Citations

Aβ deposition in the basal ganglia is common in autosomal dominant Alzheimer’s disease. Vöglein et al. report an increased severity of motor symptoms in autosomal dominant versus sporadic disease in advanced disease stages. Motor symptoms are more severe in post-codon 200 presenilin 1 mutation carriers and correlate with basal ganglia Aβ.

Abstract Introduction Quantitative in vivo measurement of brain amyloid burden is important for both research and clinical purposes. However, the existence of multiple imaging tracers presents challenges to the interpretation of such measurements. This study presents a direct comparison of Pittsburgh compound B–based and florbetapir‐based amyloid imaging in the same participants from two independent cohorts using a crossover design. Methods Pittsburgh compound B and florbetapir amyloid PET imaging data from three different cohorts were analyzed using previously established pipelines to obtain global amyloid burden measurements. These measurements were converted to the Centiloid scale to allow fair comparison between the two tracers. The mean and inter‐individual variability of the two tracers were compared using multivariate linear models both cross‐sectionally and longitudinally. Results Global amyloid burden measured using the two tracers were strongly correlated in both cohorts. However, higher variability was observed when florbetapir was used as the imaging tracer. The variability may be partially caused by white matter signal as partial volume correction reduces the variability and improves the correlations between the two tracers. Amyloid burden measured using both tracers was found to be in association with clinical and psychometric measurements. Longitudinal comparison of the two tracers was also performed in similar but separate cohorts whose baseline amyloid load was considered elevated (i.e., amyloid positive). No significant difference was detected in the average annualized rate of change measurements made with these two tracers. Discussion Although the amyloid burden measurements were quite similar using these two tracers as expected, difference was observable even after conversion into the Centiloid scale. Further investigation is warranted to identify optimal strategies to harmonize amyloid imaging data acquired using different tracers.

Quantitative activity through the TCR-proximal protein network specifies thymic positive versus negative selection.

Background . Hypertriglyceridemia and hyperglycemia coexist in 30-60% of patients with diabetes. The impact of hypertriglyceridemia regarding HbA1c assay reliability remains uncertain. Therefore, we conducted a prospective in vivo controlled study with the aim of defining the association between triglyceride levels and HbA1c. Methods . A total of 44 patients with an index-hospital admission diagnosis of diabetic ketoacidosis or hypertriglyceridemia-induced pancreatitis, as a model for acute elevation of triglycerides, were recruited. Blood samples were drawn for the measurement of HbA1c, triglycerides, glucose, and hemoglobin at baseline and subsequently 24 and 48 hours after admission. HbA1c analysis was performed with high-performance liquid chromatography Bio-Rad D10 (NGSP approved). Results . All patients completed the study protocol. A difference between mean triglycerides from day 0 (baseline) to day 2 of 1567.2 mg/dL was observed. We found a difference between mean serum HbA1c from days 0 to 2 of 0.09% [1 mmol/mol] ( p = 0.004 ). Moreover, a weak correlation between the mean difference of HbA1c and triglycerides from baseline to day 2 was found to be statistically significant ( r = 0.256 , p = 0.015 ). None of these findings, however, are clinically significant. Conclusion . Triglycerides do not impair the interpretation of HbA1c assay. Patients and clinicians can now be confident that hypertriglyceridemia is not an important factor when interpreting HbA1c results.

Obinutuzumab is used for the treatment of chronic lymphocytic leukemia. So far there are no data of using this for retreatment in patients who have received it previously. We introduced obinutuzumab for the retreatment in a chronic lymphocytic leukemia patient, who had first achieved partial remission with it and eventually relapsed over a course of 2.5 years. After retreatment with single-agent obinutuzumab, the patient achieved a partial remission again within one cycle and continues to maintain the response status. This case is a platform for considering obinutuzumab as a viable option for retreatment of chronic lymphocytic leukemia patients who have received it before, similar to the pattern of use for other anti-CD20 monoclonal antibodies in this disease, including rituximab.

Objective It is unclear whether endoscopic assessment of scars after colorectal endoscopic mucosal resection (EMR) has to include biopsies, even if endoscopy is negative. Vice versa, endoscopic diagnosis of recurrent adenoma may not require biopsy before endoscopic reinterventions. We prospectively analysed various endoscopic modalities in the diagnosis of recurrence following EMR. Design We conducted a prospective study of patients undergoing colonoscopy after EMR of large (≥20 mm) colorectal neoplasia. Endoscopists predicted recurrence and confidence level with four imaging modes: high-definition white light (WL) and narrow-band imaging (NBI) with and without near focus (NF). Separately, 26 experienced endoscopists assessed offline images. Results Two hundred and thirty patients with 255 EMR scars were included. The prevalence of recurrent adenoma was 24%. Diagnostic values were high for all modes (negative predictive value (NPV) ≥97%, positive predictive value (PPV) ≥81%, sensitivity ≥90%, specificity ≥93% and accuracy ≥93%). In high-confidence cases, NBI with NF had NPV of 100% (95% CI 98% to 100%) and sensitivity of 100% (95% CI 93% to 100%). Use of clips at initial EMR increased diagnostic inaccuracy (adjusted OR=1.68(95% CI 1.01 to 2.75)). In offline assessment, specificity was high for all imaging modes (mean: ≥93% (range: 55%–100%)), while sensitivity was significantly higher for NBI-NF (82%(72%–93%)%)) compared with WL (69%(38%–86%); p<0.001), WL-NF (68%(55%–83%); p<0.001) and NBI (71%(59%–90%); p<0.001). Conclusion Our study demonstrates very high sensitivity and accuracy for all four imaging modalities, especially NBI with NF, for diagnosis of recurrent neoplasia after EMR. Our data strongly suggest that in cases of high confidence negative optical diagnosis based on NBI-NF, no biopsy is needed to confirm absence of recurrence during colorectal EMR follow-up. A high confidence positive optical diagnosis can lead to immediate resection of any suspicious area. In all cases of low confidence, biopsy is still required. Trial registration number NCT02668198 .

Use of gadoxetate disodium, a hepatobiliary gadolinium‐based agent, in patients with chronic parenchymal liver disease offers the advantage of improved sensitivity for detecting hepatocellular carcinoma (HCC). Imaging features of liver observations on gadoxetate‐enhanced MRI may also serve as biomarkers of recurrence‐free and overall survival following definitive treatment of HCC. A number of technical and interpretative pitfalls specific to gadoxetate exist, however, and needs to be recognized when protocoling and interpreting MRI exams with this agent. This article reviews the advantages and pitfalls of gadoxetate use in patients at risk for HCC, and the potential impact on Liver Imaging Reporting and Data System (LI‐RADS) imaging feature assessment and categorization.Level of Evidence: 5Technical Efficacy Stage: 2J. Magn. Reson. Imaging 2019;49:1236–1252.