A Novel Port to Facilitate Magnetic Hyperthermia Therapy for Glioma

High-grade gliomas (HGG) are the most common primary brain malignancy and continue to be associated with a dismal prognosis (median survival rate of 15-18 months) with standard of care therapy. Magnetic hyperthermia therapy (MHT) is an emerging intervention that leverages the ferromagnetic properties of magnetic iron-oxide nanoparticles (MIONPs) to target cancer cells that are otherwise left behind after resection. We report a novel port device to facilitate localization, delivery, and temperature measurement of MIONPs within a target lesion for MHT therapy. We conducted an in-depth literature and intellectual property review to define specifications of the conceived port device. After setting the design parameters, a thorough collaboration with neurological surgeons guided the iterative modeling process. A prototype was developed using Fusion 360 (Autodesk, San Rafael, CA) and printed on a Form 3 printer (Formlabs, Medford, MA) in Durable resin. The prototype was then tested in a phantom skull printed on a Pro-Jet 660Pro 3D printer (3D Systems, Rock Hill, SC) and a brain model based on mechanical and electrochemical properties of native brain tissue. This phantom underwent MHT heating tests using an alternating magnetic field (AMF) sequence based on current MHT workflow. Successful localization, delivery, and temperature measurement were demonstrated. The purpose of this study was twofold: first, to create and validate the procedural framework for a novel device, providing the groundwork for an upcoming comprehensive animal trial and second, to elucidate a cooperative approach between engineers and clinicians that propels advancements in medical innovation.

Emerging markers of cancer cachexia and their relationship to sarcopenia

PURPOSE

Emerging biomarkers of cancer cachexia and their roles in sarcopenia and prognosis are poorly understood. Baseline assessments of anthropometrics, sarcopenia, cachexia status and biomarkers of cachexia were measured in patients with advanced cancer and healthy controls. Thereafter, relationships of the biomarkers with cachexia and sarcopenia were explored.

METHODS

A prospective case-control design was used, including 40 patients with advanced cancer and 40 gender, age-matched controls. Bioelectrical impedance [skeletal muscle index (SMI)] and hand dynamometry [hand grip strength (HGS)] assessed sarcopenia and a validated tool classified cancer cachexia. Albumin, lymphocyte and platelet counts, haemoglobin, C-reactive protein (CRP), pro-inflammatory cytokines/chemokines and citrullinated histone H3 (H3Cit) were measured.

RESULTS

Patients had significantly lower SMI (6.67 kg/m2 versus 7.67 kg/m2, p =  < 0.01) and HGS (24.42 kg versus 29.62 kg) compared to controls, with 43% being sarcopenic. Significant differences were found for albumin, lymphocyte and platelet counts, haemoglobin, CRP, and tumour necrosis factor α (TNFα), (p < 0.01). Interleukin (IL)-6 (p < 0.04), IL-8 (p = 0.02), neutrophil/lymphocyte ratio (NLR), p = 0.02, platelet/lymphocyte (PLR) ratio, p < 0.01 and systemic immune inflammatory index (SII), p < 0.01 differed significantly. No difference was observed for CXC motif chemokine ligand 5 [CXCL5 or epithelial neutrophil-activating peptide 78 (ENA78)] or H3Cit. Albumin and haemoglobin correlated negatively with total protein, skeletal muscle mass and SMI (all p < 0.01). The presence of sarcopenia associated significantly with albumin, haemoglobin and CRP.

CONCLUSION

Significant relationships and differences of haemoglobin, CRP and albumin supports future use of these biomarkers in cancer cachexia. CXCL5 and H3Cit as valuable biomarkers in cancer cachexia remains to be defined.

Abstract WP152: Changes In Thrombus Fibrin Content By Time In Patients Undergoing Thrombectomy

Introduction: Understanding clot composition and associated genomic, epigenomic, and proteomic signatures could provide insight into thrombus biology and etiology, and aid in prognosis in stroke. We report preliminary analysis of histology evaluations in subjects enrolled in the INSIGHT Registry, a multicentered ‘multi-omic’ analysis of thrombi associated with acute hemorrhagic and ischemic stroke this multi-omic clot collection registry. Our aim was to determine potential histology differences in thrombi as a consequence of infarct time (time from last known normal to thrombectomy).

Material and Methods: Subjects age ≥18 years, treated frontline with the Penumbra System for thrombectomy are included in this analysis. Patient demographics, medical history, radiographic, and procedural information are collected in conjunction with extracted clot and concurrent extracranial arterial blood. Enrollment, data collection, and data monitoring are ongoing for the INSIGHT registry. While the protocol includes analysis for proteomics and transcriptomics, for this analysis we used automated histology. An MSB Trichrome stain was used to evaluate the tissue. Composition was determined by automated pixel analysis, with the values representing ratios of the overall clot.

Results: Samples from 60 subjects who were enrolled from 10 sites between 02/2021 and 07/2021. Analysis of the thrombi successfully determined the relative portions of fibrin, red blood cells (RBCs), and platelets (PLT). The median percentage of fibrin in the thrombi was 44.0% (IQR 29.0 - 57.6; N=60). The median time interval from Last Known Well to recanalization was 4.0 hours (IQR 2.9-12.8 hours; N=55). There was no correlation between the time interval of stroke and the percent of fibrin in the thrombus (Pearson correlation coefficient -0.01, p 0.94).

Conclusion: These preliminary results demonstrate a lack of relationship between time interval of the stroke and clot histology composition with relation to fibrin. Thrombus fibrin composition is likely more related to other factors, and not predominantly related to time. We are currently investigating potential relationships to demographics and co-morbidities.

