What happens after graft loss? A large,long-term,single-center observation

The number of patients returning to dialysis after graft failure increases. Surprisingly, little is known about the clinical and immunological outcomes of this cohort. We retrospectively analyzed 254 patients after kidney allograft loss between 1997 and 2017 and report clinical outcomes such as mortality, relisting, retransplantations, transplant nephrectomies, and immunization status. Of the 254 patients, 49% had died 5 years after graft loss, while 27% were relisted, 14% were on dialysis and not relisted, and only 11% were retransplanted 5 years after graft loss. In the complete observational period, 111/254 (43.7%) patients were relisted. Of these, 72.1% of patients were under 55 years of age at time of graft loss and only 13.5% of patients were ≥65 years. Age at graft loss was associated with relisting in a logistic regression analysis. In the complete observational period, 42 patients (16.5%) were retransplanted. Only 4 of those (9.5%) were ≥65 years at time of graft loss. Nephrectomy had no impact on survival, relisting, or development of dnDSA. Patients after allograft loss have a high overall mortality. Immunization contributes to long waiting times. Only a very limited number of patients are retransplanted especially when ≥65 years at time of graft loss.     

Lumbar degenerative spondylolisthesis: factors associated with the decision to fuse

BACKGROUND CONTEXTThe indication to perform a fusion and decompression surgery as opposed to decompression alone for lumbar degenerative spondylolisthesis (LDS) remains controversial. A variety of factors are considered when deciding on whether to fuse, including patient demographics, radiographic parameters, and symptom presentation. Likely surgeon preference has an important influence as well.PURPOSEThe aim of this study was to assess factors associated with the decision of a Canadian academic spine surgeon to perform a fusion for LDS.STUDY DESIGN/SETTINGThis study is a retrospective analysis of patients prospectively enrolled in a multicenter Canadian study that was designed to evaluate the assessment and surgical management of LDS.PATIENT SAMPLEInclusion criteria were patients with: radiographic evidence of LDS and neurogenic claudication or radicular pain, undergoing posterior decompression alone or posterior decompression and fusion, performed in one of seven, participating academic centers from 2015 to 2019.OUTCOME MEASURESPatient demographics, patient-rated outcome measures (Oswestry Disability Index [ODI], numberical rating scale back pain and leg pain, SF-12), and imaging parameters were recorded in the Canadian Spine Outcomes Research Network (CSORN) database. Surgeon factors were retrieved by survey of each participating surgeon and then linked to their specific patients within the database.METHODSUnivariate analysis was used to compare patient characteristics, imaging measures, and surgeon variables between those that had a fusion and those that had decompression alone. Multivariate backward logistic regression was used to identify the best combination of factors associated with the decision to perform a fusion.RESULTSThis study includes 241 consecutively enrolled patients receiving surgery from 11 surgeons at 7 sites. Patients that had a fusion were younger (65.3±8.3 vs. 68.6±9.7 years, p=.012), had worse ODI scores (45.9±14.7 vs. 40.2±13.5, p=.007), a smaller average disc height (6.1±2.7 vs. 8.0±7.3 mm, p=.005), were more likely to have grade II spondylolisthesis (31% vs. 14%, p=.008), facet distraction (34% vs. 60%, p=.034), and a nonlordotic disc angle (26% vs. 17%, p=.038). The rate of fusion varied by individual surgeon and practice location (p<.001, respectively). Surgeons that were fellowship trained in Canada more frequently fused than those who fellowship trained outside of Canada (76% vs. 57%, p=.027). Surgeons on salary fused more frequently than surgeons remunerated by fee-for-service (80% vs. 64%, p=.004). In the multivariate analysis the clinical factors associated with an increased odds of fusion were decreasing age, decreasing disc height, and increasing ODI score; the radiographic factors were grade II spondylolisthesis and neutral or kyphotic standing disc type; and the surgeon factors were fellowship location, renumeration type and practice region. The odds of having a fusion surgery was more than two times greater for patients with a grade II spondylolisthesis or neutral and/or kyphotic standing disc type (opposed to lordotic standing disc type). Patients whose surgeon completed their fellowship in Canada, or whose surgeon was salaried (opposed to fee-for-service), or whose surgeon practiced in western Canada had twice the odds of having fusion surgery.CONCLUSIONSThe decision to perform a fusion in addition to decompression for LDS is multifactorial. Although patient and radiographic parameters are important in the decision-making process, multiple surgeon factors are associated with the preference of a Canadian spine surgeon to perform a fusion for LDS. Future work is necessary to decrease treatment variability between surgeons and help facilitate the implementation of evidence-based decision making.     

