A retrospective review of gram-negative spinal infections in a single tertiary spinal centre over six years.

Aims: Gram-negative infections are associated with comorbid patients, but outcomes are less well understood. This study reviewed diagnosis, management, and treatment for a cohort treated in a tertiary spinal centre. Methods: A retrospective review was performed of all gram-negative spinal infections (n = 32; median age 71 years; interquartile range 60 to 78), excluding surgical site infections, at a single centre between 2015 to 2020 with two- to six-year follow-up. Information regarding organism identification, antibiotic regime, and treatment outcomes (including clinical, radiological, and biochemical) were collected from clinical notes. Results: All patients had comorbidities and/or non-spinal procedures within the previous year. Most infections affected lumbar segments (20/32), with Escherichia coli the commonest organism (17/32). Causative organisms were identified by blood culture (23/32), biopsy/aspiration (7/32), or intraoperative samples (2/32). There were 56 different antibiotic regimes, with oral (PO) ciprofloxacin being the most prevalent (13/56; 17.6%). Multilevel, contiguous infections were common (8/32; 25%), usually resulting in bone destruction and collapse. Epidural collections were seen in 13/32 (40.6%). In total, five patients required surgery, three for neurological deterioration. Overall, 24 patients improved or recovered with a mean halving of CRP at 8.5 days (SD 6). At the time of review (two to six years post-diagnosis), 16 patients (50%) were deceased. Conclusion: This is the largest published cohort of gram-negative spinal infections. In older patients with comorbidities and/or previous interventions in the last year, a high level of suspicion must be given to gram-negative infection with blood cultures and biopsy essential. Early organism identification permits targeted treatment and good initial clinical outcomes; however, mortality is 50% in this cohort at a mean of 4.2 years (2 to 6) after diagnosis.

Inequities in the physical activity of disabled young people in Aotearoa New Zealand: a stakeholder SWOT analysis of the physical activity sector.

AIMS: Disabled people, particularly children and adolescents, tend to participate in less physical activity than their non-disabled peers on average. However, disabled children and youth (i.e., young people [YP]) are typically underrepresented in physical activity (PA) research, with little data available in Aotearoa New Zealand to guide policy makers to alter societal factors that contribute to disability inequities. The purpose of this study was to conduct a Strengths, Weaknesses, Opportunities, and Threats (SWOT) analysis of the PA sector in Aotearoa New Zealand with respect to PA participation and promotion among disabled YP. METHODS: Focus group discussions, underpinned by the SWOT framework, were facilitated with stakeholders (n=11) engaged in the Aotearoa New Zealand PA sector. Data were transcribed and analysed using content analysis. Desirable and accessible opportunities were essential enablers of PA in disabled YP. RESULTS: Communication, transport, equipment costs, awareness of activities, and social support were identified as factors that influence PA participation. Schools also have a considerable influence on PA participation among disabled YP, while greater funding for and cohesion/collaboration among PA providers is key to continued growth in PA participation. CONCLUSIONS: Communication, accessibility, funding, and collaborative/coordinated multi-level efforts were identified as areas in need of strengthening to provide equitable opportunities for disabled YP in Aotearoa New Zealand to participate in PA.

Identifying lupus Patient Subsets Through Immune Cell Deconvolution of Gene Expression Data in Two Atacicept Phase II Studies.

OBJECTIVE: To use cell-based gene signatures to identify patients with systemic lupus erythematous (SLE) in the phase II/III APRIL-SLE and phase IIb ADDRESS II trials most likely to respond to atacicept. METHODS: A published immune cell deconvolution algorithm based on Affymetrix gene array data was applied to whole blood gene expression from patients entering APRIL-SLE. Five distinct patient clusters were identified. Patient characteristics, biomarkers, and clinical response to atacicept were assessed per cluster. A modified immune cell deconvolution algorithm was developed based on RNA sequencing data and applied to ADDRESS II data to identify similar patient clusters and their responses. RESULTS: Patients in APRIL-SLE (N = 105) were segregated into the following five clusters (P1-5) characterized by dominant cell subset signatures: high neutrophils, T helper cells and natural killer (NK) cells (P1), high plasma cells and activated NK cells (P2), high B cells and neutrophils (P3), high B cells and low neutrophils (P4), or high activated dendritic cells, activated NK cells, and neutrophils (P5). Placebo- and atacicept-treated patients in clusters P2,4,5 had markedly higher British Isles Lupus Assessment Group (BILAG) A/B flare rates than those in clusters P1,3, with a greater treatment effect of atacicept on lowering flares in clusters P2,4,5. In ADDRESS II, placebo-treated patients from P2,4,5 were less likely to be SLE Responder Index (SRI)-4, SRI-6, and BILAG-Based Combined Lupus Assessment responders than those in P1,3; the response proportions again suggested lower placebo effect and a greater treatment differential for atacicept in P2,4,5. CONCLUSION: This exploratory analysis indicates larger differences between placebo- and atacicept-treated patients with SLE in a molecularly defined patient subset.

