Definitions and reliability assessment of elementary ultrasound lesions in giant cell arteritis: a study from the OMERACT Large Vessel Vasculitis Ultrasound Working Group

Objectives

To define the elementary ultrasound (US) lesions in giant cell arteritis (GCA) and to evaluate the reliability of the assessment of US lesions according to these definitions in a web-based reliability exercise.

Methods

Potential definitions of normal and abnormal US findings of temporal and extracranial large arteries were retrieved by a systematic literature review. As a subsequent step, a structured Delphi exercise was conducted involving an expert panel of the Outcome Measures in Rheumatology (OMERACT) US Large Vessel Vasculitis Group to agree definitions of normal US appearance and key elementary US lesions of vasculitis of temporal and extracranial large arteries. The reliability of these definitions on normal and abnormal blood vessels was tested on 150 still images and videos in a web-based reliability exercise.

Results

Twenty-four experts participated in both Delphi rounds. From originally 25 statements, nine definitions were obtained for normal appearance, vasculitis and arteriosclerosis of cranial and extracranial vessels. The ‘halo’ and ‘compression’ signs were the key US lesions in GCA. The reliability of the definitions for normal temporal and axillary arteries, the ‘halo’ sign and the ‘compression’ sign was excellent with inter-rater agreements of 91–99% and mean kappa values of 0.83–0.98 for both inter-rater and intra-rater reliabilities of all 25 experts.

Conclusions

The ‘halo’ and the ‘compression’ signs are regarded as the most important US abnormalities for GCA. The inter-rater and intra-rater agreement of the new OMERACT definitions for US lesions in GCA was excellent.

Tibial stress reaction presenting as bilateral shin pain in a man taking denosumab for giant cell tumor of the bone

Prolonged bisphosphonate use has been associated with increased risk of atypical femoral fractures. Very few cases of atypical femoral fractures have been reported with denosumab. We report a case of bilateral tibial stress reactions in a 60-year-old man with no history of osteoporosis who was on prolonged high-dose denosumab for the treatment of giant cell tumor of bone. He presented with a 3-month history of pain in his bilateral shins worsening with activity and improving with rest. Although initial radiographs were unremarkable, he was found to have changes consistent with a stress reaction on magnetic resonance imaging of the distal tibia. To our knowledge, bilateral tibial stress reactions have not been previously reported with anti-resorptive therapies (neither bisphosphonates nor denosumab). Our case is intriguing in terms of the development of stress reactions as a precursor to stress fractures which may also relate to atypical fractures. Our case suggests a possible association between denosumab use and stress reactions. Of note the indication for denosumab in our case was for the treatment of giant cell tumor of bone where the Food and Drug Administration (FDA) approved dose is substantially higher than the FDA approved dose for osteoporosis treatment. Although rare, clinicians should consider the possibility of stress fractures in patients on anti-resorptive medications such as denosumab, especially when a patient presents with new onset thigh pain, hip pain or pain over an area affecting the long bones. Evaluation by imaging of affected areas should be pursued to enable early detection and intervention, as well as prevention of morbidity and associated ongoing risk to the patient.

Inpatient complications in patients with giant cell arteritis: decreased mortality and increased risk of thromboembolism, delirium and adrenal insufficiency

OBJECTIVE

The morbidity and mortality of hospitalized GCA patients have been unexplored. The aim of this study was to analyse inpatient complications experienced by patients with GCA.

METHODS

We used the Nationwide Inpatient Sample database to study a large group of patients admitted for pneumonia, myocardial infarction (MI), ischaemic stroke and femoral neck fracture. Patients were divided into two groups based on whether or not they had a diagnosis of GCA upon admission. Outcomes evaluated included inpatient mortality and the occurrence of adrenal insufficiency, deep vein thrombosis, pulmonary embolism and delirium.

RESULTS

From 2008 to 2011, 8 203 447 patients ≥50 years of age were discharged from US hospitals after admission with pneumonia, MI, stroke and femoral neck fracture. Among these patients, 9311 (0.11%) had GCA. Admissions for pneumonia, stroke and hip fracture were more frequent in GCA patients compared with those without GCA, accounting for 41.5% vs 39.4%, 24.9% vs 19.8% and 15.4% vs 14.2% of hospitalizations, respectively (P ≤ 0.001). Admissions for MI were more common in non-GCA patients (26.6% vs 18.2%, P < 0.001). During hospitalization, 4.1% of the GCA patients died, compared with 4.8% of those without GCA [odds ratio (OR) 0.73, P < 0.001). The GCA population suffered significantly more often from deep vein thrombosis (OR 2.08, P < 0.001), pulmonary embolism (OR 1.58, P < 0.001), delirium (OR 1.60, P < 0.001) and adrenal insufficiency (OR 4.95, P < 0.001).

CONCLUSION

Hospitalized GCA patients have lower mortality compared with the general inpatient population but greater risk of venous thromboembolism, delirium and adrenal insufficiency.