Ten‐year attrition and antiretroviral therapy response among HIV‐positive adults: a sex‐based cohort analysis from eight West African countries

IntroductionSex differences have already been reported in sub‐Saharan Africa for attrition and immunological response after antiretroviral therapy (ART) initiation, but follow‐up was usually limited to the first two to three years after ART initiation. We evaluated sex differences on the same outcomes in the 10 years following ART initiation in West African adults.MethodsWe used cohort data of patients included in the IeDEA West Africa collaboration, who initiated ART between 2002 and 2014. We modelled no‐follow‐up and 10‐year attrition risks, and immunological response by sex using logistic regression analysis, survival analysis with random effect and linear mixed models respectively.ResultsA total of 71,283 patients (65.8% women) contributed to 310,007 person‐years of follow‐up in 16 clinics in eight West African countries. The cumulative attrition incidence at 10‐year after ART initiation reached 75% and 68% for men and women respectively. Being male was associated with an increased risk of no follow‐up after starting ART (5.1% vs. 4.0%, adjusted Odds Ratio: 1.25 [95% CI: 1.15 to 1.35]) and of 10‐year attrition throughout the 10‐year period following ART initiation: adjusted Hazard Ratios were 1.22 [95% CI: 1.17 to 1.27], 1.08 [95% CI: 1.04 to 1.12] and 1.04 [95% CI: 1.01 to 1.08] during year 1, years 2 to 4 and 5 to 10 respectively. A better immunological response was achieved by women than men: monthly CD4 gain was 30.2 and 28.3 cells/mL in the first four months and 2.6 and 1.9 cells/μL thereafter. Ultimately, women reached the average threshold of 500 CD4 cells/μL in their sixth year of follow‐up, whereas men failed to reach it even at the end of the 10‐year follow‐up period. The proportion of patients reaching the threshold was much higher in women than in men after 10 years since ART initiation (65% vs. 44%).ConclusionsIn West Africa, attrition is unacceptably high in both sexes. Men are more vulnerable than women on both attrition and immunological response to ART in the 10 years following ART initiation. Innovative tracing strategies that are sex‐adapted are needed for patients in care to monitor attrition, detect early high‐risk groups so that they can stay in care with a durably controlled infection.     

Current immunoassays and detection of antibodies elicited by Omicron SARS-CoV-2 infection

The present study aimed to determine whether current commercial immunoassays are adequate for detecting anti-Omicron antibodies. We analyzed the anti-SARS-CoV-2 antibody response of 23 unvaccinated individuals 1–2 months after an Omicron infection. All blood samples were tested with a live virus neutralization assay using a clinical Omicron BA.1 strain and four commercial SARS-CoV-2 immunoassays. We assessed three anti-Spike immunoassays (SARS-CoV-2 IgG II Quant [Abbott S], Wantaï anti-SARS-CoV-2 antibody ELISA [Wantaï], Elecsys Anti-SARS-CoV-2 S assay [Roche]) and one anti-Nucleocapsid immunoassay (Abbott SARS-CoV-2 IgG assay [Abbott N]). Omicron neutralizing antibodies were detected in all samples with the live virus neutralization assay. The detection rate of the Abbott S, Wantai, Roche, and Abbott N immunoassays were 65.2%, 69.6%, 86.9%, and 91.3%, respectively. The sensitivities of Abbott S and Wantai immunoassays were significantly lower than that of the live virus neutralization assay (p = 0.004, p = 0.009; Fisher's exact test). Antibody concentrations obtained with anti-S immunoassays were correlated with Omicron neutralizing antibody concentrations. These data provide clinical evidence of the loss of performance of some commercial immunoassays to detect antibodies elicited by Omicron infections. It highlights the need to optimize these assays by adapting antigens to the circulating SARS-CoV-2 strains.     