Disease trajectory of SLE clinical endpoints and covariates affecting disease severity and probability of response: Analysis of pooled patient-level placebo (Standard-of-Care) data to enable model-informed drug development.

Systemic lupus erythematosus (SLE) is an autoimmune disease affecting multiple organ systems. Many investigational agents have failed or shown only modest effects when added to standard of care (SoC) therapy in placebo-controlled trials, and only two therapies have been approved for SLE in the last 60 years. Clinical trial outcomes have shown discordance in drug effects between clinical endpoints. Herein, we characterized longitudinal disease activity in the SLE population and the sources of variability by developing a latent disease trajectory model for SLE component endpoints (Systemic Lupus Erythematosus Disease Activity Index [SLEDAI], Physician's Global Assessment [PGA], British Isles Lupus Assessment Group Index [BILAG]) and composite endpoints (Systemic Lupus Erythematosus Responder Index [SRI], BILAG-based Composite Lupus Assessment [BICLA], and Lupus Low Disease Activity State [LLDAS]) using patient-level historical SoC data from nine phase II and III studies. Across all endpoints, in predictions up to 52 weeks from the final disease trajectory model, the following baseline covariates were associated with a greater decrease in SLE disease activity and higher response to placebo + SoC: Hispanic ethnicity from Central/South America, absence of hypocomplementemia, recent SLE diagnosis, and high baseline disease activity score using SLEDAI and BILAG separately. No discernible differences were observed in the trajectory of response to placebo + SoC across different SoC medications (antimalarial and immunosuppressant such as mycophenolate, methotrexate, and azathioprine). Across all endpoints, disease trajectory showed no difference in Asian versus non-Asian patients, supporting Asia-inclusive global SLE drug development. These results describe the first population approach to support a model-informed drug development framework in SLE.

Tactical vests worn by law enforcement: is this improving stability for optimal job performance?

Objectives. The purpose of this study was to determine whether equipped tactical vests would improve postural stability of law enforcement officers (LEOs) versus a duty belt or without either condition. Methods. Volunteers were police officers (n = 25, 22 males, three females; age 42.4 ± 3.2 years; weight 101.65 ± 19.4 kg; height 178.92 ± 8.2 cm). The Institutional Review Board approved the investigation. A Bertec posturography plate (Bertec Inc., USA) determined four center of pressure (CoP) scores - eyes open stable surface (EOSS), eyes closed stable surface (ECSS), eyes open perturbed surface (EOPS), eyes closed perturbed surface (ECPS) - and four limit of stability (LoS) scores - frontal plane (LoSF), posterior plane (LoSP), left sagittal plane (LoSL), right sagittal plane (LoSR). Results. A repeated-measures multivariate analysis of variance (MANOVA) demonstrated no statistical difference within subject group CoP scores EOSS (p = 0.723), ECSS (p = 0.252), EOPS (p = 0.079) and ECPS (p = 0.137). Comparing between groups, the tactical vest demonstrated significance over the other CoP group conditions with ECPS (p = 0.001). The duty belt group showed significance with ECSS (p = 0.001). LoS variables indicated no significant results between groups. Conclusion. Tactical vests demonstrated improvements in ECPS scores (p = 0.001) compared to either group.

Predictors and outcomes of first pass efficacy in posterior circulation strokes: Insights from STAR collaboration.

