Evaluation of Skindex-16 construct validity in routinely collected psoriasis data: a retrospective analysis of the relationship between overall physician global assessment scores and Skindex-16 and measure discordance.

Patient-reported outcome measures (PROMs) capture disease severity metrics from the patient's perspective, including health-related quality of life (HRQL). Disease-specific validation of PROMs improves their clinical utility. We evaluated construct validity (HRQL) for Skindex-16 in routinely seen psoriasis patients and characterized instances of discordance between Skindex-16 scores and clinician-reported outcome measure of disease severity. We retrospectively studied psoriasis patients seen by University of Utah Dermatology from 2016 to 2020. Cross-sectional construct validity was assessed using quantile regression and Spearman correlation between overall physician global assessment (OPGA) score and Skindex-16 scores. Longitudinal within-subject correlation was performed using linear mixed models. Discordance (10th percentile or lower OPGA and 90th percentile or higher Skindex-16 score [clear skin, poor HRQL; cspHRQL] or the reverse [severe skin, good HRQL; ssgHRQL]) was characterized descriptively. 681 first-visit patients with psoriasis were included. Median overall Skindex-16 score varied by ≥ 10 points across all levels of OPGA scores. OPGA and Skindex-16 domain scores were moderately correlated (emotions ρ = 0.54, functioning ρ = 0.47, and symptoms ρ = 53). Longitudinal correlations were similar (emotion ρxy = 0.54, functioning ρxy = 0.65, symptoms ρxy = 0.47). Visits with cspHRQL discordance occurred for each Skindex-16 domain (emotions = 7, functioning = 13, symptoms = 12). The ssgHRQL group was observed within the emotions (n = 1) and functioning (n = 23) domains. Median Skindex-16 scores are different between different levels of OPGA and show moderate cross-sectional and longitudinal correlation. This supports construct validity in patients with psoriasis. Severe discordance was rare and most often for those with clear skin but poor HRQL. These discordances can prompt further patient-clinician conversation.

Efficacy and safety of ixekizumab in a randomized, double-blinded, placebo-controlled phase IIIb study of patients with moderate-to-severe genital psoriasis.

BACKGROUND: Genital psoriasis (GenPs) is a common, debilitating and difficult-to-treat manifestation of plaque psoriasis. However, few controlled, interventional studies of GenPs exist. OBJECTIVES: To determine the efficacy of ixekizumab vs. placebo in patients with moderate-to-severe GenPs with ≥ 1% involved body surface area (BSA). METHODS: Patients with moderate-to-severe GenPs, defined as a baseline static Physician's Global Assessment of Genitalia (sPGA-G) score of ≥ 3, with BSA ≥ 1% were randomized 1 : 1 to receive placebo (n = 74) or the recommended dosing of ixekizumab (n = 75). Major outcomes included the percentage of patients achieving 0 or 1 scores on the sPGA-G (primary end point), overall sPGA, GenPs Sexual Frequency Questionnaire (GenPs-SFQ) item 2, and ≥ 3-point improvement from baseline on the GenPs itch numerical rating scale. RESULTS: At week 12, ixekizumab was superior to placebo for sPGA-G 0/1 (73% vs. 8%, P < 0·001), overall sPGA 0/1 (73% vs. 3%, P < 0·001), GenPs-SFQ item 2 score of 0 or 1 (78% vs. 21%, P < 0·001) and genital itch (60% vs. 8%, P < 0·001). No candidiasis was reported, no deaths occurred and one (1%) serious adverse event was reported in a patient receiving placebo. CONCLUSIONS: Ixekizumab was superior to placebo for the treatment of moderate-to-severe GenPs with BSA ≥ 1%. The safety profile of ixekizumab was consistent with previous studies in moderate-to-severe plaque psoriasis.

Extension of ustekinumab maintenance dosing interval in moderate-to-severe psoriasis: results of a phase IIIb, randomized, double-blinded, active-controlled, multicentre study (PSTELLAR).

