The influence of purification of carp collagen used in a novel composite graft with sandwich construction of the wall on its biological properties and graft patency rates.

We compared graft outcome between two types of a novel composite three-layer carp-collagen-coated vascular graft in low-flow conditions in a sheep model. Collagen in group A underwent more cycles of purification than in group B in order to increase the ratio between collagen and residual fat. The grafts were implanted end-to-side in both carotid arteries in sheep (14 grafts in 7 sheep in group A, 18 grafts in 9 sheep in group B) and artificially stenosed on the right side. The flow in the grafts in group A decreased from 297±118 ml/min to 158±159 ml/min (p=0.041) after placement of the artificial stenosis in group A, and from 330±164ml/min to 97±29 ml/min (p=0.0052) in group B (p=0.27 between the groups). From the five surviving animals in group A, both grafts occluded in one animal 3 and 14 days after implantation. In group B, from the six surviving animals, only one graft on the left side remained patent (p=0.0017). Histology showed degradation of the intimal layer in the center with endothelization from the periphery in group A and formation of thick fibrous intimal layer in group B. We conclude that the ratio between collagen and lipid content in the novel three-layer graft plays a critical role in its patency and structural changes in vivo.

Molecular profiling in IgA nephropathy and focal and segmental glomerulosclerosis.

The aim of the study was to characterize by molecular profiling two glomerular diseases: IgA nephropathy (IgAN) and focal segmental glomerulosclerosis (FSGS) and to identify potential molecular markers of IgAN and FSGS progression. The expressions of 90 immune-related genes were compared in biopsies of patients with IgAN (n=33), FSGS (n=17) and in controls (n=11) using RT-qPCR. To identify markers of disease progression, gene expression was compared between progressors and non-progressors in 1 year follow-up. The results were verified on validation cohort of patients with IgAN (n=8) and in controls (n=6) using laser-capture microdissection, that enables to analyze gene expression separately for glomeruli and interstitium. In comparison to controls, patients with both IgAN and FSGS, had lower expression of BAX (apoptotic molecule BCL2-associated protein) and HMOX-1 (heme oxygenase 1) and higher expression of SELP (selectin P). Furthermore, in IgAN higher expression of PTPRC (protein-tyrosine phosphatase, receptor-type C) and in FSGS higher expression of BCL2L1 (regulator of apoptosis BCL2-like 1) and IL18 compared to control was observed. Validation of differentially expressed genes between IgAN and controls on another cohort using laser-capture microdissection confirmed higher expression of PTPRC in glomeruli of patients with IgAN. The risk of progression in IgAN was associated with higher expression EDN1 (endothelin 1) (AUC=0.77) and FASLG (Fas ligand) (AUC=0.82) and lower expression of VEGF (vascular endothelial growth factor) (AUC=0.8) and in FSGS with lower expression of CCL19 (chemokine (C-C motif) ligand 19) (AUC=0.86). Higher expression of EDN1 and FASLG along with lower expression of VEGF in IgAN and lower expression of CCL19 in FSGS at the time of biopsy can help to identify patients at risk of future disease progression.

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.

Hedgehog pathway overexpression in pancreatic cancer is abrogated by new-generation taxoid SB-T-1216.

The Hedgehog pathway is one of the major driver pathways in pancreatic ductal adenocarcinoma. This study investigated prognostic importance of Hedgehog signaling pathway in pancreatic cancer patients who underwent a radical resection. Tumors and adjacent non-neoplastic pancreatic tissues were obtained from 45 patients with histologically verified pancreatic cancer. The effect of experimental taxane chemotherapy on the expression of Hedgehog pathway was evaluated in vivo using a mouse xenograft model prepared using pancreatic cancer cell line Paca-44. Mice were treated by experimental Stony Brook Taxane SB-T-1216. The transcript profile of 34 Hedgehog pathway genes in patients and xenografts was assessed using quantitative PCR. The Hedgehog pathway was strongly overexpressed in pancreatic tumors and upregulation of SHH, IHH, HHAT and PTCH1 was associated with a trend toward decreased patient survival. No association of Hedgehog pathway expression with KRAS mutation status was found in tumors. Sonic hedgehog ligand was overexpressed, but all other downstream genes were downregulated by SB-T-1216 treatment in vivo. Suppression of HH pathway expression in vivo by taxane-based chemotherapy suggests a new mechanism of action for treatment of this aggressive tumor.