Background: First-pass efficacy (FPE) has been established as an important predictor of favorable functional outcomes after endovascular thrombectomy (ET) in anterior circulation strokes. In this retrospective cohort study, we investigate predictors and clinical outcomes of FPE in posterior circulation strokes (pcAIS). Methods: The Stroke Thrombectomy and Aneurysm Registry database was used to identify pcAIS patients who achieved FPE. Their baseline characteristics and outcomes were compared with the non-FPE group. The primary outcome was a 90-day modified Rankin Scale (mRS) of 0-3. Univariate (UVA) and multivariate (MVA) analyses were done to evaluate predictors of FPE. Safety outcomes included distal emboli, vessel rupture, symptomatic intracranial hemorrhage, and mortality. Results: Of 359 patients, 179 (50%) achieved FPE. Clot burden, occlusion site, and ET technique-related variables were similar between the two groups except for shorter procedure time with FPE. The primary outcome was significantly better with FPE (56.4% vs. 32.8%, p < 0.001). Complications were similar except for a higher rate of distal emboli in non-FPE group (11.1% vs. 3.2%, p = 0.032). Atrial fibrillation (Afib) had increased odds (aOR: 2.06, 95% CI; 1.24, 3.4, p = 0.005) and prior ischemic stroke had decreased odds (aOR: 0.524, 95% CI; 0.28, 0.97, p = 0.04) of FPE. Afib was the only independent predictor of FPE on MVA (1.94, 95% CI; 1.1, 3.43, p = 0.022). Conclusions: Higher rate of FPE in Afib-related pcAIS could possibly be explained by the differences in clot composition and degree of in-situ atherosclerotic disease burden. Future studies are warranted to explore the relationship of clot composition with ET outcomes.

Testing to Identify Submaximal Effort: Lifting to a Perceived 50% Effort vs. an Assigned Submaximal Load.

ABSTRACT: Swift, MC, Townsend, R, Edwards, D, and Loudon, J. Testing to identify submaximal effort: Lifting to a perceived 50% effort vs. an assigned submaximal load. J Strength Cond Res 36(8): 2115-2120, 2022-The ability to accurately measure effort during postinjury functional testing allows for the validation of displayed physical limitations by injured workers. The Cross-Reference Testing System (XRTS) has been developed to identify submaximal efforts through distraction-based dynamic material handling testing. The XRTS material handling assessment compares dynamic lifts of weights in a crate and lifts using a lever arm device. The purpose of this study was to determine whether subjects lifting an assigned submaximal load influence test results compared with subjects lifting to but not exceeding a 50% perceived effort. Subjects in group A ( n = 35) were assigned the condition to attempt to lift to but not exceed a randomly assigned weight value for both the crate lift and XRTS at 3 lifting heights. Subjects in group B ( n = 32) were asked to lift to but not exceed 37.5 lb from the same 3 lifting heights. The reproducibility of effort was measured with current validity criteria for distraction-based material handling testing. Using the percent difference values, a 2 × 3 (group, lifting height) analysis of variance (ANOVA) was performed to test the hypothesis. The alpha level was set at 0.05. The mean percent change between comparative lifts was 31.13%, 95% CI (22.51-39.75) for group A and 29.26% 95% CI (21.91-36.61) for group B. The 2 × 3 ANOVA demonstrated no significant difference ( p = 0.751) between groups. The results indicate attempting to lift to a perceived 50% effort was not significantly different from attempting to lift to but not exceed an assigned submaximal load.

Major complications of dural venous sinus stenting for idiopathic intracranial hypertension: case series and management considerations.

BACKGROUND: Venous sinus stenting (VSS) is a safe, effective, and increasingly popular treatment option for selected patients with idiopathic intracranial hypertension (IIH). Serious complications associated with VSS are rarely reported. METHODS: Serious complications after VSS were identified retrospectively from multicenter databases. The cases are presented and management strategies are discussed. RESULTS: Six major acute and chronic complications after VSS were selected from a total of 811 VSS procedures and 1466 venograms for IIH. These included an acute subdural hematoma from venous extravasation, cases of both intraprocedural and delayed stent thrombosis, an ultimately fatal cerebellar hemorrhage resulting in acute obstructive hydrocephalus, venous microcatheter perforation during venography and manometry, and a patient who developed subarachnoid hemorrhage and subdural hematoma after cerebellar cortical vein perforation. The six cases are reviewed and learning points regarding complication avoidance and management are presented. CONCLUSION: We report on six rare, major complications after VSS for IIH. Familiarity with these potential complications and appropriate timely management may allow for good clinical outcomes.

Intracranial Venous Hypertension and Venous Sinus Stenting in the Modern Management of Idiopathic Intracranial Hypertension.

Idiopathic intracranial hypertension (IIH) is a debilitating condition that has traditionally been difficult to treat. In recent years, there has been increasing focus on the role of intracranial venous hypertension in the pathophysiology of IIH. Based on increased understanding of this pathophysiology, venous sinus stenting (VSS) has emerged as a safe and reliable treatment for a certain population of patients with IIH. Stratifying patients with IIH based on the status of their venous outflow can provide insight into which patients may enjoy reduction in their symptoms after VSS and provides information regarding why some patients may have symptom recurrence. The traditional view of IIH as a disease due to obesity in young women has been cast into doubt as the understanding of the role of intracranial venous hypertension has improved.

