Primary Hyperparathyroidism and Negative Tc99 Sestamibi Imaging: To Operate or Not?

Background

The indications for surgery in primary hyperparathyroidism (1HPT) are the same for patients with and without localization on imaging. However, patients with negative imaging may not be referred for surgery or the surgeon may be reluctant to operate. We compare outcomes in patients with negative imaging to those with localization.

Methods

A review of patients who underwent primary operation for 1HPT with a preoperative Tc99 sestamibi I-123 (MIBI) scan was conducted. Imaging, laboratory, operative findings, pathologic findings, and outcomes were used to compare patients with negative scans to those with localization.

Results

A total of 2,681 patients had an operation for 1HPT with preoperative MIBI. MIBI imaging was negative in 136 (5.7 %). The negative MIBI group had a lower calcium (10.9 vs. 11.0?mg/ml, P?=?0.02), phosphorus (2.9 vs. 3.1?mg/dl, P?P?=?0.02) and no difference in parathyroid hormone, 25-OH vitamin D, or bone loss. Multigland resection was higher with a negative scan (32 vs. 13 %, P?P?P?=?0.04) and parathyroid hormone (98 vs. 196?pg/ml, P?=?0.03) than those not cured. Patients with both a negative ultrasound result and negative MIBI had a cure rate of 89 %.

Conclusions

A curative operation is performed at an acceptably lower rate with negative MIBI imaging. A decision for surgery with a negative MIBI finding should consider lower cure rates and symptom severity.     

Central role for interleukin-2 in type 1 diabetes

Type 1 diabetes presents clinically with overt hyperglycemia resulting from progressive immune-mediated destruction of pancreatic β-cells and associated metabolic dysfunction. Combined genetic and immunological studies now highlight deficiencies in both the interleukin-2 (IL-2) receptor and its downstream signaling pathway as a central defect in the pathogenesis of type 1 diabetes. Prior intervention studies in animal models indicate that augmenting IL-2 signaling can prevent and reverse disease, with protection conferred primarily by restoration of regulatory T-cell (Treg) function. In this article, we will focus on studies of type 1 diabetes noting deficient IL-2 signaling and build what we believe forms the molecular framework for their contribution to the disease. This activity results in the identification of a series of potentially novel therapeutic targets that could restore proper immune regulation in type 1 diabetes by augmenting the IL-2 pathway.     

Adherence to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist in articles published in EAACI Journals: A bibliographic study

Research data derived from observational studies are accumulating quickly in the field of allergy and immunology and a large amount of observational studies are published every year. The aim of the present study was to evaluate the adherence to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist by papers published in the three European Academy of Allergy and Clinical Immunology journals, during the period 2009–2018. To this end, we conducted a bibliographic study of up to eight randomly selected papers per year per Journal. Our literature search resulted in 223 papers. Amongst those, 80, 80 and 63 records were from Paediatric Allergy and Immunology, Allergy and Clinical and Translational Allergy, respectively; the latter was published only from 2011 on. Prospective, case control and cross-sectional designs were described in 88, 43 and 92 papers, respectively. Full reporting of all STROBE items was present in 47.4%, 45.6% and 41.2% for the cohort, cross-sectional and case-control studies, respectively. Generally, no time trend in adherence of reporting STROBE items was observed, apart from reporting funding, which increased from 60% in 2009/2010 to more than 90% in 2018. We identified a cluster of STROBE items with low proportions of full reporting constituted by the items on reporting study design in the title and methods, variables types along with their measurement/assessment, bias and confounding, study size, and grouping of variables. It appears that the STROBE checklist is a suitable tool in observational allergy epidemiology. However, adherence to the STROBE checklist appeared suboptimal.     

Service utilisation in a public post-acute rehabilitation unit following traumatic brain injury

Traumatic brain injury (TBI) causes disability in a proportion of survivors across the spectrum of injury severity. Previous research suggests physical changes are the primary focus of rehabilitation, although cognitive, emotional and behavioural difficulties cause greater concern in the long-term. There is little information about services accessed by those with mild injuries, who often have no physical disabilities. This study investigated factors determining service utilisation in a population-based sample which included 52% mild injuries (PTA ≤ 24 hours). Chi-squares and t-tests were used to examine the impact of demographic, clinical, psychological and physical variables on referral of 175 TBI patients to clinical disciplines in a public, community-based rehabilitation facility in Hobart, Tasmania. Increased service intensity (total disciplines referred to), was associated with greater injury severity (p = .006) and previous TBI (p = .041). Less traditional rehabilitation services (nursing, psychology) received more referrals than traditional disciplines (physiotherapy, occupational therapy, social work). Referral to physiotherapy and occupational therapy was associated with greater injury severity, functional dependence, hospitalisation and older age. Referral to nursing, psychology and social work was associated with more post-concussion symptoms, younger age, anxiety, depression and assault-related injury. The large number of referrals to psychology strengthens the case for including it as a core rehabilitation discipline.     

