Abstract 38: Neutrophil-Derived S100a8 and S100a9 Promotes Reticulated Thrombocytosis and Atherogenesis in Diabetes

Platelets play a critical role in atherogenesis and thrombosis-mediated myocardial ischemia, processes that are accelerated in diabetes. It remains unknown if hyperglycemia promotes platelet production and whether this contributes to enhanced atherothrombosis. Here we show that in response to hyperglycemia, neutrophil-derived S100A8/A9 interacts with the receptor for advanced glycated end-products (RAGE) on hepatic Kupffer cells resulting in increased production of interleukin-6 (IL-6), a pleiotropic cytokine implicated in inflammatory thrombocytosis. IL-6 acts on hepatocytes to enhance the production of thrombopoietin, which in turn interacts with its cognate receptor, c-MPL on megakaryocytes and bone marrow progenitor cells to promote their expansion and proliferation resulting in reticulated thrombocytosis. Lowering blood glucose using a sodium-glucose co-transporter 2 inhibitor (dapagliflozin), depleting neutrophils/Kupffer cells or inhibiting S100A8/A9 binding to RAGE (paquinimod) all reduced diabetes-induced thrombocytosis. Inhibiting S100A8/A9 also decreased atherogenesis in diabetic mice. Finally, we show that patients with type 2 diabetes have reticulated thrombocytosis, which correlates with glycated hemoglobin, and also have increased plasma S100A8/A9 levels. These studies provide novel insights into the mechanisms that regulate platelet production and may help to develop strategies to improve on current antiplatelet therapies and to reduce cardiovascular disease risk in diabetes.

A novel homozygous deletion in EXPH5 causes a skin fragility phenotype

Epidermolysis bullosa simplex (EBS) is the most common form of EB. Eight different genes have been implicated in the pathogenesis of different types of EBS, but a substantial portion of the cases cannot be attributed to mutations in known genes. Recently, recessive mutations in the gene EXPH5 (encoding exophilin-5, also known as Slac2-b) were identified in patients affected with a mild form of EBS. We used immunohistochemistry, Sanger sequencing and PCR-restriction fragment length polymorphism analysis to identify the cause of mild congenital skin fragility in a 3-year-old girl. No mutations were detected in KRT5 or KRT14, but we identified a novel homozygous deletion in EXPH5, which was found to cosegregate with the disease phenotype in the family. Our results further expand the spectrum of mutations in EXPH5. Appraisal of the present case against previously reported patients indicate that EXPH5 mutations result in a distinctive skin fragility phenotype, with minimal blistering compared with other forms of basal EBS.

Abstract 50: Procollagen C-endopeptidase Enhancer protein 2 (PCPE2) Deficiency Profoundly Affects Adipose Distribution in Mice and Humans and Links HDL Metabolism to Adipocyte Biology

Procollagen C-endopeptidase enhancer protein 2 (PCPE2) modulates selective HDL cholesterol ester uptake by SR-BI. Ldlr-/-,Pcpe2-/- mice develop greater aortic atherosclerosis despite increased concentrations of enlarged plasma HDL, suggesting PCPE2 confers functionality to HDL for reverse cholesterol transport. PCPE2 is a 52 kDa glycoprotein encoded by PCOLCE2 gene most highly expressed in adipose tissue, heart and aorta. PCPE2 has 2 CUB domains separated by a short linker, with each CUB domain containing a beta-sandwich fold, mediating a variety of protein-protein interactions. PCPE2 also contains a C-terminal netrin-like domain that binds tightly to cell surface glycosaminoglycans accounting for its location in the extracellular matrix. Because of the strong inverse correlation between HDL and triglyceride levels, and the potential role of SR-BI in triglyceride-rich lipoprotein uptake we examined Ldlr-/-,Pcpe2-/-mice fed a Western diet for 25 weeks. Ldlr-/-,Pcpe2-/- mice showed 1.7 fold increase in plasma triglyceride concentrations when compared to age and gender matched Ldlr-/- mice. We also noted that despite similar body weights, Ldlr-/-,Pcpe2-/- visceral fat pad weight was reduced 60% (p<0.001, n=9 per genotype) compared to Ldlr-/- mice, while subcutaneous fat pad weight was not significantly different. This maldistribution of adipose in Ldlr-/-,Pcpe2-/- was associated with increased fasting plasma glucose levels, elevated 25% (p<0.02) over Ldlr-/- mice. In humans, analyses showed significant correlations of subcutaneous fat PCPE2 RNA expression with DEXA traits from the TwinsUK cohort; % android fat (p<0.0002), % trunk fat (p<0.0001) and % gynoid fat (p<0.04). Additional correlations between PCPE2 mRNA abundance and candidate marker expression will also be presented using 53 human visceral fat samples. Overall these data suggest that PCPE2 plays an important role in regional fat deposition linking SR-BI mediated cholesterol ester uptake to adipose cell biology.