Endoscopic Third Ventriculostomy With "Rescue" Fourth Ventriculocisternostomy: 2-Dimensional Operative Video

This case of endoscopic third ventriculostomy (ETV) and flexible endoscopy for lysis of fourth ventricle adhesions for obstructive hydrocephalus illustrates a key anatomical variant (anastomosis of posterior communicating arteries) that increases the difficulty of ETV and should be recognized preoperatively. The video further demonstrates flexible endoscopy for lysis of a fourth ventricular web and excellent third and fourth ventricular anatomy. This patient presented with normal pressure hydrocephalus-like symptoms and magnetic resonance imaging suggestive of a fourth ventricular outflow obstruction. An ETV would be an ideal intervention with a high chance of success1 and avoiding a ventriculoperitoneal shunt or a more invasive suboccipital craniectomy for fourth ventricle exploration; however, variant anatomy and resultant medialization of the bilateral posterior communicating arteries put their location directly beneath the tuber cinereum. After discussing the risks and benefits of the proposed procedure, the patient consented to proceeding with the surgery. Patient is not identifiable either by clinical vignette or through this operative video, which is entirely intraventricular. The care rendered was standard (nonexperimental). The patient did sign consent for filming and production of the educational video submitted.  Here, we present operative video from our ETV, demonstrating an inability to confirm adequate fenestration and subsequent flexible endoscopy for fourth ventriculocisternostomy.

Magnetic resonance venography for 3-dimensional live guidance during venous sinus stenting

Purpose

The purpose of this study was to report the technique for intraprocedural guidance of endovascular Venous Sinus Stenting procedures using 3-Dimensional (3D) Magnetic Resonance Venography (MRV) as an overlay on live biplanar fluoroscopy.

Materials and methods

Venous sinus stenting procedures performed between April and December, 2017 with 3D MRV fusion for live guidance were reviewed in this study. A thin-slice, contrast-enhanced MR Venogram was used to create 2 3D models – vessels and skull – for procedural guidance via augmented fluoroscopy (Vessel ASSIST, GE Healthcare, Chicago, IL). The skull model was used in the registration of the 3D overlay on both the frontal and lateral planes, which required 1–2 min of procedural time. The vessel model was used to mark landmarks such as the cortical vein ostia and stenosis on the 3D overlay fused with biplanar fluoroscopy.

The retrospective imaging review was conducted by 3 neurointerventionalists and relied on a consensus confidence ranking on a 3-point Likert scale from 1- low confidence to 3- high confidence. The neurointerventionalists first reviewed the conventional 2-dimensional pre-stent deployment fluoroscopy images and then reviewed the corresponding images with the 3D MRV overlay. They ranked their confidence in their understanding of cortical venous anatomy for each group. Statistical analysis was performed using a Paired T Test at a 99% confidence interval.

Results

Ten cases were included in the retrospective image review. Operator confidence regarding the location of cortical veins was significantly increased using 3D MRV fusion during venous sinus stenting procedures (1.9 vs 2.9, p = .001).

Conclusion

3-Dimensional MRV fusion is feasible and helpful in understanding the venous sinus anatomy and location of important cortical veins during venous sinus stenting procedures.

To reflect human autoimmune thyroiditis, thyroid peroxidase (not thyroglobulin) antibodies should be measured in female (not sex-independent) NOD.H2h4 mice

NOD.H2^h4 mice are the most commonly used model for human autoimmune thyroiditis. Because thyroid autoimmunity develops slowly (over months), NOD.H2^h4 mice are usually exposed to excess dietary iodide to accelerate and amplify the process. However, unlike the female bias in human thyroid autoimmunity, autoantibodies to thyroglobulin (TgAb) are reported to be similar in male and female NOD.H2^h4 . We sought evidence for sexual dimorphism in other parameters in this strain maintained on regular or iodized water. Without iodide, TgAb levels are higher in males than in females, the reverse of human disease. In humans, autoantibodies to thyroid peroxidase (TPOAb) are a better marker of disease than TgAb. In NOD.H2^h4 mice TPOAb develop more slowly than TgAb, being detectable at 6 months of age versus 4 months for the latter. Remarkably, unlike TgAb, TPOAb levels are higher in female than male NOD.H2^h4 mice on both regular and iodized water. As previously observed, serum T4 levels are similar in both sexes. However, thyroid-stimulating hormone (TSH) levels are significantly higher in males than females with or without iodide exposure. TSH levels correlate with TgAb levels in male NOD.H2^h4 mice, suggesting a possible role for TSH in TgAb development. However, there is no correlation between TSH and TPOAb levels, the latter more important than TgAb in human disease. In conclusion, if the goal of an animal model is to closely reflect human disease, TPOAb rather than TgAb should be measured in older female NOD.H2^h4 mice, an approach requiring patience and the use of mouse TPO protein.

High-level intrathymic thyrotrophin receptor expression in thyroiditis-prone mice protects against the spontaneous generation of pathogenic thyrotrophin receptor autoantibodies

The thyrotrophin receptor (TSHR) A-subunit is the autoantigen targeted by pathogenic autoantibodies that cause Graves' hyperthyroidism, a common autoimmune disease in humans. Previously, we reported that pathogenic TSHR antibodies develop spontaneously in thyroiditis-susceptible non-obese diabetic (NOD).H2^h4 mice bearing a human TSHR A-subunit transgene, which is expressed at low levels in both the thyroid and thymus (Lo-expressor transgene). The present study tested recent evidence that high intrathymic TSHR expression protects against the development of pathogenic TSHR antibodies in humans. By successive back-crossing, we transferred to the NOD.H2^h4 background a human TSHR A-subunit transgene expressed at high levels in the thyroid and thymus (Hi-expressor transgene). In the sixth back-cross generation (> 98% NOD.H2^h4 genome), only transgenic offspring produced spontaneously immunoglobulin (Ig)G class non-pathogenic human TSHR A-subunit antibodies. In contrast, both transgenic and non-transgenic offspring developed antibodies to thyroglobulin and thyroid peroxidase. However, non-pathogenic human TSHR antibody levels in Hi-expressor offspring were lower than in Lo-expressor transgenic mice. Moreover, pathogenic TSHR antibodies, detected by inhibition of TSH binding to the TSHR, only developed in back-cross offspring bearing the Lo-expressor, but not the Hi-expressor, transgene. High versus low expression human TSHR A-subunit in the NOD.H2^h4 thymus was not explained by the transgene locations, namely chromosome 2 (127-147 Mb; Hi-expressor) and chromosome 1 (22.9-39.3 Mb; low expressor). Nevertheless, using thyroiditis-prone NOD.H2^h4 mice and two transgenic lines, our data support the association from human studies that low intrathymic TSHR expression is associated with susceptibility to developing pathogenic TSHR antibodies, while high intrathymic TSHR expression is protective.

