Neurological phenotype of adenosine deaminase 2 deficient patients: a cohort study.

BACKGROUND AND PURPOSE: Patients with adenosine deaminase 2 (ADA2) deficiency can present with various neurological manifestations due to vasculopathies and autoinflammation. These include ischaemic and hemorrhagic stroke, but less clearly defined neurological symptoms have also been reported. METHODS: In this cohort study, patients with confirmed ADA2 deficiency from seven university hospitals in the Netherlands were included. The frequency and recurrence rates of neurological manifestations before and after initiation of tumor necrosis factor α (TNF-α) inhibiting therapy were analyzed. RESULTS: Twenty-nine patients were included with a median age at presentation of 5 years (interquartile range 1-17). Neurological manifestations occurred in 19/29 (66%) patients and were the presenting symptom in 9/29 (31%) patients. Transient ischaemic attack (TIA)/ischaemic stroke occurred in 12/29 (41%) patients and was the presenting symptom in 8/29 (28%) patients. In total, 25 TIAs/ischaemic strokes occurred in 12 patients, one after initiation of TNF-α inhibiting therapy and one whilst switching between TNF-α inhibitors. None was large-vessel occlusion stroke. Two hemorrhagic strokes occurred: one aneurysmatic subarachnoid hemorrhage and one spontaneous intracerebral hemorrhage. Most neurological symptoms, including cranial nerve deficits, vertigo, ataxia and seizures, were caused by TIAs/ischaemic strokes and seldom recurred after initiation of TNF-α inhibiting therapy. CONCLUSIONS: Neurological manifestations, especially TIA/ischaemic stroke, are common in patients with ADA2 deficiency and frequently are the presenting symptom. Because it is a treatable cause of young stroke, for which antiplatelet and anticoagulant therapy are considered contraindicated, awareness amongst neurologists and pediatricians is important. Screening for ADA2 deficiency in young patients with small-vessel ischaemic stroke without an identified cause should be considered.

The economic burden of the postoperative management in surgically treated trauma patients with peri- and/or intra-articular fractures of the lower extremities: A prospective multicenter cohort study.

OBJECTIVES: To estimate the economic burden expressed in costs and quality of life of the post-surgical treatment of peri­ and/or intra-articular fractures in the lower extremity from a societal perspective. DESIGN: This is a quantitative study as it aims to find averages and generalize results to wider populations. The design is a cost-of-illness and quality of life study focusing on costs (in euros), Activities of Daily Living (ADL) and Quality of Life (Qol) in patients with peri­ and/or intra-articular fractures of the lower extremities. SETTING: Surgically treated trauma patients with peri­ and/or intra-articular fractures of the lower extremities during 26 weeks follow-up. Patients were included from 4 hospitals in the Netherlands. MAIN OUTCOME MEASURES: Costs, ADL and Quality Adjusted Life Years (QALY). METHODS: Cost of illness was estimated through a bottom-up method. The Dutch Eq-5D-5 L questionnaire was used to calculate utilities while Lower Extremity Functional Scale (LEFS) scores were used as a measure of ADL. Non-parametric bootstrapping was used to test for statistical differences in costs. Subgroup analyses were performed to determine the influence of work status and further sensitivity analyses were performed to test the robustness of the results. RESULTS: Total average societal costs were € 9836.96 over six months. Unexpectedly, total societal and healthcare costs were lower for patients with a paid job relative to patients without. Sensitivity analyses showed that our choice of a societal perspective and the EuroQol as our primary utility measurement tool had a significant effect on the outcomes. The ADL at baseline was respectively; 10.4 and at 26 weeks post-surgery treatment 49.5. The QoL was at baseline respectively; 0.3 and at 26 weeks post-surgery treatment 0.7. These findings are indicative of a significantly improved ADL and QoL (p ≤ 0.05) over time. CONCLUSIONS: This study reveal a substantial economic burden in monetary terms and effect on QoL of patients with peri­ and/or intra-articular fractures of the lower extremities during 26 weeks follow-up. REGISTRATION: This study was registered in the Dutch Trial Register (NTR6077). Date of registration: 01-09-2016.

Female patients are less satisfied with biological treatment for psoriasis and experience more side-effects than male patients: results from the prospective BioCAPTURE registry.