BACKGROUND: Phase III studies showed that some patients maintained response for ≥ 6 months following ustekinumab discontinuation. OBJECTIVES: To assess clinical responses with extended ustekinumab maintenance dosing intervals. METHODS: Adults with moderate-to-severe plaque psoriasis received ustekinumab at weeks 0, 4 and 16 during open-label treatment. Patients achieving a week-28 Physician's Global Assessment (PGA) score of cleared/minimal (PGA = 0/1) were randomized 1 : 4 to group 1 [approved every 12 weeks (q12 wk) maintenance] or group 2 (q12-24 wk; response-based dosing determined by time to loss of PGA = 0/1). Key end points included the number of visits with PGA = 0/1 (primary end point) and ≥ 75% improvement in Psoriasis Area and Severity Index (PASI 75) between weeks 88 and 112, and PGA/PASI responses between weeks 28 and 112. RESULTS: Overall, 378 patients achieved PGA = 0/1 at week 28 and were randomized to group 1 (n = 76) or group 2 (n = 302). Patients in group 1 had numerically greater mean numbers of visits with PGA = 0/1 than group 2 and also with PASI 75 from week 88 to 112. A higher proportion of patients in group 1 (55%) than group 2 (39%) had PGA = 0/1 at all seven visits from week 88 to 112. Maintenance of response was observed with dose-interval extension beyond q12 wk in a subset of patients. Extending the dosing interval did not affect antibody development or safety. CONCLUSIONS: Efficacy was better maintained among week-28 PGA responders randomized to continue q12 wk ustekinumab vs. extending maintenance dosing based on clinical response, although some patients maintained high levels of efficacy with up to q24 wk dosing.

Phase 3, open-label, randomized study of the pharmacokinetics, efficacy and safety of ixekizumab following subcutaneous administration using a prefilled syringe or an autoinjector in patients with moderate-to-severe plaque psoriasis (UNCOVER-A).

BACKGROUND: The efficacy of ixekizumab, an anti-interleukin-17A (anti-IL-17A) monoclonal IgG4 antibody, was demonstrated in moderate-to-severe psoriasis patients when administered via prefilled syringe (PFS). OBJECTIVE: To evaluate the effect of two drug delivery devices on the pharmacokinetics (PK) of ixekizumab as well as efficacy and safety with both devices. METHODS: In the first 12 weeks of an open-label, phase 3 study, moderate-to-severe psoriasis patients were randomized to ixekizumab delivery via PFS or autoinjector device. Randomization was stratified by weight (<80 kg, 80-100 kg, >100 kg), injection assistance (yes/no) and injection site (arm, thigh or abdomen). Following a 160-mg initial dose at week 0, patients received subcutaneous 80-mg ixekizumab as a single injection every 2 weeks for 12 weeks. Blood samples were collected following the initial 160-mg dose on days 2, 4, 7, 10 and 14 for PK analysis. Primary PK parameters were maximum concentration (Cmax ) and area under the curve (AUC0-tlast ) where tlast is the time of last sample (14 days ± 24 h). Efficacy was assessed by percent improvement on the Psoriasis Area and Severity Index (PASI) at week 12. Adverse event reporting, vital signs and clinical laboratory data were used to evaluate safety. RESULTS: Of 204 randomized patients, 192 were included in the PK analysis (PFS: 94; autoinjector: 98). The PFS and autoinjector showed similar geometric mean Cmax (90% CI) [15.0 µg/mL (13.9-16.1) vs. 14.8 µg/mL (13.8-15.9)] and geometric mean AUC0-tlast (90% CI) [157 µg × day/mL (147-168) vs. 154 µg × day/mL (144-165)]. When comparing Cmax and AUC0-tlast of the autoinjector to PFS, the geometric LS mean ratios were 0.97. At week 12, mean percent PASI improvement (via modified baseline observation carried forward) was similar with the PFS (89.3%) and autoinjector (86.9%). Both devices had safety results that were consistent with the known safety profile of ixekizumab. CONCLUSION: The PK, efficacy and safety of ixekizumab administered subcutaneously by PFS and autoinjector were similar. Clinicaltrials.gov number: NCT01777191 https://clinicaltrials.gov/ct2/show/NCT01777191.

Patient satisfaction with treatments for moderate-to-severe plaque psoriasis in clinical practice.

