Impaired Cellular and Antibody immunity after COVID-19 in Chronically Immunosuppressed Transplant Recipients.

Assessment of cellular immunity to the SARS-CoV-2 coronavirus is of great interest in chronically immunosuppressed transplant recipients (Tr), who are predisposed to infections and vaccination failures. We evaluated CD154-expressing T-cells induced by spike (S) antigenic peptides in 204 subjects-103 COVID-19 patients and 101 healthy unexposed subjects. S-reactive CD154+T-cell frequencies were a) higher in 42 healthy unexposed Tr who were sampled pre-pandemic, compared with healthy NT (p=0.02), b) lower in Tr COVID-19 patients compared with healthy Tr (p<0.0001) and were accompanied by lower S-reactive B-cell frequencies (p<0.05), c) lower in Tr with severe COVID-19 (p<0.0001), or COVID-19 requiring hospitalization (p<0.05), compared with healthy Tr. Among Tr with COVID-19, cytomegalovirus co-infection occurred in 34%; further, incidence of anti-receptor-binding-domain IgG (p=0.011) was lower compared with NT COVID-19 patients. Healthy unexposed Tr exhibit pre-existing T-cell immunity to SARS-CoV-2. COVID-19 impairs anti-S T-cell and antibody and predisposes to CMV co-infection in transplant recipients.

Immune Response in Severe and Non-Severe Coronavirus Disease 2019 (COVID-19) Infection: A Mechanistic Landscape.

The mechanisms underlying the immune remodeling and severity response in coronavirus disease 2019 (COVID-19) are yet to be fully elucidated. Our comprehensive integrative analyses of single-cell RNA sequencing (scRNAseq) data from four published studies, in patients with mild/moderate and severe infections, indicate a robust expansion and mobilization of the innate immune response and highlight mechanisms by which low-density neutrophils and megakaryocytes play a crucial role in the cross talk between lymphoid and myeloid lineages. We also document a marked reduction of several lymphoid cell types, particularly natural killer cells, mucosal-associated invariant T (MAIT) cells, and gamma-delta T (γδT) cells, and a robust expansion and extensive heterogeneity within plasmablasts, especially in severe COVID-19 patients. We confirm the changes in cellular abundances for certain immune cell types within a new patient cohort. While the cellular heterogeneity in COVID-19 extends across cells in both lineages, we consistently observe certain subsets respond more potently to interferon type I (IFN-I) and display increased cellular abundances across the spectrum of severity, as compared with healthy subjects. However, we identify these expanded subsets to have a more muted response to IFN-I within severe disease compared to non-severe disease. Our analyses further highlight an increased aggregation potential of the myeloid subsets, particularly monocytes, in COVID-19. Finally, we provide detailed mechanistic insights into the interaction between lymphoid and myeloid lineages, which contributes to the multisystemic phenotype of COVID-19, distinguishing severe from non-severe responses.

Circulating Fatty Acids Associated with Advanced Liver Fibrosis and Hepatocellular Carcinoma in South Texas Hispanics.

BACKGROUND: Hispanics in South Texas have high rates of hepatocellular carcinoma (HCC) and nonalcoholic fatty liver disease (NAFLD). Liver fibrosis severity is the strongest predictive factor of NAFLD progression to HCC. We examined the association between free fatty acids (FA) and advanced liver fibrosis or HCC in this population. METHODS: We quantified 45 FAs in plasma of 116 subjects of the Cameron County Hispanic Cohort, 15 Hispanics with HCC, and 56 first/second-degree relatives of Hispanics with HCC. Liver fibrosis was assessed by FibroScan. RESULTS: Advanced liver fibrosis was significantly associated with low expression of very long chain (VLC) saturated FAs (SFA), odd chain SFAs, and VLC n-3 polyunsaturated FAs [PUFA; AOR; 95% confidence interval (CI), 10.4 (3.7-29.6); P < 0.001; 5.7 (2.2-15.2); P < 0.001; and 3.7 (1.5-9.3); P = 0.005]. VLC n3-PUFAs significantly improved the performance of the noninvasive markers for advanced fibrosis - APRI, FIB-4, and NFS. Plasma concentrations of VLC SFAs and VLC n-3 PUFAs were further reduced in patients with HCC. Low concentrations of these FAs were also observed in relatives of patients with HCC and in subjects with the PNPLA3 rs738409 homozygous genotype. CONCLUSIONS: Low plasma concentrations of VLC n-3 PUFAs and VLC SFAs were strongly associated with advanced liver fibrosis and HCC in this population. Genetic factors were associated with low concentrations of these FAs as well. IMPACT: These results have implications in identifying those at risk for liver fibrosis progression to HCC and in screening this population for advanced fibrosis. They also prompt the evaluation of VLC n-3 PUFA or VLC SFA supplementation to prevent cirrhosis and HCC.

Impaired T-cell and antibody immunity after COVID-19 infection in chronically immunosuppressed transplant recipients.

