Identifying Patients with Polycythemia Vera at Risk of Thrombosis after Hydroxyurea Initiation: The Polycythemia Vera-Advanced Integrated Models (PV-AIM) Project.

Patients with polycythemia vera (PV) are at significant risk of thromboembolic events (TE). The PV-AIM study used the Optum® de-identified Electronic Health Record dataset and machine learning to identify markers of TE in a real-world population. Data for 82,960 patients with PV were extracted: 3852 patients were treated with hydroxyurea (HU) only, while 130 patients were treated with HU and then changed to ruxolitinib (HU-ruxolitinib). For HU-alone patients, the annualized incidence rates (IR; per 100 patients) decreased from 8.7 (before HU) to 5.6 (during HU) but increased markedly to 10.5 (continuing HU). Whereas for HU-ruxolitinib patients, the IR decreased from 10.8 (before HU) to 8.4 (during HU) and was maintained at 8.3 (after switching to ruxolitinib). To better understand markers associated with TE risk, we built a machine-learning model for HU-alone patients and validated it using an independent dataset. The model identified lymphocyte percentage (LYP), neutrophil percentage (NEP), and red cell distribution width (RDW) as key markers of TE risk, and optimal thresholds for these markers were established, from which a decision tree was derived. Using these widely used laboratory markers, the decision tree could be used to identify patients at high risk for TE, facilitate treatment decisions, and optimize patient management.

Benefit of Early Ruxolitinib Initiation Regardless of Fibrosis Grade in Patients with Primary Myelofibrosis: A Post Hoc Analysis of the Single-Arm Phase 3b JUMP Study.

Bone marrow fibrosis (BMF) is an adverse prognostic factor for myelofibrosis (MF). The single-arm, open-label, phase 3b JUMP trial (NCT01493414) assessed the safety and efficacy of the JAK1/JAK2 inhibitor ruxolitinib in patients with symptomatic MF. This post hoc analysis investigated the impact of BMF grade on response and outcomes in patients with primary MF (PMF) from the JUMP study. BMF was assessed by biopsy and graded from 0 to 3; grades 0-1 were considered low-grade fibrosis (LGF) and grades 2-3 were considered high-grade fibrosis (HGF). Patients with LGF (n = 268) had lower rates of cytopenias at baseline but showed comparable disease burden vs. patients with HGF (n = 852). The proportion of patients achieving a spleen response was greater in the LGF group vs. the HGF group at Week 24 and at any time during the study, while overall survival estimates were improved in patients with LGF vs. patients with HGF. Early initiation of ruxolitinib therapy (within 2 years of diagnosis) was associated with increased response rates in all patients. These results highlight the efficacy of ruxolitinib in symptomatic patients with PMF, with the greatest clinical improvements observed in patients with LGF and in patients who received early treatment.

CCR5Delta32 genotype is associated with outcome in type 2 diabetes mellitus.

AIMS: To test whether the genetic variant CCR5Delta32 in the CC-chemokine receptor 5, which is known to lead to CCR5 deficiency, is associated with mortality in type 2 diabetes patients. METHODS: We examined the effect of presence or absence of the CCR5Delta32 on overall and cardiovascular mortality risk in the Zwolle Outpatient Diabetes project Integrating Available Care (ZODIAC) cohort, a type 2 diabetes patient cohort. RESULTS: We studied 756 patients with a mean duration of follow-up of 5.4 (+/- 1.4) years. 194 patients died during follow up of which 83 were cardiovascular deaths. 144 subjects (19%) carried the CCR5Delta32 deletion. CCR5Delta32 carriers had an adjusted hazard ratio of 0.62 (95%CI: 0.40-0.96; p=0.03) for all-cause mortality and 0.63 (95%CI: 0.33-1.19; p=0.16) for cardiovascular mortality. CONCLUSIONS: The presence of CCR5Delta32 is associated with better survival in type 2 diabetes patients. These data suggest that it is worthwhile to explore the protective potential of pharmacological blockade of CCR5 in type 2 diabetic patients.

CCR5 deletion protects against inflammation-associated mortality in dialysis patients.

The CC-chemokine receptor 5 (CCR5) is a receptor for various proinflammatory chemokines, and a deletion variant of the CCR5 gene (CCR5 Delta 32) leads to deficiency of the receptor. We hypothesized that CCR5 Delta 32 modulates inflammation-driven mortality in patients with ESRD. We studied the interaction between CCR5 genotype and levels of high-sensitivity C-reactive protein (hsCRP) in 603 incident dialysis patients from the multicenter, prospective NEtherlands COoperative Study on the Adequacy of Dialysis (NECOSAD) cohort. CCR5 genotype and hsCRP levels were both available for 413 patients. During 5 yr of follow-up, 170 patients died; 87 from cardiovascular causes. Compared with the reference group of patients who had the wild-type CCR5 genotype and hsCRP 10 mg/L (n = 108) had an increased risk for mortality (HR: 1.82; 95% CI: 1.29 to 2.58). However, those carrying the deletion allele with hsCRP > 10 mg/L (n = 25) had a mortality rate similar to the reference group; this seemingly protective effect of the CCR5 deletion was even more pronounced for cardiovascular mortality. We replicated these findings in an independent Swedish cohort of 302 ESRD patients. In conclusion, the CCR5 Delta 32 polymorphism attenuates the adverse effects of inflammation on overall and cardiovascular mortality in ESRD.

