Aurelio Sonzogni

Impact of liver biopsy size on histological evaluation of chronic viral hepatitis: the smaller the sample, the milder the disease

BACKGROUND/AIMS In chronic viral hepatitis, liver biopsy is performed for assessing disease activity and fibrosis. In this study, we evaluated the impact of the size of liver biopsy on the grading and staging. METHODS We selected 161 liver biopsies from patients with chronic types B and C hepatitis on the basis of their length (> or =3 cm) and width (1.4 mm). Ishak scoring system was used for grading and staging. The score was blindly repeated reducing the length of the specimen from > or =3 to 1.5 cm and to 1 cm long and width from 1.4 to 1 mm. RESULTS Reducing the length of the biopsy led to an increase of cases with mild grades: 49.7% in > or =3 cm, 60.2% in 1.5 cm and 86.6% in 1 cm long specimens (P<0.001). Similarly, cases staged as having mild fibrosis significantly increased in the shorter specimens: 59% in > or =3 cm, 68.3% in 1.5 cm and 80.1% in 1 cm long specimens (P<0.001). As for the width, both grade and stage were significantly underscored in the 1 mm samples, regardless of their length. CONCLUSIONS Liver biopsy size strongly influences the grading and staging of chronic viral hepatitis. The use of fine needles should be discouraged in this setting.

Pretransplant Infusion of Mesenchymal Stem Cells Prolongs the Survival of a Semiallogeneic Heart Transplant through the Generation of Regulatory T Cells

In this study, we investigated whether mesenchymal stem cells (MSC) had immunomodulatory properties in solid organ allotransplantation, using a semiallogeneic heart transplant mouse model, and studied the mechanism(s) underlying MSC tolerogenic effects. Either single (portal vein, day −7) or double (portal vein, day −7 and tail vein, day −1) pretransplant infusions of donor-derived B6C3 MSC in B6 recipients induced a profound T cell hyporesponsiveness and prolonged B6C3 cardiac allograft survival. The protolerogenic effect was abrogated when donor-derived MSC were injected together with B6C3 hematopoietic stem cells (HSC), suggesting that HSC negatively impact MSC immunomodulatory properties. Both the induction (pretransplant) and the maintenance phase (>100 days posttransplant) of donor-derived MSC-induced tolerance were associated with CD4+CD25+Foxp3+ Treg expansion and impaired anti-donor Th1 activity. MSC-induced regulatory T cells (Treg) were donor-specific since adoptive transfer of splenocytes from tolerant mice prevented the rejection of fully MHC-mismatched donor-specific secondary allografts but not of third-party grafts. In addition, infusion of recipient-derived B6 MSC tolerized a semiallogeneic B6C3 cardiac allograft, but not a fully MHC-mismatched BALB/c graft, and expanded Treg. A double i.v. pretransplant infusion of recipient-derived MSC had the same tolerogenic effect as the combined intraportal/i.v. MSC infusions, which makes the tolerogenic protocol applicable in a clinical setting. In contrast, single MSC infusions given either peritransplant or 1 day after transplant were less effective. Altogether these findings indicate that MSC immunomodulatory properties require HSC removal, partial sharing of MHC Ags between the donor and the recipient and pretransplant infusion, and are associated with expansion of donor-specific Treg.

Disruption of the Ang II type 1 receptor promotes longevity in mice

The renin-angiotensin system plays a role in the etiology of hypertension and the pathophysiology of cardiac and renal diseases in humans. Ang II is the central product of this system and is involved in regulating immune responses, inflammation, cell growth, and proliferation by acting through Ang II type 1 receptors (AT1 and AT2). Here, we show that targeted disruption of the Agtr1a gene that encodes AT1A results in marked prolongation of life span in mice. Agtr1a-/- mice developed less cardiac and vascular injury, and multiple organs from these mice displayed less oxidative damage than wild-type mice. The longevity phenotype was associated with an increased number of mitochondria and upregulation of the prosurvival genes nicotinamide phosphoribosyltransferase (Nampt) and sirtuin 3 (Sirt3) in the kidney. In cultured tubular epithelial cells, Ang II downregulated Sirt3 mRNA, and this effect was inhibited by an AT1 antagonist. These results demonstrate that disruption of AT1 promotes longevity in mice, possibly through the attenuation of oxidative stress and overexpression of prosurvival genes, and suggests that the Ang II/AT1 pathway may be targeted to influence life span in mammals.

Hemolytic uremic syndrome: a fatal outcome after kidney and liver transplantation performed to correct factor h gene mutation.

Factor H‐associated hemolytic uremic syndrome (HUS) is a genetic form of thrombotic microangiopathy characterized by deficient factor H (HF‐1) levels/activity and uncontrolled complement activation. The disorder mostly leads to end‐stage renal disease and often recurs after kidney transplantation. We previously demonstrated that in a child with HF‐1‐associated HUS a simultaneous kidney and liver transplantation restored the defective HF‐1 with no recurrence of the disease in the transplanted kidney.

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.

Randomized Trial of Basiliximab Induction versus Steroid Therapy in Pediatric Liver Allograft Recipients Under Tacrolimus Immunosuppression

Avoidance of corticosteroids could be beneficial after pediatric liver transplantation (LTx). To test this hypothesis, we performed a randomized prospective study to compare immunosuppression with tacrolimus (TAC) and steroids versus TAC and basiliximab (BAS) after pediatric LTx. Seventy‐two patients were recruited, 36 receiving TAC and steroids and 36 TAC and BAS. The primary endpoint was the occurrence of the first rejection episode. Secondary endpoints were the cumulative incidence and severity of rejection, patient and graft survival, and incidence of adverse events. Overall 1‐year patient and graft survival rates were 91.4% and 85.5% in the steroid group, and 88.6% and 80% in the BAS group (p = NS). Patients free from rejection were 87.7% in the BAS group and 67.7% in the steroid group (p = 0.036). The use of BAS was associated with a 63.6% reduction in incidence of acute rejection episodes. Overall incidence of infection was 72.3% in the steroid group and 50% in the BAS group (p = 0.035). We conclude that the combination of TAC with BAS is an alternative to TAC and steroid immunosuppression in pediatric LTx, which allows for a significant reduction in the incidence of acute rejection and infectious complications.

