Urate-lowering therapy in patients with hyperuricemia and heart failure: A retrospective cohort study using the UK Clinical Practice Research Datalink.

BACKGROUND: Elevated serum uric acid (sUA) is associated with heart failure (HF). HYPOTHESIS: Urate-lowering therapy (ULT) in HF is associated with lower risk of HF hospitalization (hHF) and mortality. METHODS: Data on patients with HF and gout or hyperuricemia in the Clinical Practice Research Datalink database linked to the Hospital Episode Statistics and the Office for National Statistics in the United Kingdom were analyzed. Risks of hHF and all-cause mortality or cardiovascular-related mortality by ULT exposure (ULT initiated within ≤6 months of gout or hyperuricemia diagnosis) were analyzed in a propensity score-matched cohort using adjusted Cox proportional hazards regression models. RESULTS: Of 2174 propensity score-matched pairs, patients were predominantly male, aged >70 years, with mean ± standard deviation sUA 9.3 ± 1.8 (ULT-exposed) and 9.4 ± 1.9 mg/dL (ULT-unexposed). At 5 years, ULT-exposed patients had a 43% lower risk of hHF or all-cause mortality (adjusted hazard ratio [HR]: 0.57; 95% confidence interval [CI]: 0.51-0.65) and a 19% lower risk of hHF or cardiovascular-related mortality (adjusted HR: 0.81; 95% CI: 0.71-0.92) versus no ULT exposure. CONCLUSION: ULT was associated with reduced risk of adverse clinical outcomes in patients with HF and gout or hyperuricemia over 5 years.

Verinurad does not prolong QTc interval: a thorough QT study using concentration-QTc modelling.

AIM: This thorough QT/QTc (TQT) study was conducted to evaluate the risk of QT prolongation for verinurad when combined with allopurinol. Verinurad is a novel, urate anion exchanger 1 inhibitor that reduces serum urate levels by promoting urinary excretion of uric acid. It is co-administered with a xanthine oxidase inhibitor. METHODS: The TQT study (NCT04256629) was a randomized, placebo-controlled, double-blind, three-period, crossover study, conducted in healthy volunteers. A total of 24 participants received single doses of verinurad 24 mg extended release, 40 mg immediate release formulation (both co-administered with allopurinol 300 mg), and matching placebos. The primary endpoint was baseline- and placebo-adjusted Fridericia-corrected QTcF interval (ΔΔQTcF) at the concentration of interest. A prespecified linear mixed-effects concentration-QTc model was used to estimate the primary endpoint. Time-matched 12-lead digital electrocardiograms and plasma concentrations were measured at baseline and up to 48 h after dose in each participant. RESULTS: Estimated ΔΔQTcF at the highest clinically relevant scenario (76 ng/mL) was -2.7 msec (90% confidence interval [CI]: -4.6, -0.8). Furthermore, the upper 90% ΔΔQTcF CI was estimated to be below 10 msec at all observed verinurad concentrations. Supratherapeutic verinurad dose was used to achieve exposures eightfold higher than the highest clinically relevant exposure, thus waiving the need for positive control. CONCLUSIONS: As the effect on ΔΔQTcF was below the threshold for regulatory concern (10 msec) at the supratherapeutic exposure, it can be concluded that verinurad and allopurinol treatment does not induce QTcF prolongation at the highest clinically relevant exposures.

Rationale, design, demographics and baseline characteristics of the randomized, controlled, Phase 2b SAPPHIRE study of verinurad plus allopurinol in patients with chronic kidney disease and hyperuricaemia.