Abstract P5-11-15: Rolapitant for the prevention of chemotherapy-induced nausea and vomiting in breast cancer patients receiving multiple cycles of emetogenic chemotherapy

Background: Patients (pts) with breast cancer often receive highly emetogenic chemotherapy, such as anthracycline plus cyclophosphamide (AC). Additionally, young age and female gender are risk factors for chemotherapy-induced nausea and vomiting (CINV) in response to emetogenic chemotherapy. We assessed the ability of the long-acting neurokinin-1 receptor antagonist (RA), rolapitant, in the prevention of CINV over multiple cycles in pts with breast cancer

Methods: This is a post hoc analysis of the prevention of CINV in a subset of pts with breast cancer from 3 similarly-designed, randomized, placebo-controlled phase 3 trials in which pts received a single oral dose of 180 mg rolapitant or placebo before chemotherapy. All pts received an oral 5-HT3 RA + dexamethasone (active control). The regimens were cisplatin-based (n=36), AC-based (n=681) or other (n=166; carboplatin, cyclophosphamide, etc). Pts who completed cycle 1 could continue the same antiemetic treatment in multiple cycles. Endpoints for cycle 1 of chemotherapy included complete response (CR; no emesis and no use of rescue medication) and no emesis, and no nausea (maximum visual analogue scale [VAS] &lt;5 mm), in the overall (0–120 h), acute (≤24 h), and delayed (&gt;24–120 h) phases. On days 6-8 of each subsequent chemotherapy cycle, pts self-reported the incidence of emesis or nausea interfering with normal daily life.

Results: In cycle 1, CR in both the overall (62.9% rolapitant, 55.1% control; p=0.018) and delayed (66.7% rolapitant, 59.7% control; p=0.032) phases were higher with rolapitant vs control . Rolapitant also improved no emesis rates in the overall (74.4% rolapitant, 62.6% control; p&lt;0.001) and delayed (77.2% rolapitant, 68.5% control; p=0.004) phases. Although less pts were available for follow up over multiple cycles, a numerically greater proportion of rolapitant-treated pts than control pts reported no emesis (cycles 2-6) and no interfering nausea (cycles 2-5) (table). The incidence of treatment-emergent adverse events (TEAEs) was similar for rolapitant (85.2%) and control (83.2%) during cycles 1-6. The most common TEAEs occurred at comparable rates in the rolapitant and control arms: fatigue (28.5% and 29.4%, respectively), alopecia (28.5% and 31.2%, respectively), and constipation (20.0% and 20.9%, respectively).

Conclusions: Rolapitant added to 5-HT3 RA and dexamethasone therapy improved CINV control and was safe and well-tolerated in pts with breast cancer receiving multiple cycles of emetogenic chemotherapy, mostly AC and carboplatin, historically a high-risk population for CINV.

 Pt-Reported Response in Multiple Cycles, % (n/N)* No Emesis  No Interfering Nausea  CycleRolapitant 180 mgActive Controlp-value *Rolapitant 180 mgActive Controlp-value *288.3 (323/366)80.0 (308/385)0.00271.6 (262/366)68.3 (263/385)0.329390.5 (297/328)80.5 (293/364)&lt;0.00173.8 (242/328)65.9 (240/364)0.025487.5 (266/304)82.4 (277/336)0.07579.3 (241/304)72.0 (242/336)0.033594.9 (111/117)88.2 (127/144)0.05987.2 (102/117)80.6 (116/144)0.152695.3 (102/107)88.9 (120/135)0.07184.1 (90/107)83.0 (112/135)0.811* Unstratified Cochran-Mantel-Haenszel test for between rolapitant and control difference in response rate.

Citation Format: Schwartzberg L, Navari R, Arora S, Powers D, Jordan K, Rapoport B. Rolapitant for the prevention of chemotherapy-induced nausea and vomiting in breast cancer patients receiving multiple cycles of emetogenic chemotherapy [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-11-15.

Uptake of novel medical therapies in the general population

The randomized controlled trial (rct) remains the “gold standard” for establishing the efficacy of new medical therapies [...]

2012 European thyroid association guidelines for the management of familial and persistent sporadic non-autoimmune hyperthyroidism caused by thyroid-stimulating hormone receptor germline mutations

All cases of familial thyrotoxicosis with absence of evidence of autoimmunity and all children with persistent isolated neonatal hyperthyroidism should be evaluated for familial non-autoimmune autosomal dominant hyperthyroidism (FNAH) or persistent sporadic non-autoimmune hyperthyroidism (PSNAH). First, all index patients should be analysed for the presence/absence of a thyroid-stimulating hormone (TSH) receptor (TSHR) germline mutation, and if they display a TSHR germline mutation, all other family members including asymptomatic and euthyroid family members should also be analysed. A functional characterization of all new TSHR mutations is necessary. Appropriate ablative therapy is recommended to avoid relapses of hyperthyroidism and its consequences, especially in children. Therefore, in children the diagnosis of FNAH or PSNAH needs to be established as early as possible in the presence of the clinical hallmarks of the disease.

