Electrostatic subframing and compressive-sensing video in transmission electron microscopy.

We present kilohertz-scale video capture rates in a transmission electron microscope, using a camera normally limited to hertz-scale acquisition. An electrostatic deflector rasters a discrete array of images over a large camera, decoupling the acquisition time per subframe from the camera readout time. Total-variation regularization allows features in overlapping subframes to be correctly placed in each frame. Moreover, the system can be operated in a compressive-sensing video mode, whereby the deflections are performed in a known pseudorandom sequence. Compressive sensing in effect performs data compression before the readout, such that the video resulting from the reconstruction can have substantially more total pixels than that were read from the camera. This allows, for example, 100 frames of video to be encoded and reconstructed using only 15 captured subframes in a single camera exposure. We demonstrate experimental tests including laser-driven melting/dewetting, sintering, and grain coarsening of nanostructured gold, with reconstructed video rates up to 10 kHz. The results exemplify the power of the technique by showing that it can be used to study the fundamentally different temporal behavior for the three different physical processes. Both sintering and coarsening exhibited self-limiting behavior, whereby the process essentially stopped even while the heating laser continued to strike the material. We attribute this to changes in laser absorption and to processes inherent to thin-film coarsening. In contrast, the dewetting proceeded at a relatively uniform rate after an initial incubation time consistent with the establishment of a steady-state temperature profile.

The impact of direct-acting antiviral agents on liver and kidney transplant costs and outcomes.

Direct-acting antiviral medications (DAAs) have revolutionized care for hepatitis C positive (HCV+) liver (LT) and kidney (KT) transplant recipients. Scientific Registry of Transplant Recipients registry data were integrated with national pharmaceutical claims (2007-2016) to identify HCV treatments before January 2014 (pre-DAA) and after (post-DAA), stratified by donor (D) and recipient (R) serostatus and payer. Pre-DAA, 18% of HCV+ LT recipients were treated within 3 years and without differences by donor serostatus or payer. Post-DAA, only 6% of D-/R+ recipients, 19.8% of D+/R+ recipients with public insurance, and 11.3% with private insurance were treated within 3 years (P < .0001). LT recipients treated for HCV pre-DAA experienced higher rates of graft loss (adjusted hazard ratio [aHR] 1.34 1.852.10 , P < .0001) and death (aHR 1.47 1.681.91 , P < .0001). Post-DAA, HCV treatment was not associated with death (aHR 0.34 0.671.32 , P = .25) or graft failure (aHR 0.32 0.641.26 , P = .20) in D+R+ LT recipients. Treatment increased in D+R+ KT recipients (5.5% pre-DAA vs 12.9% post-DAA), but did not differ by payer status. DAAs reduced the risk of death after D+/R+ KT by 57% (0.19 0.430.95 , P = .04) and graft loss by 46% (0.27 0.541.07 , P = .08). HCV treatment with DAAs appears to improve HCV+ LT and KT outcomes; however, access to these medications appears limited in both LT and KT recipients.

The American Society of Transplantation Consensus Conference on the Use of Hepatitis C Viremic Donors in Solid Organ Transplantation.

The availability of direct-acting antiviral agents for the treatment of hepatitis C virus (HCV) infection has resulted in a profound shift in the approach to the management of this infection. These changes have affected the practice of solid organ transplantation by altering the framework by which patients with end-stage organ disease are managed and receive organ transplants. The high level of safety and efficacy of these medications in patients with chronic HCV infection provides the opportunity to explore their use in the setting of transplanting organs from HCV-viremic patients into non-HCV-viremic recipients. Because these organs are frequently discarded and typically come from younger donors, this approach has the potential to save lives on the solid organ transplant waitlist. Therefore, an urgent need exists for prospective research protocols that study the risk versus benefit of using organs for hepatitis C-infected donors. In response to this rapidly changing practice and the need for scientific study and consensus, the American Society of Transplantation convened a meeting of experts to review current data and develop the framework for the study of using HCV viremic organs in solid organ transplantation.

Kidney Transplantation From a Donor With Sickle Cell Disease.