BACKGROUND: Verinurad is a human uric acid (UA) transporter (URAT1) inhibitor known to decrease serum UA (sUA) levels and that may reduce albuminuria. In a Phase 2a study (NCT03118739), treatment with verinurad + febuxostat lowered urine albumin-to-creatinine ratio (UACR) at 12 weeks by 39% (90% confidence interval 4-62%) among patients with Type 2 diabetes mellitus, hyperuricaemia and albuminuria. The Phase 2b, randomized, placebo-controlled Study of verinurAd and alloPurinol in Patients with cHronic kIdney disease and hyperuRicaEmia (SAPPHIRE; NCT03990363) will examine the effect of verinurad + allopurinol on albuminuria and estimated glomerular filtration rate (eGFR) slope among patients with chronic kidney disease (CKD) and hyperuricaemia. METHODS: Adults (≥18 years of age) with CKD, eGFR ≥25 mL/min/1.73 m2, UACR 30-5000 mg/g and sUA ≥6.0 mg/dL will be enrolled. Approximately 725 patients will be randomized 1:1:1:1:1 to 12, 7.5 or 3 mg verinurad + allopurinol, allopurinol or placebo. An 8-week dose-titration period will precede a 12-month treatment period; verinurad dose will be increased to 24 mg at Month 9 in a subset of patients in the 3 mg verinurad + allopurinol arm. The primary efficacy endpoint the is change from baseline in UACR at 6 months. Secondary efficacy endpoints include changes in UACR, eGFR and sUA from baseline at 6 and 12 months. CONCLUSIONS: This study will assess the combined clinical effect of verinurad + allopurinol on kidney function in patients with CKD, hyperuricaemia and albuminuria, and whether this combination confers renoprotection beyond standard-of-care.

Comparison of Characteristics and Outcomes of Patients With Heart Failure With Preserved Ejection Fraction With Versus Without Hyperuricemia or Gout.

Hyperuricemia and gout are common in patients with heart failure (HF) and are associated with poor outcomes. Data describing hyperuricemia and gout in patients with HF with preserved ejection fraction (HFpEF) are limited. We used data from the Duke University Health System to describe characteristics of patients with HFpEF and hyperuricemia (serum uric acid >6 mg/dl) or gout (gout diagnosis or gout medication within the previous year) and to explore associations with 5-year outcomes (death and hospitalization). We identified 7,004 patients in the Duke University Health System with a known diagnosis of HFpEF who underwent transthoracic echocardiography between January 1, 2005 and December 31, 2017. A total of 1,136 (16.2%) patients with HFpEF also had hyperuricemia or gout. Patients with HFpEF and hyperuricemia or gout had a greater co-morbidity burden, more echocardiographic findings of cardiac remodeling, and higher unadjusted rates of all-cause death, all-cause hospitalization, and HF hospitalization compared with those with HFpEF without hyperuricemia or gout. After multivariable adjustment, patients with HFpEF and hyperuricemia or gout had a significantly higher rates of first all-cause hospitalization (adjusted hazard ratio 1.10 [95% confidence interval 1.02 to 1.19]; p = 0.020) and recurrent all-cause hospitalization (associated rate ratio 1.13 [95% confidence interval 1.01 to 1.25]; p = 0.026). After adjustment, no significant differences in death or HF hospitalization were observed. In conclusion, patients with HFpEF and hyperuricemia or gout were found to have a higher burden of co-morbidities and a higher rate of all-cause hospitalization, even after multivariable adjustment, compared to patients with HFpEF without hyperuricemia or gout.

Elevated Uric Acid Prevalence and Clinical Outcomes in Patients with Heart Failure with Preserved Ejection Fraction: Insights from RELAX.

PURPOSE: We aimed to 1) describe characteristics of patients with heart failure with preserved ejection fraction (HFpEF) enrolled in RELAX stratified by normal or elevated baseline serum uric acid (sUA) level; 2) evaluate the association between sUA level and surrogate clinical measures; and 3) assess associations between changes in sUA level over time and changes in surrogate clinical measures. METHODS: We analyzed 212 patients with HFpEF and normal or elevated (>6 mg/dL) baseline sUA measurements from the RELAX trial. Variables examined included clinical characteristics, cardiopulmonary exercise testing, 6-minute walk testing, quality of life, echocardiography, and serum biomarker testing. Baseline characteristics between groups were compared and scatter plots with quadratic regression lines and linear regression modeling were used to assess the relationship between baseline sUA and clinical measures. Kaplan-Meier curves were used to describe composite death or cardiovascular/renal hospitalization. RESULTS: The prevalence of elevated baseline sUA was 68.9%. Patients with elevated sUA had more baseline comorbidities and poorer functional status on cardiopulmonary exercise testing than those without. After adjustment, significant associations between baseline sUA levels and cystatin C, N-terminal pro B-type natriuretic peptide, high-sensitivity troponin I, and high-sensitivity C-reactive protein were identified. Higher baseline sUA was also associated with worsening peak VO2, 6-minute walk testing, and left ventricular mass. No significant association was found between baseline sUA levels and the composite of death or cardiovascular/renal hospitalization at 24 weeks. CONCLUSION: sUA is an important marker of comorbidities and functional status in patients with HFpEF. Clinical trials of sUA-lowering therapies in patients with HFpEF are promising.

