A continuous epistasis model for predicting growth rate given combinatorial variation in gene expression and environment

Quantifying and predicting growth rate phenotype given variation in gene expression and environment is complicated by epistatic interactions and the vast combinatorial space of possible perturbations. We developed an approach for mapping expression-growth rate landscapes that integrates sparsely sampled experimental measurements with an interpretable machine learning model. We used mismatch CRISPRi across pairs and triples of genes to create over 8,000 titrated changes in E. coli gene expression under varied environmental contexts, exploring epistasis in up to 22 distinct environments. Our results show that a pairwise model previously used to describe drug interactions well-described these data. The model yielded interpretable parameters related to pathway architecture and generalized to predict the combined effect of up to four perturbations when trained solely on pairwise perturbation data. We anticipate this approach will be broadly applicable in optimizing bacterial growth conditions, generating pharmacogenomic models, and understanding the fundamental constraints on bacterial gene expression. A record of this paper's transparent peer review process is included in the supplemental information.

Adenosine metabolic signature in circulating CD4+ T cells predicts remission in rheumatoid arthritis

OBJECTIVES

Long-term outcomes in rheumatoid arthritis (RA) depend on early and effective disease control. Methotrexate (MTX) remains the first-line disease modifying therapy, however there are no biomarkers with which to identify those most likely to achieve remission. To address this unmet need we explored metabolic pathways involved in MTX mechanism of action within circulating CD4+T cells in a cohort of treatment naive patients with early RA.

METHODS

Purified CD4+T cells were isolated from peripheral blood of 68 patients with early RA commencing MTX. The expression of a range of putative MTX metabolism and mechanism of action targets were explored by flow-cytometry and transcriptional analysis. From these data significant predictors of Disease Activity Score 28-C reactive protein (DAS28-CRP) remission (<2.4 at 6 months) were determined by logistic regression (clinical; flow-cytometry data) and linear modelling (gene expression data).

RESULTS

Low baseline DAS28-CRP was associated with remission at 6 months (p=0.02). Expression of the ectonucleotidase CD39, involved in ATP-ADP conversion during adenosine synthesis, was higher on CD4+CD25 High regulatory T cells at baseline in those achieving remission (molecules of equivalent fluorescence 1264 vs 847; p=0.007). Expression of other adenosine signalling elements in CD4+T cells were also upregulated at baseline in patients achieving remission: AMPD1 (p<0.001), ADORA2b (p=0.039) and ADORA3 (p=0.047). When combined into a single predictive metric, a combination of these variables outperformed baseline DAS28-CRP in prediction of early remission (area under the curve 0.92 vs 0.67, p=0.001) CONCLUSIONS: Adenosine signalling is important in the achievement of early remission with MTX in RA and biomarkers of adenosine activity may hold utility for the stratification of therapy in early disease.

Targeting the Aryl Hydrocarbon Receptor to Address the Challenges of Atopic Dermatitis

Atopic dermatitis (AD) is a chronic relapsing–remitting disease with a multifactorial etiology involving epidermal barrier and immunologic dysfunction. Topical therapies form the mainstay of AD treatment, but options are limited by adverse effects and restrictions on application site, duration, and extent of use. Tapinarof (VTAMA; Dermavant Sciences, Inc.) is a first-in-class, non-steroidal, topical aryl hydrocarbon receptor (AhR) agonist approved for the treatment of plaque psoriasis. AhR is a ligand-dependent transcription factor with wide-ranging roles, including regulation of homeostasis and immune response in skin cells. AhR expression and signaling are altered in many inflammatory skin diseases, and clinical trials with tapinarof have validated AhR as a therapeutic target capable of delivering significant efficacy. Tapinarof cream 1% once daily demonstrated efficacy versus vehicle in adults and adolescents with AD and is being investigated in the ADORING trials for the treatment of AD in adults and children down to 2 years of age. J Drugs Dermatol. 2024;23(2):23-28.  doi:10.36849/JDD.8026.

Rapid Improvements in Itch with Tapinarof Cream 1% Once Daily in Two Phase 3 Trials in Adults with Mild to Severe Plaque Psoriasis

INTRODUCTION

Patients with psoriasis report pruritus as their most bothersome symptom. Tapinarof cream 1% once daily demonstrated significant efficacy versus vehicle and was well tolerated in adults with mild to severe plaque psoriasis in two 12-week trials: PSOARING 1 (NCT03956355) and PSOARING 2 (NCT03983980). Here, we present patient-reported pruritus outcomes from these trials.

METHODS

Outcomes included a Peak Pruritus Numerical Rating Scale (PP-NRS) score of 0 or 1 (itch-free state); Dermatology Life Quality Index (DLQI) itch item scores; and Psoriasis Symptom Diary (PSD) itch item scores.

RESULTS

Analyses included 683 tapinarof- and 342 vehicle-treated patients. At baseline, mean pruritus scores were similar across trials with only 7-11% of patients reporting an itch-free state. At week 12, the proportion of tapinarof-treated patients achieving an itch-free state was 50% in both trials compared with 32% (P = 0.0007) and 27% (P < 0.0001) in the vehicle groups. Improvements were apparent at the earliest assessments with continued improvement over the course of the trials. There were rapid and statistically significant improvements in the proportion of patients with a ≥ 4-point improvement in PP-NRS for tapinarof-treated patients versus vehicle from week 2 with 68% vs 46% (P = 0.0004) and 60% vs 31% (P = 0.0001) at week 12 achieving a response in each trial. Significantly greater reductions in itch with tapinarof versus vehicle were also demonstrated at week 12 for DLQI itch item 1 (P = 0.0026 and P < 0.0001), PSD item 1 (both P < 0.0001), and PSD item 2 (both P < 0.0001).

CONCLUSION

Tapinarof was highly efficacious in reducing pruritus across multiple patient-reported outcome measures, with rapid, statistically significant, and clinically meaningful improvements. The high proportion of patients achieving the treatment target of an itch-free state at week 12 (50%) is a noteworthy clinical outcome for a non-steroidal topical cream in the treatment of mild to severe plaque psoriasis.

TRIAL REGISTRATION

Clinical trial registration information: NCT03956355, NCT03983980.

Tapinarof validates the aryl hydrocarbon receptor as a therapeutic target: A clinical review

The aryl hydrocarbon receptor (AhR) is a ligand-dependent transcription factor that has wide-ranging roles, including regulation of inflammation and homeostasis. AhR is not a cell surface receptor; rather, it exists in a cytoplasmic complex that responds to a wide variety of structurally dissimilar endogenous, microbial, and environmental ligands. The ubiquitous expression of AhR, its ability to be activated by a wide range of ligands, and its capacity to act as a master regulator for gene expression and homeostasis make it a promising new therapeutic target. Clinical trials of tapinarof cream have now validated AhR agonism as a therapeutic approach that can deliver significant efficacy for treating inflammatory skin diseases, including psoriasis and atopic dermatitis. Tapinarof 1% cream is a first-in-class, nonsteroidal, topical, AhR agonist with a pharmacokinetic profile that results in localized exposure at sites of disease, avoiding systemic safety concerns, drug interactions, or off-target effects. Psoriasis and atopic dermatitis both involve epidermal inflammation, cellular immune responses, dysregulation of skin barrier protein expression, and oxidative stress. On the basis of the clinical effectiveness of tapinarof cream for treating inflammatory skin diseases, we review how targeting AhR may offer a significant opportunity in other conditions that share key aspects of pathogenesis, including asthma, inflammatory bowel disease, eosinophilic esophagitis, ophthalmic, and nervous system diseases.