Deletion of thyrotropin receptor residue Asp403 in a hyperfunctioning thyroid nodule provides insight into the role of the ectodomain in ligand-induced receptor activation

Somatic mutations of the TSH receptor (TSHR) gene are the main cause of autonomously functioning thyroid nodules. Except for mutations in ectodomain residue S281, all of the numerous reported activating mutations are in the TSHR membrane-spanning region. Here, we describe a patient with a toxic adenoma with a novel heterozygous somatic mutation caused by deletion of ectodomain residue Asp403 (Del-D403). Subsequent in vitro functional studies of the Del-D403 TSHR mutation demonstrated greatly increased ligand-independent constitutive activity, 8-fold above that of the wild-type TSHR. TSH stimulation had little further effect, indicating that the mutation produced near maximal activation of the receptor. In summary, we report only the second TSHR ectodomain activating mutation (and the first ectodomain deletion mutation) responsible for development of a thyroid toxic adenoma. Because Del-D403 causes near maximal activation, our finding provides novel insight into TSHR structure and function; residue D403 is more likely to be involved in the ligand-mediated activating pathway than in the ectodomain inverse agonist property.

Immunoglobulin heavy chain variable region genes contribute to the induction of thyroid-stimulating antibodies in recombinant inbred mice

Graves' hyperthyroidism is an autoimmune disease occurring spontaneously in humans and caused by autoantibodies that stimulate the thyrotropin receptor. In mice, inducing Graves'-like hyperthyroidism requires in vivo expression of the thyrotropin receptor using plasmid or adenovirus vectors. However, mice with different genetic backgrounds vary markedly in their susceptibility to induced hyperthyroidism. Further, in some strains major disparities exist between the induction of hyperthyroidism and detection of thyroid-stimulating antibodies. To break tolerance, virtually all Graves' mouse models involve immunization with human thyrotropin-receptor DNA and the standard thyroid-stimulating antibody bioassay uses cells expressing the human thyrotropin receptor. We hypothesized, and now report, that disparities between hyperthyroidism and thyroid-stimulating antibody bioactivity are explained, at least in part, by differential antibody recognition of the human vs the mouse thyrotropin receptor. The genetic basis for these species differences was explored using genotyped, recombinant-inbred mouse strains. We report that loci in the immunoglobulin heavy chain variable region as well as in the major histocompatibility complex region contribute in a strain-specific manner to the development of antibodies specific for the human or the mouse thyrotropin receptor. The novel finding of a role for immunoglobulin heavy chain variable region gene involvement in thyroid-stimulating antibody epitopic specificity provides potential insight into genetic susceptibility in human Graves' disease.

Endocrine Ophthalmopathy: A Re-Evaluation of the Association with Thyroid Autoantibodies

Autoantibodies to the three major thyroid autoantigens, the TSH-receptor (TSH-R), thyroid peroxidase (TPO) and thyroglobulin (TG), have been investigated in 63 Graves' patients with severe endocrine ophthalmopathy. In agreement with other studies, TSH-R antibodies were detectable in 88% of patients and dominated the autoantibody spectrum. TPO antibodies were detectable in 60% of patients and TG antibodies in only 25% of patients. The prevalences, as well as the amounts, of all three thyroid autoantibodies were not significantly different from the values in 51 Graves' patients without clinically significant ophthalmopathy. However, in the subgroup of patients with TG antibodies, the ophthalmopathy patients displayed a shift towards IgG4 TG antibodies. Furthermore, in the same TG antibody positive subgroup, the amount of TSH-R antibody was significantly higher in the ophthalmopathy patients than in Graves' patients without ophthalmopathy. These qualitative differences in thyroid autoantibodies in patients with and without ophthalmopathy raise the possibility that further qualitative differences, such as thyroid autoantibody epitopes, may exist in patients with ophthalmopathy. Our observations, combined with recent evidence for the presence of TSH-R specific mRNA in retro-orbital tissue, suggest that it may be premature to dismiss the potential pathogenetic or diagnostic value of thyroid autoantibodies, particularly TSH-R antibodies, in Graves' ophthalmopathy.

Role of the transgenic human thyrotropin receptor A-subunit in thyroiditis induced by A-subunit immunization and regulatory T cell depletion

Transgenic BALB/c mice that express intrathyroidal human thyroid stimulating hormone receptor (TSHR) A-subunit, unlike wild-type (WT) littermates, develop thyroid lymphocytic infiltration and spreading to other thyroid autoantigens after T regulatory cell (T(reg)) depletion and immunization with human thyrotropin receptor (hTSHR) adenovirus. To determine if this process involves intramolecular epitope spreading, we studied antibody and T cell recognition of TSHR ectodomain peptides (A-Z). In transgenic and WT mice, regardless of T(reg) depletion, TSHR antibodies bound predominantly to N-terminal peptide A and much less to a few downstream peptides. After T(reg) depletion, splenocytes from WT mice responded to peptides C, D and J (all in the A-subunit), but transgenic splenocytes recognized only peptide D. Because CD4(+) T cells are critical for thyroid lymphocytic infiltration, amino acid sequences of these peptides were examined for in silico binding to BALB/c major histocompatibility complex class II (IA-d). High affinity subsequences (inhibitory concentration of 50% < 50 nm) are present in peptides C and D (not J) of the hTSHR and mouse TSHR equivalents. These data probably explain why transgenic splenocytes do not recognize peptide J. Mouse TSHR mRNA levels are comparable in transgenic and WT thyroids, but only transgenics have human A-subunit mRNA. Transgenic mice can present mouse TSHR and human A-subunit-derived peptides. However, WT mice can present only mouse TSHR, and two to four amino acid species differences may preclude recognition by CD4+ T cells activated by hTSHR-adenovirus. Overall, thyroid lymphocytic infiltration in the transgenic mice is unrelated to epitopic spreading but involves human A-subunit peptides for recognition by T cells activated using the hTSHR.