Transfer of liposomal drug carriers from the blood to the peritoneal cavity of normal and ascitic tumor-bearing mice

Summary Previously we have demonstrated that the L1210 antitumor activity of liposomal doxorubicin increased significantly as the size of the liposomal carrier was reduced from 1.0 to 0.1 m. It is demonstrated herein that empty and drug-loaded small (0.1-m diameter) liposomes accumulate efficiently into the peritoneal cavity of normal and ascitic L1210 tumor-bearing animals following i.v. administration. In normal mice injected with 100 nm DSPC/chol liposomal doxorubicin (drug-to-lipid ratio of 0.2; wt/wt) approximately 2.8 g drug could be recovered from the peritoneal cavity following peritoneal lavage at 24 h. Although this represents only 0.7% of the injected doxorubicin dose, this level of drug is 2 orders of magnitude greater than that achieved following administration of an equivalent dose of free drug (20 mg/kg). The drug levels achieved within the peritoneal cavity are dependent on the physical characteristics (size, drug-to-lipid ratio and lipid composition) of the liposomes employed. Optimal delivery is obtained employing 100 nm DSPC/chol liposomal doxorubicin, a vesicle system that is known to retain entrapped drug following i.v. administration and exhibits extended circulation lifetimes. Analysis of drug and liposome distribution within the peritoneal cavity of normal mice indicates that as much as 50% of the measured doxorubicin and liposomal lipid is cell-associated. Flow cytometric analysis of the peritoneal cells demonstrated that cell-associated doxorubicin resides almost exclusively within resident peritoneal macrophages. The increased delivery of doxorubicin to the peritoneal cavity of normal mice following i.v. administration of small (0.1-m) liposomal doxorubicin is correlated with a pronounced (>90%) and prolonged (>14-day) suppression of resident peritoneal cells. Liposomal drug accumulation increased dramatically in animals with an established L1210 ascitic tumor. More than 5% of the injected dose was found in the peritoneal cavity of these animals 24 h after treatment with DSPC/chol liposomal doxorubicin as compared with a value of 0.03% of the injected dose achieved with free drug. It is proposed that accumulation of liposomes into the peritoneal cavity of normal and tumor-bearing mice may serve as a useful model for characterizing factors mediating the transfer of liposomes from the vascular compartment to extravascular sites.     

Intravertebral vacuum phenomenon following fractures: CT study on frequency and etiology

PURPOSE: The purpose of this work was to determine the frequency and etiology of the intravertebral vacuum phenomenon (IVP). METHOD: CT examinations of 96 vertebral fractures were evaluated for IVP. Bone mineral density (BMD) was determined in nonfractured vertebrae. For calibration purposes, densities of a standard phantom measured in 30 patients who underwent quantitative CT examinations in the same time period were used and precision was calculated. RESULTS: Eleven of 96 fractures (11.5%) showed IVP. IVP was present in 4 of 20 fractures at T12 (20%), in 4 of 23 at L1 (17.4%), and 1 IVP was found at L2-4 each. Mean +/- SD age of patients with IVP was 68.3 +/- 10.5 years and without 47.8 +/- 19.4 years (p < 0.001). Mean +/- SD density of nonaffected vertebra was 45.9 +/- 17.0 mg of hydroxyapatite/ml for patients with IVP and 139.5 +/- 62.6 mg/ml for those without IVP (p < 0.0005). An average precision of 1.2% was calculated for the density measurements over the investigated time. CONCLUSION: Following vertebral fractures, IVP on CT scans is more common than presumed and increases with age. There exists a significant inverse correlation between the BMD and the frequency of IVP.     

Bildanalyse bei der Mehrschicht-Spiral-CT der Lunge mit MPR- und MIP-Rekonstruktionen

PURPOSE: To test, whether axial, coronal and sagittal MIP and MPR reconstructions of diagnostic quality can be obtained from 1-mm collimation MSCT data of the chest for the evaluation of thoracic anatomy and pathology. MATERIALS AND METHODS: 1-mm collimation MSCT scans were obtained with a pitch of 6 in an acrylic phantom and in 20 patients. Axial images were reconstructed with 0.6-mm increment. Multiplanar reformations (MPRs) and sliding thin-slab maximum intensity projections (STS-MIPs) were reconstructed in axial, coronal and sagittal planes. Images were printed in lung windows and evaluated by three readers by using a standardized evaluation scheme. RESULTS: Overall, both methods allowed good visualization of anatomic structures. MIP was superior for visualization of the pulmonary arteries (p < 0.05) while central and peripheral bronchi and the lung parenchyma were better depicted on multiplanar reconstructions. A confident diagnosis of thoracic pathology was feasible using both modalities, however MIPs appeared less usefull for evaluation of gross parenchymal abnormalities, such as pneumonic infiltrates or fibrotic changes. No significant difference in the degree of motion artifacts were detected between both modalities. CONCLUSION: MSCT data sets are ideally suited for generating MPR and MIP reconstructions. While MIPs are superior for the evaluation of thoracic vessels, MPR is advantageous for visualizing central and peripheral bronchi and the pulmonary parenchyma.     