In the United States, >100 000 patients are waiting for a kidney transplant. Given the paucity of organs available for transplant, expansion of eligibility criteria for deceased donation is of substantial interest. Sickle cell disease (SCD) is viewed as a contraindication to kidney donation, perhaps because SCD substantially alters renal structure and function and thus has the potential to adversely affect multiple physiological processes of the kidney. To our knowledge, transplantation from a donor with SCD has never been described in the literature. In this paper, we report the successful transplantation of two kidneys from a 37-year-old woman with SCD who died from an intracranial hemorrhage. Nearly 4 mo after transplant, both recipients are doing well and are off dialysis. The extent to which kidneys from donors with SCD can be safely transplanted with acceptable outcomes is unknown; however, this report should provide support for the careful expansion of kidneys from donors with SCD without evidence of renal dysfunction and with normal tissue architecture on preimplantation biopsies.

Successful Treatment of Hepatitis C in Renal Transplant Recipients With Direct-Acting Antiviral Agents.

The direct-acting antivirals (DAAs) constitute an emerging group of small molecule inhibitors that effectively treat hepatitis C virus (HCV) infection, a common comorbidity in end-stage renal disease patients. To date, there are no data to guide use of these agents in kidney transplant patients. The authors collected data from 20 consecutive kidney recipients treated with interferon-free treatment regimens for HCV at their center: 88% were infected with genotype 1; 50% had biopsy-proved advanced hepatic fibrosis on their most recent liver biopsy preceding treatment (Metavir stage 3 fibrosis [F3] or F4); and 60% had failed treatment pretransplantation with interferon-based therapy. DAA treatment was initiated a median of 888 days after renal transplantation. All patients cleared the virus while on therapy, and 100% have achieved a sustained virologic response at 12 weeks after completion of DAA therapy. The most commonly used regimen was sofosbuvir 400 mg daily in combination with simeprevir 150 mg daily. However, four different treatment approaches were used, with comparable results. The DAAs were well tolerated, and less than half of patients required calcineurin inhibitor dose adjustment during treatment. Eradication of HCV infection with DAAs is feasible after kidney transplantation with few treatment-related side effects.

A systematic review with pooled analysis of clinical presentation and immunodiagnostic testing in mucous membrane pemphigoid: association of anti-laminin-332 IgG with oropharyngeal involvement and the usefulness of ELISA.

BACKGROUND: Mucous membrane pemphigoid (MMP) is characterized by subepithelial blistering due to IgG autoantibodies targeting various components of the dermal-epidermal basement membrane zone. Immunodiagnostics play an important role in making a precise diagnosis. Measures of test sensitivity and specificity, however, typically come from studies in diseases such as bullous pemphigoid, where the exact antigenic site may not be the same. Additionally, the association of clinical phenotype and autoantibody profiles has been an area of debate. OBJECTIVE: We evaluated the sensitivity and specificity of ELISA in MMP for the known target antigens BP180 and laminin-332, as well as characterized the frequency of IgG antibodies against each laminin-332 subdomain. Lastly, we analysed whether IgG auto-antibody profiles were associated with clinical phenotype. METHODS: We performed a systematic review of Medline/PubMed to compile MMP patient demographics, clinical manifestations and immunodiagnostic results. ELISA sensitivities and specificities for autoantigens were calculated in patients with positive immunoblot or immunoprecipitationstudies. IgG reactivity for each laminin-332 subunit was recorded. Associations between positive immunological tests and clinical presentation were evaluated using chi-squared test tests or Fisher's exact test when appropriate. RESULTS: For patients with a positive immunoblot or immunoprecipitation to NC16a, ELISA using both the NC16a and C-terminal portion of BP180 demonstrated a sensitivity and specificity of 73% and 93%. However, for individuals with IgG against the C-terminal domain of BP180, the sensitivity and specificity was 43% and 56%, respectively. LN-332 ELISA demonstrated 75% sensitivity, but only for patients with IgG reactivity against the α3 subunit. In patients with laminin-332 MMP, 86.4% demonstrated IgG against the α3 subunit. IgG autoantibodies against laminin-332 are significantly associated with pharyngo-laryngeal (P < 0.0001) and oro-pharyngo-laryngeal (P = 0.006) involvement. CONCLUSIONS: Immunodiagnostics play a major role in diagnosing MMP, though limited sensitivity may necessitate several forms of testing for confirmation.

