Maxwell L. Smith

A Crucial Role for Kupffer Cell-Derived Galectin-9 in Regulation of T Cell Immunity in Hepatitis C Infection

Approximately 200 million people throughout the world are infected with hepatitis C virus (HCV). One of the most striking features of HCV infection is its high propensity to establish persistence (∼70–80%) and progressive liver injury. Galectins are evolutionarily conserved glycan-binding proteins with diverse roles in innate and adaptive immune responses. Here, we demonstrate that galectin-9, the natural ligand for the T cell immunoglobulin domain and mucin domain protein 3 (Tim-3), circulates at very high levels in the serum and its hepatic expression (particularly on Kupffer cells) is significantly increased in patients with chronic HCV as compared to normal controls. Galectin-9 production from monocytes and macrophages is induced by IFN-γ, which has been shown to be elevated in chronic HCV infection. In turn, galectin-9 induces pro-inflammatory cytokines in liver-derived and peripheral mononuclear cells; galectin-9 also induces anti-inflammatory cytokines from peripheral but not hepatic mononuclear cells. Galectin-9 results in expansion of CD4+CD25+FoxP3+CD127low regulatory T cells, contraction of CD4+ effector T cells, and apoptosis of HCV-specific CTLs. In conclusion, galectin-9 production by Kupffer cells links the innate and adaptive immune response, providing a potential novel immunotherapeutic target in this common viral infection.

Bile Acid Receptor Activation Modulates Hepatic Monocyte Activity and Improves Nonalcoholic Fatty Liver Disease

Background: The bile acid receptors FXR and TGR5 have pleiotropic functions, including immune modulation. Results: Treatment of a murine model of nonalcoholic fatty liver disease (NAFLD) with a dual FXR/TGR5 agonist decreased intrahepatic inflammation and altered the immune phenotype of monocytes. Conclusion: Bile acid receptor activation improves NAFLD. Significance: These results identify potential targeting strategies for treatment of NAFLD. Nonalcoholic fatty liver disease (NAFLD) affects a large proportion of the American population. The spectrum of disease ranges from bland steatosis without inflammation to nonalcoholic steatohepatitis and cirrhosis. Bile acids are critical regulators of hepatic lipid and glucose metabolism and signal through two major receptor pathways: farnesoid X receptor (FXR), a member of the nuclear hormone receptor superfamily, and TGR5, a G protein-coupled bile acid receptor (GPBAR1). Both FXR and TGR5 demonstrate pleiotropic functions, including immune modulation. To evaluate the effects of these pathways in NAFLD, we treated obese db/db mice with a dual FXR/TGR5 agonist (INT-767) for 6 weeks. Treatment with the agonist significantly improved the histological features of nonalcoholic steatohepatitis. Furthermore, treatment increased the proportion of intrahepatic monocytes with the anti-inflammatory Ly6Clow phenotype and increased intrahepatic expression of genes expressed by alternatively activated macrophages, including CD206, Retnla, and Clec7a. In vitro treatment of monocytes with INT-767 led to decreased Ly6C expression and increased IL-10 production through a cAMP-dependent pathway. Our data indicate that FXR/TGR5 activation coordinates the immune phenotype of monocytes and macrophages, both in vitro and in vivo, identifying potential targeting strategies for treatment of NAFLD.

2016 Comprehensive Update of the Banff Working Group on Liver Allograft Pathology: Introduction of Antibody-Mediated Rejection

The Banff Working Group on Liver Allograft Pathology reviewed and discussed literature evidence regarding antibody‐mediated liver allograft rejection at the 11th (Paris, France, June 5–10, 2011), 12th (Comandatuba, Brazil, August 19–23, 2013), and 13th (Vancouver, British Columbia, Canada, October 5–10, 2015) meetings of the Banff Conference on Allograft Pathology. Discussion continued online. The primary goal was to introduce guidelines and consensus criteria for the diagnosis of liver allograft antibody‐mediated rejection and provide a comprehensive update of all Banff Schema recommendations. Included are new recommendations for complement component 4d tissue staining and interpretation, staging liver allograft fibrosis, and findings related to immunosuppression minimization. In an effort to create a single reference document, previous unchanged criteria are also included.