Association between donor MBL promoter haplotype and graft survival and the development of BOS after lung transplantation.

BACKGROUND: Lung transplantation is a well accepted therapy for end-stage lung disease, despite high mortality rates. Mortality after transplantation is mainly caused by allograft failure in the first years after transplantation. Mannose binding lectin (MBL), a recognition molecule of innate immunity, has been associated with transplant outcome in other solid organ transplantation. In this study, the effect of donor- and recipient-MBL genotype on lung transplant outcome was investigated. MATERIALS AND METHODS: All lung transplantations performed in our center, except from retransplantations and combined lung-liver or heart-lung transplantations, were included. Genotyping of the MBL2 variants (promoter: L/H, Y/X, and P/Q allele and exon 1: A/D, A/B, and A/C allele) was performed in donor and recipient DNA. Analyses on graft survival and the development of bronchiolitis obliterans syndrome were performed with Kaplan-Meier (log rank) survival analysis. RESULTS: Of the 277 included cases, DNA was available from 189 donors and 200 recipients and genotyping of the promoter single nucleotide polymorphisms was successful in 184 donors and 198 recipients and of the exon 1 single nucleotide polymorphisms in 181 donors and 193 recipients. Patients who received a graft from a donor with an X-allele had better graft survival (P=0.007) and bronchiolitis obliterans syndrome free survival (P=0.007). Recipient MBL genotype was not associated with transplant outcome. CONCLUSION: The donor X-allele, which corresponds to the LXPA haplotype is associated with superior lung transplant outcome. Our findings might prove to be important in finding ways to optimize outcome after lung transplantation.

Renal function dependent association of AGTR1 polymorphism (A1166C) and electrocardiographic left-ventricular hypertrophy.

BACKGROUND: The association of renin-angiotensin system (RAS) polymorphisms and left-ventricular hypertrophy (LVH) may depend on the presence of risk factors for LVH, such as renal dysfunction. We studied whether renal function modulates the association between RAS polymorphisms and LVH in a cross-sectional study of 8592 inhabitants of Groningen. METHODS: Left-ventricular hypertrophy was determined with electrocardiograms, using the Cornell voltage-duration product. The following RAS polymorphisms were determined: angiotensin II type-1 receptor (AGTR1 A1166C), angiotensin-converting enzyme (ACE) insertion/deletion (I/D), and angiotensinogen (AGT G-6A). The AGTR1 A1166C and ACE I/D polymorphisms were in Hardy-Weinberg equilibrium. RESULTS: Electrocardiographic LVH was present in 417 (5.0%) subjects. Subjects with LVH were older (53 v 49 years) and overall had more cardiovascular risk factors. Using logistic regression, creatinine clearance interacted with the relationship between the AGTR1 A1166C polymorphism and LVH (beta, -0.19; P = .033). In subjects with the CC genotype, in contrast to carriers of an A allele, the prevalence of LVH increased with more pronounced renal dysfunction. Creatinine clearance also interacted with the relationship between the ACE I/D polymorphism and LVH (beta, 0.12; P = .037), although less strongly, and the other way around. Creatinine clearance did not influence the association between the AGT G-6A polymorphism and LVH (beta, -0.006; P = .491). CONCLUSIONS: In this population-based study, the AGTR1 A1166C polymorphism was associated with LVH, dependent on concomitant renal dysfunction. A weaker renal function dependent association between the ACE I/D polymorphism and LVH was also observed. Renal function should be taken into account as a relevant environmental factor for the pathogenetic effects of RAS polymorphisms.

Low levels of sRAGE are associated with increased risk for mortality in renal transplant recipients.

OBJECTIVE: Infusion of the soluble form of the receptor for advanced glycation end-products (sRAGE) was protective against atherosclerosis and nephropathy in animal models. In this study we investigated determinants of endogenous sRAGE in renal transplant recipients and whether sRAGE was associated with mortality and graft loss. METHODS AND RESULTS: A total of 591 patients participated at a median time of 6 years after transplantation. Independent determinants of sRAGE were mycophenolate mofetil medication (beta=-0.21, P<0.001), creatinine clearance (beta=-0.15, P<0.001), BMI (beta=-0.12, P=0.003) and fasting insulin concentration (beta=-0.14, P=0.001). Low sRAGE levels were associated with a 2-3 times higher risk for mortality especially after correction for creatinine clearance (P=0.006). CONCLUSION: A lack of sRAGE is a risk factor for mortality in renal transplant recipients. The putatively protective role of sRAGE and in particular its association with mycophenolate mofetil usage needs further investigation.

