Different Aspects of Classical Pathway Overactivation in Patients With C3 Glomerulopathy and Immune Complex-Mediated Membranoproliferative Glomerulonephritis

The rare and heterogeneous kidney disorder C3 glomerulopathy (C3G) is characterized by dysregulation of the alternative pathway (AP) of the complement system. C3G is often associated with autoantibodies stabilizing the AP C3 convertase named C3 nephritic factors (C3NeF). The role of classical pathway (CP) convertase stabilization in C3G and related diseases such as immune complex-mediated membranoproliferative glomerulonephritis (IC-MPGN) remains largely unknown. Here, we investigated the CP convertase activity in patients with C3G and IC-MPGN. Using a refined two-step hemolytic assay, we measured the stability of CP convertases directly in the serum of 52 patients and 17 healthy controls. In four patients, CP convertase activity was prolonged compared to healthy controls, i.e. the enzymatic complex was stabilized. In three patients (2 C3G, 1 IC-MPGN) the convertase stabilization was caused by immunoglobulins, indicating the presence of autoantibodies named C4 nephritic factors (C4NeFs). Importantly, the assay also enabled detection of non-immunoglobulin-mediated stabilization of the CP convertase in one patient with C3G. Prolonged CP convertase activity coincided with C3NeF activity in all patients and for up to 70 months of observation. Crucially, experiments with C3-depleted serum showed that C4NeFs stabilized the CP C3 convertase (C4bC2a), that does not contain C3NeF epitopes. All patients with prolonged CP convertase activity showed clear signs of complement activation, i.e. lowered C3 and C5 levels and elevated levels of C3d, C3bc, C3bBbP, and C5b-9. In conclusion, this work provides new insights into the diverse aspects and (non-)immunoglobulin nature of factors causing CP convertase overactivity in C3G/IC-MPGN.</p

Comparison of Contrast Enhanced Magnetic Resonance Angiography to Computed Tomography in Detecting Pulmonary Arteriovenous Malformations

BACKGROUND: Computed tomography (CT) is considered the imaging modality of choice to diagnose pulmonary arteriovenous malformations PAVMs. The drawback of this technique is that it requires ionizing radiation. Magnetic resonance (MR) imaging does not have the limitation, but little is known about the performance of MR compared to CT for the detection of PAVMs. The aim of this study is to investigate the sensitivity of contrast-enhanced MR angiography (CE-MRA) in the detection of PAVMs with feeding artery diameters (FAD) > 2 mm. METHODS: Patients with a grade 2 or 3 shunt on screening transthoracic contrast echocardiography (TTCE) were asked to participate. Included patients underwent chest CT and CE-MRA. CT was considered the reference standard. CT and CE-MRA scans were anonymized and assessed for the presence of PAVMs with FAD > 2 mm by one and two readers respectively. Data analysis was performed on per patient and per PAVM basis. RESULTS: Fifty-three patients were included. 105 PAVMs were detected on CT, 45 with a FAD ≥ 2 mm. In per patient analysis, sensitivity and specificity of CE-MRA were 92% and 97% respectively for reader 1 and 92% and 62% for reader 2. Negative and positive predictive value (NPV/PPV) were 93% and 96% for R1 and 90% and 67% for R2. In per PAVM analysis, sensitivity, specificity, NPV and PPV were 96%, 99%, 100% and 86% for R1 and 93%, 96%, 100% and 56% for R2, respectively. CONCLUSIONS: CE-MRA has excellent sensitivity and NPV for detection of PAVMs with FAD ≥ 2 mm and can therefore be used to detect these PAVMs. We are hopeful that future advancements in CE-MRA technology will reduce false positive rates and allow for more broad use of CE-MRA in PAVM diagnosis and management

Complications of Balloon Pulmonary Angioplasty:A Comprehensive Analysis Based on the Latest ESC Consensus Statement

Background/Objectives: The literature reports high complication rates in patients with chronic thromboembolic pulmonary hypertension (CTEPH) who undergo balloon pulmonary angioplasty (BPA), especially in patients with poor pulmonary hemodynamics. Here, we describe the complications of BPA based on the new definitions. Methods: All patients with CTEPH who completed BPA treatment before 15 September 2023 were selected from the CTEPH database. Peri-procedural complications were collected and classified according to the 2023 consensus paper on BPA treatment. Complications were analyzed in subgroups of patients with pulmonary vascular resistance (PVR), ≤ or &gt;6.6 WU, and mean pulmonary artery pressure (mPAP), ≤ or &gt;45 mmHg, at first BPA. Results: In this analysis, 87 patients (63% women; mean age 61.1 ± 14.0 years; 62% on dual PH targeted medical therapy) underwent 426 (mean 4.9 ± 1.6 per patient) BPAs. Only non-severe complications occurred in 14% of BPA treatments and in 47% of the patients; 31% patients had a thoracic complication. The thoracic complications were mild (71%) or moderate (29%). Patients with a PVR &gt; 6.6 WU (n = 8) underwent more BPA treatments (6.6 ± 1.5 versus 4.6 ± 1.5, p = 0.002), had more complications (88% versus 41% of patients, p = 0.020), and had more thoracic complications (17% vs. 7% of BPAs, p = 0.013) than patients with PVR ≤ 6.6 WU. Patients with mPAP &gt; 45 mmHg (n = 13) also had more BPA treatments (6.5 ± 1.7 versus 4.6 ± 1.4, p &lt; 0.001), more complications (77% versus 44% of patients, p = 0.027) and more thoracic complications (14% versus 8% of BPAs, p = 0.039) than patients with mPAP ≤ 45 mmHg. Conclusions: Complications occurred in 14% of BPAs and were mostly mild. Patients with severe pulmonary hemodynamics suffered more (thoracic) complications.</p

