Apheresis Technologies: An International Perspective

Abstract: The developments in apheresis techniques and their clinical applications world-wide are technologically driven. In the past, apheresis survey statistics have highlighted both the differences by region in clinical practice and in the types of technologies utilized. Such differences have provided a basis for the scientific and clinical assessments of these apheresis technologies and their clinical outcomes and have stimulated the marketing and business development of new technologies world-wide. A review of the regional practices and technologies utilized provides a perspective on the future role of apheresis and its developments in clinical practice. While technology is a driving force for the development of new techniques for clinical practice, it is not the only market force. For technology introduction, several other important issues need to be considered. Regulations at the local and, most importantly, the federal level impact the timing for new technology introduction. Reimbursement by healthcare payers is critically important from the initiation of the development of a technology through its clinical use. Clinical trials are critically important to show the safety and clinical- and cost-effectiveness of the technology in order for payers to provide reimbursement for its use, but these trials are sometimes long and costly. Research funding availability at the governmental and commercial levels critically impacts new technology investigation and its introduction. Apheresis technology developments offer new hopes and promises for the clinical team; however, their development, introduction, and utilization will be influenced by the prevailing market forces.     

Expression of cell-matrix molecules and integrin receptors in human liver grafts during chronic rejection

Abstract The inflammatory response of immune cells to target cells and cell-matrix molecules is regulated by several receptor-ligand molecules. As fibrosis develops in ongoing chronic rejection after liver transplantation, it is of interest to analyze patterns of integrin receptors and cell-matrix molecules in order to study the relation between immune cells and the stromal and parenchymal cells. In the present study, we demonstrated the expression of these molecules in chronic rejected human liver grafts using immunohistochemical techniques. The results showed a differential expression and induction of integrin receptors and cell-matrix molecules on resident liver cells, especially on sinusoids, reflecting a state of chronic inflammation and a specific interaction between integrin receptors and cell-matrix molecules. The patterns of induced integrin receptors on graft-infiltrating cells was closely related to the local production of cell-matrix molecules and reflected the final sequence of a stepwise progress of the inflammatory reaction.     

Gallstone recurrence after direct contact dissolution with methyltert-butyl ether

To determine the rate and characteristics of gallstone recurrence after direct contact dissolution with methyltert-butyl ether, 60 consecutive patients were followed for up to 4.5 years (median 2.2 years) after complete disappearance of all stone residues and debris and cessation of adjuvant bile acid therapy. Initial gallstones had been multiple in all but four patients. Twenty-eight of the 60 patients developed recurrent gallstones. The cumulative risk of gallstone recurrence (actuarial analysis) was 23±6%, 34±7%, 55±8%, and 70±9% at one, two, three, and four years, respectively. The recurrent stones were usually multiple and small (6±4 mm). Gallstone recurrence was associated with recurrent biliary pain in two patients, one of whom developed acute cholecystitis. Recurrent stones were cleared completely by bile acid medication with or without shock-wave lithotripsy in 61±15% of patients at one year (actuarial analysis). In conclusion, gallstone recurrence after successful contact dissolution of multiple stones with methyltert-butyl ether has to be expected in a high percentage of patients. Most patients, however, remain free of biliary pain during long-term follow-up.     

Plasmareninaktivität nach Orthostase und nach Diazoxid bei primärer und renaler Hypertonie