Aldose reductase drives hyperacetylation of Egr-1 in hyperglycemia and consequent upregulation of proinflammatory and prothrombotic signals

Sustained increases in glucose flux via the aldose reductase (AR) pathway have been linked to diabetic vascular complications. Previous studies revealed that glucose flux via AR mediates endothelial dysfunction and leads to lesional hemorrhage in diabetic human AR (hAR) expressing mice in an apoE(-/-) background. Our studies revealed sustained activation of Egr-1 with subsequent induction of its downstream target genes tissue factor (TF) and vascular cell adhesion molecule-1 (VCAM-1) in diabetic apoE(-/-)hAR mice aortas and in high glucose-treated primary murine aortic endothelial cells expressing hAR. Furthermore, we observed that flux via AR impaired NAD(+) homeostasis and reduced activity of NAD(+)-dependent deacetylase Sirt-1 leading to acetylation and prolonged expression of Egr-1 in hyperglycemic conditions. In conclusion, our data demonstrate a novel mechanism by which glucose flux via AR triggers activation, acetylation, and prolonged expression of Egr-1 leading to proinflammatory and prothrombotic responses in diabetic atherosclerosis.

Oesophageal involvement in bullous pemphigoid

Bullous pemphigoid (BP) is an acquired autoimmune disease that predominantly affects older people. Mucosal involvement is rare in BP. We report an unusual case of an elderly patient with BP with involvement of the oesophagus presenting as gastrointestinal (GI) bleeding. Although mucosal involvement is typically rare in BP, it should be considered in the differential diagnosis of GI bleeding in patients affected with the disease.

Comparative study of high-resolution multifrequency ultrasound of the plantar skin in patients with various types of hereditary palmoplantar keratoderma

BACKGROUND

High-variable-frequency ultrasound is used as an imaging tool for various cutaneous disorders. We utilized this tool in pachyonychia congenita (PC) patients, who typically present with plantar hyperkeratosis and often severely debilitating pain, compared to patients with epidermolytic palmoplantar keratoderma (EPPK) and mal de Meleda (MDM).

OBJECTIVE

To ascertain the feasibility of ultrasound technology for the diagnosis of PC.

METHODS

The study included a total of 16 patients, 7 with PC, 5 with EPPK and 4 with MDM, who underwent ultrasound examination of the plantar skin with high-resolution multifrequency ultrasound equipment.

RESULTS

Ultrasound scans performed over the proximal and distal plantar foot calluses in PC patients demonstrated hyperechoic dots and lines within the epidermis compatible with hyperkeratosis, engorged varicose veins in the dermis and an anechoic layer interposed between the epidermis and the dermis, corresponding to blister fluid below the calluses. In contrast to PC patients, patients with MDM and EPPK demonstrated no blisters.

CONCLUSION

PC patients, as opposed to a group of patients with MDM and EPPK, displayed subepidermal blistering beneath their calluses. This finding may help in the diagnosis of PC and in partially explaining plantar pain as part of PC symptomatology.

Utility of hospitalization following a first unprovoked seizure

OBJECTIVES

Hospital admission in otherwise healthy patients following a first unprovoked seizure is controversial. We aimed to evaluate the influence of admission in a neurology department on the identification of risk factors for seizure recurrence in patients with a first unprovoked seizure.