BACKGROUND: Treatment satisfaction among patients with moderate-to-severe psoriasis has not been studied and compared across treatments using a validated instrument. OBJECTIVES: To assess patient-reported satisfaction with systemic and phototherapy treatments for moderate-to-severe psoriasis in clinical practice and to correlate satisfaction with disease severity and quality-of-life measures. METHODS: This was a cross-sectional study of 1182 patients with moderate-to-severe psoriasis in the Dermatology Clinical Effectiveness Research Network in the U.S.A. Patients receiving either topical therapies only; monotherapy with oral systemic therapies, biologics or narrowband ultraviolet B phototherapy; or combination therapy with biologics and methotrexate completed the Treatment Satisfaction Questionnaire for Medication version II. RESULTS: Median unadjusted overall satisfaction scores were highest for patients receiving biologic monotherapies, biologic-methotrexate combinations, or phototherapy (83.3); scores were lowest for those receiving topical therapies only or acitretin (66.7). In fully adjusted models, compared with patients receiving methotrexate monotherapy, those receiving adalimumab, etanercept, ustekinumab, phototherapy or adalimumab with methotrexate had significantly higher median overall satisfaction scores by 7.2-8.3 points, while those receiving topical therapies only had significantly lower overall satisfaction by 8.9 points. Adjusted convenience scores were lowest for patients receiving topical therapies only or infliximab. Modest but significant correlations were found between the overall satisfaction subscale and both the Psoriasis Area and Severity Index (ρ = -0.36, P < 0.001) and the Dermatology Life Quality Index (ρ = -0.47, P < 0.001). CONCLUSIONS: Discernible differences were found in treatment satisfaction among therapies, particularly regarding treatment effectiveness and convenience. Further application of treatment satisfaction measures may inform treatment decisions and guideline development.

Can intensity of long-term follow-up for survivors of childhood and teenage cancer be determined by therapy-based risk stratification?

OBJECTIVE: To determine the feasibility of therapy-based, risk-stratified follow-up guidelines for childhood and teenage cancer survivors by evaluating adverse health outcomes in a survivor cohort retrospectively assigned a risk category. DESIGN: Retrospective cohort study. SETTING: Tertiary level, single centre, paediatric cancer unit in South East Scotland. PARTICIPANTS: All children and teenagers diagnosed with cancer (<19 years) between 1 January 1971 and 31 July 2004, who were alive more than 5 years from diagnosis formed the study cohort. Each survivor was retrospectively assigned a level of follow-up, based on their predicted risk of developing treatment-related late effects (LEs; levels 1, 2 and 3 for low, medium and high risk, respectively). Adverse health outcomes were determined from review of medical records and postal questionnaires. LEs were graded using the Common Terminology Criteria for Adverse Event, V.3. RESULTS: 607 5-year survivors were identified. Risk stratification identified 86 (14.2%), 271 (44.6%) and 250 (41.2%) as levels 1, 2 and 3 survivors, respectively. The prevalence of LEs for level 1 survivors was 11.6% with only one patient with grade 3 or above toxicity. 35.8% of level 2 survivors had an LE, of whom 9.3%, 58.8%, 18.5%, 10.3% and 3% had grades 1, 2, 3, 4 and 5 toxicity, respectively. 65.2% of level 3 survivors had LE, of whom 5.5% (n=9), 34.4% (n=56), 36.2% (n=59), 22.1% (n=36) and 1.8% (n=3) had grades 1, 2, 3, 4 and 5 toxicity, respectively. CONCLUSIONS: Therapy-based risk stratification of survivors can predict which patients are at significant risk of developing moderate-to-severe LEs and require high-intensity long-term follow-up. Our findings will need confirmation in a prospective cohort study that has the power to adjust for all potentially confounding variables.

Sleep quality and other patient-reported outcomes improve after patients with psoriasis with suboptimal response to other systemic therapies are switched to adalimumab: results from PROGRESS, an open-label Phase IIIB trial.

BACKGROUND: Psoriasis is associated with poor health-related quality of life, including sleep impairment. OBJECTIVE: To assess the extent of sleep impairment, the effect of adalimumab on sleep and other patient-reported outcomes, and correlations between changes in these outcomes and sleep quality in patients with psoriasis. METHODS: Patients in the 16-week, open-label, Phase IIIb PROGRESS trial had chronic plaque psoriasis and suboptimal response to prior therapy (etanercept, methotrexate or narrowband ultraviolet B phototherapy). Adalimumab was self-injected subcutaneously (80 mg at week 0, then 40 mg every other week from week 1). The focus for this analysis was the Medical Outcomes Study Sleep Scale. Other patient-reported outcomes included the Dermatology Life Quality Index (DLQI), Psoriasis Area and Severity Index (PASI), Physician's Global Assessment, a visual analogue scale for psoriasis/psoriatic arthritis (PsA) pain, and the Work Productivity and Activity Index Questionnaire-Specific Health Problems. RESULTS: Patients with psoriasis had impaired sleep at baseline. The degree of sleep impairment was significantly associated with the extent of work productivity for all sleep measures and, for some sleep measures, was associated with DLQI impairment, clinical severity measured by PASI, the presence of PsA, and depression. Adalimumab treatment significantly improved sleep quality by 15% from baseline, as well as DLQI score, pain and work productivity. The improvement in sleep was partially explained (R(2 ) = 0·16, P < 0·001) by improvements in the objectively measured psoriasis signs in PASI. CONCLUSIONS: Adalimumab treatment improved sleep outcomes and other patient-reported outcomes including health-related quality of life, work productivity, daily activity and disease-related pain.