Bacteraemia in febrile neutropenic cancer patients

A total of 2142 patients with febrile neutropenia resulting from cancer chemotherapy were registered in two observational studies and followed prospectively in different institutions. There were 499 (23%) patients with bacteraemia who are reviewed here. The relative frequencies of Gram-positive, Gram-negative and polymicrobial bacteraemias were 57%, 34% and 10% with respective mortality rates of 5%, 18% and 13%. Mortality rates were significantly higher in bacteraemic patients than in non-bacteraemic patients; a trend for higher mortality was observed (without reaching statistical significance) in those patients in whom bacteraemia was associated with a clinical site of infection compared to bacteraemic patients without any clinical documentation. Prophylactic antibiotics but not granulopoiesis stimulating factors were associated with a lower incidence of Gram-negative bacteraemia; however, neither prophylactic approach influenced the subsequent rate of complications in the patients who developed bacteraemia. The present study also confirms that the MASCC scoring system can identify a group of bacteraemic patients with a relatively low risk of complications and death (MASCC >/=21). On the other hand, in patients with very low levels of the MASCC score (<15), and then with predicted very unfavourable risk, the rate of complications and death was dramatically high, irrespective of the microbiological nature of the bacteraemia.

TSH receptor-adenovirus-induced Graves' hyperthyroidism is attenuated in both interferon-gamma and interleukin-4 knockout mice; implications for the Th1/Th2 paradigm

The role of the Th1/Th2 balance in the pathogenesis of murine Graves' hyperthyroidism is controversial. In BALB/c mice injected with adenovirus expressing TSH receptor (TSHR-adeno model), we found that suppression of TSHR-specific Th1 immune responses by exogenous interleukin-4 (IL-4), alpha-galactosylceramide or helminth (Schistosoma mansoni) infection was associated with inhibition of hyperthyroidism, indicating the critical role for Th1 cytokines. In contrast, BALB/c IL-4 knockout (KO), but not interferon-gamma (IFN-gamma) KO mice failed to develop Graves' hyperthyroidism when injected with TSHR-expressing M12 B lymphoma cells (TSHR-M12 model), suggesting the importance of Th2 cytokine IL-4. To reconcile differences in these two models, we used IL-4 KO and IFN-gamma KO BALB/c mice in the TSHR-adeno model. Unlike wild-type (wt) BALB/c mice in which 60% developed hyperthyroidism, only 13 and 7% of IL-4 KO and IFN-gamma KO mice, respectively, became hyperthyroid. Thyroid stimulating antibodies were positive in most hyperthyroid mice. TSHR antibody titres determined by TSH binding inhibition and ELISA were comparable in all three groups. IgG1 and IgG2a TSHR antibody titres were similar in IFN-gamma KO and wt mice, whereas IgG1 TSHR antibody titres and TSHR-specific splenocyte IFN-gamma secretion were lower in IL-4 KO than in IFN-gamma KO and wt mice, respectively. Our results clearly implicate both IFN-gamma and IL-4 in development of hyperthyroidism in the TSHR-adeno model. These data, together with the previous report, also indicate different cytokine requirements in these two Graves' models, with IFN-gamma being more important in the TSHR-adeno than the TSHR-M12 model. Moreover, our previous and present observations indicate a difference in the role of exogenous versus endogenous IL-4 in TSHR-adenovirus induced Graves' hyperthyroidism.

Interactions between the mannose receptor and thyroid autoantigens

Thyroid autoantigens require internalization and processing by antigen-presenting cells to induce immune responses. Besides pinocytosis, antigen uptake can be receptor-mediated. The mannose receptor (ManR) has a cysteine rich domain (CR) and eight carbohydrate recognition domains (CRD) that bind glycosylated proteins. The TSH receptor (TSHR), thyroid peroxidase (TPO) and thyroglobulin (Tg) are glycoproteins. To investigate a role for the ManR in thyroid autoimmunity, we tested the interaction between these autoantigens and chimeric ManRs. Plasmids encoding the CR-domain linked to IgG-Fc (CR-Fc) and CDR domains 4-7 linked to IgG-Fc (CDR4-7-Fc) were expressed and purified with Protein A. Enzyme-linked immunosorbent assay (ELISA) plates were coated with human thyroid autoantigens and CR-Fc or CRD4-7-Fc binding detected with peroxidase-conjugated anti-IgG-Fc. CRD4-7-Fc binding was highest for the TSHR, followed by Tg and was minimal for TPO. CR-Fc bound to Tg but not to TSHR or TPO. The interaction between the TSHR and CRD-Fc was calcium-dependent; it was inhibited by mannose (not galactose), and required a glycosylated TSHR A-subunit. Moreover, precomplexing the TSHR A-subunit with CRD-Fc (but not CR-Fc), or adding mannose (but not galactose), decreased in vitro responses of splenocytes from TSHR-immunized mice. Our data indicate that the ManR may participate in autoimmune responses to Tg and the TSHR but not to TPO. Most important, ManR binding of heavily glycosylated TSHR A-subunits suggests a mechanism by which the minute amounts of A-subunit protein shed from the thyroid may be captured by antigen-presenting cells located in the gland or in draining lymph nodes.