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.

Incidental hepatocellular carcinoma: risk factors and long-term outcome after liver transplantation.

BACKGROUND: Orthotopic liver transplantation (OLT) currently represents the treatment of choice for early hepatocellular carcinoma (HCC). Preoperatively known HCC (pkHCC) is diagnosed via imaging methods before OLT or before HCC is found postoperatively in the liver explant, denoted as incidental HCC (iHCC). The aim of this study was a comprehensive analysis of the post-transplantation survival of patients with iHCC and the identification of risk factors of iHCC occurrence in cirrhotic liver. METHODS: We retrospectively reviewed 33 adult cirrhotic patients with incidentally found HCC, comparing them with 606 tumor-free adult cirrhotic patients with end-stage liver disease (group Ci) who underwent OLT in our center from January 1995 to August 2012. Within the same period, a total of 84 patients underwent transplantation for pkHCC. We compared post-transplantation survivals of iHCC, Ci, and pkHCC patients. In the group of cirrhotic patients (Ci + iHCC), we searched for risk factors of iHCC occurrence. RESULTS: There was no difference in sex, Model for End-Stage Liver Disease score, and time spent on the waiting list in either group. In the multivariate analysis we identified age >57 years (odds ratio [OR], 3.37; 95% confidence interval [CI], 1.75-8.14; P < .001), hepatitis C virus or alcoholic liver disease (OR, 3.89; 95% CI, 1.42-10.7; P < .001), and alpha-fetoprotein level >6.4 µg/L (OR, 6.65; 95% CI, 2.82-15.7; P = .002) to be independent predictors of iHCC occurrence. Both the 1-, 3-, and 5-year overall survival (OS) and the 1-, 3- and 5-year recurrence-free survival (RFS) differed in iHCC patients compared with the Ci group (iHCC: OS 79%, 72%, and 68%, respectively; RFS 79%, 72%, and 63%, respectively; vs Ci: OS = RFS: 93%, 94%, and 87%, respectively; P < .001). CONCLUSIONS: The survival of iHCC patients is worse than in tumor-free cirrhotic patients, but similar to pkHCC patients. The independent risk factors for iHCC occurrence in cirrhotic liver are age, hepatitis C virus, or alcoholic liver disease etiology of liver cirrhosis and alpha-fetoprotein level.

[Evaluation of safe resection margins in tumours of parenchymatous organs]. / Problematika stanovení bezpecných resekcních okraju u nádoru parenchymatózních orgánu

The definition of a safe surgical margin in tumours of parenchymatous organs has been the subject of frequent debates and a number of studies. This topic is not generally unified for parenchymatous organs and has many organ specifics. Moreover, there are still controversies in the diagnostic criteria and the definitions of positive resection margins, in indications of perioperative examinations of resection margins, and in the prognostic significance of margin involvement in different parenchymatous organs. The consensus in terminology and standardization of histopathological examination procedures is also very desirable across the diagnostic areas.

[Histopathological differential diagnosis of primary liver tumors]. / Problematika diferenciální diagnostiky primárních nádoru jater.

The most common primary hepatic malignancy is hepatocellular carcinoma, which constitutes 80-85% of all malignant epithelial neoplasms originating in the liver. The second most common primary hepatic malignancy is cholangiocellular carcinoma. In recent years, remarkable progress has been made in elucidating the molecular pathology of hepatic tumors. Advances in our understanding of molecular subtypes have led to a creation of a new classification system of hepatocellular adenomas, with important genotype-phenotype correlations and easy application to routine diagnostic practice. In the field of early hepatic neoplasia, a consensus on the definition of dysplastic nodules and early hepatocellular carcinoma has been reached. Immunohistochemical detection of glypican-3 and stromal invasion are used for the differential diagnosis. A lot of problems still exist in the category of mixed hepatocellular and cholangiocellular carcinoma. Although this category is recognized in the WHO classification, confusing terminology has been generated to describe tumors with morphological features of both HCC and CC. We further specify problems and pitfalls of the differential histopathological diagnosis of liver malignant tumors.