Response to ustekinumab in a patient with both severe psoriasis and hypertrophic cutaneous lupus.

Psoriasis is an autoimmune inflammatory disease that has recently been treated with a novel treatment, ustekinumab, a human monoclonal antibody that targets the Th17 pathway. Discoid lupus is a subset of chronic cutaneous lupus erythematosus. Recent studies have suggested the Th17 pathway may be involved in cutaneous lupus. We present a case of a 41-year-old man with both severe psoriasis and hypertrophic discoid lupus treated with ustekinumab. After three doses of 45 mg subcutaneous injections at day 1, week 4, and week 16, his psoriasis plaques cleared and his hypertrophic discoid lupus plaques showed moderate improvement. Following a fourth dose of 90 mg his lupus plaques showed marked improvement. Ustekinumab may be a promising therapy for this and other forms of cutaneous lupus.

Survivors of childhood cancer lost to follow-up can be re-engaged into active long-term follow-up by a postal health questionnaire intervention.

UNLABELLED: Lifelong long-term follow-up (LTFU) is recommended for all survivors of childhood cancer. National guidelines recommend risk-stratified levels of follow-up by a multidisciplinary team, in an age-appropriate environment. Many survivors do not participate in long-term follow-up. OBJECTIVE: To re-engage childhood cancer survivors lost to follow-up in late effects programmes by means of postal questionnaire. POPULATION AND METHODS: Retrospective cohort study of all children (<19 years) diagnosed with cancer in a single institution in the UK between 1971 and 2003. All lost to follow-up survivors (not seen in clinic >2 years) were sent a postal health and well-being questionnaire. RESULTS: 831 patients were diagnosed with childhood cancer between 1971 and 2003, with 575 long-term survivors (overall survival rate 69%). Information was available on 550 survivors (males 290 (53%), median age (range) at review 18.8 (5.4-44.2) years and at diagnosis 5.0 (0.0-18.8) years, and disease free survival (range) was 10.8 (1.0-37.4) years. Of the 550 survivors, 256 (46%) were lost to follow-up. 99 (39%) of lost to follow-up survivors returned completed postal questionnaires (58% female). 45% of responders reported at least one late effect, 36% mild-moderate, and 8% severe-life threatening. 19% reported two or more late effects. 74% of all childhood cancer survivors are now in active follow-up. CONCLUSIONS: Almost half (46%) of all long-term survivors of childhood cancer are lost to follow-up, Postal follow-up is an effective means of re-engaging more than one third of survivors of childhood cancer in active long-term follow-up, half of whom had at least one late effect.

A short-term pharmacodynamic model for monitoring aggrecanase activity: injection of monosodium iodoacetate (MIA) in rats and assessment of aggrecan neoepitope release in synovial fluid using novel ELISAs.