Effects of rosuvastatin on the immune system in healthy volunteers with normal serum cholesterol.

BACKGROUNDHMG-CoA reductase inhibitors (statins) are prescribed to millions of people. Statins are antiinflammatory independent of their cholesterol-reducing effects. To date, most reports on the immune effects of statins have assayed a narrow array of variables and have focused on cell lines, rodent models, or patient cohorts. We sought to define the effect of rosuvastatin on the "immunome" of healthy, normocholesterolemic subjects.METHODSWe conducted a prospective study of rosuvastatin (20 mg/d × 28 days) in 18 statin-naive adults with LDL cholesterol <130 mg/dL. A panel of >180 immune/biochemical/endocrinologic variables was measured at baseline and on days 14, 28, and 42 (14 days after drug withdrawal). Drug effect was evaluated using linear mixed-effects models. Potential interactions between drug and baseline high-sensitivity C-reactive protein (hsCRP) were evaluated.RESULTSA wide array of immune measures changed (nominal P < 0.05) during rosuvastatin treatment, although the changes were modest in magnitude, and few met an FDR of 0.05. Among changes noted were a concordant increase in proinflammatory cytokines (IFN-γ, IL-1ß, IL-5, IL-6, and TNF-α) and peripheral blood neutrophil frequency, and a decline in activated Treg frequency. Several drug effects were significantly modified by baseline hsCRP, and some did not resolve after drug withdrawal. Among other unexpected rosuvastatin effects were changes in erythrocyte indices, glucose-regulatory hormones, CD8+ T cells, and haptoglobin.CONCLUSIONRosuvastatin induces modest changes in immunologic and metabolic measures in normocholesterolemic subjects, with several effects dependent on baseline CRP. Future, larger studies are warranted to validate these changes and their physiological significance.TRIAL REGISTRATIONClinicalTrials.gov NCT01200836.FUNDINGThis research was supported by the Intramural Research Program of the NIH, National Institute of Environmental Health Sciences (Z01 ES102005), and the trans-NIH Center for Human Immunology.

Triple therapy with low-dose dapagliflozin plus saxagliptin versus dual therapy with each monocomponent, all added to metformin, in uncontrolled type 2 diabetes.

AIM: To evaluate the efficacy and safety of triple therapy with low-dose dapagliflozin plus saxagliptin added to metformin in uncontrolled type 2 diabetes. MATERIALS AND METHODS: This 24-week, double-blind trial (NCT02681094) randomized 883 patients (glycated haemoglobin [HbA1c] 7.5-10.0%) on metformin ≥1500 mg/d to add-on dapagliflozin 5 mg/d plus saxagliptin 5 mg/d or to add-on of either monocomponent. The primary endpoint was change in HbA1c from baseline. RESULTS: Baseline mean ± SD patient characteristics were: age 56.7 ± 10.5 years; HbA1c 8.2 ± 0.9%; and diabetes duration 7.6 ± 6.1 years. Triple therapy significantly decreased HbA1c versus dual therapy (-1.03% vs. -0.63% [dapagliflozin] vs. -0.69% [saxagliptin]; P < .0001). More patients achieved HbA1c <7.0% with triple versus dual therapy (41.6% vs. 21.8% [dapagliflozin; P < .0001] vs. 29.8% [saxagliptin; P = .0018]). Triple therapy significantly decreased fasting plasma glucose (-1.5 mmol/L vs. -1.1 mmol/L [dapagliflozin; P = .0135] vs. -0.7 mmol/L [saxagliptin; P < .0001]) and body weight (-2.0 kg vs. -0.4 kg [saxagliptin; P < .0001]), and ß-hydroxybutyrate levels were lower than with dapagliflozin plus metformin (mean difference -0.51; P = .0009). Urinary tract/genital infections and hypoglycaemia occurred in <5.0% and 5.8% of patients, respectively, with triple therapy. CONCLUSIONS: Triple therapy with once-daily dapagliflozin 5 mg, saxagliptin 5 mg and metformin significantly improved glycaemic control versus dual therapy with either agent added to metformin in uncontrolled type 2 diabetes, and was generally well tolerated.