Zusammenfassung 1. Nach Blutdrucksenkung durch schnelle intravenöse Injektion vonDiazoxid kommt es bei 35% der Kranken mit primärem Hochdruck zu einem Anstieg der Plasmareninaktivität. Das Ausbleiben des Reninanstiegs bei der Mehrzahl der fortgeschrittenen primären Hypertonie wird, ebenso wie die abgeschwächte Stimulierbarkeit der Reninsekretion durch Natriummangel, auf eine (adaptiv) verminderte Empfindlichkeit der intrarenalen Receptoren zurückgeführt. Die Blutdrucksenkung durch Diazoxid ist bei positiv und negativ reagierenden Kranken gleich groß.2. Nach einer definiertenOrthostase von 60 min Dauer bei 70° Schräglagerung fehlt ein Plasmareninanstieg bei 63% der untersuchten Patienten mit primärer Hypertonie, wofür ebenfalls eine herabgesetzte Ansprechbarkeit intrarenaler Receptoren verantwortlich gemacht werden muß. Eine Orthostase-negative Reaktion wird ebenso wie eine solche nach Diazoxid häufiger bei primärer Hypertonie in einem fortgeschrittenem, aber auch schon in einem frühen Stadium beobachtet, in dem der Plasmareninanstieg auf Natriumentzug noch intakt ist.3. Die Reninsekretion verhält sich beiprimärer Hypertonie nach Diazoxid, Orthostase und Natriumentzug nicht übereinstimmend, was für die Existenz verschiedener intrarenaler Mechanismen spricht, die die Reninfreisetzung im iuxtaglomerulären Apparat beeinflussen. Patinten mitrenalem Hochdruck weisen dagegen ein übereinstimmendes positives oder negatives Verhalten der Reninsekretion nach Diazoxid und nach Orthostase auf.4. Für diedifferentialdiagnostische Abgrenzung einer funktionell wirksamen Nierenarterienstenose von einer primären Hypertonie ist weder der Diazoxidtest noch — ohne gleichzeitigen Natriumentzug — in der durchgeführten Versuchsanordnung der Orthostasetest geeignet. Zum Nachweis einer funktionell wirksamen Nierenarterienstenose empfiehlt sich die getrennte Plasmareninbestimmung in den Nierenvenen oder als Suchmethode die Doppelstimulation durch 3tägigen Natriumentzug und Orthostase am letzten Tag der Natriumrestriktion.

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Summary 1. After blood pressure reduction by rapid intravenous injection of diazoxide plasma renin activity is increased in 35% of primary hypertension. The absence of plasma renin increase in the majority of advanced primary hypertension is explained by an (adaptive) diminished sensibility of the intrarenal receptors. The reduction of blood pressure is equal in diazoxide responsive and unresponsive patients.2. A plasma renin increase failed in 63% of primary hypertension after upright posture by tilting to 70° for 60 minutes. This result is also explained by a diminished sensibility of the intrarenal receptors for renin secretion. An unresponsive reaction to upright posture and diazoxide is more frequent in advanced primary hypertension, but is observed also in an early stage, in which plasma renin stimulation by sodium deficiency is maintained.3. The stimulation of the renin secretion in primary hypertension is not equal after upright posture, diazoxide and sodium restriction supporting the existence of several intrarenal mechanism controlling the iuxtaglomerular apparatus. In renal hypertension on the contrary, there is a corresponding positive or negative reaction of renin secretion after diazoxide and upright posture.4. For the differential diagnosis of a functional renal artery stenosis neither the diazoxide test nor — without sodium restriction — the orthostase test is suitable. For the evidence of the functional significance of a renal artery stenosis the separated estimation of plasma renin activity in both renal veins or as a sreening test the double stimulation by sodium restriction for 3 days and upright posture is recommended.

     

Up-regulation of endothelial nitric oxide synthase inhibits pulmonary leukocyte migration following lung ischemia-reperfusion in mice