BACKGROUND: Female sex has been reported as a predictor for treatment discontinuation with biological therapies for psoriasis, although reasons remain unclear. It can be hypothesized that lower satisfaction with biological treatment in women might add to the lower drug survival rates. OBJECTIVES: To identify possible differences in satisfaction with biological treatment between female and male patients using the Treatment Satisfaction Questionnaire for Medication (TSQM). METHODS: Data of psoriasis patients treated with biologics were obtained from the prospective, multicentre, daily-practice BioCAPTURE registry. Longitudinal TSQM data were analysed by linear mixed models. Relevant patient characteristics were incorporated as possible confounding factors. Post hoc analysis of adverse events was performed in order to investigate differences between sexes. RESULTS: We included 315 patients with 396 corresponding treatment episodes (137 adalimumab, 90 etanercept, 137 ustekinumab, 24 secukinumab and 8 infliximab). Almost forty per cent of the patients were female. Women had significantly lower baseline PASI scores (P = 0.01). Longitudinal analyses demonstrated lower TSQM scores for 'side-effects' (P = 0.05) and 'global satisfaction' (P = 0.01) in female patients compared with male patients over 1 year of treatment. Women reported more relevant adverse events in the context of biologic treatment compared to men (rate ratio 1.79; P < 0.001), with more fungal (rate ratio 2.20; P = 0.001) and herpes simplex infections (rate ratio 3.25; P = 0.005). CONCLUSIONS: This study provides a prospective, longitudinal analysis of treatment satisfaction with biologics in female and male patients with psoriasis. Women were slightly less satisfied with treatment regarding side-effects and global satisfaction. Differences in treatment satisfaction and side-effects might add to the fact that women discontinue biological treatments more often.

Comparison of the 1- and 5-year effectiveness of adalimumab, etanercept and ustekinumab in patients with psoriasis in daily clinical practice: results from the prospective BioCAPTURE registry.

BACKGROUND: The efficacy of etanercept and ustekinumab in psoriasis has been compared in one randomized controlled trial. Comparison of the long-term effectiveness of biologics in daily-practice psoriasis treatment is currently lacking. OBJECTIVES: To compare the effectiveness between the three widely used outpatient biologics adalimumab, etanercept and ustekinumab in daily-practice psoriasis treatment and to correct for confounders. METHODS: Data were extracted from the prospective, multicentre BioCAPTURE registry. Multilevel linear regression analyses (MLRAs) and generalized estimating equation (GEE) analyses were performed on the course of mean Psoriasis Area and Severity Index (PASI) and PASI 75 (≥ 75% reduction vs. baseline). Both models were corrected for confounders. Subgroup analyses for biological dose were performed. RESULTS: We included 356 patients with 513 treatment episodes: 178 adalimumab, 245 etanercept and 90 ustekinumab. MLRA showed a similar effectiveness between adalimumab, etanercept and ustekinumab after 1 year, but the highest effectiveness for ustekinumab during 5 years of treatment (P = 0·047; ustekinumab vs. etanercept, P = 0·019). GEE analysis revealed a higher chance of attaining PASI 75 with adalimumab and ustekinumab than with etanercept at 1 year of treatment. A higher than label dose was more often used in patients treated with etanercept (adalimumab, etanercept and ustekinumab: respectively 31·5%, 55·1% and 17% after 1 year, P < 0·001; 39·3%, 71·4% and 24% after 5 years, P < 0·001). CONCLUSIONS: Compared with etanercept, ustekinumab had the highest effectiveness during 5 years of treatment. Patients receiving adalimumab and ustekinumab more often reached PASI 75 than those on etanercept at 1 year of treatment. Dose escalation was more frequent in etanercept and adalimumab than in ustekinumab.

Comparing treatment goals for psoriasis with treatment decisions in daily practice: results from a prospective cohort of patients with psoriasis treated with biologics: BioCAPTURE.