The Immunome in Two Inherited Forms of Pulmonary Fibrosis.

The immunome (immune cell phenotype, gene expression, and serum cytokines profiling) in pulmonary fibrosis is incompletely defined. Studies focusing on inherited forms of pulmonary fibrosis provide insights into mechanisms of fibrotic lung disease in general. To define the cellular and molecular immunologic phenotype in peripheral blood, high-dimensional flow cytometry and large-scale gene expression of peripheral blood mononuclear cells and serum proteomic multiplex analyses were performed and compared in a cohort with familial pulmonary fibrosis (FPF), an autosomal dominant disorder with incomplete penetrance; Hermansky-Pudlak syndrome pulmonary fibrosis (HPSPF), a rare autosomal recessive disorder; and their unaffected relatives. Our results showed high peripheral blood concentrations of activated central memory helper cells in patients with FPF. Proportions of CD38+ memory CD27- B-cells, IgA+ memory CD27+ B-cells, IgM+ and IgD+ B-cells, and CD39+ T helper cells were increased whereas those of CD39- T helper cells were reduced in patients affected with either familial or HPSPF. Gene expression and serum proteomic analyses revealed enrichment of upregulated genes associated with mitosis and cell cycle control in circulating mononuclear cells as well as altered levels of several analytes, including leptin, cytokines, and growth factors. In conclusion, dysregulation of the extra-pulmonary immunome is a phenotypic feature of FPF or HPSPF. Further studies investigating the blood immunome are indicated to determine the role of immune system dysregulation in the pathogenesis of pulmonary fibrosis. Clinical Trial Registration: www.ClinicalTrials.gov, identifiers NCT00968084, NCT01200823, NCT00001456, and NCT00084305.

The Lifespan and Turnover of Microglia in the Human Brain.

The hematopoietic system seeds the CNS with microglial progenitor cells during the fetal period, but the subsequent cell generation dynamics and maintenance of this population have been poorly understood. We report that microglia, unlike most other hematopoietic lineages, renew slowly at a median rate of 28% per year, and some microglia last for more than two decades. Furthermore, we find no evidence for the existence of a substantial population of quiescent long-lived cells, meaning that the microglia population in the human brain is sustained by continuous slow turnover throughout adult life.

Effects of Glimepiride versus Saxagliptin on ß-Cell Function and Hypoglycemia: A Post Hoc Analysis in Older Patients with Type 2 Diabetes Inadequately Controlled with Metformin.