TNF-α: a treatment target or cause of sarcoidosis?

Sarcoidosis is a systemic granulomatous disease that affects numerous organs, commonly manifesting at the lungs and skin. While corticosteroids remain the first line of treatment, tumour necrosis factor alpha (TNF-α) inhibitors have been investigated as one potential steroid sparing treatment for sarcoidosis. TNF-α is one of many components involved in the formation of granulomas in sarcoidosis. While there have been larger scale studies of biologic TNF-α inhibition in systemic sarcoidosis, studies in cutaneous disease are limited. Paradoxically, in some patients treated with biologic TNF-α inhibitors for other diseases, treatment can induce the development of sarcoidosis. In the light of this complexity, we discuss the role of TNF-α in granuloma formation, the therapeutic role of TNF-α inhibition and immunologic abnormalities following treatment with these TNF-α inhibitors including drug-specific alterations involving interferon-γ, lymphotoxin-α, TNF receptor 2 (TNFR2) and T-regulatory cells.

An Assessment of HIV-Infected Patients Dying in Care for Deceased Organ Donation in a United States Urban Center.

Organ transplantation is an acceptable option for human immunodeficiency virus (HIV)-infected patients with end-stage kidney or liver disease. With worse outcomes on the waitlist, HIV-infected patients may actually be disproportionately affected by the organ shortage in the United States. One potential solution is the use of HIV-infected deceased donors (HIVDD), recently legalized by the HIV Organ Policy Equity (HOPE) Act. This is the first analysis of patient-specific data from potential HIVDD, retrospectively examining charts of HIV-infected patients dying in care at six HIV clinics in Philadelphia, Pennsylvania from January 1, 2009 to June 30, 2014. Our data suggest that there are four to five potential HIVDD dying in Philadelphia annually who might yield two to three kidneys and three to five livers for transplant. Extrapolated nationally, this would approximate 356 potential HIVDD yielding 192 kidneys and 247 livers annually. However, several donor risk indices raise concerns about the quality of kidneys that could be recovered from HIVDD as a result of older donor age and comorbidities. On the other hand, livers from these potential HIVDD are of similar quality to HIV-negative donors dying locally, although there is a high prevalence of positive hepatitis C antibody.

AST/ASTS workshop on increasing organ donation in the United States: creating an "arc of change" from removing disincentives to testing incentives.

The American Society of Transplantation (AST) and American Society of Transplant Surgeons (ASTS) convened a workshop on June 2-3, 2014, to explore increasing both living and deceased organ donation in the United States. Recent articles in the lay press on illegal organ sales and transplant tourism highlight the impact of the current black market in kidneys that accompanies the growing global organ shortage. We believe it important not to conflate the illegal market for organs, which we reject in the strongest possible terms, with the potential in the United States for concerted action to remove all remaining financial disincentives for donors and critically consider testing the impact and acceptability of incentives to increase organ availability in the United States. However, we do not support any trials of direct payments or valuable considerations to donors or families based on a process of market-assigned values of organs. This White Paper represents a summary by the authors of the deliberations of the Incentives Workshop Group and has been approved by both AST and ASTS Boards.

Increased risk of breakthrough infection among cytomegalovirus donor-positive/recipient-negative kidney transplant recipients receiving lower-dose valganciclovir prophylaxis.