MATERIALS AND METHODS

We retrospectively reviewed the medical records of patients with a first unprovoked seizure, who were admitted to the neurology departments at two medical centers between 2007 and 2009. Risk factors for seizure recurrence included the following: abnormal neurological examination, abnormal brain CT scan, and epileptiform discharges on the EEG.

RESULTS

The study group included 97 patients (52 men) aged 18-85 years (mean 42). Eighty-seven (90%) patients were admitted following a generalized tonic-clonic seizure. Risk factors were identified in the emergency room (ER) in 36 (37%) patients, mainly including abnormalities of the neurological examination and brain CT scan. Nineteen (20%) patients had a risk factor which was not apparent during ER evaluation, consisting of epileptiform activity on the EEG. Five (5%) patients had recurrent seizures during admission, three of them without risk factors during the ER evaluation.

CONCLUSIONS

Risk factors for seizure recurrence were detected during admission in nearly a quarter of the patients who presented to the emergency room with a first unprovoked seizure. Because the main advantage of admission is the EEG recording, we suggest that an early EEG should be obtained in these patients either during admission or through a special accelerated outpatient arrangement.

Non-syndromic autosomal recessive congenital ichthyosis in the Israeli population

BACKGROUND

Autosomal recessive congenital ichthyosis (ARCI) is the term given to a complex and heterogeneous group of cornification disorders associated with mutations in at least eight distinct genes. Mutation distribution and prevalence rates are instrumental for the design of diagnostic strategies in ARCI but have not yet been systematically explored in the Israeli population. Previous data suggest that the demographic features specific to Middle Eastern populations, such as a high frequency of consanguineous marriages, may have an effect on the molecular epidemiology of genodermatoses.

METHODS

We systematically assessed all families with ARCI presenting at our clinics over a period of 9 years, using a combination of homozygosity mapping, direct sequencing and PCR-restriction fragment length polymorphism assays.

RESULTS

In total, 20 families with ARCI were assessed, and causative mutations were identified in 7 genes: TGM1 (30% of patients), ALOX12B (20%), ABCA12 (5%), CYP4F22 (10%), ALOXE3 (10%), LIPN (5%) and NIPAL4 (5%) Two families (10%) had mutations mapped to an ARCI-associated locus on 12p11.2-q13, while no mutation was found for one additional kindred. In the subgroup of families of Arab Muslim origin, mutations were identified most frequently in ALOX12B and TGM1 (31%), whereas the other subgroups displayed a subtype distribution very similar to that previously reported in western populations.

CONCLUSIONS

The present data point to the need for population-tailored mutation screening strategies in genetically heterogeneous genodermatoses, based on the relative prevalence of the disease subsets.

Best treatment practices for pachyonychia congenita

BACKGROUND

Numerous therapeutic modalities have been proposed to treat the manifestations of pachyonychia congenita (PC). While research hopes lie with molecular therapies, patients are in need of answers regarding the efficacy of conventional treatments.

AIM OF THE STUDY

To determine patients' experience and preferences regarding conventional treatments for PC.

METHODS

The study population included 120 PC patients from 20 countries. The study was based on a patient survey developed by physicians and researchers from the International Pachyonychia Congenita Consortium and conducted via the internet. Using an effectiveness scale of 1 to 5, the patients were asked to grade treatments for different manifestations, including keratoderma, cysts, follicular hyperkeratosis, fingernail and toenail involvement.

RESULTS

Patients reported surgical treatments being most effective for cysts and mechanical treatments the most effective conventional therapeutic approach for all other investigated manifestations. The other conventional medical treatments were found to be non-effective to only slightly effective. Among patients with keratoderma, older people were more likely to report beneficial effect from mechanical treatments (P = 0.04), topical retinoids (P = 0.04) and topical steroids (P = 0.02). Likewise, females were more inclined to report filing and grinding beneficial than males (P = 0.02). Finally, carriers of KRT16 and KRT6a were more likely to benefit from keratolytics than carriers of mutations in KRT17 (P = 0.04).

CONCLUSIONS

None of the currently available therapeutic options for PC are ideal, although they provide some relief, with mechanical/surgical options being preferred over medical therapies. These results emphasize the need for more efficient and targeted therapies.