PURPOSE: The management of hyperglycemia is challenging in older patients with type 2 diabetes owing to excess fragility and risk for adverse outcomes should hypoglycemia episodes occur. We evaluated baseline ß-cell function as a potential risk factor for the development of hypoglycemia when saxagliptin or glimepiride was added in patients aged ≥65 years whose type 2 diabetes was poorly controlled on stable metformin monotherapy. METHODS: A post hoc analysis of data from the GENERATION (Efficacy and Tolerability of Saxagliptin Compared with Glimepiride in Elderly Patients with Type 2 Diabetes: A Randomized, Controlled Study) trial, which enrolled 720 patients aged ≥65 years, was conducted. ß-Cell function was assessed using homeostasis model assessment-2%ß (HOMA-2%ß). FINDINGS: The percentage of patients experiencing any hypoglycemia event (ie, symptomatic event or event of plasma glucose concentration <54 mg/dL regardless of symptoms) was lower with saxagliptin compared with glimepiride (5.8% vs 34.8%). Regardless of treatment, patients with lower (median HOMA-2%ß ≤39.1% [≤median]) versus higher (HOMA-2%ß above median value [>median]) baseline ß-cell function had a higher hypoglycemia event rate (1.27 vs 0.82 events/patient-year; adjusted incidence rate ratio [IRR] = 1.800; 95% CI, 1.501-2.159). In patients receiving glimepiride, the hypoglycemia event rate was higher in patients with baseline HOMA-2%ß ≤median versus >median (2.29 vs 1.60 events/patient-year; adjusted IRR = 1.737; 95% CI, 1.439-2.097); corresponding saxagliptin hypoglycemia event rates were too low to draw meaningful conclusions (0.16 vs 0.09 events/patient-year; adjusted IRR = 2.457; 95% CI, 1.148-5.256). The association between lower ß-cell function at baseline and increased prevalence of hypoglycemia was particularly strong in patients aged ≥75 years (adjusted IRR = 2.409; 95% CI, 1.686-3.442; P < 0.001), although it was also significant in patients aged 65 to <75 years old (adjusted IRR, 1.654; 95% CI, 1.339-2.043; P < 0.001). IMPLICATIONS: In patients with lower ß-cell function, the addition of a sulfonylurea to a metformin regimen was associated with an increased risk for hypoglycemia compared with that in patients with higher ß-cell function; low hypoglycemia event rates with the addition of saxagliptin limited equivalent assessments. These findings in older patients are especially relevant because morbidity associated with hypoglycemia is higher in this age group. ClinicalTrials.gov identifier: NCT01006603 (ClinicalTrials.gov).

Saxagliptin Efficacy and Safety in Patients With Type 2 Diabetes and Moderate Renal Impairment.

INTRODUCTION: Type 2 diabetes (T2D) is the leading cause of chronic kidney disease (CKD). The recommended dose of the dipeptidyl peptidase-4 inhibitor saxagliptin is 2.5 mg in patients with moderate or severe renal impairment (creatinine clearance ≤50 mL/min). In this post hoc analysis, we assessed the effect of saxagliptin 2.5 and 5 mg/day versus placebo on glycemic measures in patients with T2D and estimated glomerular filtration rate 45-60 mL/min/1.73 m(2). METHODS: Efficacy and safety data were pooled from nine 24-week, randomized, placebo-controlled clinical trials. RESULTS: The majority (56-61%) of patients were women aged <65 years with glycated hemoglobin (A1C) 8.1-8.2%; half of the patients had a T2D duration ≥5 years. Mean change from baseline in A1C was significantly greater with saxagliptin 2.5 (-0.6%, P = 0.036 vs placebo) and 5 mg/day (-0.9%, P < 0.001 vs placebo) compared with placebo (-0.2%). There were numerically greater reductions in fasting plasma glucose and 2-h postprandial glucose, and a significantly greater proportion of patients achieved A1C <7% with saxagliptin 5 mg/day (44.8%) compared with placebo (20.0%, P = 0.004 vs placebo). The incidence of hypoglycemia was not significantly different across groups (16.2% in the saxagliptin 5-mg/day, 12.2% in the saxagliptin 2.5-mg/day, and 11.3% in the placebo groups). CONCLUSION: These results suggest that saxagliptin 2.5 and 5 mg/day improve glycemic control and are generally well tolerated in patients with T2D and moderate CKD. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT00121641, NCT00316082, NCT00698932, NCT00918879, NCT00121667, NCT00661362, NCT00313313, NCT00295633, NCT00757588. FUNDING: AstraZeneca, Gaithersburg, MD, USA.

Rosuvastatin Alters the Proteome of High Density Lipoproteins: Generation of alpha-1-antitrypsin Enriched Particles with Anti-inflammatory Properties.