Endogenous nitric oxide (NO) is known to modulate post-ischemic inflammatory response in various organs. However, the role of nitric oxide synthase isoforms (NOS) in mediating pulmonary post-ischemic inflammatory response is poorly understood. We therefore studied post-ischemic endothelial adhesion molecule expression and leukocyte migration in endothelial NOS knockout (eNOS-KO) mice subjected to pulmonary ischemia and reperfusion in vivo. Under anesthesia and mechanical ventilation, the left pulmonary hilum in wild-type (WT) and eNOS-KO mice was clamped for 1 hour, followed by reperfusion for up to 24 hours. In WT mice, we observed a selective up-regulation of both eNOS mRNA and protein in lung tissue, while inducible NOS (iNOS) and neuronal NOS (nNOS) remained unchanged. Survival in eNOS-KO mice was reduced due to severe pulmonary edema, underlining an increased susceptibility to ischemia-reperfusion (I/R) injury. Interstitial tissue infiltration by CD18- and CD11a-positive white blood cells as well as lung tissue water content peaked at 5 hours of reperfusion and were found significantly higher than in WT mice. Enhanced leukocyte-endothelial interaction was associated with pronounced up-regulation of vascular cell adhesion molecule (VCAM) in eNOS-KO mice during post-ischemic reperfusion. We conclude that eNOS attenuates post-ischemic inflammatory injury to the lung most probably via inhibition of endothelial adhesion molecule expression.     

Evolutionary dynamics of the human immunoglobulin kappa locus and the germline repertoire of the Vkappa genes

We have determined the entire nucleotide sequence of the human immunoglobulin kappa locus, comprising a total of 1,010,706 nucleotides. The 76 Vkappa genes found by a hybridization-based approach and their classification in 7 families were confirmed. A Vkappa orphon located near the locus was also sequenced. In addition, we identified 55 novel Vkappa relics and truncated pseudogenes, which establish 5 new families. Among these 132 Vkappa genes, 46 have open reading frames. According to the databases and the literature, 32 unique Vkappa genes and 5 identical gene pairs form VJ-joints, 27 unique genes and 4 gene pairs are transcribed, and 25 unique genes and 4 gene pairs produce functional proteins. The Vkappa gene locus contains a 360-kb inverted duplication, which harbors 118 Vkappa genes. A comparison of the duplicated Vkappa genes suggests positive selection on the complementarity-determining regions of the duplicated genes by point mutations. The entire duplication unit was divided into 13 blocks, each of which has its distinct nucleotide sequence identity to its duplication counterpart (98.1 - 99.9 %). An inversion-mediated mechanism is suggested to generate the high-homology blocks. Based on the homology blocks and the mutation rates, the inverted duplication is assumed to have taken place approximately 5 million years ago. An orphon Vkappa gene near the kappa locus and a cluster of five Vkappa orphons on chromosome 22 have no counterparts within the kappa locus. This suggests possible mechanisms of the transposition of orphon Vkappa genes.     

Manual semantic tagging to improve access to information in narrative electronic medical records

OBJECTIVE: To assess effectiveness of information retrieval from narrative patient records utilizing manually supplied semantic tags. DESIGN: Retrospective evaluation of narrative electronic record notes with respect to consistency of manually supplied semantic tags. Assessment of retrieval effectiveness using string matching methods and methods based on structural characteristics of data. SETTING: Department of Neurology in a Norwegian university hospital using a document based electronic patient record system offering template assisted manual semantic indexing of textual record notes. MEASUREMENTS: Proportion of consistently tagged information. Retrieval effectiveness expressed as recall (sensitivity) and precision (positive predictive value). RESULTS: Seventy-five percent of the content was consistently tagged. Retrieval models based on simple string matching performed better than models based on semantic tags alone with respect to best mean recall and mean precision at high recall-levels. Models combining both simple string matching and semantic tagging performed better than separate models with respect to best mean recall (0.95) and mean precision at high levels of recall. CONCLUSION: Although template assisted semantic indexing of narrative electronic patient record notes showed suboptimal consistency, it significantly improved retrieval effectiveness with respect to best mean recall obtained by individual strategies and with respect to precision at any recall level.     

