OPTN/SRTR 2020 Annual Data Report: Living Donor Collective

The first successful solid organ transplant was a living donor kidney transplant in 1954. Since then, living donation has been an important source of organs for kidney and liver transplants in the United States. Unfortunately, the demand for organs has not kept pace with the supply, and unlike deceased donor transplant, there has been little growth in the number of living donor transplants over the past decade. To better understand possible barriers to living donation and long-term risks attributable to donation, the Health Resources and Services Administration (HRSA) directed the Scientific Registry of Transplant Recipients (SRTR) to establish a national registry of all living donor candidates and donors evaluated at US transplant programs to acquire lifetime follow-up information. Other goals include understanding the factors associated with candidate approval and variation in approval practices across centers. A pilot program was conducted from June 2018 through September 2020 to inform baseline data collection and registration processes. In September 2020, the registry began recruiting additional sites evaluating candidates for living donation. Here, we describe candidates registered at participating living donor kidney and liver programs, from June 2018 through the end of 2020. Not all programs submitted data throughout the whole period. Data for kidney and liver living donor candidates are presented separately.

Intraoperative sonography: a technique for localizing focal forms of congenital hyperinsulinism in the pancreas

Congenital hyperinsulinism (CHI), syn. nesidioblastosis, is the most frequent cause of persistent, recurrent hypoglycemia in infancy. One third of patients show a single circumscribed focus. Enucleation of the focus and the removal of all affected β-cells with preservation of healthy tissue is the treatment of choice. The intrapancreatic choledochus as well as the ductus pancreaticus major must remain intact. The diagnostic gold standard is 18F-DOPA-PET/CT. Intraoperative sonography is carried out to correctly visualize the focus preoperatively localized by PET/CT in situ during the operation. The enucleation of the focus was carried out 3 - 20 days after PET/CT in 5 patients at an age of 3.5 - 14 months. Intraoperative ultrasound was carried out with high-capacity devices of different manufacturers under use of broadband probes (9 - 14 MHz). The localization by intraoperative ultrasound was accurate in all 5 patients with focal CHI, with regard to the intraoperative localization as previously described by PET/CT and histology. D. choledochus and D. pancreaticus major were separated intraoperatively by ultrasound. 3 of 5 patients were cured by complete enucleation of the focus. Nevertheless, the entire intraoperative identification of the segmented focus is still problematic. Characteristic sonographic features of a CHI focus are: hypoechogenicity, variable homogeneous and inhomogenous texture, blurred, irregular limitation without capsule, filiform, lobular processes, and insular dispersal into the surrounding tissue. Intraoperative high-resolution sonography helps the pediatric surgeon to determine size, configuration and topography of a CHI focus.

Surface bound plasmin promotes migration of Streptococcus pneumoniae through reconstituted basement membranes

Penetration of basement membrane is believed to be an essential step in the pathogenesis of bacterial meningitis. Consequently Streptococcus pneumoniae strains were tested for their ability to adhere to reconstituted basement membrane (Matrigel) and in a proceeding step penetrate this membrane by the use of surface activated plasmin. A majority of S. pneumoniae strains tested were found to adhere to reconstituted basement membrane as well as to the purified laminin component. Three out of seventeen strains also adhered to the collagen IV component. All the investigated strains also demonstrated a capacity to bind plasminogen with up to 42,000 plasminogen binding sites per bacterium as estimated by Scatchard analysis. Two strains selected for optimal adhesion and plasminogen binding were further tested for basement membrane penetration using a dual chamber model. Our data show that penetration was achieved within 3-4 h in the presence of plasminogen whereas without plasminogen no strain was able to penetrate during a 21 h incubation. The results suggest a potential role of surface associated plasminogen in bacterial penetration of basement membranes and extracellular matrix.

Binding to human extracellular matrix by Neisseria meningitidis

Adhesion of Neisseria meningitidis strains to extracellular matrix (ECM) and purified matrix components was examined. Most strains bound to subendothelial ECM as well as to immobilized fibronectin and types I, III, and V collagen. Strains from healthy carriers adhered significantly better than isolates from patients. The binding site was localized to the central 75-kDa cell-binding domain of the fibronectin molecule. This domain has not been described previously to interact with bacterial structures.

Interaction of Haemophilus influenzae with the mammalian extracellular matrix

The adhesiveness of 2 unencapsulated nonfimbriated strains of Haemophilus influenzae, 23459 and 23330, and the encapsulated fimbriated strain 770235 to extracellular matrix (ECM) and to its isolated components was studied, as was the potential of H. influenzae plasminogen receptors to enhance degradation of ECM and bacterial penetration through basement membrane. All strains exhibited efficient adhesiveness to reconstituted basement membrane and to ECM from cultured human endothelial cells. Strains 23459 and 23330 efficiently adhered to immobilized laminin, fibronectin, and various collagens. Strain 770235 adhered efficiently to fibronectin and type I and III collagens and with low efficiency to laminin. With all 3 strains, plasmin generated on H. influenzae plasminogen receptors degraded laminin and fibronectin as well as ECM from human endothelial cells. Plasmin bound on H. influenzae cells also potentiated penetration of bacteria through a basement membrane preparation reconstituted on membrane filters. These results give evidence for a role of ECM adherence and plasminogen activation in the spread of H. influenzae through tissue barriers.

[Lung resection in arteriovenous fistula]

Arteriovenous fistulas of the lung occur as a disease limited to the lung, or as a pulmonary manifestation of hereditary Rendu-Osler-Weber's disease. Typical complications are haemoptysis, haemothorax and cerebral embolism. We report on 3 patients in whom arteriovenous fistulas of the lung were removed by wedge excision or lobectomy. One of them had already suffered cerebral infarction. The indication for operative removal of single lesions is always given with respect to the severe complications of this disease. Decrease of the right-to-left shunt volume can usually be achieved.

Studies on the mechanism of hyaluronate lyase action

Hyaluronate lyase from streptococci group A was purified by chromatography on DEAE-Sephadex A-50 and on Biogel P-150, thereby enriching it about 1,000-fold and separating it into two enzyme fractions with the same amino acid composition. The photooxidation of hyaluronate lyase in the presence of methylene blue results in rapid inactivation of the enzyme. The histidine content of the enzyme is decreased considerably, but also the content of methionine, tyrosine, and lysine is lowered. The enzyme is inhibited, but incompletely so, by N-tosyl-L-phenyl-alanine-chloromethyl ketone (TPCK) and N-alpha-p-tosyl-L-lysine chloromethyl ketone (TLCK). Hyaluronic acid methyl ester, prepared form hyaluronic acid and diazomethane, is not split by hyaluronate lyase (EC 4.2.2.1.). Hyaluronic acid methyl ester is not a competitive inhibitor of hyaluronate lyase. For the mechanism of the enzymatic elimination reaction a proton transfer between histidine of the enzyme and the carboxylate group of hyaluronate is proposed.