Characterization of anticoagulant heparinoids by immunoprofiling

Heparinoids are used in the clinic as anticoagulants. A specific pentasaccharide in heparinoids activates antithrombin III, resulting in inactivation of factor Xa and–when additional saccharides are present–inactivation of factor IIa. Structural and functional analysis of the heterogeneous heparinoids generally requires advanced equipment, is time consuming, and needs (extensive) sample preparation. In this study, a novel and fast method for the characterization of heparinoids is introduced based on reactivity with nine unique anti-heparin antibodies. Eight heparinoids were biochemically analyzed by electrophoresis and their reactivity with domain-specific anti-heparin antibodies was established by ELISA. Each heparinoid displayed a distinct immunoprofile matching its structural characteristics. The immunoprofile could also be linked to biological characteristics, such as the anti-Xa/anti-IIa ratio, which was reflected by reactivity of the heparinoids with antibodies HS4C3 (indicative for 3-O-sulfates) and HS4E4 (indicative for domains allowing anti-factor IIa activity). In addition, the immunoprofile could be indicative for heparinoid-induced side-effects, such as heparin-induced thrombocytopenia, as illustrated by reactivity with antibody NS4F5, which defines a very high sulfated domain. In conclusion, immunoprofiling provides a novel, fast, and simple methodology for the characterization of heparinoids, and allows high-throughput screening of (new) heparinoids for defined structural and biological characteristics

Contiguous gene deletion of ELOVL7, ERCC8 and NDUFAF2 in a patient with a fatal multisystem disorder

Contiguous gene syndromes affecting the mitochondrial oxidative phosphorylation system have been rarely reported. Here, we describe a patient with apparent mitochondrial encephalomyopathy accompanied by several unusual features, including dysmorphism and hepatopathy, caused by a homozygous triple gene deletion on chromosome 5. The deletion encompassed the NDUFAF2, ERCC8 and ELOVL7 genes, encoding complex I assembly factor 2 (also known as human B17.2L), a protein of the transcription-coupled nucleotide excision repair (TC-NER) machinery, and a putative elongase of very long-chain fatty acid synthesis, respectively. Detailed evaluation of cultured skin fibroblasts revealed disturbed complex I assembly, depolarization of the mitochondrial membrane, elevated cellular NAD(P)H level, increased superoxide production and defective TC-NER. ELOVL7 mRNA was not detectable in these cells and no alterations in fatty acid synthesis were found. By means of baculoviral complementation we were able to restore the aberrations, thereby establishing causative links between genotype and cell-physiological phenotype. This first chromosomal microdeletion illustrates that beside primary defects in mitochondrial genes also additional genes possibly contribute to the disease phenotype, providing an additional explanation for the broad clinical symptoms associated with these disorder

Localization and functional characterization of glycosaminoglycan domains in the normal human kidney as revealed by phage display-derived single chain antibodies

Glycosaminoglycans (GAG) play an important role in renal homeostasis. They are strongly negatively charged polysaccharides that bind and modulate a myriad of proteins, including growth factors, cytokines, and enzymes. With the aid of specific phage display-derived antibodies, the distribution of heparan sulfate (HS) and chondroitin sulfate (CS) domains in the normal human kidney was studied. HS domains were specifically located in basement membranes and/or surfaces of renal cells and displayed a characteristic distribution over the nephron. A characteristic location in specific parts of the tubular system was also observed. CS showed mainly an interstitial location. Immunoelectron microscopy indicated specific ultrastructural location of domains. Only partial overlap with any of seven different proteoglycan core proteins was observed. Two HS domains, one highly sulfated (defined by antibody HS4C3) and one low sulfated (defined by antibody RB4Ea12), were studied for their cell biologic relevance with respect to the proliferative effect of FGF-2 on human mesangial cells in vitro. Fibroblast growth factor 2 (FGF-2) binding was HS dependent. Addition of purified HS4C3 antibody but not of the RB4Ea12 antibody counteracted the binding and the proliferative effect of FGF-2, indicating that the HS4C3 domain is involved in FGF-2 handling by mesangial cells. In conclusion, specific GAG domains are differentially distributed in the normal human kidney and are likely involved in binding of effector molecules such as FGF-2. The availability of tools to identify and study relevant GAG structures allows the development of glycomimetica to halt, for instance, mesangial proliferation and matrix production as seen in diabetic nephropathy