Susceptibility rather than resistance to hyperthyroidism is dominant in a thyrotropin receptor adenovirus-induced animal model of Graves' disease as revealed by BALB/c-C57BL/6 hybrid mice

We investigated why TSH receptor (TSHR) adenovirus immunization induces hyperthyroidism more commonly in BALB/c than in C57BL/6 mice. Recent modifications of the adenovirus model suggested that using adenovirus expressing the TSHR A subunit (A-subunit-Ad), rather than the full-length TSHR, and injecting fewer viral particles would increase the frequency of hyperthyroidism in C57BL/6 mice. This hypothesis was not fulfilled; 65% of BALB/c but only 5% of C57BL/6 mice developed hyperthyroidism. TSH binding inhibitory antibody titers were similar in each strain. Functional TSHR antibody measurements provided a better indication for this strain difference. Whereas thyroid-stimulating antibody activity was higher in C57BL/6 than BALB/c mice, TSH blocking antibody activity was more potent in hyperthyroid-resistant C57BL/6 mice. F(1) hybrids (BALB/c x C57BL/6) responded to A-subunit-Ad immunization with hyperthyroidism and TSHR antibody profiles similar to those of the hyperthyroid-susceptible parental BALB/c strain. In contrast, ELISA of TSHR antibodies revealed that the IgG subclass distribution in the F(1) mice resembled the disease-resistant C57BL/6 parental strain. Because the IgG subclass distribution is dependent on the T helper 1/T helper 2 cytokine balance, this paradigm can likely be excluded as an explanation for susceptibility to hyperthyroidism. In summary, our data for BALB/c, C57BL/6, and F(1) strains suggest that BALB/c mice carry a dominant gene(s) for susceptibility to induction of a thyroid-stimulating antibody/TSH blocking antibody balance that results in hyperthyroidism. Study of this genetic influence will provide useful information on potential candidate genes in human Graves' disease.

Evidence that factors other than particular thyrotropin receptor T cell epitopes contribute to the development of hyperthyroidism in murine Graves' disease

Immunization with thyrotropin receptor (TSHR)-adenovirus is an effective approach for inducing thyroid stimulating antibodies and Graves' hyperthyroidism in BALB/c mice. In contrast, mice of the same strain vaccinated with TSHR-DNA have low or absent TSHR antibodies and their T cells recognize restricted epitopes on the TSHR. In the present study, we tested the hypothesis that immunization with TSHR-adenovirus induces a wider, or different, spectrum of TSHR T cell epitopes in BALB/c mice. Because TSHR antibody levels rose progressively from one to three TSHR-adenovirus injections, we compared T cell responses from mice immunized once or three times. Mice in the latter group were subdivided into animals that developed hyperthyroidism and those that remained euthyroid. Unexpectedly, splenocytes from mice immunized once, as well as splenocytes from hyperthyroid and euthyroid mice (three injections), all produced interferon-gamma in response to the same three synthetic peptides (amino acid residues 52-71, 67-86 and 157-176). These peptides were also the major epitopes recognized by TSHR-DNA plasmid vaccinated mice. We observed lesser responses to a wide range of additional peptides in mice injected three times with TSHR-adenovirus, but the pattern was more consistent with increased background 'noise' than with spreading from primary epitopes to dominant secondary epitopes. In conclusion, these data suggest that factors other than particular TSHR T cell epitopes (such as adenovirus-induced expression of conformationally intact TSHR protein), contribute to the generation of thyroid stimulating antibodies with consequent hyperthyroidism in TSHR-adenovirus immunized mice.

The oral NK(1) antagonist, aprepitant, given with standard antiemetics provides protection against nausea and vomiting over multiple cycles of cisplatin-based chemotherapy: a combined analysis of two randomised, placebo-controlled phase III clinical trials

In early clinical trials, the NK(1) receptor antagonist, aprepitant (EMEND(R)) was shown to improve the protection provided by the best available therapy (hereafter referred to as 'standard therapy': a 5-HT(3) receptor antagonist and dexamethasone) against chemotherapy-induced nausea and vomiting over multiple cycles of cisplatin-based chemotherapy. To further study the sustainment of antiemetic efficacy of aprepitant plus standard therapy over more than one cycle of chemotherapy, we examined combined data from the multiple cycles extensions of two phase III clinical trials of oral aprepitant plus standard therapy for the prevention of chemotherapy-induced nausea and vomiting. Data were pooled from two multicentre, randomised, double-blind, placebo-controlled studies with identical design and treatment regimens. Cancer patients receiving a first cycle of cisplatin-based (>or=70 mg/m(2)) chemotherapy were randomised to one of two treatment groups as follows: the standard therapy group received ondansetron 32 mg intravenously (i.v.) and dexamethasone 20 mg on day 1 and dexamethasone 8 mg twice daily (b.i.d.) on days 2-4. The aprepitant group received aprepitant 125 mg, ondansetron 32 mg i.v., and dexamethasone 12 mg on day 1, aprepitant 80 mg and dexamethasone 8 mg on days 2-3, and dexamethasone 8 mg on day 4. Patients had the option to receive the same blinded treatment for up to five additional cycles. The analysis used a combined exploratory endpoint of no emesis and no significant nausea (i.e. nausea which interfered with a patient's normal activities) over the 5 days following cisplatin, for up to six cycles of chemotherapy. A cumulative probabilities approach incorporating a model for transitional probabilities was used to analyse the data. Tolerability was assessed by reported adverse events and physical and laboratory assessments. Baseline characteristics, reasons for discontinuation, and drop-out rates were similar between groups. In every cycle, the estimated probabilities (rates) of no emesis and no significant nausea were significantly higher (P<0.006) in the aprepitant group: in the first cycle, rates were 61% in the aprepitant group (N=516) and 46% in the standard therapy group (N=522), and thereafter, rates for the aprepitant regimen remained higher throughout (59% (N=89) versus 40% (N=78) for the standard therapy, by cycle 6). Repeated dosing with aprepitant over multiple cycles was generally well tolerated. Compared with patients who received standard therapy alone (a 5-HT(3) antagonist plus dexamethasone), those who received aprepitant in addition to standard therapy had consistently better antiemetic protection that was well maintained over multiple cycles of highly emetogenic chemotherapy

Thyrotrophin receptor-specific memory T cell responses require normal B cells in a murine model of Graves' disease