[Biliary (cholestatic) complications in the liver graft biopsy samples early after transplantation]. / Biliární (cholestatické) komplikace v bio-psiích jater casne po transplantaci.

During the first three months after a liver transplant, cholestasis of various type and degree represents 1 of the most frequent morphological findings in liver graft biopsies. The morphology of cholestasis is typical for all conditions with bile duct impairment but also for other conditions with more severe impairment of hepatocytes, including rejection and recurrence of viral hepatitides. Histological diagnosis represents the gold standard in addressing liver graft dysfunction causes, and in the majority of cases it allows for distinguishing between the main categories of diseases resulting in cholestasis. Usually a combination of various changes can be identified as a cause of the liver graft dysfunction early after transplantation. Therefore, the interpretation of limited morphological characteristics, which usually represent a certain type of tissue reaction, not the cause, is complicated. The close cooperation between the hepatologist and pathologist has become a necessary prerequisite for the best possible interpretation of the morphological conclusion.

Urgent liver transplantation for chemotherapy-induced HBV reactivation: a suitable option in patients recently treated for malignant lymphoma.

BACKGROUND: Hepatitis B (HBV) reactivation induced by chemotherapy is a problem currently encountered in the management of malignancies. HBV reactivation occurs particularly in patients who were not checked for HBV status, and therefore have not undergone antiviral prophylaxis. HBV reactivation may ultimately lead to fulminant liver failure (FLF). Liver transplantation (OLT), the only remaining effective treatment option, is generally denied for subjects with a recent history of malignancy. CASE REPORTS: We described retrospectively three cases of FLF caused by HBV reactivation in two men and one woman undergoing rituximab-containing chemotherapy for malignant lymphomas: follicular, diffuse large B-cell and lymphoplasmacytic types. The two men reactivated after eight cycles of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone and the one woman after 13 cycles of rituximab monotherapy; their hematologic disease was in remission. All three patients were hepatitis B surface antigen (HBsAg)-positive with high HBV DNA levels. Neither man had been screened for HBV before chemotherapy; the woman had been treated with lamivudine (LAM) experiencing an HBV flare-up due to emergence of LAM resistance. All patients fulfilled King's College criteria for urgent OLT upon admission to the transplant center and underwent an urgent OLT. Their hemato-oncologic prognosis was considered to be favorable. All three patients are alive (54, 46, and 37 months post-transplantation), tumor-free and HBsAg negative on a standard HBV prophylaxis regimen: hepatitis B immunoglobulin and LAM + adefovir or tenofovir. CONCLUSIONS: Before chemotherapy appropriate prophylaxis for HBV reactivation should always be administered to at-risk patients. However, if reactivation with FLF occurs, OLT should not be generally denied. The prognosis of the hematologic malignancy should be assessed; OLT should be considered for patients in remission with a favorable long-term prognosis, for our data suggest acceptable survival.

Glomus tumor of the stomach: a case report and review of the literature.

Glomus tumor is a benign soft tissue neoplasm which commonly affects the subungual region of the fingers. But the tumors can also arise in the other sites such as the antrum of the stomach. We are reporting a case of a glomus tumor of the stomach in a 71-year-old female patient who presented with dyspepsia. The tumor was confined to the lamina muscularis propria, it consisted of round cells with small uniform nuclei, which surrounded thin walled blood vessels. Immunohistochemistry revealed the tumor to be positive for smooth muscle actin, vimentin, calponin, h-caldesmon and negative for c-KIT, S-100, CD34, CD99, synaptophysin, chromogranin, desmin and EMA. The proliferation marker Ki-67 was positive in less than 5% of tumor cell nuclei. Glomus tumors are usually benign but malignant cases have been published. Criteria for the malignant potential of gastric glomus tumors remain poorly defined.

Guidelines for the diagnosis of antibody-mediated rejection in pancreas allografts-updated Banff grading schema.