Tapinarof cream 1% once daily for the treatment of plaque psoriasis: Patient-reported outcomes from the PSOARING 3 trial

BACKGROUND

Tapinarof cream 1% once daily demonstrated significant efficacy versus vehicle and was well tolerated in two 12-week, phase 3 pivotal trials in adults with mild-to-severe plaque psoriasis.

OBJECTIVE

To assess long-term, health-related quality of life and patient satisfaction with tapinarof.

METHODS

Patients completing the 12-week trials were eligible for 40 weeks of open-label tapinarof based on Physician Global Assessment score in PSOARING 3, with a 4-week follow-up. Dermatology Life Quality Index was assessed at every visit; Patient Satisfaction Questionnaire responses were assessed at week 40 or early termination.

RESULTS

Seven hundred sixty-three (91.6%) eligible patients enrolled; 78.5% completed the Patient Satisfaction Questionnaire. DLQI scores improved and were maintained. By week 40, 68.0% of patients had a DLQI of 0 or 1, indicating no impact of psoriasis on health-related quality of life. Most patients strongly agreed or agreed with all Patient Satisfaction Questionnaire questions assessing confidence in tapinarof and satisfaction with efficacy (62.9%-85.8%), application ease and cosmetic elegance (79.9%-96.3%), and preference for tapinarof versus prior psoriasis therapies (55.3%-81.7%).

LIMITATIONS

Open-label; no control; may not be generalizable to all forms of psoriasis.

CONCLUSIONS

Continued and durable improvements in health-related quality of life, high rates of patient satisfaction, and positive perceptions of tapinarof cream were demonstrated.

Micro-RNA content of circulating extracellular vesicles in early rheumatoid arthritis as biomarkers and mediators of methotrexate efficacy

OBJECTIVES

Extracellular vesicles (EVs) are abundant in body fluids, contributing to intercellular signalling by transferring cargo that includes microRNAs (miRs) - themselves implicated in pathobiology. For the first time we evaluated the potential of EV miRs to contribute diagnostic information in early RA, predict methotrexate (MTX) efficacy or shed light on the drug's mechanism of action.

METHODS

798 miRs isolated from serum-derived EVs of 46 patients with untreated RA, 23 with untreated polymyalgia rheumatica (PMR; inflammatory disease control group) and 12 in whom significant inflammatory disease had been excluded (non-inflammatory controls; NICs) were profiled (Nanostring); the same measurements were made for RA patients after 6 months' MTX treatment. Analyses took multiple testing into account.

RESULTS

28 EV miRs were robustly differentially expressed between early RA (but not PMR) patients and NICs after correction for age and sex, suggesting discriminatory value. Cross-validated partial least squared-discriminant analysis also indicated the predictive potential of a distinct baseline EV miR signature with respect to MTX-induced remission at 6 months. The change in expression of 13 miRs over the course of MTX treatment differed significantly between responders and non-responders, and four of those exhibiting increased relative abundance amongst responders have known roles in regulating the pathogenic potential of synovial fibroblasts, namely miR-212-3p, miR-338-5p, miR-410-3p, and miR-537.

CONCLUSION

Our data highlight the potential of serum EV miRs as diagnostic and therapeutic biomarkers, highlighting a novel potential mechanism via which MTX may exert its therapeutic effect in early RA that warrants further investigation.

Tapinarof Cream 1% Once Daily for the Treatment of Plaque Psoriasis: Case Photography of Clinical Outcomes from Three Phase 3 Trials

Tapinarof cream 1% (VTAMA®; Dermavant Sciences, Inc.) is a non-steroidal, topical, aryl hydrocarbon receptor agonist approved by the US Food and Drug Administration (FDA) to treat plaque psoriasis in adults and under investigation for the treatment of psoriasis in children down to 2 years of age, and for atopic dermatitis in adults and children down to 2 years of age. The PSOARING phase 3 clinical trial program evaluated tapinarof cream 1% once daily (QD) in adults with mild to severe plaque psoriasis for up to 52 weeks (NCT03956355, NCT03983980, NCT04053387). Here we present case photography documenting outcomes in the PSOARING trials. Cases illustrate various outcomes across different body areas, including responses meeting the formal FDA-mandated regulatory endpoint of a Physician Global Assessment (PGA) score of 0 (clear) or 1 (almost clear) and a decrease of at least 2 points from baseline at week 12, meaningful clinical improvement not meeting this formal endpoint, patient-reported outcomes, and pre-specified adverse events of special interest (AESIs). Tapinarof cream 1% QD demonstrated rapid and highly statistically significant efficacy, with improvements in disease activity and quality of life. In addition, a high rate (40.9%; n = 312/763) of complete disease clearance (PGA = 0) was achieved, and improvements exceeding National Psoriasis Foundation treatment goals were demonstrated. After first achieving complete disease clearance (PGA = 0), patients treated with tapinarof experienced an approximately 4-month remittive effect off therapy. Incidence and severity of folliculitis and contact dermatitis AESIs were generally mild or moderate, localized to the site of application, and associated with low discontinuation rates. Medical images are of importance in trials of dermatologic therapies to inform clinical decision-making and enhance patient assessment. Tapinarof cream 1% QD is efficacious and well tolerated in patients with mild to severe plaque psoriasis, with clinically relevant improvements seen early in the course of treatment.Clinicaltrials.gov numbers: NCT03956355, NCT03983980, NCT04053387.

301 Tapinarof cream 1% once daily for the treatment of extensive atopic dermatitis in adolescents and children: 4-week maximal use trial

There is a need for efficacious non-steroidal topical therapies for atopic dermatitis (AD) without restrictions relating to duration, the extent of use and application sites. Tapinarof (VTAMA®; Dermavant Sciences, Inc., USA) is a first-in-class, non-steroidal, topical, aryl hydrocarbon receptor agonist approved by the Food and Drug Administration for the treatment of plaque psoriasis in adults and under investigation for the treatment of psoriasis in children down to 2 years of age and for AD in adults and children down to 2 years of age. Tapinarof cream 1% once daily (QD) demonstrated significant efficacy vs. vehicle at 12 weeks and was well tolerated in adults and adolescents and with moderate to severe AD in a previously reported phase 2b trial (NCT02564055). To assess the safety, tolerability, pharmacokinetics (PK) and efficacy of tapinarof cream 1% QD in adolescents and children with extensive AD. In this open-label, maximal use, phase 2 trial (NCT05186805), adolescents and children, aged 2–17 years, with a clinical diagnosis of AD, a validated Investigator Global Assessment in Atopic Dermatitis™ (vIGA-AD™) score ≥3, and percent body surface area (%BSA) involvement of ≥ 25% for adolescents (12–17 years) or ≥35% for children (2–11 years) were assigned tapinarof cream 1% QD for 27 days. Primary endpoints include adverse events, mean investigator-assessed local tolerability scores (overall and sensitive areas) and PK parameters. Secondary endpoints include a change in vIGA-AD™, Eczema Area Severity Index (EASI), %BSA affected, and Peak Pruritus-Numeric Rating Scale scores at each trial visit. Eligible patients completing this trial have the option to enrol in an open-label, long-term extension trial (NCT05142774) to receive up to an additional 48 weeks of tapinarof cream 1% QD treatment. Overall, 36 patients aged 2–17 years were enrolled at nine sites in the US and Canada. Of these patients, equal proportions (33.3% [12/36]) were young children (2–6 years), children (7–11 years) and adolescents (12–17 years); 66.7% (24/36) were male and mean age (standard deviation [SD]) was 8.9 (4.9) years. At baseline, 77.8% (28/36) had a vIGA-AD™ score of 3 (moderate) and 8/36 (22.2%) had a score of 4 (severe). At baseline, the mean (SD) %BSA affected was 52.4% (19.1%), 42.0% (10.0%) and 33.9% (8.6%) for young children, children and adolescents, respectively. The overall mean (SD) EASI score was 23.8 (9.2). This trial will assess the safety, tolerability, PK and efficacy of tapinarof cream 1% QD in 36 adolescents and children down to 2 years of age with extensive, moderate-to-severe AD.