Distinguishing Constraints on Financial Inclusion and Their Impact on GDP, TFP, and the Distribution of Income.

A general equilibrium model featuring multiple realistic sources of financial frictions is developed to study how different constraints interact in equilibrium. We highlight, distinguish, and evaluate their differential impacts and rich interactions. The economic impact of financial inclusion policies in an economy depends not only on which constraint is alleviated, but also on the tightness of other constraints. Policy instruments should target the most binding constraint, which likely varies across countries. Moreover, there are important tradeoffs between financial inclusion, GDP, and the distribution of income. The transitional dynamics also differ from those in steady states. Policy makers should consider both.

The antimicrobial activity and biocompatibility of a controlled gentamicin-releasing single-layer sol-gel coating on hydroxyapatite-coated titanium.

AIMS: The aim of this study was to develop a single-layer hybrid organic-inorganic sol-gel coating that is capable of a controlled antibiotic release for cementless hydroxyapatite (HA)-coated titanium orthopaedic prostheses. METHODS: Coatings containing gentamicin at a concentration of 1.25% weight/volume (wt/vol), similar to that found in commercially available antibiotic-loaded bone cement, were prepared and tested in the laboratory for: kinetics of antibiotic release; activity against planktonic and biofilm bacterial cultures; biocompatibility with cultured mammalian cells; and physical bonding to the material (n = 3 in all tests). The sol-gel coatings and controls were then tested in vivo in a small animal healing model (four materials tested; n = 6 per material), and applied to the surface of commercially pure HA-coated titanium rods. RESULTS: The coating released gentamicin at > 10 × minimum inhibitory concentration (MIC) for sensitive staphylococcal strains within one hour thereby potentially giving effective prophylaxis for arthroplasty surgery, and showed > 99% elution of the antibiotic within the coating after 48 hours. There was total eradication of both planktonic bacteria and established bacterial biofilms of a panel of clinically relevant staphylococci. Mesenchymal stem cells adhered to the coated surfaces and differentiated towards osteoblasts, depositing calcium and expressing the bone marker protein, osteopontin. In the in vivo small animal bone healing model, the antibiotic sol-gel coated titanium (Ti)/HA rod led to osseointegration equivalent to that of the conventional HA-coated surface. CONCLUSION: In this study we report a new sol-gel technology that can release gentamicin from a bioceramic-coated cementless arthroplasty material. In vitro, local gentamicin levels are in excess of what can be achieved by antibiotic-loaded bone cement. In vivo, bone healing in an animal model is not impaired. This, thus, represents a biomaterial modification that may have the potential to protect at-risk patients from implant-related deep infection. Cite this article: Bone Joint J 2021;103-B(3):522-529.

Revision total elbow arthroplasty: Is it safe to perform a single-stage revision for presumed aseptic loosening based on clinical assessment, normal inflammatory markers, and a negative aspiration?

BACKGROUND: Revision total elbow arthroplasty (TEA) is a challenging procedure that is becoming increasingly common. In our unit, we regard it as essential to exclude infection as the underlying cause of TEA loosening. In all patients with arthroplasty loosening, we undertake a careful history and examination, perform radiographs, monitor inflammatory markers, and undertake a joint aspiration. If any investigation suggests infection as the etiology, then a 2-stage revision is undertaken. Open biopsies are not routinely performed. The aim was to ascertain from our outcomes whether it is safe to perform a single-stage revision for presumed aseptic loosening using these criteria. METHODS: A retrospective review of a consecutive series of revision TEAs was performed in our unit over a 10-year period (2008-2018). Single-stage revisions performed for presumed aseptic loosening were identified. Case notes, radiographs, bloods, aspiration results, and microbiology of tissue samples taken at revision were reviewed. RESULTS: A total of 123 revision elbow arthroplasty cases were performed in the study period. Sixty cases were revised for preoperatively proven infection, instability, or implant failure and were excluded from this study. In 63 cases, aseptic loosening was diagnosed based on history, clinical examination, blood markers, and aspiration. There were 21 dual-component and 42 single-component revisions. In the dual-component revision group, tissue samples taken at the time of revision were positive in only 1 case (5%). In the single-component revision group, positive culture samples were present in 3 cases (7%). χ2 analysis showed no significant difference between single- and dual-component revisions (P = .76). No cases with positive culture samples from either group have required subsequent revision surgery. CONCLUSION: Given the results of this study, we conclude that is safe to perform single-stage revision arthroplasty for implant loosening based on history, examination, normal inflammatory markers, and negative aspiration results without the need for open biopsy.