Inhibition of VEGFR-2 Reverses Type 1 Diabetes in NOD Mice by Abrogating Insulitis and Restoring Islet Function

The dysregulation of receptor tyrosine kinases (RTKs) in multiple cell types during chronic inflammation is indicative of their pathogenic role in autoimmune diseases. Among the many RTKs, vascular endothelial growth factor receptor (VEGFR) stands out for its multiple effects on immunity, vascularization, and cell migration. Herein, we examined whether VEGFR participated in the pathogenesis of type 1 diabetes (T1D) in nonobese diabetic (NOD) mice. We found that RTK inhibitors (RTKIs) and VEGF or VEGFR-2 antibodies reversed diabetes when administered at the onset of hyperglycemia. Increased VEGF expression promoted islet vascular remodeling in NOD mice, and inhibition of VEGFR activity with RTKIs abrogated the increase in islet vascularity, impairing T-cell migration into the islet and improving glucose control. Metabolic studies confirmed that RTKIs worked by preserving islet function, as treated mice had improved glucose tolerance without affecting insulin sensitivity. Finally, examination of human pancreata from patients with T1D revealed that VEGFR-2 was confined to the islet vascularity, which was increased in inflamed islets. Collectively, this work reveals a previously unappreciated role for VEGFR-2 signaling in the pathogenesis of T1D by controlling T-cell accessibility to the pancreatic islets and highlights a novel application of VEGFR-2 antagonists for the therapeutic treatment of T1D.In type 1 diabetes (T1D), genetic and environmental risk factors lead to immune dysregulation, provoking an autoimmune response directed toward insulin-producing β-cells of the islets of Langerhans. Previous investigations have estimated that β-cells or islets in nonobese diabetic (NOD) mice and humans are diminished to 10–30% of their initial mass (1,2), and the residual islets are largely dysfunctional when hyperglycemia is first detected (1,2). However, low levels of C-peptide can be detected in T1D patients as far out as 1–2 years postdiagnosis, indicating a window of opportunity for therapies that can restore or preserve islet mass and function (3).Multitarget receptor tyrosine kinase inhibitors (RTKIs), such as sunitinib, were originally designed to target malignant tumors that express dysregulated tyrosine kinases, including platelet-derived growth factor (PDGF)-R, c-FMS, or c-Kit. However, these inhibitors also target vascular endothelial growth factor (VEGF) receptors (VEGFRs), which are elevated in the parenchyma and tissue vasculature in many tumor microenvironments and during chronic inflammation. VEGF regulates vasculogenesis and angiogenesis largely through activation of VEGFR-2 (4). In addition to stimulating endothelial cell mitogenesis and cell migration, VEGF also has effects on a limited number of other cell types, including stimulation of monocyte/macrophage migration. Studies of transgenic mice lacking VEGFR-1 (5) or that express VEGFR-1 with a “dead” kinase domain (6) reveal that VEGFR-1 functions as a negative regulator of vasculogenesis and angiogenesis. Similarly, VEGFR-2 deficiency is embryonically lethal in mice but is attributed to a nonfunctional and underdeveloped vascular system (7). The phenotypes of VEGFR-1 and VEGFR-2–null mice indicate that, although VEGF-A has limited function through VEGFR-1, the vascular remodeling functions of VEGF-A are largely mediated through the activation of VEGFR-2.Tyrosine kinase inhibitors (TKIs) have shown efficacy in mouse models of muscular dystrophy (8), multiple sclerosis (9), rheumatoid arthritis (10–12), and psoriasis (13). TKI can prevent and reverse diabetes in NOD mice (14–16). Imatinib, which predominantly targets c-abl and PDGF, reversed diabetes in NOD mice (14), but other RTKIs with distinct inhibitory profiles (e.g., sunitinib) were even more effective, suggesting that the precise constellations of TK targets were critical for maximum efficacy. In this regard, the VEGF-A/VEGFR-2 pathway, a key target of sunitinib, stands out as a key kinase regulating the pathogenesis of several of these inflammatory disorders (17–19). Intriguingly, VEGF serum levels are elevated in T1D patients compared with healthy controls and positively correlate with increased HbA_1c levels (20).In this study, we determined whether VEGFR-2 might be involved in the pathogenesis of T1D and tested the therapeutic efficacy of VEGFR-2 inhibition in the NOD mouse model of T1D. We report that inhibition of VEGFR-2 by RTKIs or blocking antibodies rapidly reversed diabetes and maintains euglycemia with continued drug administration. Reversal of diabetes was attributed to an abrogation of vascular remodeling in the pancreatic islets, which impairs T-cell trafficking and the severity of insulitis, ultimately improving glucose tolerance. Histological analysis of human and mouse pancreata revealed a positive correlation between the severity of insulitis and islet vascularity, implicating inflammation as a major driving force in the vascular remodeling observed in the islets. Collectively, our findings suggest that VEGF/VEGFR-2 signaling serves a critical gatekeeper function by controlling essential remodeling of the vasculature that is necessary for T cells to gain access to tissues.