One-year safety and efficacy of tapinarof cream for the treatment of plaque psoriasis: Results from the PSOARING 3 trial

BACKGROUND

Tapinarof cream 1% once daily, an aryl hydrocarbon receptor-modulating agent, was significantly more efficacious than vehicle and well tolerated in two 12-week phase 3 trials in adults with mild to severe plaque psoriasis.

OBJECTIVE

To assess long-term safety, efficacy, remittive effect, durability of response, and tolerability of tapinarof.

METHODS

Patients completing the 12-week trials were eligible for 40-weeks' open-label treatment and 4-weeks' follow-up. Treatment was based on the Physician Global Assessment (PGA) score. Patients entering with PGA≥1 received tapinarof until PGA = 0. Patients with PGA = 0 discontinued tapinarof and were monitored for remittive effect. Patients with PGA≥2 were re-treated until PGA = 0.

RESULTS

Overall, 91.6% (n = 763) of eligible patients enrolled; 40.9% of patients achieved complete disease clearance (PGA = 0), and 58.2% entering with PGA≥2 achieved PGA = 0 or 1. Mean duration of off therapy remittive effect for patients achieving PGA = 0 was 130.1 days. No new safety signals were observed. Most frequent adverse events were folliculitis (22.7%), contact dermatitis (5.5%), and upper respiratory tract infection (4.7%).

LIMITATIONS

Open-label; no control; may not be generalizable to all forms of psoriasis; remittive effect/response rate potentially underestimated.

CONCLUSIONS

Efficacy improved beyond the 12-week trials, with a 40.9% complete disease clearance rate, ∼4-month off therapy remittive effect, durability on therapy, and consistent safety.

OA26 Erythrocyte mean corpuscular volume as a surrogate marker for methotrexate polyglutamation during early treatment in rheumatoid arthritis

Background/Aims

The long-term outcomes for patients with rheumatoid arthritis (RA) depend on early and effective disease control. Methotrexate remains the key first-line disease-modifying therapy for the majority of patients. The gradual onset of action of methotrexate has been proposed to be linked to the build-up of intracellular stores of the drug, achieved through the process of polyglutamation. This is a complex and expensive assay. Recent work has shown an association between the increase in mean corpuscular volume (MCV) of erythrocytes and improvements in disease activity. This study seeks to relate intracellular methotrexate and 5-methyl-tetrahydrofolate polyglutamate concentrations with changes in MCV and their association with early ‘steroid free’ remission in RA patients.

Methods

68 drug-naïve, newly diagnosed RA patients were recruited form the Newcastle Early Arthritis Clinic (NEAC). These patients were followed up for 6 months with serial blood sampling and quantification of the erythrocyte methotrexate and 5-methyl-tetrahydrofolate polyglutamate levels by liquid chromatography-mass spectrometry (LC-MS). This was then related to the contemporaneous erythrocyte MCV values from the clinical monitoring bloods on those occasions and the treatment outcome at 6 months. The outcome measure used was 4 component DAS28CRP remission (&lt;2.4) with only the baseline intramuscular steroid permitted for the definition of remission.

Results

The majority of patients displayed a gradual increase in MCV over the first 6 months of treatment (MCV change from patient baseline used to normalise the data). When grouped by the ‘steroid free’ remission outcome, there was a divergence in MCV change with greater MCV increases observed in those achieving remission from 4 months of treatment onward (p &lt; 0.05). In the same patient group, the accumulation of longer chain methotrexate polyglutamates (chain length 3 to 5) was observed to follow a similar trend to MCV with higher polyglutamate concentrations in those achieving the remission outcome from 2 months of treatment (P &lt; 0.05). When the contemporaneous MCV and MTX polyglutamate samples were compared, an association was observed between the longer chain MTX polyglutamates and the change in MCV values (R2 = 0.39, p &lt; 0.001), but not between intracellular 5-methyl-tetrahydrofolate and MCV (R2 = 0.01, p = NS).

Conclusion

Change in MCV shows an association with early remission induction with MTX therapy in treatment-naïve RA patients. This change in MCV appears to be associated with the accumulation of intracellular MTX metabolites, rather than via depletion of intracellular folates. MCV may therefore represent a tractable proxy measure of methotrexate polyglutamation for application in larger studies or for the purpose of drug monitoring.

Disclosure

P.M. Brown: None. A.G. Pratt: None. A.E. Anderson: None. A.W. Morgan: None. J.D. Isaacs: None.

Phase 3 Trials of Tapinarof Cream for Plaque Psoriasis

BACKGROUND

Tapinarof cream is a topical aryl hydrocarbon receptor-modulating agent under investigation for the treatment of psoriasis. Tapinarof modulates the expression of interleukin-17 and the skin-barrier proteins filaggrin and loricrin.

METHODS

We conducted two identical phase 3 randomized trials of tapinarof in patients with mild-to-severe plaque psoriasis. Adults with a baseline Physician's Global Assessment (PGA) score of 2 (mild) to 4 (severe) (on a scale from 0 to 4, with higher scores indicating more severe psoriasis) and a percent of total body-surface area affected of 3 to 20% were randomly assigned in a 2:1 ratio to use tapinarof 1% cream or vehicle cream once daily for 12 weeks. The primary end point, PGA response, was a PGA score of 0 (clear) or 1 (almost clear) and a decrease from baseline of at least 2 points at week 12. Secondary efficacy end points at week 12 were a reduction of at least 75% in the Psoriasis Area and Severity Index (PASI) score, a PGA score of 0 or 1, the mean change from baseline in the percent of body-surface area affected, and a reduction of at least 90% in the PASI score. Patient-reported outcomes were the mean changes from baseline to week 12 in the proportion of patients who had a decrease of at least 4 points in the Peak Pruritus Numeric Rating Scale (PP-NRS) score (range, 0 [no itch] to 10 [worst imaginable itch]), the PP-NRS total score, the Dermatology Life Quality Index total score, and the Psoriasis Symptom Diary score.

RESULTS

In trials 1 and 2, a total of 692 and 674 patients, respectively, were screened, with 510 and 515 patients being enrolled. A PGA response occurred in 35.4% of the patients in the tapinarof group and in 6.0% of those in the vehicle group in trial 1 and in 40.2% and 6.3%, respectively, in trial 2 (P<0.001 for both comparisons). Results for secondary end points and patient-reported outcomes were generally in the same direction as those for the primary end point. Adverse events with tapinarof cream included folliculitis, nasopharyngitis, contact dermatitis, headache, upper respiratory tract infection, and pruritus.