Outcomes of Endoscopic Versus Open Spring Assisted Surgery for Sagittal Craniosynostosis.

Spring-assisted surgery (SAS) has been shown to be an effective technique for correction of isolated sagittal craniosynostosis in patients less than 6 months of age. At their institution, the authors adopted a minimally invasive technique in 2010, using a shorter incision and an endoscope. A retrospective chart review of 101 patients with isolated, nonsyndromic, sagittal craniosynostosis, who underwent SAS, was performed in order to compare perioperative and clinical outcomes of the open (n = 51) and minimally-invasive (n = 50) approaches. Surgeries were performed by 2 neurosurgeons and 3 plastic surgeons, between 2005 and 2018. The pre and postoperative cephalic indices were not significantly different in both groups. Minimally-invasive spring placement required a longer operative time than the open approach, with the mean minimally-invasive operative time at 65 minutes, compared to 53 minutes (P < 0.0001). Spring removal operative time was not significantly different, with the minimally-invasive operative time at 31 minutes versus 29 minutes (P = 0.48). There were no significant differences in major or minor complications when comparing the open and minimally-invasive approaches. In conclusion, both the open and the minimally-invasive SAS techniques are effective for early correction of isolated sagittal craniosynostosis, although the minimally-invasive approach requires a longer operative time for spring placement.

Translational strategies in drug development for knee osteoarthritis.

Osteoarthritis (OA) is a common disease worldwide with large unmet medical needs. To bring innovative treatments to OA patients, we at Merck have implemented a comprehensive strategy for drug candidate evaluation. We have a clear framework for decision-making in our preclinical pipeline, to design our clinical proof-of-concept trials for OA patients. We have qualified our strategy to define and refine dose and dosing regimen, for treatments administered either systemically or intra-articularly (IA). We do this through preclinical in vitro and in vivo studies, and by back-translating results from clinical studies in OA patients.

Cannabinoids in the Treatment of Back Pain.

Marijuana is increasingly utilized for the treatment of multiple medical problems, including back pain, in the United States. Although there is strong preclinical evidence supporting the promise of cannabinoids in the treatment of back pain, there is a paucity of clinical data supporting their use in clinical practice. Opioids are an important medication for the treatment of acute and chronic back pain, but utilization of opioid-based regimens have likely contributed to the growing opioid epidemic. The significant risk of morbidity, mortality, and dependence secondary to opioid medications have increased the interest in nonopioid medications, including cannabinoid-based pain regimens, in treating back pain. This review will provide an overview on the pharmacology, drug delivery methods, clinical evidence, and safety considerations critical to understanding the potential role of cannabinoids in the treatment of back pain.

Endovascular management of acute postprocedural flow diverting stent thrombosis.

INTRODUCTION: Postprocedural thrombosis is a rare complication after flow diverting stent (FD) implantation for aneurysm treatment with few reported cases in the literature. Management strategies and outcomes associated with this complication have not been reported. METHODS: A multicenter retrospective series of cases of acute postprocedural FD thrombosis were compiled and prevalence was calculated based on procedural volumes over a 7 year period. Acute postprocedural FD thrombosis was defined as the development of neurologic deficit with angiographic imaging demonstrating acute thrombus within the index FD stent at least 2 hours following completion of the implantation procedure. RESULTS: A total of 10 cases of postprocedural thrombosis were identified at five participating centers among a total of 768 patients treated (prevalence 1.3%). Thrombosis occurred a median of 5.5 days after implantation (range 0-83 days). 9/10 patients underwent emergent angiography with intent to perform endovascular reperfusion. A variety of different endovascular treatments were used, including aspiration thrombectomy, retrievable stent thrombectomy, balloon angioplasty, and intra-arterial thrombolytic infusion, without any procedural complications. There were no instances of FD migration, stent kinking, or aneurysm rupture. 90% of patients achieved Thrombolysis in Cerebral Infarction 2B or greater revascularization. Favorable clinical outcomes (modified Rankin Scale score of 0-2) at 3 months were achieved in 88% of patients. CONCLUSION: Acute postprocedural thrombosis of an FD is a rare complication that occurs in approximately 1-2% of patients after aneurysm treatment. Patients presenting with acute postprocedural FD thrombosis should be aggressively managed using large vessel occlusion thrombectomy techniques, as good angiographic and clinical outcomes are possible.