BACKGROUND: Treatment goals have been developed to optimize daily clinical practice psoriasis care, but have not yet been studied in real life. OBJECTIVES: To investigate to what extent treatment decisions made by dermatologists in daily clinical practice for patients with psoriasis on biologics are already in accordance with treatment goals without the active application of the treatment goals algorithm. METHODS: Data were extracted from a prospective daily practice cohort of patients with psoriasis on biologics. Analysis was done on effectiveness (Psoriasis Area and Severity Index score) and quality of life (Dermatology Life Quality Index questionnaire). Treatment decisions such as dosage adjustments, combination treatments, or switching therapy were compared with the treatment goals algorithm. RESULTS: In 64% (253 of 395) of visits, physicians followed the treatment goals algorithm. There were 162 (41%) visits in which there should have been a treatment modification according to treatment goals (group Modify) and a modification was indeed made in 59 of these 162 visits (36%). In 233 (59%) visits no treatment modification was necessary (group Continue) and therapy was indeed not modified in 194 of 233 visits (83%). CONCLUSIONS: Physicians acted in accordance with treatment goals in the majority of patient visits. In the patient group not achieving these goals, physicians should have modified therapy according to treatment goals but continued the same therapeutic regimen in the majority of visits. Optimizing therapy and defining barriers in the latter group might increase treatment results in daily practice psoriasis care.

'Happy' drug survival of adalimumab, etanercept and ustekinumab in psoriasis in daily practice care: results from the BioCAPTURE network.

BACKGROUND: Drug survival is a marker for treatment success. To date, no analyses relating dermatological quality-of-life measures to drug survival have been published. OBJECTIVES: (i) To describe 1-year drug survival for adalimumab, etanercept and ustekinumab in a daily practice psoriasis cohort, and (ii) to introduce the concept of 'happy' drug survival, defined as Dermatology Life Quality Index (DLQI) ≤ 5 combined with being 'on drug' at a specific time point. METHODS: Data were extracted from a prospective registry. Drug survival was analysed using Kaplan-Meier estimates. 'Happy' drug survival was calculated, with data split into 'happy' (DLQI ≤ 5) vs. 'unhappy' (DLQI > 5) at baseline and months 3, 6, 9 and 12. RESULTS: 249 treatment episodes were included (101 adalimumab, 82 etanercept, 66 ustekinumab). The 1-year drug survival rates for ustekinumab, adalimumab and etanercept were 85%, 74% and 68%, respectively. Ustekinumab showed a better confounder-corrected drug survival vs. etanercept [hazard ratio (HR) 3·8, P = 0·02] and a trend towards better survival vs. adalimumab (HR 2·3, P = 0·1). At baseline, the majority (n = 115, 73%) was considered 'unhappy' and a minority 'happy' (n = 42, 27%) (ratio 'happy':'unhappy' was 1 : 2.7). The percentage of treatment episodes with 'happy' on-drug patients increased to 79% after 1 year. CONCLUSIONS: Ustekinumab showed a better overall drug survival than etanercept, and a trend towards a better overall drug survival than adalimumab. After 1 year, patients reported to be 'happy' in 79% of episodes and 'unhappy' in 21%. We introduced the new concept of 'happy' drug survival because the proportion of on-drug patients with good quality of life is an important indicator for treatment success.

Satisfaction of treatment with biologics is high in psoriasis: results from the Bio-CAPTURE network.

BACKGROUND: Although the effectiveness of biologics for psoriasis has been measured extensively with objective outcome measures, studies based on subjective, patient-reported outcome measures remain scarce. OBJECTIVES: To investigate satisfaction with medication, as measured by the Treatment Satisfaction Questionnaire for Medication (TSQM) for biologics in daily practice psoriasis care in the first 6 months of treatment; and to identify possible differences in satisfaction with medication between patients experienced (biologics-experienced) and inexperienced (biologics-inexperienced) in the use of biologics. METHODS: TSQM baseline measurements were compared using measurements taken after 6 months, using the Wilcoxon signed-rank test for paired comparisons. Intention-to-treat with last observation carried forward (ITT with LOCF) and as-treated analyses were performed. The difference between biologics-experienced and biologics-inexperienced patients for TSQM was analysed using ITT with LOCF. At 6 months, outcomes for biologics-experienced and biologics-inexperienced patients were compared using the Mann-Whitney U-test. RESULTS: One hundred and six patients were eligible for analysis, and treated with etanercept (n = 34), adalimumab (n = 49) or ustekinumab (n = 23). Fifty-four per cent of patients were biologics-inexperienced. A statistically significant improvement was seen in all domains of the TSQM ('effectiveness', 'side-effects', 'convenience' and 'global satisfaction') by comparison of months 3 or 6 with baseline (all P ≤ 0·02). After 6 months, biologics-inexperienced patients scored better on the 'global satisfaction' domain than biologics-experienced patients (P < 0·01). CONCLUSIONS: We provide a prospective, longitudinal analysis of TSQM for biologics in daily practice psoriasis care. High satisfaction rates were achieved. The 'effectiveness' and 'convenience' domains showed the most room for improvement.