CONCLUSIONS

Tapinarof 1% cream once daily was superior to vehicle control in reducing the severity of plaque psoriasis over a period of 12 weeks but was associated with local adverse events and headache. Larger and longer trials are needed to evaluate the efficacy and safety of tapinarof cream as compared with existing treatments for psoriasis. (Funded by Dermavant Sciences; PSOARING 1 and 2 ClinicalTrials.gov numbers, NCT03956355 and NCT03983980, respectively.).

17-Beta Hydroxysteroid Dehydrogenase 13 Deficiency Does Not Protect Mice From Obesogenic Diet Injury

BACKGROUND AND AIMS

17-Beta hydroxysteroid dehydrogenase 13 (HSD17B13) is genetically associated with human nonalcoholic fatty liver disease (NAFLD). Inactivating mutations in HSD17B13 protect humans from NAFLD-associated and alcohol-associated liver injury, fibrosis, cirrhosis, and hepatocellular carcinoma, leading to clinical trials of anti-HSD17B13 therapeutic agents in humans. We aimed to study the in vivo function of HSD17B13 using a mouse model.

APPROACH AND RESULTS

Single-cell RNA-sequencing and quantitative RT-PCR data revealed that hepatocytes are the main HSD17B13-expressing cells in mice and humans. We compared Hsd17b13 whole-body knockout (KO) mice and wild-type (WT) littermate controls fed regular chow (RC), a high-fat diet (HFD), a Western diet (WD), or the National Institute on Alcohol Abuse and Alcoholism model of alcohol exposure. HFD and WD induced significant weight gain, hepatic steatosis, and inflammation. However, there was no difference between genotypes with regard to body weight, liver weight, hepatic triglycerides (TG), histological inflammatory scores, expression of inflammation-related and fibrosis-related genes, and hepatic retinoid levels. Compared to WT, KO mice on the HFD had hepatic enrichment of most cholesterol esters, monoglycerides, and certain sphingolipid species. Extended feeding with the WD for 10 months led to extensive liver injury, fibrosis, and hepatocellular carcinoma, with no difference between genotypes. Under alcohol exposure, KO and WT mice showed similar hepatic TG and liver enzyme levels. Interestingly, chow-fed KO mice showed significantly higher body and liver weights compared to WT mice, while KO mice on obesogenic diets had a shift toward larger lipid droplets.

CONCLUSIONS

Extensive evaluation of Hsd17b13 deficiency in mice under several fatty liver-inducing dietary conditions did not reproduce the protective role of HSD17B13 loss-of-function mutants in human NAFLD. Moreover, mouse Hsd17b13 deficiency induces weight gain under RC. It is crucial to understand interspecies differences prior to leveraging HSD17B13 therapies.

Characterization of essential domains in HSD17B13 for cellular localization and enzymatic activity

Human genetic studies recently identified an association of SNPs in the 17-β hydroxysteroid dehydrogenase 13 (HSD17B13) gene with alcoholic and nonalcoholic fatty liver disease development. Mutant HSD17B13 variants devoid of enzymatic function have been demonstrated to be protective from cirrhosis and liver cancer, supporting the development of HSD17B13 as a promising therapeutic target. Previous studies have demonstrated that HSD17B13 is a lipid droplet (LD)-associated protein. However, the critical domains that drive LD targeting or determine the enzymatic activity have yet to be defined. Here we used mutagenesis to generate multiple truncated and point-mutated proteins and were able to demonstrate in vitro that the N-terminal hydrophobic domain, PAT-like domain, and a putative α-helix/β-sheet/α-helix domain in HSD17B13 are all critical for LD targeting. Similarly, we characterized the predicted catalytic, substrate-binding, and homodimer interaction sites and found them to be essential for the enzymatic activity of HSD17B13, in addition to our previous identification of amino acid P260 and cofactor binding site. In conclusion, we identified critical domains and amino acid sites that are essential for the LD localization and protein function of HSD17B13, which may facilitate understanding of its function and targeting of this protein to treat chronic liver diseases.

The promise and pitfalls of composite endpoints in sepsis and COVID-19 clinical trials

Composite endpoints reveal the tendency for statistical convention to arise locally within subfields. Composites are familiar in cardiovascular trials, yet almost unknown in sepsis. However, the VITAMINS trial in patients with septic shock adopted a composite of mortality and vasopressor-free days, and an ordinal scale describing patient status rapidly became standard in COVID studies. Aware that recent use could incite interest in such endpoints, we are motivated to flag their potential value and pitfalls for sepsis research and COVID studies.

Expression of STAT3-regulated genes in circulating CD4+ T cells discriminates rheumatoid arthritis independently of clinical parameters in early arthritis

OBJECTIVES

Dysregulated signal transduction and activator of transcription-3 (STAT3) signalling in CD4+ T cells has been proposed as an early pathophysiological event in RA. We sought further evidence for this observation, and to determine its clinical relevance.

METHODS

Microarray technology was used to measure gene expression in purified peripheral blood CD4+ T cells from treatment-naïve RA patients and disease controls newly recruited from an early arthritis clinic. Analysis focused on 12 previously proposed transcripts, and concurrent STAT3 pathway activation was determined in the same cells by flow cytometry. A pooled analysis of previous and current gene expression findings incorporated detailed clinical parameters and employed multivariate analysis.

RESULTS

In an independent cohort of 161 patients, expression of 11 of 12 proposed signature genes differed significantly between RA patients and controls, robustly validating the earlier findings. Differential regulation was most pronounced for the STAT3 target genes PIM1, BCL3 and SOCS3 (>1.3-fold difference; P < 0.005), each of whose expression correlated strongly with paired intracellular phospho-STAT3. In a meta-analysis of 279 patients the same three genes accounted for the majority of the signature's ability to discriminate RA patients, which was found to be independent of age, joint involvement or acute phase response.

CONCLUSION

The STAT3-mediated dysregulation of BCL3, SOCS3 and PIM1 in circulating CD4+ T cells is a discriminatory feature of early RA that occurs independently of acute phase response. The mechanistic and functional implications of this observation at a cellular level warrant clarification.

17-Beta Hydroxysteroid Dehydrogenase 13 Is a Hepatic Retinol Dehydrogenase Associated With Histological Features of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a common cause of chronic liver disease. A single-nucleotide polymorphism (SNP), rs6834314, was associated with serum liver enzymes in the general population, presumably reflecting liver fat or injury. We studied rs6834314 and its nearest gene, 17-beta hydroxysteroid dehydrogenase 13 (HSD17B13), to identify associations with histological features of NAFLD and to characterize the functional role of HSD17B13 in NAFLD pathogenesis. The minor allele of rs6834314 was significantly associated with increased steatosis but decreased inflammation, ballooning, Mallory-Denk bodies, and liver enzyme levels in 768 adult Caucasians with biopsy-proven NAFLD and with cirrhosis in the general population. We found two plausible causative variants in the HSD17B13 gene. rs72613567, a splice-site SNP in high linkage with rs6834314 (r² = 0.94) generates splice variants and shows a similar pattern of association with NAFLD histology. Its minor allele generates simultaneous expression of exon 6-skipping and G-nucleotide insertion variants. Another SNP, rs62305723 (encoding a P260S mutation), is significantly associated with decreased ballooning and inflammation. Hepatic expression of HSD17B13 is 5.9-fold higher (P = 0.003) in patients with NAFLD. HSD17B13 is targeted to lipid droplets, requiring the conserved amino acid 22-28 sequence and amino acid 71-106 region. The protein has retinol dehydrogenase (RDH) activity, with enzymatic activity dependent on lipid droplet targeting and cofactor binding site. The exon 6 deletion, G insertion, and naturally occurring P260S mutation all confer loss of enzymatic activity. Conclusion: We demonstrate the association of variants in HSD17B13 with specific features of NAFLD histology and identify the enzyme as a lipid droplet-associated RDH; our data suggest that HSD17B13 plays a role in NAFLD through its enzymatic activity.