FAMILY FIRMS, BANK RELATIONSHIPS, AND FINANCIAL CONSTRAINTS: A COMPREHENSIVE SCORE CARD.

We examine the effect of financial constraints on firm investment and cash flow. We combine data from the Spanish Mercantile Registry and the Bank of Spain Credit Registry to classify firms according to whether they are family-owned, not family-owned, or belong to a family-linked network of firms and according to their number of banking relations (with none, one, or several banks). Our empirical strategy is structural, based on a dynamic model solved numerically to generate the joint distribution of firm capital (size), investment and cash flow, both in cross-sections and in panel data. We consider three alternative financial settings: saving only, borrowing and lending, and moral hazard constrained state-contingent credit. We estimate each setting via maximum likelihood and compare across these financial regimes. Based on the estimated financial regime, we show that family firms, especially those belonging to networks based on ownership, are associated with a more flexible market or contract environment and are less financially constrained than non-family firms. This result survives stratifications of family and non-family firms by bank status, region, industry and time period. Family firms are better able to allocate funds and smooth investment across states of the world and over time, arguably done informally or using the cash flow generated at the level of the network. We also validate our structural approach by demonstrating that it performs well in traditional categories, by stratifying firms by size and age and find that smaller and younger firms are more constrained than larger and older firms.

Comparison of de novo IgM and IgG anti-HLA DSAs between belatacept- and calcineurin-treated patients: An analysis of the BENEFIT and BENEFIT-EXT trial cohorts.

Preventing conversion of donor-specific anti-HLA antibodies (DSAs) from an IgM-to-IgG could a way to prevent chronic rejection. We evaluated whether belatacept-treated patients (belatacept less-intensive [LI] or more-intensive [MI] regimens) have a lower rate of conversion than do cyclosporine A (CsA)-treated patients. We included 330 HLA-mismatched patients from 2 phase 3 trials with either (a) complete donor/recipient HLA-A, -B, -DR, and -DQ loci typing or (b) incomplete HLA typing with IgG DSAs detected pretransplant or posttransplant. IgM and IgG DSAs were tested with single antigen beads at 0, 6, 12, 24, and 36 months posttransplant. The overall (preexisting or de novo) rates of IgM- and IgG-positive DSAs were 29% and 34%, respectively. The pretransplant IgM and IgG DSA-positive frequencies were similar between treatment groups. The IgG-positive dnDSA rate was significantly higher in the CsA-treated group (34%) compared with the belatacept-LI (8%) and belatacept-MI (11%) (P < .001) groups. In IgM-positive dnDSA patients, the IgG-positive dnDSA rate of conversion was 2.8 times higher in the CsA group than in the combined belatacept groups (P = .006). However, the observed association between belatacept treatment and more limited conversion of IgM-to-IgG dnDSAs was based on a limited number of patients and requires further validation.

Development of a Molecular Signature to Monitor Pharmacodynamic Responses Mediated by In Vivo Administration of Glucocorticoids.

OBJECTIVE: To develop an objective, readily measurable pharmacodynamic biomarker of glucocorticoid (GC) activity. METHODS: Genes modulated by prednisolone were identified from in vitro studies using peripheral blood mononuclear cells from normal healthy volunteers. Using the criteria of a >2-fold change relative to vehicle controls and an adjusted P value cutoff of less than 0.05, 64 up-regulated and 18 down-regulated genes were identified. A composite score of the up-regulated genes was generated using a single-sample gene set enrichment analysis algorithm. RESULTS: GC gene signature expression was significantly elevated in peripheral blood leukocytes from normal healthy volunteers following oral administration of prednisolone. Expression of the signature increased in a dose-dependent manner, peaked at 4 hours postadministration, and returned to baseline levels by 48 hours after dosing. Lower expression was detected in normal healthy volunteers who received a partial GC receptor agonist, which is consistent with the reduced transactivation potential of this compound. In cohorts of patients with systemic lupus erythematosus and patients with rheumatoid arthritis, expression of the GC signature was negatively correlated with the percentages of peripheral blood lymphocytes and positively correlated with peripheral blood neutrophil counts, which is consistent with the known biology of the GC receptor. Expression of the signature largely agreed with reported GC use in these populations, although there was significant interpatient variability within the dose cohorts. CONCLUSION: The GC gene signature identified in this study represents a pharmacodynamic marker of GC exposure.