COVID-19 in solid organ transplant recipients: A national cohort study from Sweden

Solid organ transplant (SOT) recipients run a high risk for adverse outcomes from COVID-19, with reported mortality around 19%. We retrospectively reviewed all known Swedish SOT recipients with RT-PCR confirmed COVID-19 between March 1 and November 20, 2020 and analyzed patient characteristics, management, and outcome. We identified 230 patients with a median age of 54.0 years (13.2), who were predominantly male (64%). Most patients were hospitalized (64%), but 36% remained outpatients. Age >50 and male sex were among predictors of transition from outpatient to inpatient status. National early warning Score 2 (NEWS2) at presentation was higher in non-survivors. Thirty-day all-cause mortality was 9.6% (15.0% for inpatients), increased with age and BMI, and was higher in men. Renal function decreased during COVID-19 but recovered in most patients. SARS-CoV-2 antibodies were identified in 78% of patients at 1–2 months post-infection. Nucleocapsid-specific antibodies decreased to 38% after 6–7 months, while spike-specific antibody responses were more durable. Seroprevalence in 559 asymptomatic patients was 1.4%. Many patients can be managed on an outpatient basis aided by risk stratification with age, sex, and NEWS2 score. Factors associated with adverse outcomes include older age, male sex, greater BMI, and a higher NEWS2 score.     

DNA repair synthesis following irradiation with 254-nm and 312-nm ultraviolet light is not diminished in fibroblasts from patients with dysplastic nevus syndrome

The DNA excision repair capacity of 23 primary fibroblast lines from patients with dysplastic nevus syndrome was investigated and DNA repair synthesis (unscheduled DNA synthesis) was determined after UV exposure. Seventeen fibroblast lines from normal donors served as controls. The dose/response experiments included up to ten dose levels and two wavelength ranges: UV-C (using a low-pressure mercury lamp emitting predominantly 254-nm light) and UV-B (artificial sunlamp radiation centering around 312-nm light). For each dose level, silver grains over fibroblast nuclei were counted by visual inspection. Twelve cell lines were also evaluated for both UV wavelength ranges using a new semi-automatic image analyzing system. This system included components for rapid sequential identification of both fibroblast nuclei and silver grains sited above them. Silver grains over 100 nuclei were determined for each UV dose level. Dose/response curves were established and analyzed by linear regression. As a quantitative term for assessing DNA excision repair capacity of a cell line we calculated the linear increase (G ₀) in the number of grains per nucleus, when the UV dose was multiplied by the factor e (i.e. 2.72). The sensitivity of grain detection and resolution ofoverlapping grains was approximately threefold better in visual than in automatic counting, especially when there were more than 70 grains over nuclei. The time recired for visual conting, however, was tenfold that of automatic counting. The varianceweighted meanG ₀ ^v,w of all fibroblast lines from patients with dysplastic nevus syndrome was found to be 79.1 (±1.8-grains/nucleus, that of fibroblast lines from normal donors was 74.2 (±1.7) grains/nucleus. This difference revealed a slightly better repair capability for cell lines from patients but was at the borderline of detection and, therefore, should not be overinterpreted. From the experimental accuracy achieved by determination of the varianceweighted means of the two groups, we would have been able to detect a difference of 7 and more grains [> 2 x (_normal + _patients)]. The variance-weighted meanG _o ^v,w of all fibroblast lines from patients with dysplastic nevus syndrome was found to be 76.4 (±1.4) grains/nucleus, whereas that of fibroblast lines from normal donors was only 66.6 (±1.8) grains/nucleus. This difference was statistically significant and, contrary to expectation, revealed better, not worse post-UV DNA repair capability in cell lines from patients that in those from normal donors. From the experimental accuracy achieved by determination of the variance-weighted means of the two groups, we would have been able to detect a difference of 6.4 or more grains [> 2 x (_normal + _patients)]. Variation between cell lines belonging to the same group was expressed by the standard deviation. On average, the standard deviation was in the range 18.2–21.1 grains/nucleus. This variation did not reflect experimental inaccuracy but different responses of individual cell lines to UV irradiation. On the basis of our data, we consider the hypothesis that patients with dysplastic nevus syndrome are prone to melanoma development because of a general defect in post-UV DNA repair to be improbable.This work was supported by the Deutsche Forschungsgemeinschaft, SFB 136