LOPP chemotherapy as a first-line treatment for dogs with T-cell lymphoma

BACKGROUND

The aim of this study was to describe the use of a lomustine (CCNU), vincristine, procarbazine and prednisolone (LOPP) protocol used for treatment of chemotherapy naive T-cell lymphoma patients and to describe the response rate, toxicity and disease-free interval compared historically to CHOP chemotherapy.

MATERIALS AND METHODS

Retrospective case study of 31 dogs with naïve T-cell lymphoma treated with a lomustine (CCNU), vincristine, procarbazine and prednisolone (LOPP) protocol.

RESULTS

Thirty-one dogs with T cell lymphoma were treated. The overall response rate was 97%. Of the 30 dogs that had a response to LOPP chemotherapy, the median disease free interval was 176 days (range 0-1745 days). The median overall survival time for this study group was 323 days (range 51-1758 days). All deaths in this study were attributable to lymphoma.

CONCLUSION

LOPP chemotherapy for T cell lymphoma is well tolerated with a low toxicity profile and an excellent overall response rate. This protocol showed minimal toxicity and comparable disease free interval and survival times for canine high grade T cell lymphoma treated with CHOP.

Rheumatoid arthritis: an evolutionary force in biologics

The advent of biologic therapy has transformed the outcomes of patients with Rheumatoid Arthritis (RA), but has also highlighted important issues for their development. Early attempts at T-cell driven therapies gave mixed results with difficulties extrapolating from non-human models to first in man trials. There is currently one T-cell modulating therapy - abatacept - licenced for use in RA. Cytokine inhibition has proven to be more fruitful with a number of anti-TNF and IL6 agents either licenced for use in RA or in development. The B-cell depleting therapy rituximab has also shown good efficacy as a chemotherapy agent repurposed for RA treatment. Overall the biologics show good efficacy in RA and have been shown to retard progression of radiographic joint damage. However, this benefit comes with a burden of increased infection risk and a financial cost significantly higher than conventional disease modifying therapies. As a result current UK licencing holds the biologics in reserve following failure of a conventional therapy and the presence of moderate to severely active disease. The long term use of the biologics in RA has highlighted the risk of immunogenicity, with significant proportions of patients developing anti-drug antibodies and losing therapeutic effect. The side effect profile and cost also raise the question around duration of therapy and trials of drug tapering following disease remission are now taking place with several biologic agents. Our inability to stratify patients to the most appropriate biologic drug (stratified or precision medicine) has also catalysed a large and critically important research agenda. Beyond identifying new biologic targets, the development of biosimilar agents will likely drive the future shape of the RA biologics market as lower cost alternatives are developed, thereby improving access to these therapies.

IL-6-driven STAT signalling in circulating CD4+ lymphocytes is a marker for early anticitrullinated peptide antibody-negative rheumatoid arthritis

Objectives

A previously identified signal transduction and activator of transcription-3 (STAT3) target-enriched gene signature in circulating CD4+ T cells of patients with early rheumatoid arthritis (RA) was prominent in autoantibody-negative individuals. Here, interleukin (IL)-6-mediated STAT signalling was investigated in circulating lymphocytes of an independent early arthritis patient cohort, seeking further insight into RA pathogenesis and biomarkers of potential clinical utility.

Methods

Constitutive and IL-6-induced expression of phosphorylated STAT1 (pSTAT1) and pSTAT3 was determined in T and B cells using Phosflow cytometric analysis in patients with RA and controls. Contemporaneous levels of serum cytokines were measured by immunoassay. Induced gene expression was measured in cultured CD4+T cells by quantitative real-time PCR.

Results

Among circulating lymphocytes of 187 patients with early arthritis, constitutive pSTAT3 correlated with serum IL-6 levels maximally in CD4+ T cells. Increased constitutive pSTAT3, but not pSTAT1, was observed in circulating CD4+ T cells of patients with early anticitrullinated peptide autoantibody (ACPA)-negative RA compared with disease controls, and these levels decreased alongside markers of disease activity with IL-6R-targeted treatment. Among patients presenting with seronegative undifferentiated arthritis (UA) the ratio of constitutive pSTAT3:pSTAT1 in CD4+ T cells contributed substantially to an algorithm for predicting progression to classifiable RA during a median of 20 months follow-up (area under receiver operator characteristic curve=0.84; p<0.001).

Conclusions

Our findings support a particular role for IL-6-driven CD4+ T cell activation via STAT3 during the induction of RA, particularly as a feature of ACPA-negative disease. CD4+ T cell pSTAT measurements show promise as biomarkers of UA–RA progression and now require independent validation.

Rheumatoid arthritis: from palliation to remission in two decades

The last 20 years have seen a transformation in the landscape of rheumatoid arthritis, which has changed from being a life limiting condition to a chronic but often remitting illness. The importance of early disease control, the better use of existing therapies, and the development of new therapies have all been key to this success. The future of therapy now lies in the identification of stratifying biomarkers, to allow more rational delivery of treatment. The ultimate goal remains the reintroduction of immune tolerance to potentially achieve a 'cure.'

Effectiveness of etoposide chemomobilization in lymphoma patients undergoing auto-SCT

The effectiveness of stem cell mobilization with G-CSF in lymphoma patients is suboptimal. We reviewed our institutional experience using chemomobilization with etoposide (VP-16; 375 mg/m(2) on days +1 and +2) and G-CSF (5 μg/kg twice daily from day +3 through the final day of collection) in 159 patients with lymphoma. This approach resulted in successful mobilization (>2 × 10(6) CD34+ cells collected) in 94% of patients (83% within 4 apheresis sessions). Fifty-seven percent of patients yielded at least 5 × 10(6) cells in 2 days and were defined as good mobilizers. The regimen was safe with a low rate of rehospitalization. Average costs were $14 923 for good mobilizers and $27 044 for poor mobilizers (P<0.05). Using our data, we performed a 'break-even' analysis that demonstrated that adding two doses of Plerixafor to predicted poor mobilizers at the time of first CD34+ cell count would achieve cost neutrality if the frequency of good mobilizers were to increase by 21%, while the frequency of good mobilizers would need to increase by 25% if three doses of Plerixafor were used. We conclude that chemomobilization with etoposide and G-CSF in patients with lymphoma is effective, with future opportunities for cost-neutral improvement using novel agents.

LX4211, a dual SGLT1/SGLT2 inhibitor, improved glycemic control in patients with type 2 diabetes in a randomized, placebo-controlled trial

Thirty-six patients with type 2 diabetes mellitus (T2DM) were randomized 1:1:1 to receive a once-daily oral dose of placebo or 150 or 300 mg of the dual SGLT1/SGLT2 inhibitor LX4211 for 28 days. Relative to placebo, LX4211 enhanced urinary glucose excretion by inhibiting SGLT2-mediated renal glucose reabsorption; markedly and significantly improved multiple measures of glycemic control, including fasting plasma glucose, oral glucose tolerance, and HbA(1c); and significantly lowered serum triglycerides. LX4211 also mediated trends for lower weight, lower blood pressure, and higher glucagon-like peptide-1 levels. In a follow-up single-dose study in 12 patients with T2DM, LX4211 (300 mg) significantly increased glucagon-like peptide-1 and peptide YY levels relative to pretreatment values, probably by delaying SGLT1-mediated intestinal glucose absorption. In both studies, LX4211 was well tolerated without evidence of increased gastrointestinal side effects. These data support further study of LX4211-mediated dual SGLT1/SGLT2 inhibition as a novel mechanism of action in the treatment of T2DM.