De novo donor-specific human leukocyte antigen antibodies early after kidney transplantation

Background Our aim was to determine the incidence of de novo donor-specific human leukocyte antigen (HLA) antibody (dnDSA) during the first year after kidney transplantation and the impact of early dnDSA on acute rejection and protocol biopsy findings. Methods We selected all patients who received a kidney transplant at our center between July 2010 and March 2012. Single antigen bead assay was performed at 1, 4 and 12 months after transplantation. Only DSAs with a mean fluorescence intensity (MFI) of greater 999 were included. Results We included 245 kidney transplant recipients who did not have a DSA before transplantation. At 12 months, 8.2% of the patients developed dnDSA; 2.4% of them were to HLA class I and 6.5% to HLA class II. Of the 32 patients with a dnDSA at 1 or 4 months, only 8 (25%) persisted at 12 months. The risk of antibody-mediated rejection (AMR) was higher in the dnDSA group. For the dnDSA group with MFI of 3,000 or greater (compared with the group with MFI<3,000), the hazard ratio for AMR was 10.6 (95% confidence interval, 2.27–49.5). The cumulative incidence of AMR or mixed rejection at 1 year was 30% in the group with dnDSA MFI level of 3,000 or greater but only 4% for the group with dnDSA with MFI less than 3,000. On 1-year protocol biopsies, the dnDSA group showed more interstitial inflammation, tubulitis, and glomerulitis. Conclusion We conclude that dnDSA occurring during the first posttransplantation year may be transient, and the risk of AMR is higher in patients with a dnDSA MFI level that is greater than 3,000.

Usual interstitial pneumonia-pattern fibrosis in surgical lung biopsies. Clinical, radiological and histopathological clues to aetiology

Pulmonary fibrosis in surgical lung biopsies is said to have a ‘usual interstitial pneumonia-pattern’ (UIP-pattern) of disease when scarring of the parenchyma is present in a patchy, ‘temporally heterogeneous’ distribution. These biopsies are one of the more common non-neoplastic specimens surgical pathologists encounter and often pose a number of challenges. UIP is the expected histopathological pattern in patients with clinical idiopathic pulmonary fibrosis (IPF), but the UIP-pattern can be seen in other conditions on occasion. Most important among these are the rheumatic interstitial lung diseases (RILD) and chronic hypersensitivity pneumonitis (CHrHP). Because theses entities have different mechanisms of injury, approach to therapy, and expected clinical progression, it is imperative for the surgical pathologist to correctly classify them. Taken in isolation, the UIP-pattern seen in patients with IPF may appear to overlap with that of RILD and CHrHP, at least when using the broadest definition of this term (patchy fibrosis). However, important distinguishing features are nearly always present in our experience, and the addition of a multidisciplinary approach will often resolve the critical differences between these diseases. In this manuscript, we review the distinguishing clinical, radiologic and histopathological features of UIP of IPF, RILD and CHrHP, based, in part, on the existing literature, but also lessons learned from a busy lung biopsy consultation practice.

Transplanting Kidneys from Deceased Donors With Severe Acute Kidney Injury

Our aim was to determine outcomes with transplanting kidneys from deceased donors with acute kidney injury, defined as a donor with terminal serum creatinine ≥2.0 mg/dL, or a donor requiring acute renal replacement therapy. We included all patients who received deceased donor kidney transplant from June 2004 to October 2013. There were 162 AKI donor transplant recipients (21% of deceased donor transplants): 139 in the standard criteria donor (SCD) and 23 in the expanded criteria donor (ECD) cohort. 71% of the AKI donors had stage 3 (severe AKI), based on acute kidney injury network (AKIN) staging. Protocol biopsies were done at 1, 4, and 12 months posttransplant. One and four month formalin‐fixed paraffin embedded (FFPE) biopsies from 48 patients (24 AKI donors, 24 non‐AKI) underwent global gene expression profiling using DNA microarrays (96 arrays). DGF was more common in the AKI group but eGFR, graft survival at 1 year and proportion with IF/TA>2 at 1 year were similar for the two groups. At 1 month, there were 898 differentially expressed genes in the AKI group (p‐value <0.005; FDR <10%), but by 4 months there were no differences. Transplanting selected kidneys from deceased donors with AKI is safe and has excellent outcomes.