OBJECTIVE: To develop a short-term in vivo model in rats, with an enzyme-linked immunosorbent assay (ELISA) readout for specific aggrecanase-cleaved aggrecan fragments, to facilitate testing of aggrecanase inhibitors. METHODS: Monosodium iodoacetate (MIA), a metabolic inhibitor, was injected into the right knee joint of male Lewis rats and the release of aggrecanase-cleaved fragments of aggrecan containing the NITEGE or ARGN neoepitope was measured in the synovial fluid at 7 days post MIA injection using novel ELISAs. The ELISAs utilize a commercial antibody directed against the hyaluronic-acid binding region (HABR) of aggrecan, in combination with either an alpha-NITEGE antibody (NITEGE ELISA) or an alpha-ARGS/BC3 antibody (ARGS ELISA), to detect aggrecanase-cleavage of aggrecan within the interglobular domain (IGD). Aggrecan fragments present in in vitro digests, in cytokine-treated cartilage explant culture supernatants and in rat synovial fluid lavage samples were detected and quantified using the two ELISAs. Small molecule inhibitors of aggrecanase activity were dosed orally on days 3-7 to determine their ability to inhibit MIA-induced generation of the NITEGE and ARGN neoepitopes measured in the rat synovial fluid. RESULTS: The NITEGE assay was shown to specifically detect the N-terminal fragment of aggrecan comprising the G1 domain and the NITEGE neoepitope sequence. This assay can readily measure aggrecanase-cleaved bovine, human and rat aggrecan without the need for deglycosylation. The ARGS assay specifically detects C-terminal fragments of aggrecan comprising the ARGS/ARGN neoepitope and the G2 domain. Keratan sulfate (KS) residues of aggrecan interfere with this ELISA, and hence this assay works well with native rat articular cartilage aggrecan (that lacks KS residues) and with deglycosylated bovine and human aggrecan. Injection of MIA into the rat knee joints resulted in a time-dependent increase in the release of aggrecanase-cleaved aggrecan fragments into the synovial fluid and treatment with an aggrecanase inhibitor resulted in a dose-dependent inhibition of the generation of these neoepitopes. CONCLUSIONS: We have established a short-term in vivo model in rats that involves measurement of synovial fluid biomarkers that are dependent on aggrecanase activity in the joint. The short duration of the model combined with the mechanistic biomarker readout makes it very useful for the initial in vivo screening of aggrecanase inhibitors prior to testing them in time and resource-intensive disease models of osteoarthritis (OA).

Development of a novel clinical biomarker assay to detect and quantify aggrecanase-generated aggrecan fragments in human synovial fluid, serum and urine.

OBJECTIVE: Proteolytic degradation of aggrecan in articular cartilage is a hallmark feature of osteoarthritis (OA). The present study was aimed at developing a sensitive enzyme linked immunosorbent assay (ELISA) for the detection of aggrecanase-cleaved fragments of aggrecan in human serum and urine to facilitate the clinical development of aggrecanase inhibitors for OA. METHODS: The BC3 monoclonal antibody that detects the ARGS neoepitope sequence in aggrecanase-cleaved aggrecan was engineered and optimized using complementarity determining region (CDR)-saturation mutagenesis to improve its binding affinity to the neoepitope. A sandwich ELISA (BC3-C2 ELISA) was developed using the optimized alpha-ARGS antibody (BC3-C2) as capture antibody and a commercially available antibody directed against the hyaluronic-acid binding region (HABR) of aggrecan as detection antibody. Aggrecanase-cleaved fragments of aggrecan present in in vitro digests, human cartilage explant culture supernatants and in human synovial fluid, serum and urine were detected and quantified using this ELISA. RESULTS: The optimized antibody had a 4-log improvement in affinity for the ARGS containing peptide compared to the parental BC3 antibody, while maintaining the ability to not cross-react with a spanning peptide. The BC3-C2 ELISA demonstrated the ability to detect aggrecanase-cleaved aggrecan fragments in the native state, without the need for deglycosylation. This ELISA was able to measure aggrecanase-generated ARGS containing aggrecan fragments in human articular cartilage (HAC) explant cultures in the basal state (without cytokine stimulation). Treatment with an aggrecanase inhibitor resulted in a dose-dependent inhibition of ARGS neoepitope released into the culture supernatant. The ELISA assay also enabled the detection of ARGS containing fragments in human synovial fluid, serum and urine, suggesting its potential utility as a biomarker of aggrecanase activity. CONCLUSIONS: We have developed a novel ELISA using an optimized ARGS antibody and have demonstrated for the first time, an ELISA-based measurement of aggrecan degradation products in human serum and urine. This assay has the potential to serve as a mechanistic drug activity biomarker in the clinic and is expected to significantly impact/accelerate the clinical development of aggrecanase inhibitors and other disease modifying drugs for OA.

The forkhead transcription factor FOXL2 is expressed in somatic cells of the human ovary prior to follicle formation.