The role of B cells as antigen-presenting cells is being recognized increasingly in immune responses to infections and autoimmunity. We compared T cell responses in wild-type and B cell-deficient mice immunized with the thyrotrophin receptor (TSHR), the major autoantigen in Graves' disease. Three B cell-deficient mouse strains were studied: JHD (no B cells), mIgM (membrane-bound monoclonal IgM+ B cells) and (m + s)IgM (membrane-bound and secreted monoclonal IgM). Wild-type and B cell-deficient mice (BALB/c background) were studied 8 weeks after three injections of TSHR or control adenovirus. Only wild-type mice developed IgG class TSHR antibodies and hyperthyroidism. After challenge with TSHR antigen, splenocyte cultures were tested for cytokine production. Splenocytes from TSHR adenovirus injected wild-type and mIgM-mice, but not from JHD- or (m + s)IgM- mice, produced interferon (IFN)-gamma in response to TSHR protein. Concanavalin A and pokeweed mitogen induced comparable IFN-gamma secretion in all groups of mice except in the JHD strain in which responses were reduced. The absence in (m + s)IgM mice and presence in mIgM mice of an anamnestic response to TSHR antigen was unrelated to lymphoid cell types. Surprisingly, although TSHR-specific antibodies were undetectable, low levels of serum IgG were present in mIgM- but not (m + s)IgM mice. Moreover, IFN-gamma production by antigen-stimulated splenocytes correlated with IgG levels. In conclusion, T cell responses to TSHR antigen developed only in mice with IgG-secreting B cells. Consequently, in the TSHR-adenovirus model of Graves' disease, some normal B cells appear to be required for the development of memory T cells.

Addition of the Oral NK1 Antagonist Aprepitant to Standard Antiemetics Provides Protection Against Nausea and Vomiting During Multiple Cycles of Cisplatin-Based Chemotherapy

Purpose: This analysis evaluated whether the antiemetic efficacy of the NK1 receptor antagonist aprepitant (EMEND™, Merck, Whitehouse Station, NJ) plus standard antiemetics could be sustained for up to six cycles of cisplatin-based chemotherapy.

Patients and Methods: Patients receiving cisplatin ≥ 70 mg/m2 were blindly assigned to receive one of the following three regimens: (1) aprepitant 375 mg 1 hour before cisplatin on day 1 and aprepitant 250 mg on days 2 to 5 (n = 35); (2) aprepitant 125 mg before cisplatin and aprepitant 80 mg on days 2 to 5 (n = 81); or (3) placebo before cisplatin on days 2 to 5 (n = 86). All groups received ondansetron 32 mg and dexamethasone 20 mg before cisplatin, and dexamethasone 8 mg on days 2 to 5. The primary end point was complete response (no emesis and no rescue therapy) over 5 days following cisplatin in up to six cycles. A cumulative probability analysis using a model for transitional probabilities was used to analyze the data. The aprepitant 375/250-mg regimen was discontinued early in light of new pharmacokinetic data.

Results: In the first cycle, 64% of patients in the aprepitant group and 49% in the standard therapy group had a complete response. Thereafter, complete response rates for the aprepitant group were still 59% by cycle 6, but decreased to 34% by cycle 6 for the standard therapy group. Reasons for discontinuation were similar across treatment groups.

Conclusion: Compared with patients who received standard therapy, those who received only the aprepitant regimen had better and more sustained protection against chemotherapy-induced nausea and vomiting over multiple cycles.

Insight into antibody responses induced by plasmid or adenoviral vectors encoding thyroid peroxidase, a major thyroid autoantigen

Plasmid and adenoviral vectors have been used to generate antibodies in mice that resemble human autoantibodies to the thyrotrophin receptor. No such studies, however, have been performed for thyroid peroxidase (TPO), the major autoantigen in human thyroiditis. We constructed plasmid and adenovirus vectors for in vivo expression of TPO. BALB/c mice were immunized directly by intramuscular injection of TPO-plasmid or TPO-adenovirus, as well as by subcutaneous injection of dendritic cells (DC) infected previously with TPO-adenovirus. Intramuscular TPO-adenovirus induced the highest, and TPO-plasmid the lowest, TPO antibody titres. Mice injected with TPO-transfected DC developed intermediate levels. Antibodies generated by all three approaches had similar affinities (Kd approximately 10(-9)M) and recognized TPO expressed on the cell-surface. Their epitopes were analysed in competition assays using monoclonal human autoantibodies that define the TPO immunodominant region (IDR) recognized by patients with thyroid autoimmune disease. Surprisingly, high titre antibodies generated using adenovirus interacted with diverse TPO epitopes largely outside the IDR, whereas low titre antibodies induced by DNA-plasmid recognized restricted epitopes in the IDR. This inverse relationship between antibody titre and restriction to the IDR is likely to be due to epitope spreading following strong antigenic stimulation provided by the adenovirus vector. However, TPO antibody epitope spreading does not occur in Hashimoto's thyroiditis, despite high autoantibody levels. Consequently, these data support the concept that in human thyroid autoimmunity, factors besides titre must play a role in shaping an autoantibody epitopic profile.