The first Banff proposal for the diagnosis of pancreas rejection (Am J Transplant 2008; 8: 237) dealt primarily with the diagnosis of acute T-cell-mediated rejection (ACMR), while only tentatively addressing issues pertaining to antibody-mediated rejection (AMR). This document presents comprehensive guidelines for the diagnosis of AMR, first proposed at the 10th Banff Conference on Allograft Pathology and refined by a broad-based multidisciplinary panel. Pancreatic AMR is best identified by a combination of serological and immunohistopathological findings consisting of (i) identification of circulating donor-specific antibodies, and histopathological data including (ii) morphological evidence of microvascular tissue injury and (iii) C4d staining in interacinar capillaries. Acute AMR is diagnosed conclusively if these three elements are present, whereas a diagnosis of suspicious for AMR is rendered if only two elements are identified. The identification of only one diagnostic element is not sufficient for the diagnosis of AMR but should prompt heightened clinical vigilance. AMR and ACMR may coexist, and should be recognized and graded independently. This proposal is based on our current knowledge of the pathogenesis of pancreas rejection and currently available tools for diagnosis. A systematized clinicopathological approach to AMR is essential for the development and assessment of much needed therapeutic interventions.

[How to improve the histopathological diagnosis of hepatocellular carcinoma in daily practice?]. / Jak v praxi zlepsit histopatologickou diagnostiku hepatocelulárního karcinomu.

Hepatocellular carcinoma (HCC) is one of the most common cancers in the world with an increasing incidence. Recently, an East-West consensus on the histopathologic criteria for the diagnosis of high-grade dysplastic nodules and early hepatocellular carcinoma was published. In addition to classical morphological criteria such as nucleocytoplasmic ratio, thickness of cell plates, mitotic index, and architectural disturbance, a new one--the stromal invasion--was recognized as a crucial criterion for the diagnosis of early HCC. Immunohistochemical detection of glypican--3 was shown as a specific marker for HCC that can be used to distinguish between the benign hepatocellular lesions and HCC.

[Fibrosing cholestatic hepatitis--disease not only of transplanted patients. A report of eight cases]. / Fibrotizující cholestatická hepatitida--onemocneni nejen transplantovaných pacientu.

Fibrosing cholestatic hepatitis (FCH) is a rapidly progressive, sometimes fatal form of hepatitis B or C in patients who are under immunosuppressive treatment. This condition was originally described in hepatitis B virus-infected recipients after a liver transplantation. It is characterized clinically by cholestatic hepatic dysfunction, and pathologically by marked hepatocyte swelling, cholestasis, periportal peritrabecular fibrosis, and only mild inflammation. Here we present 8 patients with hepatitis B and C related FCH. Three patients developed FCH after liver transplantation, two of them died due to hepatic failure. One recipient of a kidney/pancreas transplant developed "de novo" hepatitis C with features of FCH. He underwent antiviral treatment and survived with good liver function, unfortunately both of his grafts failed. Four patients suffered from a reactivation of their respective hepatitis B infections after chemotherapy treated hematological malignancy. Three of them needed an urgent liver transplantation and survived with good liver function and with a remission of their hematological diseases. The last patient died due to liver failure. Although FCH is a rare variant of viral hepatitis, it should be emphasized that prompt diagnosis is important for the management of patients.

[Autoimmune pancreatitis with biliary tree and liver involvement as a part of IgG4-related autoimmune sclerosing disease. Case report]. / Autoimunní pankreatitida s postizením zlucovodu a jater jako soucást IgG4 pozitivního onemocnení (IgG4-related autoimmune sclerosing disease). Kazuistika.

We report a rare case of autoimmune pancreatitis associated with sclerosing cholangitis, kidney, and salivary glands involvement. Abdominal ultrasound and CT scan showed enlarged pancreas, multiple nodular mass in the liver and kidney. ERCP showed features compatible with primary sclerosing cholangitis. The working clinical diagnosis considered malignant tumor with liver metastases. Histological examination of the liver biopsy sample revealed inflammatory process with numerous IgG4 positive plasma cells. The diagnostic conclusion of IgG4-related autoimmune sclerosing disease was drawn. The serum IgG level was elevated. Treatment with steroids improved the clinical course, all masses in the liver and kidneys disappeared, and laboratory tests were normalized. Now, 4 years after diagnosis the patient is free of all symptoms.