Microembolism, silent brain infarcts and dementia

Cognitive decline becomes more prevalent than ever in parallel with the increasing life expectancy of the population. Alzheimer' disease (AD) and cerebral vascular lesions are common in the elderly and represent, with increased age, the most frequent contributors to cognitive decline. It is now believed that these pathologies frequently coexist in the same brain. The border discriminating vascular dementia from AD is blurred and challenges our understanding of these clinical entities. Further research, at both basic and clinical levels, is mandatory in order to better understand the interactions of vascular ischemic injury and primary degenerative physiopathologies of the brain, in order to prevent and better manage patients with cognitive decline. We review recent published clinical evidence of silent brain ischemia as a contributor to cognitive decline and dementia. Microemboli, from both cardiac and vascular origins, have been shown to be associated with structural changes in the brain. The role of transcranial Doppler as an objective tool for detecting and quantifying microemboli is discussed in light of recent clinical evidence.

Successful hip arthroplasty in an adult male with severe factor XI deficiency using Hemoleven®, a factor XI concentrate

Severe factor XI (sFXI) deficiency is a rare bleeding disorder (RBD). FXI replacement is most often required for surgical hemostasis. Plasma, the sole US treatment option, is often complicated by life-threatening allergic reactions. In such circumstances, the FDA offers a mechanism for institution-industry collaboration to facilitate limited use of replacement products licensed abroad. A 58 years old man with sFXI deficiency, required hip replacement. In the past, he received prophylactic plasma for thyroidectomy and experienced a severe allergic reaction. A single use institutional IND FDA application was initiated in collaboration with LFB (Les Ulis, France) to access Hemoleven®, a plasma-derived FXI concentrate. The application required an investigator-initiated IRB-approved protocol for treatment and safety/efficacy monitoring that included: preoperative thrombophilia, FXI inhibitor and pharmacokinetic (PK) evaluations; peri- postoperative administration of ≤ 4 doses of 10-15 U/kg Hemoleven® ; DIC monitoring; postoperative thromboprophylaxis; observation for product efficacy and potential complications. PK study demonstrated the expected 1.8% FXI recovery per U/kg with half-life of 62 hours. Mild D-Dimer elevation was noted 6-9 hours post-infusion. The initial dose (15 U/kg) was administered 15 hours before surgery; subsequently, 3 doses (10 U/kg) were infused every 72 hours. Hemostasis was excellent. No complications were observed. Collaboration allowed for successful patient access to Hemoleven® with excellent PK, safety, and efficacy. This case underscores the need for additional efforts to ensure safe and effective licensed replacement therapies for RBD patients.

Clinical, radiological and pathological correlates of leukoaraiosis

INTRODUCTION

Leukoaraiosis is characterized by an abnormal appearance of the brain white matter on imaging. Its pathogenesis is still a matter of investigation. The purpose of this study was to investigate the radiological, clinical and pathological correlates of leukoaraiosis.

METHODS

The study population consisted of 93 deceased patients. The pre-mortem T2W magnetic resonance images were evaluated for the presence and grading of leukoaraiosis. The clinical and pathological characteristics based on the clinical charts and autopsy reports were evaluated. Tissue specimens of the blocks of 19 brains that demonstrated severe leukoaraiosis and those of five control brains were excised and stained.

RESULTS

The variables found to be significantly associated with leukoaraiosis were age and a clinical history of Parkinson's disease. Other risk factors and pathological markers of atherosclerosis were not significantly correlated with leukoaraiosis. No significant difference was found between the scoring of the myelin integrity, glial fibrillary acidic protein, cluster of differentiation 68 and smooth muscle actin. There was a significant difference with respect to thickening of vessels walls.

CONCLUSIONS

Our pathological results indicate that structural vascular abnormalities characterized by vessel wall thickening are associated with leukoaraiosis, supporting the assertion that vascular changes and ischemia generate leukoaraiosis. The relations between parkinsonism and leukoaraiosis may be explicable through vascular effects on the circuitry of the basal ganglia.