Statins lower plasma cholesterol by as much as 50%, thus reducing future cardiovascular events. However, the physiological effects of statins are diverse and not all are related to low density lipoprotein cholesterol (LDL-C) lowering. We performed a small clinical pilot study to assess the impact of statins on lipoprotein-associated proteins in healthy individuals (n = 10) with normal LDL-C (<130 mg/dL), who were treated with rosuvastatin (20 mg/day) for 28 days. Proteomic analysis of size-exclusion chromatography isolated LDL, large high density lipoprotein (HDL-L), and small HDL (HDL-S) fractions and spectral counting was used to compare relative protein detection before and after statin therapy. Significant protein changes were found in each lipoprotein pool and included both increases and decreases in several proteins involved in lipoprotein metabolism, complement regulation and acute phase response. The most dramatic effect of the rosuvastatin treatment was an increase in α-1-antirypsin (A1AT) spectral counts associated with HDL-L particles. Quantitative measurement by ELISA confirmed an average 5.7-fold increase in HDL-L associated A1AT. Molecular modeling predictions indicated that the hydrophobic reactive center loop of A1AT, the functional domain responsible for its protease inhibitor activity, is likely involved in lipid binding and association with HDL was found to protect A1AT against oxidative inactivation. Cell culture experiments, using J774 macrophages, demonstrated that the association of A1AT with HDL enhances its antiprotease activity, preventing elastase induced production of tumor necrosis factor α. In conclusion, we show that statins can significantly alter the protein composition of both LDL and HDL and our studies reveal a novel functional relationship between A1AT and HDL. The up-regulation of A1AT on HDL enhances its anti-inflammatory functionality, which may contribute to the non-lipid lowering beneficial effects of statins.

Dynamics of oligodendrocyte generation and myelination in the human brain.

The myelination of axons by oligodendrocytes has been suggested to be modulated by experience, which could mediate neural plasticity by optimizing the performance of the circuitry. We have assessed the dynamics of oligodendrocyte generation and myelination in the human brain. The number of oligodendrocytes in the corpus callosum is established in childhood and remains stable after that. Analysis of the integration of nuclear bomb test-derived (14)C revealed that myelin is exchanged at a high rate, whereas the oligodendrocyte population in white matter is remarkably stable in humans, with an annual exchange of 1/300 oligodendrocytes. We conclude that oligodendrocyte turnover contributes minimally to myelin modulation in human white matter and that this instead may be carried out by mature oligodendrocytes, which may facilitate rapid neural plasticity.

Ultra-low dose interleukin-2 promotes immune-modulating function of regulatory T cells and natural killer cells in healthy volunteers.

Low-dose interleukin-2 (IL-2) expands regulatory T cells (Tregs) and natural killer (NK) cells after stem cell transplantation (SCT) and may reduce graft-versus-host disease (GVHD). We hypothesized that ultra-low dose (ULD) IL-2 could serve as an immune-modulating agent for stem cell donors to prevent GVHD following SCT. However, the safety, dose level, and immune signatures of ULD IL-2 in immune-competent healthy subjects remain unknown. Here, we have characterized the phenotype and function of Tregs and NK cells as well as the gene expression and cytokine profiles of 21 healthy volunteers receiving 50,000 to 200,000 units/m(2)/day IL-2 for 5 days. ULD IL-2 was well tolerated and induced a significant increase in the frequency of Tregs with increased suppressive function. There was a marked expansion of CD56(bright) NK cells with enhanced interferon-γ (IFN-γ) production. Serum cytokine profiling demonstrated increase of IFN-γ induced protein 10 (IP-10). Gene expression analysis revealed significant changes in a highly restricted set of genes, including FOXP3, IL-2RA, and CISH. This is the first study to evaluate global immune-modulating function of ULD IL-2 in healthy subjects and to support the future studies administrating ULD IL-2 to stem cell donors.

Global analyses of human immune variation reveal baseline predictors of postvaccination responses.