Absence of glutamine supplementation prevents differentiation of murine calvarial osteoblasts to a mineralizing phenotype

Osteoblasts in vitro differentiate from a proliferating to a mineralizing phenotype upon transfer to a medium rich in beta-glycerophosphate and ascorbic acid. The nutritional requirements of the cells at different stages of this differentiation process are not known. In other cell types, nutritional supplementation during surgery can improve the outcome in terms of speed of patient recovery and prognosis. There is therefore the potential for supplementation at the site of fracture repair or bone grafting with critical osteoblast nutritional factors to potentially accelerate healing. In this study we investigate which common cell nutrients are required for the proliferating and mineralizing stages of osteoblast differentiation. Medium containing 5.5 mM glucose was sufficient to achieve maximal proliferation of primary calvarial osteoblasts and human osteoblast cell lines, with some added benefit of additional glutamine supplementation. However, when cells were stimulated to mineralize, glucose was insufficient to support their energetic requirements. Only when cells were supplemented with glucose together with glutamine were high levels of osteocalcin expression observed together with mineralized nodules in culture, suggesting that this would be a useful combination to assess in cultures of primary human osteoblasts to determine whether it may have beneficial effects during fracture surgery, bone grafting, and fixation of uncemented arthroplasty implants.

The tryptophan hydroxylase inhibitor LX1031 shows clinical benefit in patients with nonconstipating irritable bowel syndrome

BACKGROUND & AIMS

Serotonin (5-hydroxytryptamine [5-HT]) has an important role in gastrointestinal function. LX1031 is an oral, locally acting, small molecule inhibitor of tryptophan hydroxylase (TPH). Local inhibition of TPH in the gastrointestinal tract might reduce mucosal production of serotonin (5-HT) and be used to treat patients with nonconstipating irritable bowel syndrome (IBS).

METHODS

We evaluated 2 dose levels of LX1031 (250 mg or 1000 mg, given 4 times/day) in a 28-day, multicenter, randomized, double-blind, placebo-controlled study of 155 patients with nonconstipating IBS. 5-hydroxyindoleacetic acid (5-HIAA), a biomarker of pharmacodynamic activity, was measured in urine samples at baseline (24 hours after LX1031 administration), and at weeks 4 and 6 (n = 76).

RESULTS

Each dose of LX1031 was safe and well-tolerated. The primary efficacy end point, relief of IBS pain and discomfort, improved significantly in patients given 1000 mg LX1031 (25.5%), compared with those given placebo, at week 1 (P = .018); with nonsignificant improvements at weeks 2, 3, and 4 (17.9%, 16.3%, and 11.6%, respectively). Symptom improvement correlated with a dose-dependent reduction in 5-HIAA, a marker for TPH inhibition, from baseline until week 4. This suggests the efficacy of LX1031 is related to the extent of inhibition of 5-HT biosynthesis. Stool consistency significantly improved, compared with the group given placebo, at weeks 1 and 4 (P < .01) and at week 2 (P < .001).

CONCLUSIONS

In a phase 2 study, LX1031 was well tolerated, relieving symptoms and increasing stool consistency in patients with nonconstipating IBS. Symptom relief was associated with reduced levels of 5-HIAA in urine samples. This marker might be used to identify patients with nonconstipating IBS who respond to inhibitors of 5-HT synthesis.

Use of stent grafts in lower extremity trauma

BACKGROUND

Permanent endovascular stenting is gradually becoming recognized as a safe and efficacious method for treating a variety of arterial diseases. The literature on its application in trauma care is sparse, although indications for usage continue to evolve.

METHODS

We retrospectively reviewed all penetrating extremity trauma treated with endovascular therapy at our medical center between 2005 and 2008.

RESULTS

We present three patients with three different arterial lesions in the superficial femoral artery (SFA) which were caused by penetrating injury. The arterial lesions include a mid-thigh SFA pseudoaneurysm, an intimal disruption of the distal SFA, and an arteriovenous fistula involving the SFA and superficial femoral vein. All were treated with expanded polytetrafluoroethylene-covered stents and showed excellent short-term results. A percutaneous approach to this problem may reduce blood loss, decrease length of stay, involve fewer iatrogenic nerve injuries, and facilitate shorter recovery time, as compared with open approaches.

CONCLUSIONS

Endovascular-covered stent placement for traumatic arterial extremity injury was used with excellent results and no morbidity in this small series of patients. Endovascular solutions for arterial extremity injuries warrant further investigation for short- and long-term results.

Isotope turnover studies in uncontrolled diabetes and the effects of insulin

Turnover rates of glucose, free fatty acids (FFA) and leucine have been measured in newly diagnosed, uncontrolled insulin-dependent diabetic (IDD) patients. The results have been compared with data collected from the same patients while on conventional insulin therapy as well as after overnight intravenous infusion of insulin with sustained normoglycaemia. The data have been analysed by compartmental and non-compartmental methods and the results have been compared with simultaneously collected data on respiratory exchange. Oxidation rates of 14C-labelled substrates have also been measured. Tracer studies were done on established diabetics after insulin withdrawal and subsequent intravenous infusion of insulin at different rates. The results confirm the in vivo importance of the glucose-fatty acid cycle, indicating that when glucose, FFA and ketone bodies are available in excess it is FFA and ketones that are metabolized in preference to glucose. The data emphasize the importance of increased production rates rather than decreased utilization rates in producing high concentrations of substrates in the plasma of insulin-deficient patients.

Cost-effectiveness analysis of levonorgestrel intrauterine system and thermal balloon ablation for heavy menstrual bleeding

OBJECTIVE

To compare the cost-effectiveness of levonorgestrel intrauterine system (LNG-IUS) (Mirena; Schering Co., Turku, Finland) and thermal balloon ablation (Thermachoicetrade mark; Gynecare Inc., Menlo Park, CA, USA) for the treatment of heavy menstrual bleeding.

DESIGN

An open, pragmatic, prospective randomised trial.

SETTING

A menstrual disorders clinic at National Women's Hospital, Auckland, New Zealand.

POPULATION

Seventy-nine women with self-defined heavy menstrual bleeding randomised to the LNG-IUS (40 women) or the thermal balloon ablation (39 women).

METHODS

Decision tree modelling using primary source data was used to identify the incremental cost-effectiveness of the two treatments.

MAIN OUTCOME MEASURES

Direct and indirect costs of medical treatment, including treatment costs, subsequent medical procedures, lost income and medical treatment for failed procedures. The change in quality of life as assessed by the Short Form-36 (SF-36) measured between time of treatment and 24 months was the primary outcome measure. Economic modelling examined the expected cost and outcome for a woman entering each treatment. Sensitivity analysis explored the robustness of the results.

RESULTS

The expected cost of treatment was $NZ1241 ($US869) for the LNG-IUS and $NZ2418 ($US1693) for the thermal balloon ablation. The LNG-IUS was associated with an increase of 15 points on the SF-36 scale, compared with 12 points for the thermal balloon ablation. Sensitivity analysis indicates that the results are robust to a 25% decrease in the price of the primary cost drivers and to variations in the rates of failed treatment between the conditions.