Nuclear Expression of S100A4 Calcium-Binding Protein Increases Cholangiocarcinoma Invasiveness and Metastasization

Cholangiocarcinoma (CCA) carries a severe prognosis because of its strong invasiveness and early metastasization. In several patients, otherwise eligible for surgical resection, micrometastasis are already present at the time of surgery. The mechanisms responsible for CCA invasiveness are unclear. S100A4, a member of the S100 family of small Ca2+‐binding proteins, is expressed in mesenchymal cells, regulates cell motility in several cell types, and is expressed in some epithelial cancers. Thus, we aimed to study the role of S100A4 in CCA invasiveness and metastasization. The expression of S100A4 was studied by immunohistochemistry in 93 human liver samples of CCA patients undergoing surgical resection and correlated with metastases development (67 cases) and patient survival following surgery using log rank tests and multivariate analysis. S100A4 expression was studied in EGI‐1 and TFK‐1, human CCA cell lines with and without nuclear S100A4 expression, respectively. Metastatic properties of CCA cells were assessed by xenotransplantation in severe combined immunodeficiency (SCID) mice after transduction with lentiviral vectors encoding firefly luciferase gene. Proliferation, motility (wound healing), invasiveness (Boyden chamber), and metalloproteinases (MMPs) secretion were studied in CCA cells, with or without lentiviral silencing of S100A4. Nuclear expression of S100A4 by neoplastic ducts was a strong predictor of metastasization and reduced survival after resection (P < 0.01). EGI‐1 CCA cells showed stronger metastatic properties than TFK‐1 when xenotransplanted in SCID mice. S100A4‐silenced EGI‐1 cells showed significantly reduced motility, invasiveness, and MMP‐9 secretion in vitro, without changes in cell proliferation. Conclusion: Nuclear S100A4 identifies a subset of CCA patients with a poor prognosis after surgical resection. Nuclear expression of S100A4 increases CCA cells invasiveness and metastasization, indicating that S100A4 may also represent a potential therapeutic target. (HEPATOLOGY 2011; 54:890–899)

Late graft dysfunction and autoantibodies after liver transplantation in children: preliminary results of an Italian experience.

Late graft dysfunction (GD) associated with the development of autoantibodies is a common event after pediatric liver transplantation (OLTx) and can present in 2 clinicohistological subsets: de novo autoimmune hepatitis (DNAH) and early chronic rejection (ECR). Sixty out of 247 children developed autoantibodies after OLTx. GD was demonstrated in 22 (37%); based on histology, patients were divided in a DNAH and an ECR group. Portal/periportal inflammatory infiltrate with interface/lobular hepatitis was suggestive for DNAH. Pericentral hepatocytes confluent dropout with a variable degree of central vein endothelitis, but not with ductopenia (loss of >50% of interlobular bile ducts), was diagnosed as ECR. Nine patients had DNAH and 13 ECR. Five out of 9 in the DNAH group were on cyclosporin (CsA) and 4/9 were on tacrolimus (Tac). In the ECR group, 11 children were treated with CsA and 2 with Tac. All DNAH patients had normal liver function tests on steroids and azathioprine (AZA). Five patients with ECR recovered by increasing calcineurin inhibitors (CNIs) dosage, but in 8/13, including 7 switched from CsA to Tac, AZA and steroids were added to obtain remission of disease. Two patients developed late chronic rejection. DNAH and ECR associated with autoantibodies are forms of late GD after OLTx. DNAH improves after standard treatment of autoimmune hepatitis. ECR has a good response to increased doses of CNIs, although ductopenic chronic rejection may occur. In conclusion, the early differential diagnosis of these conditions and an appropriate treatment seem to allow good overall results reflected by a graft survival of more than 90%. Liver Transpl 12:573–577, 2006.

Minimal evidence of transdifferentiation from recipient bone marrow to parenchymal cells in regenerating and long-surviving human allografts

Liver, small intestine, and heart allografts in residence for 4 days to 16 years were analyzed by simultaneous XY fluorescent in situ hybridization to search for evidence of the recently described process of transdifferentiation of recipient bone marrow stem cells to allograft parenchymal cells. These studies were carried out in an effort to find conditions associated with maximal levels of engraftment or expansion of the recipient parenchymal cells. Despite prolonged survival up to 16 years, regeneration after severe preservation injury or use of split livers, only rare, isolated and tentatively identified recipient hepatocytes were detected in liver allografts. In intestinal allografts, despite survival of up to 8 years and extensive mucosal regeneration because of severe damage from acute rejection, there was no crypt replacement by recipient epithelial cells. In cardiac allografts, no recipient myocytes were detected despite recipient survival for 2–3 days and 3–4 weeks after myocardial infarcts at 5 and 8 years after transplantation.

Favorable outcome of primary liver transplantation in children with cirrhosis and hepatocellular carcinoma.

Romano F, Stroppa P, Bravi M, Casotti V, Lucianetti A, Guizzetti M, Sonzogni A, Colledan M, D’Antiga L. Favorable outcome of primary liver transplantation in children with cirrhosis and hepatocellular carcinoma.
Pediatr Transplantation 2011: 15: 573–579.