Treatment of anastomotic leak after oesophagectomy for oesophageal cancer : large, collaborative, observational TENTACLE cohort study

Background: Anastomotic leak is a severe complication after oesophagectomy. Anastomotic leak has diverse clinical manifestations and the optimal treatment strategy is unknown. The aim of this study was to assess the efficacy of treatment strategies for different manifestations of anastomotic leak after oesophagectomy. Methods: A retrospective cohort study was performed in 71 centres worldwide and included patients with anastomotic leak after oesophagectomy (2011-2019). Different primary treatment strategies were compared for three different anastomotic leak manifestations: interventional versus supportive-only treatment for local manifestations (that is no intrathoracic collections; well perfused conduit); drainage and defect closure versus drainage only for intrathoracic manifestations; and oesophageal diversion versus continuity-preserving treatment for conduit ischaemia/necrosis. The primary outcome was 90-day mortality. Propensity score matching was performed to adjust for confounders. Results: Of 1508 patients with anastomotic leak, 28.2 per cent (425 patients) had local manifestations, 36.3 per cent (548 patients) had intrathoracic manifestations, 9.6 per cent (145 patients) had conduit ischaemia/necrosis, 17.5 per cent (264 patients) were allocated after multiple imputation, and 8.4 per cent (126 patients) were excluded. After propensity score matching, no statistically significant differences in 90-day mortality were found regarding interventional versus supportive-only treatment for local manifestations (risk difference 3.2 per cent, 95 per cent c.i. -1.8 to 8.2 per cent), drainage and defect closure versus drainage only for intrathoracic manifestations (risk difference 5.8 per cent, 95 per cent c.i. -1.2 to 12.8 per cent), and oesophageal diversion versus continuity-preserving treatment for conduit ischaemia/necrosis (risk difference 0.1 per cent, 95 per cent c.i. -21.4 to 1.6 per cent). In general, less morbidity was found after less extensive primary treatment strategies. Conclusion: Less extensive primary treatment of anastomotic leak was associated with less morbidity. A less extensive primary treatment approach may potentially be considered for anastomotic leak. Future studies are needed to confirm current findings and guide optimal treatment of anastomotic leak after oesophagectom

Erratum to “Practice variation in anastomotic leak after esophagectomy:Unravelling differences in failure to rescue (vol 49, pg 974, 2023)

The publisher regrets that when the article was published the following collaboration authors from the “TENTACLE – Esophagus collaborative group” appeared incorrectly in the main author list due to a technical error: Writing Committee, Joos Heisterkamp, Fatih Polat, Jeroen Schouten, Pritam Singh, Study collaborators. This has now been corrected. The publisher would like to apologise for any inconvenience caused

Practice variation in anastomotic leak after esophagectomy: Unravelling differences in failure to rescue

Introduction: Failure to rescue (FTR) is an important outcome measure after esophagectomy and reflects mortality after postoperative complications. Differences in FTR have been associated with hospital resection volume. However, insight into how centers manage complications and achieve their outcomes is lacking. Anastomotic leak (AL) is a main contributor to FTR. This study aimed to assess differences in FTR after AL between centers, and to identify factors that explain these differences. Methods: TENTACLE – Esophagus is a multicenter, retrospective cohort study, which included 1509 patients with AL after esophagectomy. Differences in FTR were assessed between low-volume (<20 resections), middle-volume (20–60 resections) and high-volume centers (≥60 resections). Mediation analysis was performed using logistic regression, including possible mediators for FTR: case-mix, hospital resources, leak severity and treatment. Results: FTR after AL was 11.7%. After adjustment for confounders, FTR was lower in high-volume vs. low-volume (OR 0.44, 95%CI 0.2–0.8), but not versus middle-volume centers (OR 0.67, 95%CI 0.5–1.0). After mediation analysis, differences in FTR were found to be explained by lower leak severity, lower secondary ICU readmission rate and higher availability of therapeutic modalities in high-volume centers. No statistically significant direct effect of hospital volume was found: high-volume vs. low-volume 0.86 (95%CI 0.4–1.7), high-volume vs. middle-volume OR 0.86 (95%CI 0.5–1.4). Conclusion: Lower FTR in high-volume compared with low-volume centers was explained by lower leak severity, less secondary ICU readmissions and higher availability of therapeutic modalities. To reduce FTR after AL, future studies should investigate effective strategies to reduce leak severity and prevent secondary ICU readmission