A major goal of systems biology is the development of models that accurately predict responses to perturbation. Constructing such models requires the collection of dense measurements of system states, yet transformation of data into predictive constructs remains a challenge. To begin to model human immunity, we analyzed immune parameters in depth both at baseline and in response to influenza vaccination. Peripheral blood mononuclear cell transcriptomes, serum titers, cell subpopulation frequencies, and B cell responses were assessed in 63 individuals before and after vaccination and were used to develop a systematic framework to dissect inter- and intra-individual variation and build predictive models of postvaccination antibody responses. Strikingly, independent of age and pre-existing antibody titers, accurate models could be constructed using pre-perturbation cell populations alone, which were validated using independent baseline time points. Most of the parameters contributing to prediction delineated temporally stable baseline differences across individuals, raising the prospect of immune monitoring before intervention.

Neurogenesis in the striatum of the adult human brain.

In most mammals, neurons are added throughout life in the hippocampus and olfactory bulb. One area where neuroblasts that give rise to adult-born neurons are generated is the lateral ventricle wall of the brain. We show, using histological and carbon-14 dating approaches, that in adult humans new neurons integrate in the striatum, which is adjacent to this neurogenic niche. The neuronal turnover in the striatum appears restricted to interneurons, and postnatally generated striatal neurons are preferentially depleted in patients with Huntington's disease. Our findings demonstrate a unique pattern of neurogenesis in the adult human brain.

Baseline levels and temporal stability of 27 multiplexed serum cytokine concentrations in healthy subjects.

BACKGROUND: Cytokines are humoral molecules that elicit regulatory function in immunologic pathways. The level and type of cytokine production has become critical in distinguishing physiologic from pathologic immune conditions. Cytokine profiling has become an important biomarker discovery tool in monitoring of the immune system. However, the variations in cytokine levels in individual subjects over time in healthy individuals have not been extensively studied. In this study, we use multiplex bead arrays to evaluate 27 analytes in paired serum samples taken seven days apart from 144 healthy individuals in order to assess variations over a short time period. METHODS: Fluorescent bead-based immunoassay (Luminex) was used to measure 27 analytes in serum samples. Measurements were performed on matched samples from 144 healthy donors. To assess inter-plate variability, one arbitrarily selected serum sample was analyzed on each of the first ten plates as bridge sample. RESULTS: Using the bridge sample, we showed minimal inter-plate variations in the measurement of most analytes. In measurement of cytokines from the 144 patients at two time points, we found that three cytokines (IL-2, IL-15 and GM-CSF) were undetectable and five analytes (RANTES, MCP-1, VEGF, MIP-1ß and PDGF-BB) showed significant difference in concentrations at Day 0 compared to Day 7. CONCLUSIONS: The current study demonstrated higher variations in cytokine levels among individuals than were observed for samples obtained one week apart from identical donors. These data suggest that a serum sample from each subject for use as a baseline measurement is a better control for clinical trials rather than sera from a paired cohort.

Addition of rapamycin to anti-CD3 antibody improves long-term glycaemia control in diabetic NOD mice.

AIMS/HYPOTHESIS: Non-Fc-binding Anti CD3 antibody has proven successful in reverting diabetes in the non-obese diabetes mouse model of type 1 diabetes and limited efficacy has been observed in human clinical trials. We hypothesized that addition of rapamycin, an mTOR inhibitor capable of inducing operational tolerance in allogeneic bone marrow transplantation, would result in improved diabetes reversal rates and overall glycemia. METHODS: Seventy hyperglycemic non-obese diabetic mice were randomized to either a single injection of anti CD3 alone or a single injection of anti CD3 followed by 14 days of intra-peritoneal rapamycin. Mice were monitored for hyperglycemia and metabolic control. RESULTS: Mice treated with the combination of anti CD3 and rapamycin had similar rates of diabetes reversal compared to anti CD3 alone (25/35 vs. 22/35). Mice treated with anti CD3 plus rapamycin had a significant improvement in glycemia control as exhibited by lower blood glucose levels in response to an intra-peritoneal glucose challenge; average peak blood glucose levels 30 min post intra-peritoneal injection of 2 gr/kg glucose were 6.9 mmol/L in the anti CD3 plus rapamycin group vs. 10 mmo/L in the anti CD3 alone (P<0.05). CONCLUSIONS/INTERPRETATION: The addition of rapamycin to anti CD3 results in significant improvement in glycaemia control in diabetic NOD mice.