caspase-3 antibodies. Stained tissue sections were evaluated by digital image analysis. RESULTS: A significant reduction in mean (SEM) T cell numbers was found in both lesional epidermis (baseline 37 (11) cells/mm, 48 hours 26 (11), p = 0.028) and synovial tissue (67 (56) cells/mm(2)v 32 (30), p = 0.043) after infliximab treatment, but not after placebo treatment (epidermis 18 (8) v 43 (20), NS; synovium 110 (62) v 46 (21), NS). Similarly, the number of macrophages in the synovial sublining was significantly reduced after anti-TNFalpha treatment (100 (73) v 10 (8), p = 0.043). The changes in cell numbers could not be explained by induction of apoptosis at the site of inflammation. CONCLUSIONS: The effects of anti-TNFalpha therapy in psoriasis and psoriatic arthritis may be explained by decreased cell infiltration in lesional skin and inflamed synovial tissue early after initiation of treatment.

Adult↗

[European standard regarding clothing and protection against ultraviolet radiation].

Overexposure to ultraviolet radiation (UVR) causes skin damage. An increasing awareness of this must result in people consciously wanting to protect themselves from UVR by means of clothing. The first part of the European standard on UVR-protective clothing--about test methods--is now available. In the second part the classification and labelling of UVR-protective clothing are detailed. The degree of protection the clothing provides against UVR is expressed as the ultraviolet-protection factor (UPF). The UPF is inversely proportional to the quantity of UVR which the clothing allows through. UVR-protective clothing which satisfies the European standard will bear the European UPF label '40+'. To obtain this label the entire clothing must have a UPF of at least 40. The wording: 'Sun exposure causes skin damage', 'Only covered areas are protected' and 'The protection offered by this item may be reduced with use or if the material is stretched or wet' must be added to the label.

Clothing↗

Causes, investigation and treatment of leg ulceration.

Chronic ulceration of the lower leg is a frequent condition, with a prevalence of 3-5% in the population over 65 years of age. The incidence of ulceration is rising as a result of the ageing population and increased risk factors for atherosclerotic occlusion such as smoking, obesity and diabetes. Ulcers can be defined as wounds with a 'full thickness depth' and a 'slow healing tendency'. In general, the slow healing tendency is not simply explained by depth and size, but caused by an underlying pathogenetic factor that needs to be removed to induce healing. The main causes are venous valve insufficiency, lower extremity arterial disease and diabetes. Less frequent conditions are infection, vasculitis, skin malignancies and ulcerating skin diseases such as pyoderma gangrenosum. But even rarer conditions exist, such as the recently discovered combination of vasculitis and hypercoagulability. For a proper treatment of patients with leg ulcers, it is important to be aware of the large differential diagnosis of leg ulceration.

Arterial Occlusive Diseases↗