CONCLUSION

The LNG-IUS would appear to be cost-effective when compared with the thermal balloon ablation for treatment of heavy menstrual bleeding.

Are adjuvant therapies for tonsillectomy evidence based?

Our aim was to ascertain the current practice of adjuvant therapy for tonsillectomy and to determine whether it is evidence based. Anonymized postal questionnaires were sent to all UK otolaryngology consultants registered with the specialty association, and a literature search was performed using relevant search terms in all possible combinations. Among the responders there was little enthusiasm for routine intra-operative local anaesthesia, post-operative topical benzydamine hydrochloride (Difflam) spray or post-operative antibiotics. This is consistent with the lack of robust evidence to support any of these practices. Paracetamol (acetaminophen) is prescribed by almost 90 per cent for post-operative analgesia, and the current literature supports its efficacy and safety. Further, most practitioners combine paracetamol with opioids and/or non-steroidal anti-inflammatory drugs (NSAIDs). Evidence to support the additional use of these agents is, however, non-existent or limited. Some aspects of tonsillectomy care are uniform and evidence based. Others are heterogeneous and suffer from lack of adequate data in the literature.

Alternative parenteral anticoagulation with argatroban, a direct thrombin inhibitor

Argatroban, a direct thrombin inhibitor, effectively inhibits free and clot-bound thrombin without the need of a cofactor and exerts dose-dependent anticoagulant effects that are rapidly active and rapidly reversible (elimination half-life: 39-51 min). Argatroban provides predictable parenteral anticoagulation and is well tolerated with an acceptably low bleeding risk in a variety of clinical settings, including heparin-induced thrombocytopenia, acute ischemic stroke, percutaneous coronary intervention and hemodialysis. This review will discuss the clinical pharmacology and utility of argatroban; in particular, clinical trial experiences will be discussed in patients with, or at risk of, heparin-induced thrombocytopenia (where heparins must be avoided) including those requiring hemodialysis or percutaneous coronary intervention, and in patients with acute ischemic stroke (where heparins are not generally recommended).

Argatroban Anticoagulation in Patients With Acute Ischemic Stroke (ARGIS-1)

Background and Purpose— Direct thrombin inhibitors, including argatroban, represent an anticoagulant class distinct from heparins. We investigated the safety of 2 levels of argatroban anticoagulation in acute ischemic stroke.

Methods— This multicenter, randomized, double-blinded, placebo-controlled study included 171 patients with acute (≤12 hours from onset) stroke and National Institutes of Health Stroke Scale (NIHSS) scores of 5 to 22. Patients received continuous intravenous argatroban (100 μg/kg bolus) at 3 μg/kg per minute (n=59) or 1 μg/kg per minute (n=58), respectively, adjusted to target activated partial thromboplastin times (aPTTs) 2.25× and 1.75× baseline or placebo (n=54) for 5 days. The primary outcome was symptomatic intracranial hemorrhage (ICH) at 30 days.

Results— Baseline characteristics including neurologic deficits (median NIHSS score 9) were comparable between groups. Argatroban at mean doses of 2.7 and 1.2 μg/kg per minute increased aPTTs significantly ( P <0.001), with mean aPTTs at or near target values throughout infusion. Symptomatic ICH was not significantly different between groups (high-dose argatroban, 5.1%; low-dose argatroban, 3.4%; placebo, 0%; P ≥0.18), with 3 events during argatroban infusion and 2 events ≥7 days after stopping infusion. No significant between-group differences occurred in asymptomatic ICH (7 events), major systemic hemorrhage (no event), or 90-day mortality (13.4% overall).

Conclusions— In this first North American randomized, double-blinded, placebo-controlled study of direct thrombin inhibition in acute ischemic stroke, argatroban at each dose evaluated significantly prolonged aPTTs without increasing ICH or major bleeding. These results suggest that argatroban provides safe anticoagulation in acute ischemic stroke, warranting future studies powered to evaluate its efficacy and more precisely estimate event rates.

Stroke in patients with heparin-induced thrombocytopenia and the effect of argatroban therapy

OBJECTIVE

To investigate the frequency, mortality rate, and characteristics of stroke in heparin-induced thrombocytopenia and the effect of argatroban therapy in that setting.

DESIGN

Retrospective analysis of two prospective studies of argatroban therapy in heparin-induced thrombocytopenia.

SETTING

Hospitalized care.

PATIENTS

Patients were 960 patients with heparin-induced thrombocytopenia (767 argatroban-treated patients, 193 historical controls).

INTERVENTIONS

Argatroban 2 microg x kg x min, adjusted to achieve activated partial thromboplastin times 1.5-3 times baseline

MEASUREMENTS AND MAIN RESULTS

Case records were reviewed to identify patients with stroke present at or within 37 days of study entry and to assess 37-day outcomes. Stroke occurred in 30 (3.1%) patients (stroke at entry, n = 9; new stroke during follow-up, n = 24; more than one stroke, n = 4). By logistic regression with treatment, protocol, age, and gender as covariates, females were significantly more likely to suffer stroke (odds ratio, 2.48; 95% confidence interval, 1.11-5.53; p =.026) and stroke-associated mortality (odds ratio, 4.10; 95% CI, 1.12-15.01; p =.033), and argatroban-treated patients had significantly reduced odds, vs. control, of new stroke (odds ratio, 0.31; 95% confidence interval, 0.10-0.96; p =.041) and stroke-associated mortality (odds ratio, 0.18; 95% confidence interval, 0.03-0.92; p =.039). Stroke (odds ratio, 3.66; 95% confidence interval, 1.73-7.73; p <.001) and age (odds ratio per year, 1.017; 95% confidence interval, 1.004-1.029; p =.008) were significant predictors of all-cause death. In the argatroban group, baseline platelet counts were significantly less in patients with, vs. without, stroke (medians, 42 x 10/L vs. 72 x 10/L; p =.006). Of 35 stroke events, 33 (94%) were ischemic and two (6%) were hemorrhagic (one per group, none during argatroban infusion); 30 (86%) were present at or within 13 days of entry.

CONCLUSIONS

Stroke, particularly ischemic stroke, is common in heparin-induced thrombocytopenia and significantly increases mortality risk. Stroke in heparin-induced thrombocytopenia occurs most often in females, in patients with more severe thrombocytopenia, and within 2 wks of heparin-induced thrombocytopenia presentation. Argatroban therapy vs. control significantly reduces the likelihood of new stroke and stroke-associated mortality in heparin-induced thrombocytopenia without increasing intracranial hemorrhage.

Coronary heart disease risk assessment in diabetes mellitus: comparison of UKPDS risk engine with Framingham risk assessment function and its clinical implications

AIMS

To assess differences between absolute coronary heart disease (CHD) risks calculated by Joint British Societies (JBS) risk calculator and UKPDS risk engine and its impact on CHD primary prevention management in diabetes mellitus (DM).

METHODS

Seven hundred Type 2 DM patients without arterial complications were identified from nine general practices in the Scarborough area. Their absolute 10-year CHD risks were calculated. The differences in the proportion of patients identified for aspirin and statin under JBS and National Institute for Clinical Excellence (NICE) guidelines by these two methods were determined. The proportion of additional patients identified for statin in the Scarborough population as a consequence of CHD risk threshold reduction from 30 to 15% (as recommended by NICE) was also determined.