«Low Carb»-Diäten bei Adipositas

Diäten mit niedrigem Kohlenhydratgehalt («Low-Carb»-Diäten) sind in den letzten Jahren in angelsächsischen Ländern in Mode gekommen, nachdem kontrollierte Studien im Vergleich zu fettarmen Diäten eine 3–6 kg stärkere Gewichtsabnahme zeigten. Allerdings waren die Unterschiede nur in den ersten sechs Monaten, nicht aber nach zwölf Monaten statistisch signifikant. Die Gründe für die spezifische gewichtsreduzierende Wirkung dieser Diäten sind in der initialen Phase ein Wasserverlust. Später spielen mehre Faktoren, wie eine beschränkte Nahrungsmittelauswahl, die sättigende Wirkung der reichlich konsumierten Proteine und die appetithemmende Wirkung der Ketose eine Rolle. Die kontrollierten Studien zeigten auch, dass das LDL-Cholesterin nicht anstieg, ja es wurde sogar eine günstige Zunahme des HDL-C und eine Abnahme der Serumtriglyzeride beobachtet. Auch wenn diese Diäten offenbar über beschränkte Zeit «funktionieren», sind sie problematisch, da eine hohe Proteineinnahme oft mit einer erhöhten Zufuhr von gesättigten Fetten einhergeht, zudem die Aufnahme von pflanzlichen Schutzstoffen (Antioxidantien und wasserlösliche Vitamine) und von Nahrungsfasern gering ist. Damit ist ihre präventive Wirkung auf atherosklerotische Erkrankungen, auf Hypertonie, Diabetes und nahrungsabhängige Krebsformen fraglich. Zudem verleiden «Low-Carb»-Diäten auf Dauer und führen zu ernährungsmäßigem Außenseitertum. Sie sind aus all diesen Gründen deshalb grundsätzlich abzulehnen. Sinnvolle Ernährungsformen bei Adipositas sollten zeitlich unbeschränkt durchgeführt werden können und mit mehr körperlicher Bewegung und Verhaltenstherapie kombiniert werden.

Hedgehog signaling regulation of homeodomain protein islet duodenum homeobox-1 expression in pancreatic beta-cells

Insulin gene expression in pancreatic beta-cells is regulated by signals from developmental morphogen proteins known as hedgehogs (Hhs). By analyzing 5'-deletion insulin promoter-reporter constructs in transient transfections of clonal INS-1 beta-cells, we located activating Hh-responsive regions within the rat insulin I promoter that include the glucose-response elements Far (E2) and Flat (A2/A3). Activation of Hh signaling in INS-1 cells by ectopic Hh expression increased (and inhibition of Hh signaling with the Hh-specific inhibitor cyclopamine decreased) transcriptional activation of a multimerized FarFlat enhancer-reporter construct. In DNA-binding studies, nuclear extracts from INS-1 cells activated by ectopic Hh expression increased (and extracts from INS-1 cells treated with cyclopamine decreased) protein binding to a radiolabeled FarFlat oligonucleotide probe. An antiserum directed against the transcription factor islet duodenum homeobox-1 (IDX-1), a regulator of pancreas development and activator of the insulin gene promoter, attenuated the binding activity of Hh-responsive protein complexes. Nuclear IDX-1 protein levels on Western blots were increased by ectopic Hh expression, thereby providing a mechanism for Hh-mediated regulation of the insulin promoter. Addition of cyclopamine to INS-1 cells decreased IDX-1 messenger RNA expression. In transient transfections of a -4.5-kb mouse IDX-1 promoter-reporter construct, ectopic Hh expression increased (and cyclopamine administration decreased) transcriptional activation of the IDX-1 promoter in a dose-dependent manner. Thus, the IDX-1 gene is a direct regulatory target of Hh signaling in insulin-producing pancreatic beta-cells. We propose that Hh signaling activates the insulin gene promoter indirectly via the direct activation of IDX-1 expression. Because IDX-1 gene expression is essential for insulin gene expression, pancreatic beta-cell development, and normal glucose homeostasis, our findings that Hh signaling regulates IDX-1 expression in the endocrine pancreas suggest possible novel therapeutic approaches for diabetes mellitus.

Hedgehog signaling regulation of insulin production by pancreatic beta-cells

Hedgehogs (Hhs) are intercellular signaling molecules that regulate tissue patterning in mammalian development. Mammalian Hhs include Sonic hedgehog (Shh), Indian hedgehog (Ihh), and Desert hedgehog (Dhh). The absence of Shh expression is required for the early development of the endocrine and exocrine pancreas, but whether Hh signaling functions in the fully developed adult endocrine pancreas is unknown. Here we report that Hhs Ihh and Dhh and their receptors patched (Ptc) and smoothened are expressed in the endocrine islets of Langerhans of the fully developed rat pancreas and in the clonal gamma-cell line INS-1. We demonstrate the coexpression of Ptc with insulin in beta-cells of mouse pancreatic islets, indicating that beta-cells are targets of active Hh signaling. The administration of cyclopamine, a Hh signaling inhibitor, decreases both insulin secretion from and insulin content of INS-1 cells. The effects of Hh signaling on insulin production occur at the transcriptional level because activation of Hh signal transduction by ectopic expression of Shh increases rat insulin I promoter activation in a dose-dependent manner in transient transfections of INS-1 and MIN6 beta-cell lines. In contrast, inhibition of Hh signaling with increasing concentrations of cyclopamine progressively reduces insulin promoter activity. Furthermore, the treatment of INS-1 cells with cyclopamine diminishes endogenous insulin mRNA expression. We propose that Hh signaling is not restricted to patterning in early pancreas development but also continues to signal in differentiated beta-cells of the endocrine pancreas in regulating insulin production. Thus, defective Hh signaling in the pancreas should be considered as a potential factor in the pathogenesis of type 2 diabetes.