Assessment of Latent Factors Contributing to Error: Addressing Surgical Pathology Error Wisely

CONTEXT Methods to improve surgical pathology patient safety include measuring the frequency of error in specific steps of the surgical pathology testing process, root cause analysis of active and latent components, and implementation of quality improvement initiatives. OBJECTIVE To determine the frequency and cause of near-miss events in the specimen accessioning, setup, and biopsy-only gross examination testing steps of anatomic pathology. DESIGN We used an observational checklist method to identify near-miss events. We performed root cause analysis to determine latent factors contributing to near-miss events. We conducted observations for 45 hours during 5 days, involving the accessioning and processing of 335 specimens. RESULTS We detected a total of 2310 process-dependent and 266 operator-dependent near-miss events, resulting in a near-miss-event frequency of 5.5 per specimen. Root cause analysis showed that all process and operator near-miss events were associated with multiple system latent factors, including lack of standardized protocols, appropriate knowledge transfer, and focus on safety culture. CONCLUSION We conclude that the increased focus on surgical pathology near-miss events will reveal latent factors that may be targeted for improvement.

Directed peer review in surgical pathology.

Second pathologist peer review is used in many surgical laboratory quality-assurance programs to detect error. Directed peer review is 1 method of second review and involves the selection of specific case types, such as cases from a particular site of anatomic origin. The benefits of using the directed peer review method are unique and directed peer review detects both errors in diagnostic accuracy and precision and this detection may be used to improve practice. We utilize the Lean quality improvement A3 method of problem solving to investigate these issues. The A3 method defines surgical pathology diagnostic error and describes the current state in surgical pathology, performs root cause analysis, hypothesizes an ideal state, and provides opportunities for improvement in error reduction. Published data indicate that directed peer review practices may be used to prevent active cognitive errors that lead to patient harm. Pathologists also may use directed peer review data to target latent factors that contribute to error and improve diagnostic precision.

Banff Histopathological Consensus Criteria for Preimplantation Kidney Biopsies.

The Banff working group on preimplantation biopsy was established to develop consensus criteria (best practice guidelines) for the interpretation of preimplantation kidney biopsies. Digitally scanned slides were used (i) to evaluate interobserver variability of histopathologic findings, comparing frozen sections with formalin‐fixed, paraffin‐embedded tissue of wedge and needle core biopsies, and (ii) to correlate consensus histopathologic findings with graft outcome in a cohort of biopsies from international medical centers. Intraclass correlations (ICCs) and univariable and multivariable statistical analyses were performed. Good to fair reproducibility was observed in semiquantitative scores for percentage of glomerulosclerosis, arterial intimal fibrosis and interstitial fibrosis on frozen wedge biopsies. Evaluation of frozen wedge and core biopsies was comparable for number of glomeruli, but needle biopsies showed worse ICCs for glomerulosclerosis, interstitial fibrosis and tubular atrophy. A consensus evaluation form is provided to help standardize the reporting of histopathologic lesions in donor biopsies. It should be recognized that histologic parameters may not correlate with graft outcome in studies based on organs deemed to be acceptable after careful clinical assessment. Significant limitations remain in the assessment of implantation biopsies.

Evaluating the Connections Between Primary Care Practice and Clinical Laboratory Testing: A Review of the Literature and Call for Laboratory Involvement in the Solutions

CONTEXT Growing evidence has demonstrated a high frequency of quality gaps in laboratory medicine, with recent studies estimating that 15% to 54% of primary care medical errors reported by primary care physicians and staff are related to the testing process. However, there is lack of evidence-based performance metrics in the preanalytic and postanalytic phases of the testing pathway for primary care practices. OBJECTIVE To use results of the literature review to assist in the development of quality indicators that could improve preanalytic and postanalytic processes in primary care-based laboratory medicine. DATA SOURCES Literature in Ovid/MEDLINE from 2001 through 2011 was searched as a primary source of information. Ninety-five peer-reviewed and non-peer-reviewed publications were retrieved following title and abstract review and 10 articles were reviewed in their entirety by the authors. A systematic review of the literature was conducted regarding the connections between clinical laboratories and primary care offices and the resulting errors. Root causes of errors were categorized into 7 major themes: process failures, delays, communication gaps, errors in judgment and cognition, influence of minorities/language, practice culture, and lack of patient centeredness. Selected articles were evaluated for evidence quality using the Systematic Evidence Review and Evaluation Methods for Quality Improvement grading scale developed by the Centers for Disease Control and Prevention. CONCLUSIONS The focused literature review documented 7 key error themes in the laboratory medicine/primary care testing process. Performance metrics related to these themes are proposed that deserve future study for evidence-based improvement.