Bilateral proximal tibia fracture.

A bilateral fracture of the proximal tibia is rare in children. We describe a girl with a bilateral fracture just distal of the epiphyseal plate after minimal trauma.

[An adult with mechanical ileus in association with non-rotation of the intestine]. / Een volwassene met een strengileus samenhangend met non-rotatie van de darm.

A mechanical ileus was considered in the differential diagnosis of a 28-year-old man who presented to the Emergency Clinic with acute, severe, painful cramps in the lower abdomen of 2 hours' duration, without radiation and with an urge to move constantly. An emergency laparotomy was then performed, revealing non-rotation of the intestine; the last segment ofthe small intestine was pinched off by a strangulation. Several strangulations were cleaved, after which the symptoms disappeared. Non-rotation, a form of malrotation, is a congenital anomaly of intestinal rotation. In adults, non-rotation is a rare diagnosis with a variable presentation. Surgical intervention is necessary in both the acute and the more chronic presentation. The chronic presentation is usually discovered by chance in patients who have had aspecific recurrent abdominal complaints for a long time; if malrotation is suspected, additional investigation, for example by means of a gastrointestinal contrast study, is necessary before resorting to surgery. In the acute situation, immediate surgery is the only proper decision. Surgical intervention comprises reduction of the volvulus, inspection of the mesenteric bands (Ladd's bands) that run from the coecum to the lateral peritoneum and compress the duodenum, and an appendectomy: the Ladd procedure.

Keratinocyte-derived growth factors play a role in the formation of hypertrophic scars.

In predisposed individuals, wound healing can lead to hypertrophic scar or keloid formation, characterized by an overabundant extracellular matrix. It has recently been shown that hypertrophic scars are accompanied by abnormal keratinocyte differentiation and proliferation, and significantly increased acanthosis, compared with normal scars. This study addressed the question of whether the development of normal and hypertrophic scars is regulated by differences in the growth factor profiles of both the epidermis and the dermis. The presence of interleukin-1alpha (IL-1alpha), IL-1beta, tumour necrosis factor-alpha (TNF-alpha), platelet-derived growth factor (PDGF), transforming growth factor-beta1 (TGF-beta1), and basic fibroblast growth factor (bFGF) was investigated in biopsies taken from breast reduction scars at 3 and 12 months following surgery. The samples were analysed by immunohistological methods and categorized as scars that remained hypertrophic (HH), became normal (HN) or remained normal after 12 months (NN). The epidermal expression of IL-1alpha was significantly increased in NN scars compared with HN and HH scars 3 and 12 months following operation, whereas the dermal expression showed no difference. PDGF was significantly increased in the dermis of normal scars after 3 months and in both the epidermis and the dermis of hypertrophic scars after 12 months. IL-1beta, TNF-alpha, TGF-beta and bFGF showed no differences. It is hypothesized that impaired production of keratinocyte-derived growth factors, such as IL-1alpha, leads to a decrease in the catabolism of the dermal matrix, whereas augmented epidermal PDGF production leads to increased formation of the dermal matrix in hypertrophic scars. These observations support the possibility that the epidermis is involved in preventing the formation of hypertrophic scars.

Pharmacological effects of a specific leukotriene B(4) receptor antagonist (VML 295) on blood leukocytes, cutaneous inflammation and epidermal proliferation.

