Post-transplant recurrent hepatitis C: immunohistochemical detection of hepatitis C virus core antigen and possible pathogenic implications

Assessment of hepatitis c core antigen in epithelial salivary gland neoplasms (ex-vivo study)

BACKGROUND

Salivary gland neoplasms (SGNs) pose a challenge to both pathologists and clinicians. Despite research, the etiology of these neoplasms remains unclear. This study aimed to identify any potential association between the presence of hepatitis C virus (HCV) at the protein or gene level and epithelial salivary gland neoplasms.

METHODS

Formalin-fixed paraffin-embedded (FFPE) blocks of epithelial salivary gland neoplasms were retrieved from the archives of the Oral and Maxillofacial Pathology Department, Faculty of Dentistry, Cairo University within the 5-year period from 2016 to 2020. Immunohistochemistry was used to assess HCV core antigen, while reverse transcription polymerase chain reaction was employed for the evaluation of HCV RNA.

RESULTS

A total of 44 specimens were collected, 28 of which were benign neoplasms and 16 were malignant neoplasms. There was a statistically significant difference in HCV positivity between the two groups (P-value = 0.036). Benign tumors showed a statistically significant lower percentage of positive cases than malignant tumors. The localization of staining was also evaluated, revealing various patterns of HCV core antigen expression, including diffuse cytoplasmic, patchy cytoplasmic, nuclear, and a combination of nuclear and cytoplasmic expression. There was no statistically significant difference between the expression patterns in benign and malignant tumors (P-value = 0.616). Given that Pleomorphic Adenoma and Mucoepidermoid Carcinoma were the predominant tumor types in this study, four cases were selected for RNA detection. HCV RNA was detected in all cases using RT-PCR.

CONCLUSIONS

HCV core antigen is frequently detected in SGNs and is suggested to be a potential risk factor for the development of these neoplasms. Further studies are required to discover other biomarkers, their roles, and the pathways associated with HCV in SGNs.

Acute Viral Hepatitis: Beyond A, B, and C

From the standpoint of the surgical pathologist "hepatitis" is defined as the set of histologic patterns of lesions found in livers infected by hepatotropic viruses, by non-hepatotrophic viruses leading to liver inflammation in the context of systemic infection, or due to an autoimmune disease, drug, or toxin involving the liver. This article is centered on the histologic patterns of injury in acute viral hepatitis, encompassing the hepatotropic viruses A, B, C, D, and E and the "icteric hemorrhagic fevers" (dengue, hantavirus, yellow fever). A brief mention of viruses causing hepatitis in immunosuppressed patients also is presented.

HCV NS3Ag: a reliable and clinically useful predictor of antiviral outcomes in genotype 1b hepatitis C virus-infected patients

Since hepatitis C virus (HCV) non-structural 3 (NS3) protease inhibitor (PI) combined with pegylated interferon/ribavirin (PR) has been approved for chronic HCV genotype (GT) 1b infection, a reliable and clinically useful predictor combining with serum HCV RNA to predict early virologic response, breakthrough, and relapse is important during HCV antiviral treatment. We evaluated the role of HCV NS3 antigen (HCV NS3Ag) on the prediction of virologic response in patients with HCV GT1b during PR or PR/simeprevir (triple) therapy. Three hundred patients were recruited, and HCV RNA and HCV NS3Ag were tested at baseline and weeks 2, 4, 12, 24, 48, and 72. NS3Ag and HCV RNA were significantly related (r(2) = 0.67) in the whole patient selection. The kinetic pattern of HCV RNA and HCV NS3Ag during triple treatment was similar. HCV NS3Ag levels in the triple group closely followed those of HCV RNA; the r(2) values were 0.756 (baseline), 0.837 (2 weeks), 0.989 (4 weeks), and 0.993 (12 weeks), respectively. For patients treated with PR, the positive and negative predictive values (PPVs and NPVs) for viral response were 96.31 % and 67.19 %, respectively, at week 4 by using the decrease of NS3Ag (dHCV NS3Ag) combined with HCV RNA. At week 12, the PPV was similar at 94.16 %, while the NPV reached 87.26 %. The PPV and NPV for the prediction of relapse and breakthrough were 90.6 % and 76.7 %, respectively. HCV NS3Ag is a valuable marker and could be a supplementary predictor of HCV RNA for the prediction of antiviral response, breakthrough, or relapse during HCV antiviral treatment.

Histopathological evaluation of recurrent hepatitis C after liver transplantation: A review

Although the morphological features of hepatitis C virus (HCV) recurrence after orthotopic liver transplantation (OLT) have been well established in the last decades, the differential diagnosis still represents a challenge for the pathologist, especially early recurrent hepatitis C vs mild acute cellular rejection. The present review focuses on the role of the pathologist and the pathology laboratory in the management of recipients with recurrent hepatitis C, the usefulness of early and late post-OLT liver biopsies, and the potential role of ancillary techniques (immunohistochemistry and reverse transcription-polymerase chain reaction, RT-PCR). The English literature on the topic is reviewed, focusing on the histopathology, the immunohistochemistry and the use of RT-PCR on HCV-positive post-OLT biopsies. The different histopathological illustrations of early and chronic recurrent hepatitis C are presented, with special focus on the main differential diagnoses and those features with prognostic relevance (cholestasis above all). The usefulness of ancillary techniques are discussed, especially HCV RNA quantitation by RT-PCR. Finally, the usefulness of long-term protocol biopsies is addressed: their usefulness for the study of allograft disease progression is clear, but their meaning in the long term is still debated. The significance of plasma cell infiltrate in HCV-positive allografts, the prognostic weight of graft steatosis, and the impact of donor age in recurrent hepatitis C also represent additional open issues.