Dendritic cells infected with adenovirus expressing the thyrotrophin receptor induce Graves' hyperthyroidism in BALB/c mice

Dendritic cells (DCs) are the most potent antigen-presenting cells and a prerequisite for the initiation of primary immune response. This study was performed to investigate the contribution of DCs to the initiation of Graves' hyperthyroidism, an organ-specific autoimmune disease in which the thyrotrophin receptor (TSHR) is the major autoantigen. DCs were prepared from bone marrow precursor cells of BALB/c mice by culturing with granulocyte macrophage-colony stimulating factor and interleukin-4. Subcutaneous injections of DCs infected with recombinant adenovirus expressing the TSHR (but not beta-galactosidase) in syngeneic female mice induced Graves'-like hyperthyroidism (8 and 35% of mice after two and three injections, respectively) characterized by stimulating TSHR antibodies, elevated serum thyroxine levels and diffuse hyperplasitc goiter. TSHR antibodies determined by ELISA were of both IgG1 (Th2-type) and IgG2a (Th1-type) subclasses, and splenocytes from immunized mice secreted interferon-gamma (a Th1 cytokine), not interleukin-4 (a Th2 cytokine), in response to TSHR antigen. Surprisingly, IFN-gamma secretion, and induction of antibodies and disease were almost completely suppressed by co-administration of alum/pertussis toxin, a Th2-dominant adjuvant, whereas polyriboinosinic polyribocytidylic acid, a Th1-inducer, enhanced splenocyte secretion of IFN-gamma without changing disease incidence. These observations demonstrate that DCs efficiently present the TSHR to naive T cells to induce TSHR antibodies and Graves'-like hyperthyroidism in mice. In addition, our results challenge the previous concept of Th2 dominance in Graves' hyperthyroidism and provide support for the role of Th1 immune response in disease pathogenesis.

Similarities and differences in the phenotype of members of an Italian family with hereditary non-autoimmune hyperthyroidism associated with an activating TSH receptor germline mutation

Constitutively activating germline mutations of the TSH receptor (TSH-R) are considered the cause of hereditary non-autoimmune hyperthyroidism. In this study, 10 members (8 affected and 2 unaffected) of an Italian family with hereditary non-autoimmune hyperthyroidism were investigated for the presence of mutations in the TSH-R gene. The clinical features of the disease were also analyzed. PCR-amplified fragments of the TSH-R gene were obtained from genomic DNA extracted from peripheral blood leukocytes of each family member and analyzed by direct nucleotide sequencing and restriction analysis. An identical germline TSH-R mutation was detected in all the patients with hyperthyroidism but in none of the unaffected family members. The mutation was heterozygotic and determined the substitution of valine for methionine (codon 463; ATG-->GTG) in the second transmembrane domain of the TSH-R. When expressed in chinese hamster ovary (CHO) cells, the Val463 mutant TSH-R induced constitutive activation of the TSH receptor. Analysis of the clinical features of our family and those of other families with hereditary non-autoimmune hyperthyroidism, including one with the same Val463 mutation, revealed wide variability in the phenotypical expression of the disease. Our findings indicate that an activating germline mutation in the TSH-R gene plays a key role in hereditary non-autoimmune hyperthyroidism although the onset of clinical manifestations and the evolution of the disease seem to depend heavily on other factors, thus far unidentified. The absence of a clear correlation between mutant genotypes and phenotypic expression of the disease currently limits the prognostic value of genetic testing in families with hereditary non-autoimmune hyperthyroidism.

Evidence for a simplified view of autoantibody interactions with the thyrotropin receptor

Recently, many exceptions have been reported that undermine the concept that the epitopes for thyroid-stimulating autoantibodies (TSAb) and thyrotropin-blocking autoantibodies (TBAb) lie within the N-terminal and C-terminal portions of the thyrotropin receptor (TSHR) ectodomain, respectively. Here we have used a new approach to examine the issue by attempting to neutralize autoantibodies with the purified, N-terminal 289 amino acids of the TSHR ectodomain (TSHR-289), essentially the A subunit. Immunoglobulin G (IgG) with TSAb activity from 10 patients with Graves' disease was preincubated with or without purified active or inactive TSHR-289. Active, but not inactive, TSHR-289 completely neutralized TSAb activity in all sera. We then tested the ability of active TSHR-289 to neutralize TBAb activity in two rare hypothyroid patients with pure TBAb activity lacking agonist activity. IgG from both patients was extremely potent in the TBAb assay. Unlike with TSAb, preincubation of the IgG with a large excess of active TSHR-289 (20 microg/mL) revealed a remarkable divergence. TBAb activity from one patient was totally neutralized whereas in the other patient TBAb activity was totally unaffected. In conclusion, using a new approach, we confirm that the major portion of the TSAb epitope in the 418 amino acid ectodomain lies upstream of residue 289 (within the A subunit). In contrast, TBAb that cause hyperthyroidism can be more heterogeneous, with epitopes that lie largely upstream (A subunit) or downstream (B subunit) of residue 289.

Naked TSH receptor DNA vaccination: A TH1 T cell response in which interferon-gamma production, rather than antibody, dominates the immune response in mice

Two approaches have been developed to induce TSH receptor antibodies in mice with properties resembling those in Graves' disease, the Shimojo model of injecting live fibroblasts coexpressing the TSH receptor and major histocompatibility complex antigen Class II, and TSH receptor-DNA vaccination. Thyroid-stimulating antibodies appear to occur less commonly after DNA vaccination, but there has been no direct comparison of these models. We performed a three-way comparison of 1) AKR/N and 2) BALB/c mice vaccinated with TSH receptor-DNA and 3) AKR/N mice injected with fibroblasts expressing the TSH receptor and the major histocompatibility complex antigen class II of AKR/N mice. TSH receptor-DNA vaccinated mice had low or undetectable levels of TSH receptor antibodies determined by ELISA or flow cytometry. Nonspecific binding precluded comparisons with sera from Shimojo mice by these assays. TSH binding inhibition and thyroid-stimulating antibody were undetectable in TSH receptor-DNA vaccinated mice. In Shimojo mice, TSH binding inhibition was positive in approximately 60%, and thyroid-stimulating antibodies were positive in hyperthyroid animals. Unlike the negative antibody data, splenocytes from TSH receptor-vaccinated (but not Shimojo) mice proliferated and produced the Th1 cytokine interferon-gamma in response to TSH receptor antigen. In conclusion, DNA vaccination is less effective at inducing TSH receptor antibodies than the Shimojo approach, but it permits the future characterization of TSH receptor-specific T cells generated without adjuvant.