VML 295 (LY 293111) is a potent and specific leukotriene(4) receptor antagonist. It has previously been shown in human volunteers that VML 295 at a dosage of 48 mg twice daily inhibits the ex vivo leukotriene B(4) (LTB(4))-induced upregulation of CD11b on peripheral blood neutrophils. A clear dose-response relatinship was shown. In addition, VML 295 inhibits various inflammatory aspects resulting from LTB(4) challenge of the skin, again showing a dose-response relationship. In view of the large variation in the elimination half-life of VML 295 (25-88.5 h) in individual human subjects, the present pharmacological study was designed to provide information on the pharmacodynamics of the drug by the assessment of VML 295 plasma concentrations, ex vivo LTB(4)-induced CD11b upregulation of neutrophils, neutrophil accumulation in the skin following epicutaneous application of LTB(4) and epidermal regeneration following standardized surface trauma. A group of 36 healthy volunteers were treated in a double-blind study with VML 295 at 200 mg twice daily, VML 295 at 200 mg once daily or placebo for 7 days. Before treatment, at the end of treatment and following discontinuation of treatment, VML 295 plasma concentrations and CD11b upregulation of blood neutrophils were assessed. In 18 subjects, the effects of the three treatments on LTB(4)-induced inflammatory were assessed before and at the end of treatment, and in the remaining 18 subjects the effects of these treatments on epidermal regeneration were assessed similarly. VML 295 at 200 mg either twice or once daily has a profound inhibitory effect on ex vivo LTB(4)-induced CD11b upregulation of blood neutrophils, LTB(4)-induced neutrophil accumulation in the skin, trauma-induced hyperproliferation of the epidermis and regenerative keratinization. The twice daily dose schedule was significantly more effective than the once daily regimen in reducing ex vivo CD11b stimulation of neutrophils, in blood samples collected 24 h after discontinuation of VML 295 treatment. The twice daily schedule tended to be more efficient in skin biopsies, although this difference was not statistically significant in the number of subjects investigated. A plasma concentration of 100 ng/ml proved to be the threshold for these effects. The profound biological effects, both systemically and cutaneously, as well as the safety profile, make VML 295 a promising drug for skin disorders characterized by epidermal proliferation and neutrophil accumulation.

Sequences throughout the basic beta-1,3-glucanase mRNA coding region are targets for homology dependent post-transcriptional gene silencing.

In the transgenic tobacco line T17, plants homozygous for the gn1 transgene display developmentally regulated post-transcriptional silencing of basic beta-1,3-glucanase genes. Previously, it has been shown that silencing involves a markedly increased turnover of silencing-target glucanase mRNAs. Using a two-component viral reporter system facilitated a comparison, in a quantitat- ive manner, of the relative silencing efficiencies of various sequences derived from the gn1 transgene. The results show that target sites for the silencing mechanism are present throughout the coding region of the gn1 mRNA. Similar-sized coding region sequences along the entire gn1 mRNA display a similar susceptibility to the silencing mechanism. The susceptibility to silencing increases as the coding region elements increase in size. Relative to internal sequences, the 5' and 3' terminal regions of the gn1 mRNA are inefficient targets for the silencing machinery. Importantly, sequences of the gn1 transgene that are not part of the mature gn1 mRNA are not recognized by the silencing machinery when expressed in chimeric viral RNAs. These results show that the glucanase silencing mechanism in T17 plants is primarily directed against gn1 mRNA-internal sequences and that terminal sequences of the gn1 mRNA are relatively unaffected by the silencing mechanism.

Familial primary cryofibrinogenemia.

BACKGROUND: To our best knowledge this is the second case ever described of familial primary cryofibrinogenemia (CFG). PATIENTS: A 29-year-old Moroccan female and two of her three children suffered from painful purpura, slow healing small ulcerations and edema of both feet during the winter season. Laboratory investigations revealed the presence of cryofibrinogen in their blood plasma. All three patients were otherwise healthy and no associated disease could be demonstrated. CONCLUSIONS: The diagnosis of CFG has to be considered in patients with livedo reticularis, edema, painful purpura and slow healing ulcera after cold exposure. Cryofibrinogen-precipitates in the blood plasma have to be determined. Because secondary CFG occurs much more frequently than the primary form, it is important to rule out associated diseases through extensive physical examination and laboratory investigations. This communication also stresses the importance of a through family history of patients with CFG. An autosomal dominant mode of inheritance is supposed.