OBJECTIVE: We compared the effectiveness of lower-dose (LD) (450 mg/day for 6 months) to standard-dose (SD) (900 mg/day for 6 months) valganciclovir (VGCV) prophylaxis for prevention of cytomegalovirus (CMV) infection and disease in high-risk CMV donor-positive/recipient-negative (D+/R-) kidney recipients. METHODS: We performed a single-center, retrospective cohort study, in a 750-bed academic medical center, involving a total of 90 evaluable CMV high-risk kidney recipients. All patients were retrospectively followed from day of transplantation to November 1, 2012, or to the development of CMV infection or disease, death, or loss to follow-up. CMV screening was only done if suggestive symptoms or abnormal laboratory values were present. Our immunosuppressive protocol otherwise did not differ between periods. RESULTS: In total, 45 consecutive eligible patients initiated SD prophylaxis in the 22 months before the institutional protocol change regarding CMV prophylaxis. One patient developed CMV infection in the setting of non-adherence. In the 16 months after the protocol update, 45 consecutive eligible patients receiving LD prophylaxis were evaluated: 6 developed CMV infection while receiving prophylaxis (P = 0.11). Ganciclovir (GCV)-resistant infection was confirmed in 1 patient in the LD prophylaxis group. Late-onset CMV infection or disease occurred in 11 patients (24%) in the SD group and in 12 patients (27%) in the LD group (P = 0.86). More patients in the SD group developed leukopenia (75% vs. 44%, P < 0.01). During the study period, no significant differences were seen between the groups in mean mg/kg exposure to rabbit anti-thymocyte globulin induction courses, mean tacrolimus troughs, number of rejection episodes, mean estimated renal function, graft survival, or patient survival. Overall mean follow-up (± standard deviation) was 357 days (± 53) in the SD group and 320 days (± 103) in the LD group (P = 0.03). CONCLUSION: Breakthrough CMV infection while receiving VGCV prophylaxis occurred more often after the institutional protocol revision to LD VGCV prophylaxis. Given our concern for increased risk of breakthrough infection and GCV resistance when prophylaxis is under-dosed, our institutional protocols were revised back to SD prophylaxis for all CMV D+/R- kidney transplant recipients.

Solid organ transplantation from hepatitis B virus-positive donors: consensus guidelines for recipient management.

Use of organs from donors testing positive for hepatitis B virus (HBV) may safely expand the donor pool. The American Society of Transplantation convened a multidisciplinary expert panel that reviewed the existing literature and developed consensus recommendations for recipient management following the use of organs from HBV positive donors. Transmission risk is highest with liver donors and significantly lower with non-liver (kidney and thoracic) donors. Antiviral prophylaxis significantly reduces the rate of transmission to liver recipients from isolated HBV core antibody positive (anti-HBc+) donors. Organs from anti-HBc+ donors should be considered for all adult transplant candidates after an individualized assessment of the risks and benefits and appropriate patient consent. Indefinite antiviral prophylaxis is recommended in liver recipients with no immunity or vaccine immunity but not in liver recipients with natural immunity. Antiviral prophylaxis may be considered for up to 1 year in susceptible non-liver recipients but is not recommended in immune non-liver recipients. Although no longer the treatment of choice in patients with chronic HBV, lamivudine remains the most cost-effective choice for prophylaxis in this setting. Hepatitis B immunoglobulin is not recommended.

Mortality and cardiovascular disease among older live kidney donors.

Over the past two decades, live kidney donation by older individuals (≥55 years) has become more common. Given the strong associations of older age with cardiovascular disease (CVD), nephrectomy could make older donors vulnerable to death and cardiovascular events. We performed a cohort study among older live kidney donors who were matched to healthy older individuals in the Health and Retirement Study. The primary outcome was mortality ascertained through national death registries. Secondary outcomes ascertained among pairs with Medicare coverage included death or CVD ascertained through Medicare claims data. During the period from 1996 to 2006, there were 5717 older donors in the United States. We matched 3368 donors 1:1 to older healthy nondonors. Among donors and matched pairs, the mean age was 59 years; 41% were male and 7% were black race. In median follow-up of 7.8 years, mortality was not different between donors and matched pairs (p = 0.21). Among donors with Medicare, the combined outcome of death/CVD (p = 0.70) was also not different between donors and nondonors. In summary, carefully selected older kidney donors do not face a higher risk of death or CVD. These findings should be provided to older individuals considering live kidney donation.

Transcriptional targets of the schizophrenia risk gene MIR137.