The MCRA toolbox of models and data to support chemical mixture risk assessment

A model and data toolbox is presented to assess risks from combined exposure to multiple chemicals using probabilistic methods. The Monte Carlo Risk Assessment (MCRA) toolbox, also known as the EuroMix toolbox, has more than 40 modules addressing all areas of risk assessment, and includes a data repository with data collected in the EuroMix project. This paper gives an introduction to the toolbox and illustrates its use with examples from the EuroMix project. The toolbox can be used for hazard identification, hazard characterisation, exposure assessment and risk characterisation. Examples for hazard identification are selection of substances relevant for a specific adverse outcome based on adverse outcome pathways and QSAR models. Examples for hazard characterisation are calculation of benchmark doses and relative potency factors with uncertainty from dose response data, and use of kinetic models to perform in vitro to in vivo extrapolation. Examples for exposure assessment are assessing cumulative exposure at external or internal level, where the latter option is needed when dietary and non-dietary routes have to be aggregated. Finally, risk characterisation is illustrated by calculation and display of the margin of exposure for single substances and for the cumulation, including uncertainties derived from exposure and hazard characterisation estimates.</p

Complications of Balloon Pulmonary Angioplasty: A Comprehensive Analysis Based on the Latest ESC Consensus Statement

Background/Objectives: The literature reports high complication rates in patients with chronic thromboembolic pulmonary hypertension (CTEPH) who undergo balloon pulmonary angioplasty (BPA), especially in patients with poor pulmonary hemodynamics. Here, we describe the complications of BPA based on the new definitions. Methods: All patients with CTEPH who completed BPA treatment before 15 September 2023 were selected from the CTEPH database. Peri-procedural complications were collected and classified according to the 2023 consensus paper on BPA treatment. Complications were analyzed in subgroups of patients with pulmonary vascular resistance (PVR), ≤ or >6.6 WU, and mean pulmonary artery pressure (mPAP), ≤ or >45 mmHg, at first BPA. Results: In this analysis, 87 patients (63% women; mean age 61.1 ± 14.0 years; 62% on dual PH targeted medical therapy) underwent 426 (mean 4.9 ± 1.6 per patient) BPAs. Only non-severe complications occurred in 14% of BPA treatments and in 47% of the patients; 31% patients had a thoracic complication. The thoracic complications were mild (71%) or moderate (29%). Patients with a PVR > 6.6 WU (n = 8) underwent more BPA treatments (6.6 ± 1.5 versus 4.6 ± 1.5, p = 0.002), had more complications (88% versus 41% of patients, p = 0.020), and had more thoracic complications (17% vs. 7% of BPAs, p = 0.013) than patients with PVR ≤ 6.6 WU. Patients with mPAP > 45 mmHg (n = 13) also had more BPA treatments (6.5 ± 1.7 versus 4.6 ± 1.4, p < 0.001), more complications (77% versus 44% of patients, p = 0.027) and more thoracic complications (14% versus 8% of BPAs, p = 0.039) than patients with mPAP ≤ 45 mmHg. Conclusions: Complications occurred in 14% of BPAs and were mostly mild. Patients with severe pulmonary hemodynamics suffered more (thoracic) complications

Crystal IS on the move

Introduction: Whether pediatric patients with differentiated thyroid carcinoma (DTC) are at risk of developing treatment-related adverse effects on cardiac function is unknown. We therefore studied in long-term survivors of pediatric DTC the prevalence of cardiac dysfunction and atrial fibrillation in relation to treatment variables, and the association between cardiac dysfunction and plasma biomarkers. Methods: In this nationwide prospective multicenter study, cardiac assessments were performed in 66 adult survivors of pediatric DTC (age at diagnosis 18 years and follow-up 5 years after diagnosis) treated in the Netherlands between 1970 and 2009. Assessment included echocardiography, plasma biomarkers (N-terminal pro-brain natriuretic peptide, high-sensitive troponin-T, galectin-3), and 24-hour Holter electrocardiography. Echocardiographic measurements were compared with retrospective data of 66 sex- and age-matched unaffected Dutch controls. Diastolic dysfunction was defined as an early diastolic septal and/or lateral tissue velocity (e) less than 2 SD of mean age-adjusted reference data. Results: The survivors (86.4% women) had at DTC diagnosis a median age of 16 years. Median follow-up was 17 years. Left ventricular ejection fraction <50% was found in one survivor, and median global longitudinal systolic strain was near normal. Diastolic dysfunction was present in 14 asymptomatic survivors (21.2%). Overall, diastolic function of survivors was lower compared with controls (emean 14.5 versus 15.8cm/s, P=0.006). Older attained age and higher waist circumference were associated with decreased diastolic function, whereas thyrotropin levels and cumulative administered radioiodine dose were not. In survivors, biomarkers were not associated with diastolic dysfunction; atrial fibrillation was not observed. Conclusion: While systolic function is unaffected, diastolic dysfunction is frequently observed in asymptomatic long-term survivors of pediatric DTC, which may suggest early cardiac agin