Interactions between germ cells and surrounding somatic cells are central to ovarian development as well as later function. Disruption of these interactions arising from abnormalities in either cell type can lead to premature ovarian failure (POF). The forkhead transcription factor FOXL2 is a candidate POF factor, and mutations in the FOXL2 gene are associated with syndromic and non-syndromic ovarian failure. Foxl2-deficient mice display major defects in primordial follicle activation with consequent follicle loss, and earlier roles in gonadal development and sex determination have also been suggested. However, despite its importance no data presently exist on its expression in the developing human ovary. Expression of FOXL2 mRNA was demonstrated in the human fetal ovary between 8 and 19 weeks gestation, thus from soon after sex determination to primordial follicle development. Expression in the ovary was higher after 14 weeks than at earlier gestation weeks and was very low in the fetal testis at all ages examined. Immunolocalization revealed FOXL2 expression to be confined to somatic cells, both adjacent to germ cells and those located in the developing ovarian stroma. These cells are the site of action of oocyte-derived activin signalling, but in vitro treatment of human fetal ovaries with activin failed to reveal any regulation of FOXL2 transcription by this pathway. In summary, the expression of FOXL2 in somatic cells of the developing human ovary before and during follicle formation supports a conserved and continuing role for this factor in somatic/germ cell interactions from the earliest stages of human ovarian development.

Biochemical markers and the FDA Critical Path: how biomarkers may contribute to the understanding of pathophysiology and provide unique and necessary tools for drug development.

The aim of this review is to discuss the potential usefulness of a novel class of biochemical markers, neoepitopes, in the context of the US Food and Drug Administration (FDA) Critical Path Initiative, which emphasizes biomarkers of safety and efficacy as areas of pivotal interest. Examples of protein degradation fragments--neoepitopes--that have proven useful for research on bone and cartilage are collagen type I and collagen type II degradation products, respectively. These markers have utility in the translational approach, as they can be used to estimate safety and efficacy in both preclinical models and clinical settings. Biochemical markers of tissue degradation may provide optimal tools, which in combination with other techniques, prove essential to drug discovery and development.

Plaque thickness and morphology in psoriasis vulgaris associated with therapeutic response.

BACKGROUND: The Utah Psoriasis Initiative (UPI) is an expanding database that is being used to identify and characterize phenotypic variants of psoriasis and explore genotype-phenotype relationships. We recently reported distinct morphological variants of psoriasis that are characterized by thickness of lesions (induration) in the untreated state. OBJECTIVES: To explore the clinical relevance of these morphological variants. METHODS: For these analyses, we used the phenotypic data from 282 additional subjects gathered at enrollment into the UPI and compared their phenotype with that of the original 500 patients reported previously. The analysis was further expanded via a longitudinal follow-up of 286 subjects from the original 500 case cohort. RESULTS: Firstly, the initial findings were confirmed. Expansion of the cohort used for the original observation by about 50% and reanalysis showed that there was no alteration in the proportions of patients expressing thin- and thick-plaque disease phenotypes. Secondly, analysis of the larger cohort showed that this morphological phenotype had clinical relevance: those patients with thin-plaque disease were more likely to report a complete therapeutic response to topical corticosteroids and phototherapy. In contrast, plaque thickness did not appear to be a factor in response to systemic agents. CONCLUSIONS: Using a patient's baseline plaque morphology to choose a primary treatment modality may result in earlier disease improvement and reduce the cost of therapy.

Detailed genetic characterization of the interleukin-23 receptor in psoriasis.

Using a multi-tiered, case-control association design, scanning 25 215 gene-centric SNPs, we previously identified two psoriasis susceptibility genes: IL12B and IL23R. These results have recently been confirmed. To better characterize the IL23R psoriasis-association, we used a fine mapping strategy to identify 59 additional IL23R-linked SNPs, which were genotyped in our three independent, white North American sample sets (>2800 individuals in toto). A sliding window of haplotype association demonstrates colocalization of psoriasis susceptibility effects within the boundaries of IL23R across all sample sets, thereby decreasing the likelihood that neighboring genes, particularly IL12RB2, are driving the association at this region. Additional haplotype work identified two 5-SNP haplotypes with strong protective effects, consistent across our three sample sets (OR(common)=0.67; P(comb)=4.32E-07). Importantly, heterogeneity of effect was extremely low between sample sets for these haplotypes (P(Het)=0.961). Together, these protective haplotypes attain a frequency of 16% in controls, declining to 11% in cases. The characterization of association patterns within IL23R to specific predisposing/protective variants will play an important role in the elucidation of psoriasis etiology and other related phenotypes. Further, this work is essential to lay the foundation for the role of IL23R genetics in response to pharmaceutical therapy and dosage.