An increased coronary risk is paradoxically associated with common cholesteryl ester transfer protein gene variations that relate to higher high-density lipoprotein cholesterol: a population-based study.

BACKGROUND: Several cholesteryl ester transfer protein (CETP) polymorphisms affect high-density lipoprotein (HDL) cholesterol, but the impact of CETP gene variants on incident coronary disease in the general population is uncertain after correction for their effect on HDL cholesterol. DESIGN: We determined relationships between the CETP -629C-->A promoter (n = 8141), the TaqIB (n = 8289), and the I405V (n = 8265) polymorphisms, serum lipids, C-reactive protein, and clinical factors with incident coronary heart disease (defined as death from or hospitalization for myocardial infarction, ischemic heart disease, or coronary intervention) during a median of 4.94 yr follow-up. SUBJECTS: A predominantly Caucasian general population was studied. RESULTS: HDL cholesterol was 0.08 mmol/liter higher in -629A carriers than in -629CC homozygotes (P < 0.001). The unadjusted coronary hazard was 1.26 [95% confidence interval (CI), 0.95-1.68; P = 0.11] in A carriers compared with CC homozygotes and increased to 1.46 (95% CI, 1.10-1.95; P = 0.01) after adjustment for HDL cholesterol. This effect remained after additional adjustment for apolipoprotein A-I, triglycerides, C-reactive protein, age, and gender. Likewise, the HDL-cholesterol-adjusted hazard ratio was also higher in AA than in CC homozygotes (hazard ratio, 1.72; 95% CI, 1.22-2.42; P < 0.01). Similar findings were obtained with the TaqIB polymorphism. The 405V allele was weakly associated with incident coronary heart disease after HDL cholesterol adjustment (P = 0.09). CONCLUSIONS: A common CETP promoter polymorphism, which beneficially contributes to higher HDL cholesterol, is paradoxically associated with increased incidence of coronary disease in the general population. Thus, CETP gene variation may affect coronary risk apart from the level of HDL cholesterol.

Expression of L-CCR in HEK 293 cells reveals functional responses to CCL2, CCL5, CCL7, and CCL8.

It has become clear in the past years that chemokines and chemokine receptors are pivotal regulators of cellular communication and trafficking. In addition to the approximately 20 chemokine receptors that have been cloned and described, various orphan receptors with a chemokine receptor-like structure are known. We have investigated the orphan mouse chemokine receptor (L-CCR) in HEK 293 cells, a receptor that was originally described in a mouse macrophage cell line. Cells expressing this receptor show pertussis toxin-sensitive chemotaxis and small intracellular calcium transients in response to the chemokines CCL2, CCL7, CCL8, and CCL5. Biotinylated CCL2 binds to L-CCR-expressing cells, and transfection experiments with an L-CCR-green fluorescent protein fusion protein showed L-CCR expression in the membranes of recombinant HEK 293 cells. Although radioligand binding was not detected, it is suggested that L-CCR is a functional chemokine receptor.

LPS-induced expression of a novel chemokine receptor (L-CCR) in mouse glial cells in vitro and in vivo.

There is increasing evidence that chemokines, specialized regulators of the peripheral immune system, are also involved in the physiology and pathology of the CNS. It is known that glial cells (astrocytes and microglia) express various chemokine receptors like CCR1, -3, -5, and CXCR4. We have investigated the possible expression of the known CC chemokine receptors (CCR1-8 and D6) in murine glial cells. In addition, we examined possible glial expression of the orphan CC chemokine receptor L-CCR that has been identified previously in murine macrophages. We report here expression of L-CCR mRNA in murine astrocytes and microglia. Furthermore, L-CCR mRNA expression was strongly induced after application of bacterial lipopolysaccharide (LPS), both in vitro and in vivo. Functional studies and binding experiments using biotinylated monocyte chemoattractant protein (MCP)-1 (CCL2) indicate that CCL2 could be a candidate chemokine ligand for glial L-CCR. Based on the data presented, it is suggested that L-CCR is a functional glial chemokine receptor that is important in neuroimmunology.

Chemokines in the brain: neuroimmunology and beyond.

Chemokines in the brain have been recognised as essential elements in neurodegenerative diseases and related neuroinflammation. Recent studies suggest that in addition to the orchestration of chemotaxis of immune cells, chemokines are also involved in neurodevelopment and neurophysiological signalling.