Bone Mineral Density in Adult Survivors of Pediatric Differentiated Thyroid Carcinoma:A Longitudinal Follow-Up Study

Background: Survivors of pediatric differentiated thyroid carcinoma (DTC) receive thyrotropin-suppressive therapy to minimize disease recurrence. However, knowledge about long-term effects of subclinical hyperthyroidism on bone mineral density (BMD) in pediatric DTC survivors is scarce, as is the information regarding long-term consequences of permanent hypoparathyroidism on BMD. We evaluated BMD in pediatric DTC survivors and investigated if BMD was affected by subclinical hyperthyroidism and/or permanent hypoparathyroidism during long-term follow-up. Methods: In this nationwide longitudinal study, we determined BMD in the lumbar spine and femur by dual energy X-ray absorptiometry in 65 pediatric DTC survivors. Measurements were repeated after minimal 5 years of follow-up in 46 pediatric DTC survivors. BMD results were evaluated according to the recommendations of the International Society for Clinical Densitometry (ISCD) and WHO. At both visits, we determined biochemical parameters and markers of bone resorption (C-terminal telopeptide of type I collagen [β-CTX]) and formation (N-propeptide of type I collagen [PINP] and osteocalcin). Results: First and second BMD measurements were done after a median follow-up of 17.0 (interquartile range [IQR] 8.0-25.0) and 23.5 (IQR 14.0-30.0) years after diagnosis, respectively. Median age at diagnosis was 15 years (IQR 13.0-17.0). Twenty-nine percent of the survivors had subclinical hyperthyroidism. In most survivors, BMD T-and Z-scores were within the reference range during both BMD evaluations. However, after 23.5 years of follow-up, a low BMD was found in 13.0%. In the 13 survivors with permanent hypoparathyroidism, BMD values did not differ after 5 years of follow-up compared with baseline values or in comparison with the 33 survivors without permanent hypoparathyroidism. During follow-up, turnover markers β-CTX and PINP remained stable. Conclusions: This longitudinal study of pediatric DTC survivors demonstrated normal and stable median lumbar spine and femur BMD values after a median time of 17 and 23.5 years after diagnosis. However, compared with controls, a lower BMD was still found in 13.0% after prolonged follow-up despite intensive follow-up. Based on the studied follow-up period, these data do not provide convincing evidence in support of standard monitoring of bone mass among DTC survivors, but may be restricted to individual cases at low frequency. Trial Registration: This follow-up study was registered in The Netherlands Trial Register under no. NL3280 (www.trialregister.nl/trial/3280)

3D Variation in delineation of head and neck organs at risk

<p>Abstract</p> <p>Background</p> <p>Consistent delineation of patient anatomy becomes increasingly important with the growing use of highly conformal and adaptive radiotherapy techniques. This study investigates the magnitude and 3D localization of interobserver variability of organs at risk (OARs) in the head and neck area with application of delineation guidelines, to establish measures to reduce current redundant variability in delineation practice.</p> <p>Methods</p> <p>Interobserver variability among five experienced radiation oncologists was studied in a set of 12 head and neck patient CT scans for the spinal cord, parotid and submandibular glands, thyroid cartilage, and glottic larynx. For all OARs, three endpoints were calculated: the Intraclass Correlation Coefficient (ICC), the Concordance Index (CI) and a 3D measure of variation (3D SD).</p> <p>Results</p> <p>All endpoints showed largest interobserver variability for the glottic larynx (ICC = 0.27, mean CI = 0.37 and 3D SD = 3.9 mm). Better agreement in delineations was observed for the other OARs (range, ICC = 0.32-0.83, mean CI = 0.64-0.71 and 3D SD = 0.9-2.6 mm). Cranial, caudal, and medial regions of the OARs showed largest variations. All endpoints provided support for improvement of delineation practice.</p> <p>Conclusions</p> <p>Variation in delineation is traced to several regional causes. Measures to reduce this variation can be: (1) guideline development, (2) joint delineation review sessions and (3) application of multimodality imaging. Improvement of delineation practice is needed to standardize patient treatments.</p