Variants in the 5q31 cytokine gene cluster are associated with psoriasis.

A multitiered genetic association study of 25 215 single-nucleotide polymorphisms (SNPs) in three case-control sample sets (1446 patients and 1432 controls) identified three IL13-linked SNPs (rs1800925, rs20541 and rs848) associated with psoriasis. Although the susceptibility effects at these SNPs were modest (joint allelic odds ratios (ORs): 0.76 to 0.78; P(comb): 1.3E-03 to 2.50E-04), the association patterns were consistent across the sample sets, with the minor alleles being protective. Haplotype analyses identified one common, susceptible haplotype CCG (joint allelic OR=1.27; P(comb)=1.88E-04) and a less common, protective haplotype TTT (joint allelic OR=0.74; P(comb)=7.05E-04). In combination with the other known genetic risk factors, HLA-C, IL12B and IL23R, the variants reported here generate an 11-fold psoriasis-risk differential. Residing in the 5q31 cytokine gene cluster, IL13 encodes an important T-cell-derived cytokine that regulates cell-mediated immunity. These results provide the foundation for additional studies required to fully dissect the associations within this cytokine-rich genomic region, as polymorphisms in closely linked candidate genes, such as IRF1, IL5 or IL4, may be driving these results through linkage disequilibrium.

Thresholds of potential concern as benchmarks in the management of African savannahs.

In the Kruger National Park (KNP), South Africa, ecosystem managers use a series of monitoring endpoints, known as thresholds of potential concern (TPCs), to define the upper and the lower levels of accepted variation in ecosystems. For woody vegetation, the current TPC suggests that woody cover should not drop by more than 80% of its 'highest ever' value. In this paper, we explore the utility of palaeoecological data in informing TPCs. We use calibrated fossil pollen data to explore variability in vegetation at two sites over the past 5000 years, to provide a long-term record of changes in woody vegetation cover and a context for interpreting more recent vegetation change. The fossil pollen data are calibrated using studies of modern pollen and vegetation from KNP; arboreal pollen percentage was simulated using pollen-landscape modelling software for savannah landscapes of varying woody vegetation cover, and the relationship between vegetation and pollen data was quantified using nonlinear regression. This quadratic equation was then applied to fossil pollen data in order to estimate woody vegetation cover from arboreal pollen percentages. Our results suggest that the TPCs have not been exceeded during the period represented in the pollen record, because estimated woody vegetation cover has remained above 20% of its highest ever value. By comparing the fossil pollen data with TPCs, our study demonstrates how palaeoecological data can be presented in a form that is directly relevant to management objectives.

NXY-059, a free radical--trapping agent, substantially lessens the functional disability resulting from cerebral ischemia in a primate species.

BACKGROUND AND PURPOSE: NXY-059 is a novel nitrone with free radical-trapping properties that has a considerable neuroprotective effect in rats. We have now examined the efficacy of this drug at reducing long-term functional disability in a primate model of stroke. METHODS: Twelve monkeys were trained and tested on a variety of behavioral tasks used to dissociate and quantify motor and spatial deficits. Five minutes after permanent occlusion of the right middle cerebral artery, monkeys received a 1-mL intravenous infusion of either saline or NXY-059 (28 mg x kg(-1)), and osmotic minipumps, model 2001D, were implanted subcutaneously to provide continuous drug or saline infusion for 48 hours. Drug-filled pumps released NXY-059 at 16 mg x kg(-1) x h(-1). The monkeys were retested 3 and 10 weeks after surgery to assess functional disability. Surgery, behavioral testing, and histology were all done blinded to treatment condition. RESULTS: NXY-059-treated monkeys were significantly better at reaching with their hemiparetic arm than were saline-treated monkeys when retested 3 weeks (P:<0.01) and 10 weeks (P:<0.01) after surgery. Drug treatment also significantly lessened the degree of spatial perceptual neglect (P:<0.01), a debilitating though ameliorating consequence of this infarct. NXY-059 treatment reduced the overall amount of brain damage by >50% of saline-treatment values, with similar levels of protection afforded to both white and gray matter. CONCLUSIONS: This novel drug has a substantial protective effect, lessening the disability caused by an experimentally induced stroke in a primate species. These findings provide considerable encouragement for the clinical development of NXY-059.