RESULTS

UKPDS risk engine calculated significantly higher mean 10-year CHD risk (UKPDS vs. JBS, 21.5 vs. 18.3%, P < 0.0001). Both methods identified approximately 65% of patients to be eligible for aspirin and statin if NICE recommendations were followed. At a risk threshold of 30%, the UKPDS risk engine identified more patients for statin. Reducing the CHD risk threshold from 30 to 15% for statin initiation will identify an additional 0.5% of the total population for this treatment.

CONCLUSIONS

Both methods are comparable in identifying at-risk patients under NICE recommendations. A high proportion has risk levels that merits primary CHD prevention. Lowering the risk threshold for statin treatment has a small numerical impact on the whole population.

The distribution of carotid endarterectomy procedures among surgeons and hospitals in New York state: is regionalization of specialized vascular care occurring?

INTRODUCTION

In a published analysis of all carotid endarterectomies (CEAs) performed in New York state from 1990 to 1995, perioperative mortality rate was inversely correlated with surgeon and hospital CEA volume, was significantly higher when CEAs were performed by surgeons who performed less than five CEAs annually, and was significantly lower in hospitals where surgeons performed more than 100 CEAs annually. The purpose of this study was to determine whether this information has influenced practice patterns in New York state.

METHODS

The database of the Center for Medical Consumers was queried to determine the volume distribution among surgeons and hospitals of all CEAs performed in New York state in 1999 and 2000.

RESULTS

During 1999, 695 surgeons in 169 hospitals performed 9458 CEAs (mean, 13.6 per surgeon). Three hundred fifty-three surgeons (51%) performed less than five CEAs, and 180 (26%) performed only one CEA during the year. Only 41 surgeons (6%) performed more than 50 CEAs. Likewise, in only 28 of the hospitals (17%) were more than 100 CEAs performed during 1999, whereas in 73 of the hospitals (43%) 20 or less CEAs were carried out during the year. During 2000, 684 surgeons performed 8196 CEAs in 165 hospitals. Three hundred fifty-three (52%) performed less than five CEAs, and 229 (33%) performed only one CEA during the year. Only 33 surgeons (5%) performed more than 50 CEAs during 2000. In only 26 hospitals (16%) were more than 100 CEAs performed during 2000, whereas in 71 hospitals (43%) 20 or less CEAs were carried out.

CONCLUSION

It appears that published compelling evidence that operator and institutional volume influence outcome has not influenced referral patterns or led to a regionalization of CEA care in New York state. Robust educational programs directed to patients and referring physicians appear indicated.

Comparison of acustimulation and ondansetron for the treatment of established postoperative nausea and vomiting

BACKGROUND

This study was designed to evaluate transcutaneous electrical acupoint stimulation (acustimulation) using the ReliefBand compared with ondansetron for the treatment of established postoperative nausea and vomiting (PONV) after outpatient laparoscopic surgery.

METHODS

After the authors obtained institutional review board approval and written informed consent, 268 outpatients were enrolled in this randomized, double-blind, placebo- and sham-controlled study. All patients received antiemetic prophylaxis with metoclopramide, 10 mg intravenously, or droperidol, 0.625 mg intravenously, after induction of anesthesia. A total of 90 patients developed PONV in the recovery units and were randomized to one of three treatment groups: (1) the ondansetron group received 4 mg intravenous ondansetron and a sham ReliefBand; (2) the acustimulation group received 2 ml intravenous saline and a ReliefBand; and (3) the combination group received 4 mg intravenous ondansetron and a ReliefBand. A rescue antiemetic (10 mg intravenous metoclopramide) was administered only if the PONV symptoms persisted for 15 min or longer after initiating the treatment. A blinded observer recorded the recovery times, emetic symptoms, rescue antiemetics, maximum nausea scores, complete response to study treatment, and time to achieve discharge criteria. Postdischarge side effects, as well as patient satisfaction and quality of recovery scores, were assessed at 24 and 72 h after surgery.

RESULTS

The combination group had a significantly higher complete response rate than the acustimulation group (73% vs.40%, P <0.01). In addition, fewer patients (8 vs. 18) in the combination (vs. acustimulation) group experienced subsequent emetic events (P < 0.03). However, there were no significant differences between the three groups with respect to patient satisfaction and quality of recovery scores.

CONCLUSIONS

Acustimulation with the ReliefBand can be used as an alternative to ondansetron for the treatment of established PONV. However, the use of ondansetron (4 mg intravenously) in combination with the ReliefBand device improved the complete response rate to the acustimulation therapy.

Lack of pharmacokinetic interactions between argatroban and warfarin

The potential for pharmacokinetic interactions between argatroban and warfarin was studied. In a randomized, crossover study, healthy volunteers participated in three treatment periods, each separated by a nine-day washout interval. Drug regimens consisted of a single oral 7.5-mg dose of warfarin, intravenous argatroban infused at a rate of 1.25 micrograms/kg/min for 100 hours, or both. Blood samples were collected at intervals up to 104 hours to determine clearance (CL) and the apparent first-order elimination rate constant (kel) for argatroban and the area under the concentration-versus-time curve (AUC) and maximum concentration (Cmax) for R- and S-warfarin. An interaction was defined as a > 25% difference in the magnitude of the pharmacokinetic values between administration of one drug alone and coadministration with the other agent. Twelve adult subjects were enrolled. The mean CL and lel for argatroban administered alone differed by < 7% from the mean values when the two drugs were coadministered. When warfarin was administered alone, the mean Cmax and AUC of R- and S-warfarin differed from the mean values when the two drugs were coadministered by < 10%. Prothrombin time was prolonged comparably when argatroban was administered alone and with warfarin. No deaths or serious adverse events were reported. No significant pharmacokinetic interactions were detected between i.v. argatroban 1.25 micrograms/kg/min and a single 7.5-mg oral dose of warfarin. Argatroban was well tolerated when administered alone or with warfarin.

Semiautomated data analysis of flow cytometric estimation of fetomaternal hemorrhage in D- women

BACKGROUND

Accurate and reliable measurement of the volume of fetal D+ cells in D- women is required for adequate anti-D prophylaxis. A semiautomated flow cytometry assay based on a standardized calibration curve that was created with simulated fetomatemal hemorrhage (FMH) mixtures was developed.

STUDY DESIGN AND METHODS

A calibration range of 0.083- to 2-percent D+ cells in the D-RBC mixtures (2-44 mL calculated FMH) was analyzed by use of a flow cytometer (XL-MCL, Coulter Electronics Ltd). Linear regression analysis of the calibration curve data with computer software (Excel, Microsoft) allowed semiautomated determination of the FMH volume. To optimize the assay, fresh versus frozen and thawed RBCs, RBCs from adults who are heterozygous for D or cord RBCs, and indirect- or direct-labeling techniques were evaluated by use of MoAbs.

RESULTS

Fresh RBCs from adults heterozygous for D were chosen for routine use, although equivalent calibration curves were obtained with all cells tested (n = 12 calibration assays; r2 = 0.999; mean SD, 14%). A monoclonal anti-D reagent (Therad 10, Diagnostics Scotland) worked well in both indirect-(anti-IgG F(ab)-FITC) and direct-(anti-D-FITC) labeling methods compared to the use of BRAD-3 FITC. In routine practice, the FMH volumes obtained were mainly lower than those obtained in the Kleihauer Betke test when there was less than 4 mL of FMH.

CONCLUSION

Semiautomated data acquisition and calibration curve analysis represents a further step toward standardization of flow cytometry for accurate FMH quantification and facilitates evaluation and control of day-to-day variations between laboratories, flow cytometers, and operators.