Hepatitis C recurrence: the Achilles heel of liver transplantation

Hepatitis C virus (HCV) infection is the most common indication for liver transplantation worldwide; however, recurrence post transplant is almost universal and follows an accelerated course. Around 30% of patients develop aggressive HCV recurrence, leading to rapid fibrosis progression (RFP) and culminating in liver failure and either death or retransplantation. Despite many advances in our knowledge of clinical risks for HCV RFP, we are still unable to accurately predict those most at risk of adverse outcomes, and no clear consensus exists on the best approach to management. This review presents a critical overview of clinical factors shown to influence the course of HCV recurrence post transplant, with particular focus on recent data identifying the important role of metabolic factors, such as insulin resistance, in HCV recurrence. Emerging data for genetic markers of HCV recurrence and their usefulness for predicting adverse outcomes will also be explored.

Imaging of hepatitis C virus infection in liver grafts after liver transplantation

BACKGROUND & AIMS

The detection of native hepatitis C virus (HCV) antigens in liver tissue may be relevant to diagnostic purposes and to better understand the pathogenesis of HCV infection. The aim of our study was to characterize HCV antigens in liver grafts.

METHODS

We selected 32 liver transplant (LT) recipients with recurrent hepatitis C. HCV core and NS5A antigens were detected in formalin-fixed, paraffin-embedded (FFPE) liver biopsies obtained immediately after graft reperfusion (negative controls), during the acute phase of HCV infection (1-6 months) and during follow-up (7-74 months) after LT. Viral antigens were assessed by immunohistochemistry and confocal microscopy.

RESULTS

All reperfusion biopsies were negative for both antigens. Core protein was detected in 75% and 33% of acute phase and follow-up biopsies, respectively. HCV antigens were not detected in any of the 10 samples from patients who cleared HCV after antiviral treatment. Immunostaining was hepatocellular, with a granular cytoplasmic pattern and a wide spectrum of intensity. We found a significant association between viral load and the presence of HCV core-positive hepatocytes (p=0.004). NS5A colocalized strongly with core (66%) and adipophilin (36%), supporting the localization of core and NS5A around lipid droplets. A detailed three-dimensional analysis showed that NS5A surrounded the core and adipophilin-positive areas.

CONCLUSIONS

HCV antigens can be detected in FFPE liver biopsies by immunohistochemistry. The in vivo colocalization of core and NS5A proteins around the lipid droplets supports that the latter may play a role in virus particle production, similar to what reported in vitro.

Management of posttransplant hepatitis C infection

PURPOSE OF REVIEW

Chronic hepatitis C virus (HCV) infection is the leading cause of liver transplantation. Outcome of HCV-associated liver transplantation has been worse than transplantation from other causes. This is mostly related to universal recurrence of HCV in the allograft leading to graft and patient loss or retransplantation. Current antiviral therapies (AVTs) are inadequate and ineffective in the vast majority of the patients with intolerable side effects in most. However, a sustained virologic response (SVR) is associated with improved graft and patient survival. New specifically targeted AVTs for HCV (STAT-C) agents in development will significantly improve the success of AVT. This review focuses on recent data in peritransplant management of HCV with special emphasis on predictors of outcome, diagnosis, prevention and control of reinfection with newer treatments on the horizon.

RECENT FINDINGS

In the immediate pretransplant setting, AVT should be considered in select patients to eradicate the virus. Careful donor selection, immunosuppression (IMS) modulation with steroid and calcineurin inhibitor (CNI) minimization, avoidance of T-cell-depleting treatments and acute rejection episodes, and control of metabolic syndrome can improve allograft outcomes and improve the response to AVT. AVT prior to significant damage to the allograft is strongly recommended.

SUMMARY

With modified novel IMS protocols, careful donor selection, and AVT prior to significant damage to the allograft we can improve the outcome of posttransplant hepatitis C infection. Albeit there are no available data on new antiviral agents, STAT-Cs will have a significant impact in this setting in the near future.

Visualizing hepatitis C virus infections in human liver by two-photon microscopy

BACKGROUND & AIMS

Although hepatitis C virus (HCV) is a common cause of cirrhosis and liver cancer, efforts to understand the pathogenesis of HCV infection have been limited by the low abundance of viral proteins expressed within the liver, which hinders the detection of infected cells in situ. This study evaluated the ability of advanced optical imaging techniques to determine the extent and distribution of HCV-infected cells within the liver.

METHODS

We combined 2-photon microscopy with virus-specific, fluorescent, semiconductor quantum dot probes to determine the proportion of hepatocytes that were infected with virus in frozen sections of liver tissue obtained from patients with chronic HCV infection.

RESULTS

Viral core and nonstructural protein 3 antigens were detected readily in liver tissues from patients with chronic infection without confounding tissue autofluorescence. Specificity was confirmed by blocking with specific antibodies and by tissue colocalization of distinct viral antigens. Between 7% and 20% of hepatocytes were infected in patients with plasma viral RNA loads of 10(5) IU/mL or greater. Infected cells were in clusters, which suggested spread of the virus from cell to cell. Double-stranded RNA, a product of viral replication, was abundant within cells at the center of such clusters, but often scarce in cells at the periphery, consistent with more recent infection of cells at the periphery.

CONCLUSIONS

Two-photon microscopy provides unprecedented sensitivity for the detection of HCV proteins and double-stranded RNA. Studies using this technology indicate that HCV infection is a dynamic process that involves a limited number of hepatocytes. HCV spread between cells is likely to be constrained by host responses.