Hepatocyte growth factor and antibodies to HLA and MICA antigens in heart transplant recipients.

Recent unconfirmed literature data suggest that elevated concentrations of the multifunctional cytokine hepatocyte growth factor (HGF) might be a marker of increased incidence of acute rejection after organ transplantation. The aim of this study was to test the hypothesis that HGF levels may correlate with the rejection and/or with the production of HLA and MHC Class I chain-related antigens A (MICA) specific antibodies. Sixty-three heart transplant recipients were included into the study. Hundred and eighty-five endomyocardial biopsies (EMB) obtained up to 6 months after transplantation were retrospectively analyzed for signs of cellular (CR) and antibody-mediated rejection (AMR). Pre- and post-transplant sera were tested for HGF concentrations and antibodies to HLA class I, class II and MICA antigens by xMap technology (Luminex). Pre-transplant HGF did not correlate with the incidence of CR or AMR. However, higher HGF concentrations correlated significantly with HLA antibody production before and after transplantation (P = 0.006 and P < 0.0001 respectively). Patients with both HLA class I and class II antibodies before transplantation had significantly lower AMR-free survival. Furthermore, recipients with pre-transplant donor-specific antibodies (DSA) had significantly lower AMR-free survival (50%) than recipients without pre-transplant HLA antibodies (90%) and patients with antibodies not specific to donor antigens (92%) (P = 0.005). Post-transplant MICA antibodies tended to be more frequent in patients with AMR (P = 0.063). In conclusion, elevated HGF concentrations in our study were not associated with the incidence of CR and/or AMR but with the presence of HLA-specific antibodies. Testing for DSA before heart transplantation by Luminex may be helpful for the identification of patients with increased risk of AMR.

Leflunomide derivate FK 778 in accelerated renal injury in transgenic rat.

Renal ischaemia/reperfusion (I/R) injury and hypertension represent major alloantigen-independent risk factors contributing to the development of chronic allograft nephropathy. In a model of accelerated major histocompatibility complex-independent renal injury, we evaluated the effect of leflunomide derivate - FK778 - on the progression of accelerated nephropathy. Thirty-six uninephrectomized hypertensive transgenic (m-REN-2)-27 rats received a clip on renal pedicle for 45 minutes. Animals were treated with FK778 3 mg/kg/day (I/R 3 mg, N = 12), 10 mg/kg/day (I/R 10 mg, N = 12) or placebo (N = 12) via gavage for 16 weeks. Eighteen animals were sham-operated and treated with FK778 3 mg/kg/day (sham 3 mg, N = 6), 10 mg/kg/day (sham 10 mg, N = 6) or were untreated (sham, N = 6). Proteinuria and blood pressure were evaluated throughout and the kidneys were harvested for morphological and immunohistochemical analysis at the end of the experiment. At week 16, rats with I/R injury and FK778 treatment had lower proteinuria compared with placebo-treated rats (I/R 3 mg: 48.42 +/- 26.16, I/R 10 mg 27.28 +/- 21.86 vs. Placebo: 70.13 +/- 50.19 mg/day, P < 0.05). The untreated sham group exhibited lower proteinuria compared with FK778-treated sham groups (Sham 3 mg: 24.23 +/- 10.89; Sham 10 mg: 17.37 +/- 4.13; Sham: 14.23 +/- 1.18) There was no difference in glomerulosclerosis and interstitial fibrosis among the treated groups. In the untreated animals the rate of interstitial fibrosis decline reached statistical significance (Placebo vs. Sham: 1.125 +/- 0.641 % vs. 0.250 +/- 0.500 %, P < 0.05). There was higher CD5+ leukocyte infiltration in the placebotreated group. FK778-treated rats displayed amelioration of some changes induced by the I/R injury. Our observation also suggests potential nephrotoxicity of FK778.