Hypertrophic scarring is associated with epidermal abnormalities: an immunohistochemical study.

The role of epidermal keratinocytes in the early phases of normal unimpaired wound healing has been studied extensively. However, little is known about the cell biological processes in the epidermis and the basal membrane zone during the later phases of dermal matrix formation and remodelling of the scar tissue. This study investigated epidermal growth and differentiation and maturation of the basal membrane zone. Biopsies were taken from (clinically) hypertrophic and non-hypertrophic scars at 3 and 12 months after a breast-reduction operation. Tissues were analysed using immunohistochemical techniques. The data showed that epidermal abnormalities with respect to differentiation persist up to 3 months, as witnessed by the expression of cytokeratin 16. Remarkably, hypertrophic scars that remained hypertrophic throughout the period of analysis (up to 12 months) showed significantly more cytokeratin 16 expression at 3 months, when compared either with normal scars or with hypertrophic scars that became normal after 12 months. Staining for Ki-67 antigen, a marker for cell proliferation, revealed an increase in basal keratinocyte proliferation rate in 3-month-old hypertrophic scars compared with non-hypertrophic scars. After 12 months, this difference had disappeared completely and the number of cycling basal cells had returned to normal values. Three-month-old hypertrophic scars showed more acanthosis than non-hypertrophic scars of the same age, irrespective of whether they remained hypertrophic or became normal scars. After 12 months, this difference was no longer present. Staining for various heparan sulphate proteoglycan epitopes revealed that restoration of the basal membrane was incomplete at 3 months, but was complete at 12 months with respect to this component. No differences in the expression of several components of the basal membrane zone (heparan sulphate proteoglycan, laminin, tenascin) were noted between hypertrophic and non-hypertrophic scars. These data show that in the early phase of hypertrophic scarring, epidermal abnormalities are found compared with normal wound healing. In addition, early (3 months) epidermal abnormalities are associated with the clinical outcome at 12 months. These findings raise the possibility that the epidermal compartment is involved in the pathogenic process.

Human epidermal keratinocytes are a source of tenascin-C during wound healing.

Tenascin-C is a large hexameric extracellular matrix glycoprotein that is expressed in a temporally and spatially restricted pattern associated with stromal-epithelial interactions. In adult human skin, the expression level of tenascin-C is low, but tenascin-C is abundantly present in the dermal compartment during embryogenesis and wound healing and in skin tumors. Herein we have investigated the cellular source of tenascin-C production in human skin, both in vivo and in vitro, by using immunohistochemistry, mRNA in situ hybridization, western blotting, and an enzyme-linked immunosorbent assay. In addition we studied the cell-matrix interaction between epidermal keratinocytes and purified tenascin-C. By using in vitro culture models, we found that keratinocytes not only synthesize and secrete tenascin-C but can also deposit tenascin-C in de-epidermized dermis in a pattern that is very similar to that in vivo. In vivo, during wound healing of normal human skin, we found tenascin-C extracellularly in the wound bed and also in a granular pattern within the neo-epidermis. By mRNA in situ hybridization, we could identify the basal migrated keratinocytes as the main source of tenascin-C in the early phase of wound healing. In the granulation phase, tenascin-C expression by the keratinocytes is downregulated. Cultured keratinocytes were found to adhere poorly to tenascin-C, and those that did adhere retained a rounded morphology. We conclude that human keratinocytes are a major source of tenascin-C during the early phase of wound healing, and we hypothesize that tenascin-C is unlikely to be an adhesive substrate for migrating keratinocytes.

Basal membrane heparan sulphate proteoglycan expression during wound healing in human skin.