Genome-wide association studies (GWAS) have strongly implicated MIR137 (the gene encoding the microRNA miR-137) in schizophrenia. A parsimonious hypothesis is that a pathway regulated by miR-137 is important in the etiology of schizophrenia. Full evaluation of this hypothesis requires more definitive knowledge about biological targets of miR-137, which is currently lacking. Our goals were to expand knowledge of the biology of miR-137 by identifying its empirical targets, and to test whether the resulting lists of direct and indirect targets were enriched for genes and pathways involved in risk for schizophrenia. We overexpressed miR-137 in a human neural stem cell line and analyzed gene expression changes at 24 and 48 h using RNA sequencing. Following miR-137 overexpression, 202 and 428 genes were differentially expressed after 24 and 48 h. Genes differentially expressed at 24 h were enriched for transcription factors and cell cycle genes, and differential expression at 48 h affected a wider variety of pathways. Pathways implicated in schizophrenia were upregulated in the 48 h findings (major histocompatibility complex, synapses, FMRP interacting RNAs and calcium channels). Critically, differentially expressed genes at 48 h were enriched for smaller association P-values in the largest published schizophrenia GWAS. This work provides empirical support for a role of miR-137 in the etiology of schizophrenia.

A randomized, crossover pharmacokinetic study comparing generic tacrolimus vs. the reference formulation in subpopulations of kidney transplant patients.

An exploratory, post hoc analysis was performed using data from a prospective, multicenter, open-label, randomized, two-period (14 d per period), two-sequence, crossover, steady-state pharmacokinetic study comparing generic tacrolimus (Sandoz) vs. reference tacrolimus in stable renal transplant patients receiving their pre-study twice-daily dose. Pharmacokinetic parameters were compared in 68 patients according to gender, African American ethnicity, the presence or absence of diabetes, and use of steroids. The ratios of tacrolimus AUC0-12 h , Cmax , and C12 with generic vs. reference tacrolimus were calculated using the geometric mean (GM) of dose-normalized values at days 14 and 28. Mean (SD) tacrolimus dose at baseline was 5.7 (4.2) mg/d. There were no consistent differences in dose-normalized AUC0-12 h , C12 , Cmax, or tmax between the generic and reference preparations within subpopulations. The 90% confidence intervals (CI) for the ratios of dose-normalized AUC0-12 h and C12 with generic vs. reference tacrolimus were within 80-125% for all subpopulations, as were 90% CIs for Cmax other than for females, African Americans, and non-diabetics, which is not unexpected given the wide variability of tacrolimus Cmax and the small subpopulation sizes. These exploratory results suggest that this generic tacrolimus preparation would be expected to offer comparable bioavailability to the reference drug in these patient subpopulations.

Early rehospitalization after kidney transplantation: assessing preventability and prognosis.

Early rehospitalization after kidney transplantation (KT) is common and may predict future adverse outcomes. Previous studies using claims data have been limited in identifying preventable rehospitalizations. We assembled a cohort of 753 adults at our institution undergoing KT from January 1, 2003 to December 31, 2007. Two physicians independently reviewed medical records of 237 patients (32%) with early rehospitalization and identified (1) primary reason for and (2) preventability of rehospitalization. Mortality and graft failure were ascertained through linkage to the Scientific Registry of Transplant Recipients. Leading reasons for rehospitalization included surgical complications (15%), rejection (14%), volume shifts (11%) and systemic and surgical wound infections (11% and 2.5%). Reviewer agreement on primary reason (85% of cases) was strong (kappa = 0.78). Only 19 rehospitalizations (8%) met preventability criteria. Using logistic regression, weekend discharge (odds ratio [OR] 1.59, p = 0.01), waitlist time (OR 1.10, p = 0.04) and longer initial length of stay (OR 1.42, p = 0.03) were associated with early rehospitalization. Using Cox regression, early rehospitalization was associated with mortality (hazard ratio [HR] 1.55; p = 0.03) but not graft loss (HR 1.33; p = 0.09). Early rehospitalization has diverse causes and presents challenges as a quality metric after KT. These results should be validated prospectively at multiple centers to identify vulnerable patients and modifiable processes-of-care.