Assessment of T-cell immunity to the COVID-19 coronavirus requires reliable assays and is of great interest, given the uncertain longevity of the antibody response. Some recent reports have used immunodominant spike (S) antigenic peptides and anti-CD28 co-stimulation in varying combinations to assess T-cell immunity to SARS-CoV-2. These assays may cause T-cell hyperstimulation and could overestimate antiviral immunity in chronically immunosuppressed transplant recipients, who are predisposed to infections and vaccination failures. Here, we evaluate CD154-expressing T-cells induced by unselected S antigenic peptides in 204 subjects-103 COVID-19 patients and 101 healthy unexposed subjects. Subjects included 72 transplanted and 130 non-transplanted subjects. S-reactive CD154+T-cells co-express and can thus substitute for IFNγ (n=3). Assay reproducibility in a variety of conditions was acceptable with coefficient of variation of 2-10.6%. S-reactive CD154+T-cell frequencies were a) higher in 42 healthy unexposed transplant recipients who were sampled pre-pandemic, compared with 59 healthy non-transplanted subjects (p=0.02), b) lower in Tr COVID-19 patients compared with healthy transplant patients (p<0.0001), c) lower in Tr patients with severe COVID-19 (p<0.0001), or COVID-19 requiring hospitalization (p<0.05), compared with healthy Tr recipients. S-reactive T-cells were not significantly different between the various COVID-19 disease categories in NT recipients. Among transplant recipients with COVID-19, cytomegalovirus co-infection occurred in 34%; further, CMV-specific T-cells (p<0.001) and incidence of anti-receptor-binding-domain IgG (p=0.011) were lower compared with non-transplanted COVID-19 patients. Healthy unexposed transplant recipients exhibit pre-existing T-cell immunity to SARS-CoV-2. COVID-19 infection leads to impaired T-cell and antibody responses to SARS-CoV-2 and increased risk of CMV co-infection in transplant recipients.

Prevalence of Aflatoxin-Associated TP53R249S Mutation in Hepatocellular Carcinoma in Hispanics in South Texas.

We aimed to determine whether aflatoxin dietary exposure plays a role in the high incidence of hepatocellular carcinoma (HCC) observed among Hispanics in South Texas. We measured TP53R249S somatic mutation, hallmark of aflatoxin etiology in HCC, using droplet digital PCR and RFLP. TP53R249S mutation was detected in 3 of 41 HCC tumors from Hispanics in South Texas (7.3%). We also measured TP53R249S mutation in plasma cell-free DNA (cfDNA) from 218 HCC patients and 96 Hispanic subjects with advanced fibrosis or cirrhosis, from South Texas. The mutation was detected only in Hispanic and Asian HCC patients, and patients harboring TP53R249S mutation were significantly younger and had a shorter overall survival. The mutation was not detected in any Hispanic subject with advanced fibrosis or cirrhosis. Genes involved in cell-cycle control of chromosomal replication and in BRCA1-dependent DNA damage response were enriched in HCCs with TP53R249S mutation. The E2F1 family members, E2F1 and E2F4, were identified as upstream regulators. TP53R249S mutation was detected in 5.7% to 7.3% of Hispanics with HCC in South Texas. This mutation was associated with a younger age and worse prognosis. TP53R249S was however not detected in Hispanics in South Texas with cirrhosis or advanced fibrosis. Aflatoxin exposure may contribute to a small number of HCCs in Hispanics in South Texas, but the detection of TP53R249S mutation in plasma cfDNA is not a promising biomarker of risk assessment for HCC in subjects with cirrhosis or advanced fibrosis in this population. Cancer Prev Res; 11(2); 103-12. ©2017 AACR.

A multicenter study of 30 days complications after deceased donor liver transplantation in the model for end-stage liver disease score era.

Knowledge of risk factors for posttransplant complications is likely to improve patient outcomes. Few large studies of all early postoperative complications after deceased donor liver transplantation (DDLT) exist. Therefore, we conducted a retrospective, cohort study of 30-day complications, their risk factors, and the impact on outcomes after DDLT. Three centers contributed data for 450 DDLTs performed from January 2005 through December 2009. Data included donor, recipient, transplant, and outcome variables. All 30-day postoperative complications were graded by the Clavien-Dindo system. Complications per patient and severe (≥ grade III) complications were primary outcomes. Death within 30 days, complication occurrence, length of stay (LOS), and graft and patient survival were secondary outcomes. Multivariate associations of risk factors with complications and complications with LOS, graft survival, and patient survival were examined. Mean number of complications/patient was 3.3 ± 3.9. At least 1 complication occurred in 79.3%, and severe complications occurred in 62.8% of recipients. Mean LOS was 16.2 ± 22.9 days. Graft and patient survival rates were 84% and 86%, respectively, at 1 year and 74% and 76%, respectively, at 3 years. Hospitalization, critical care, ventilatory support, and renal replacement therapy before transplant and transfusions during transplant were the significant predictors of complications (not the Model for End-Stage Liver Disease score). Both number and severity of complications had a significant impact on LOS and graft and patient survival. Structured reporting of risk-adjusted complications rates after DDLT is likely to improve patient care and transplant center benchmarking. Despite the accomplished reductions in transfusions during DDLT, opportunities exist for further reductions. With increasing transplantation of sicker patients, reduction in complications would require multidisciplinary efforts and institutional commitment. Pretransplant risk characteristics for complications must factor in during payer contracting.