Heparan sulphate proteoglycans (HSPGs) are integral components of the basement membrane (BM) in various tissues. HSPGs are important in the assembly and structure of the BM, and their putative functions include regulation of basement membrane permeability, binding of growth factors, and a role in cellular adhesion. In this study the expression of HSPG was examined during wound healing in human skin, using monoclonal antibodies (MAbs) that recognize the HSPG core protein and two different heparan sulphate (HS) epitopes, and the dynamics of HSPG expression were investigated in relation to epidermal cellular proliferation and permeability of the BM. Healing of excisional wounds in healthy volunteers was studied from day 0 up to 1 year. Intact human skin showed strong continuous staining of the dermo-epidermal BM and the vascular BM with all MAbs. Up to day 4 after wounding, staining for HSPG was absent under the ingrowing epidermis, with any of the MAbs, indicating that no complete BM was present. From day 7 onwards, the BM of the neo-epidermis showed positive staining for the HSPG core protein and a low sulphated HS epitope, and after day 14, the staining intensity was similar to normal skin. The staining patterns of these HSPG epitopes were similar to that of laminin. The staining pattern with a MAb against an epitope in the highly sulphated part of HS was found to be distinct from the other BM markers studied. This epitope was absent under the neo-epidermis up to 2 months after wounding. One year after wounding, the epitope was found to be present again. We observed that only in the time period between 2 months and 1 year had the epidermis normalized with respect to the number of cycling cells and the absence of high molecular weight plasma proteins. These findings suggest a correlation between normalization of epidermal proliferation, BM permeability, and regeneration of BM HS. It is proposed that complete BM maturation following skin wounding is a slow process and may account for the epidermal abnormalities that persist for a considerable period of time after wound healing.

Expression of SKALP/elafin during wound healing in human skin.

Skin-derived antileukoproteinase (SKALP), also known as elafin, is a proteinase inhibitor with specificity for polymorphonuclear leucocyte (PMN)- derived elastase and proteinase-3. SKALP is absent in normal human epidermis, but is strongly induced in inflammatory dermatoses such as psoriasis. SKALP is putatively involved in the regulation of cutaneous inflammation by inhibiting PMN derived proteinases. The aim of this study was to investigate SKALP expression and PMN infiltration during wound healing in human skin. This was examined in healing excisional wounds in normal skin and in impaired healing in various types of chronic venous ulcers. Tissues were analysed using immunohistochemistry and Northern blot analysis. Healing of excisional wounds was studied from day 0 to day 14. An influx of PMN was seen rapidly after wounding and was maximal between day 2 and 4 and then subsided. SKALP was induced within 48 h and was expressed in the suprabasal keratinocytes of the wound edge and the migrating epidermal sheet. SKALP expression was maximal on day 4 and was downregulated at the time of complete reepithelialization (7-14 days). In venous ulcers, PMN were abundant in the wound bed and scarce under the wound edge. SKALP was strongly expressed in the keratinocytes of the wound edge in all types of ulcers studied. In the wound bed, SKALP was not detectable. Our results suggest that SKALP plays a role in the acute, inflammatory phase of wound healing. From the kinetics and topology of SKALP expression we surmise that it negatively regulates PMN infiltration.

Tenascin expression during wound healing in human skin.

In adult human skin, the expression of the extracellular matrix glycoprotein tenascin is limited. Under hyperproliferative conditions such as psoriasis and epidermal tumours, dermal tenascin expression is strongly upregulated. The aim of this study was to investigate the pattern and kinetics of tenascin expression in human skin during wound healing and to address the question of whether keratinocytes can directly interact with tenascin during re-epithelialization. Tenascin expression was investigated in excisional wounds in normal human skin, in explants of normal human skin, and in chronic venous ulcers, using immunohistochemistry. No tenascin staining was found directly underneath the leading edge of the sheet of migrating keratinocytes in the excisional wounds and explants. In the excisional wounds and the ulcers, dermal tenascin was strongly upregulated in areas adjacent to hyperproliferative epidermis. These hyperproliferative areas are located approximately 10-50 cells behind the leading edge, as assessed by staining for the Ki-67 antigen and the proliferating cell nuclear antigen (PCNA). At the later stages of normal wound healing and in the chronic ulcers, tenascin was also detected in the wound bed. In these areas, the dermal-epidermal junction stained positive for laminin but was negative for heparan sulphate. The absence of the latter basement membrane component suggests that the formation of a new basement membrane is not completed in these wounds. These findings suggest that tenascin is not a substrate for migrating keratinocytes; that the rapid induction of tenascin expression in the papillary dermis during wound healing results from interaction with the hyperproliferative epidermis; and that in the later stages of wound healing, keratinocytes can potentially interact with tenascin in the wound bed, because the basement membrane of the neo-epidermis is incomplete.