Coagulative interstitial laser-induced thermotherapy of benign prostatic hyperplasia: online imaging with a T2-weighted fast spin-echo MR sequence--experience in six patients

PURPOSE: To determine if hypointense lesions clearly outline on T2-weighted fast spin-echo (SE) magnetic resonance (MR) images obtained during coagulative interstitial laser-induced thermotherapy (LITT) of a prostate with benign hyperplasia. MATERIALS AND METHODS: In six patients with benign prostatic hyperplasia (BPH), 12 LITT treatments were followed online with repetitive axial T2-weighted fast SE imaging (repetition time, 3,700 msec; echo time, 138 msec; acquisition time, 19 seconds). Development, time course, correlation with interstitial tissue temperature, and diameters of hypointense lesions around the laser diffusor tip were investigated. Lesion diameters on T2-weighted images acquired during LITT were compared with diameters of final lesions on T2-weighted images and unperfused lesions on enhanced T1-weighted SE images obtained at the end of therapy. RESULTS: Hypointense lesions developed within 20-40 seconds of LITT. Average correlation coefficients between interstitial temperature development and signal intensity development were 0.92 during LITT and 0.90 after LITT. Regression slopes were significantly steeper during LITT (0.67% signal intensity change per degree Celsius) than after LITT (0.47% per degree Celsius; P = .038). Lesions remained visible after LITT for all procedures. Average maximum diameters of lesions were 1-3 mm larger during LITT than after LITT (P = .0006-.019). CONCLUSION: Repetitive T2-weighted fast SE MR imaging during interstitial coagulative LITT of BPH demonstrates the development of permanent hypointense prostate lesions. However, posttherapeutic lesion diameters tend to be overestimated during LITT.     

Three-dimensional analysis of the width of the subacromial space in healthy subjects and patients with impingement syndrome

OBJECTIVE: The aim of this study was to per form a three-dimensional analysis of the width of the subacromial space during passive and active arm abduction in healthy volunteers and patients with impingement syndrome. SUBJECTS AND METHODS: The shoulders of 10 healthy subjects and 10 patients with impingement syndrome were imaged with an open MR system during abduction, with and without activation of the shoulder muscles. An apparatus was designed for applying an adduction force of 10 N to the distal humerus during image acquisition, and the minimal acromiohumeral distance was measured after three-dimensional reconstruction. RESULTS: In the 10 healthy volunteers, muscle activity led to a significant decrease (-32%; p < .05) of the acromiohumeral distance at 60 degrees of abduction, whereas at 120 degrees of abduction the distance was significantly increased (+44%; p < .05). In these volunteers, muscle activation caused no significant effect at 90 degrees of abduction. However, in the 10 patients with impingement syndrome, muscle activity led to a significant decrease in the width of the subacromial space compared with that of the healthy contralateral side (-68%; p < .05). CONCLUSION: Muscle activity and arm position were found to cause systematic changes in the width of the subacromial space. However, functional deficits of the supraspinous muscle in patients with early-stage impingement syndrome were not apparent during muscle relaxation.     

Evaluation of the middle and inner ear structures: comparison of hybrid rendering, virtual endoscopy and axial 2D source images

Recent developments in 3D reconstructions can enhance the quality and diagnostic value of axial 2D image data sets with direct benefits for clinical practice. To show the possible advantages of a hybrid rendering method [color-coded 3D shaded-surface display (SSD)- and volume rendering method] with the possibility of virtual endoscopy we have specifically highlighted the use in relation to the middle and inner ear structures. We examined 12 patients with both normal findings and postoperative changes, using image data sets from high-resolution spiral computed tomography (HRSCT). The middle and inner ear was segmented using an interactive threshold interval density volume-growing method and visualized with a color-coded SSD rendering method. The temporal bone was visualized using a transparent volume rendering method. The 3D- and virtual reconstructions were compared with the axial 2D source images. The evaluated middle and inner ear structures could be seen in their complete form and correct topographical relationship, and the 3D- and virtual reconstructions indicated an improved representation and spatial orientation of these structures. A hybrid and virtual endoscopic method could add information and improve the value of imaging in the diagnosis and management of patients with middle or inner ear diseases making the understanding and interpretation of axial 2D CT image data sets easier. The introduction of an improved rendering algorithm aids radiological diagnostics, medical education, surgical planning, surgical training, and postoperative assessment. Received: 22 July 1998; Revised: 15 April 1999; Accepted: 19 April 1999