How do we manage post-OLT redundant bile duct?

AIM: To address endoscopic outcomes of post-Orthotopic liver transplantation (OLT) patients diagnosed with a "redundant bile duct" (RBD). METHODS: Medical records of patients who underwent OLT at the Liver Transplant Center, University Texas Health Science Center at San Antonio Texas were retrospectively analyzed. Patients with suspected biliary tract complications (BTC) underwent endoscopic retrograde cholangiopancreatography (ERCP). All ERCP were performed by experienced biliary endoscopist. RBD was defined as a looped, sigmoid-shaped bile duct on cholangiogram with associated cholestatic liver biomarkers. Patients with biliary T-tube placement, biliary anastomotic strictures, bile leaks, bile-duct stones-sludge and suspected sphincter of oddi dysfunction were excluded. Therapy included single or multiple biliary stents with or without sphincterotomy. The incidence of RBD, the number of ERCP corrective sessions, and the type of endoscopic interventions were recorded. Successful response to endoscopic therapy was defined as resolution of RBD with normalization of associated cholestasis. Laboratory data and pertinent radiographic imaging noted included the pre-ERCP period and a follow up period of 6-12 mo after the last ERCP intervention. RESULTS: One thousand two hundred and eighty-two patient records who received OLT from 1992 through 2011 were reviewed. Two hundred and twenty-four patients underwent ERCP for suspected BTC. RBD was reported in each of the initial cholangiograms. Twenty-one out of 1282 (1.6%) were identified as having RBD. There were 12 men and 9 women, average age of 59.6 years. Primary indication for ERCP was cholestatic pattern of liver associated biomarkers. Nineteen out of 21 patients underwent endoscopic therapy and 2/21 required immediate surgical intervention. In the endoscopically managed group: 65 ERCP procedures were performed with an average of 3.4 per patient and 1.1 stent per session. Fifteen out of 19 (78.9%) patients were successfully managed with biliary stenting. All stents were plastic. Selection of stent size and length were based upon endoscopist preference. Stent size ranged from 7 to 11.5 Fr (average stent size 10 Fr); Stent length ranged from 6 to 15 cm (average length 9 cm). Concurrent biliary sphincterotomy was performed in 10/19 patients. Single ERCP session was sufficient in 6/15 (40.0%) patients, whereas 4/15 (26.7%) patients needed two ERCP sessions and 5/15 (33.3%) patients required more than two (average of 5.4 ERCP procedures). Single biliary stent was sufficient in 5 patients; the remaining patients required an average of 4.9 stents. Four out of 19 (21.1%) patients failed endotherapy (lack of resolution of RBD and recurrent cholestasis in the absence of biliary stent) and required either choledocojejunostomy (2/4) or percutaneous biliary drainage (2/4). Endoscopic complications included: 2/65 (3%) post-ERCP pancreatitis and 2/10 (20%) non-complicated post-sphincterotomy bleeding. No endoscopic related mortality was found. The medical records of the 15 successful endoscopically managed patients were reviewed for a period of one year after removal of all biliary stents. Eleven patients had continued resolution of cholestatic biomarkers (73%). One patient had recurrent hepatitis C, 2 patients suffered septic shock which was not associated with ERCP and 1 patient was transferred care to an outside provider and records were not available for our review. CONCLUSION: Although surgical biliary reconstruction techniques have improved, RBD represents a post-OLT complication. This entity is rare however, endoscopic management of RBD represents a reasonable initial approach.

Pulsatile perfusion of kidney allografts.

PURPOSE OF REVIEW: The purpose of this article is to describe the current use of pulsatile kidney perfusion during organ preservation and the effects on kidney allograft outcomes and utilization. RECENT FINDINGS: As of spring 2008, there were 75 629 candidates on the kidney waiting list in the USA according to United Network for Organ Sharing data. In 2006, a total of 1815 deceased donor expanded criteria donors kidneys were transplanted, and approximately 80% of those kidneys had cold ischemic time of over 12 h. The utilization of kidney pulsatile perfusion varies extensively throughout the USA with rates of 7-12% in our institution. SUMMARY: Data on the use of pulsatile hypothermic perfusion for kidneys during organ preservation are limited and mostly retrospective. Most authors agree that pulsatile perfusion is safe and leads to a decrease in delayed graft function, especially for marginal kidneys from extended criteria or deceased donors. The long-term effects of delayed graft function on graft survival remain to be seen. With the recent large-sampled international prospective randomized trial recently completed, we may see more kidneys pulsatile perfused. This may lead to an increase in the utilization of otherwise discarded kidneys, though these data are difficult to extrapolate.