Rapid Virological Response After Early Treatment with a Combined Therapy of Ledipasvir and Sofosbuvir in HCV Genotype 4 After Living Donor Liver Transplantation in a HCC Downstaged Patient: Case Report and Review of the Literature

A simple, rapid and sensitive sandwich immunoassay based on poly(N-isopropylacrylamide) for the detection of alpha-fetoprotein

Alpha-fetoprotein (AFP), as a tumor marker, plays a vital role in the diagnosis of liver cancer. In this work, a novel sandwich immunoassay based on a thermosensitive polymer, poly(N-isopropylacrylamide) (PNIPAM), was developed for the detection of AFP. This immunoassay could realize one-step rapid reaction within 1 h, and facilitate the separation of the target molecules by incorporating PNIPAM. In this method, a conjugate of PNIPAM and capture antibody (Ab1) was successfully synthesized as a capture probe and the synthetic method of PNIPAM-Ab1 was simple, while the detection antibody (Ab2) was labeled with fluorescein isothiocyanate (FITC) to form a fluorescent detection probe. By employing a sandwich immunoassay, the method achieved quantitative determination of AFP, exhibiting a wide linear range from 5 ng/mL to 200 ng/mL and a low detection limit of 2.44 ng/mL. Furthermore, it was successfully applied to the analysis of spiked human serum samples and the screening of patients with hepatic diseases in clinical samples, indicating its potential application prospect in the diagnosis of liver cancer.

Pre-emptive Treatment of HCV after Living Donor Liver Transplantation with Direct-Acting Antiviral Agents

BACKGROUND

Hepatitis C virus (HCV) universally recurs after liver transplantation (LT). Although the introduction of direct-acting antiviral agents (DAAs) has revolutionized the treatment of HCV infection, no optimal treatment for HCV recurrence after LT has been developed.

METHODS

This study retrospectively evaluated the efficacy of DAAs as a pre-emptive treatment for recurrent HCV infection after living donor liver transplantation (LDLT). From January 2010 to December 2016, 70 patients received pegylated interferon (PegIFN) and 35 patients were treated with DAA-based regimens to treat recurrent HCV after LDLT. All antiviral treatments were pre-emptive.

RESULTS

Genotype 1b was the most common HCV type (61.9%). Twenty-two recipients in the DAA group were treated with ledipasvir/sofosbuvir, nine received daclatasvir plus asunaprevir, three received sofosbuvir, and one received sofosbuvir plus daclatasvir. All 35 patients (100%) in the DAA group achieved a sustained virologic response (SVR), a percentage significantly higher than that (71.4%) in the PegIFN group (p < 0.001). In the PegIFN group, the 1-, 3-, and 5-year graft survival rates were 85.7, 73.9, and 70.7%, respectively, whereas those in the DAA group were 100, 100, and 100%, respectively (p = 0.008).

CONCLUSION

DAA-based regimens are an effective treatment for HCV recurrence after LDLT, resulting in an improved SVR and better graft survival than PegIFN.

Alpha-Fetoprotein and Hepatocellular Carcinoma Immunity

Hepatocarcinoma is one of the most prevalent gastroenterological cancers in the world with less effective therapy. As an oncofetal antigen and diagnostic marker for liver cancer, alpha-fetoprotein (AFP) possesses a variety of biological functions. Except for its diagnosis in liver cancer, AFP has become a target for liver cancer immunotherapy. Although the immunogenicity of AFP is weak and it could induce the immune escapes through inhibiting the function of dendritic cells, natural killer cells, and T lymphocytes, AFP has attracted more attention in liver cancer immunotherapy. By in vitro modification, the immunogenicity and immune response of AFP could be enhanced. AFP-modified immune cell vaccine or peptide vaccine has displayed the specific antitumor immunity against AFP-positive tumor cells and laid a better foundation for the immunotherapy of liver cancer.

Advances with using CRISPR/Cas-mediated gene editing to treat infections with hepatitis B virus and hepatitis C virus

Chronic infections with hepatitis B and hepatitis C viruses (HBV and HCV) account for the majority of cases of cirrhosis and hepatocellular carcinoma. Current therapies for the infections have limitations and improved efficacy is necessary to prevent complications in carriers of the viruses. In the case of HBV persistence, the replication intermediate comprising covalently closed circular DNA (cccDNA) is particularly problematic. Licensed therapies have little effect on cccDNA and HBV replication relapses following treatment withdrawal. Disabling cccDNA is thus key to curing HBV infections and application of gene editing technology, such as harnessing the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 9 (Cas9) system, has curative potential. Several studies have reported good efficacy when employing CRISPR/Cas technologies to disable HBV replication in cultured cells and in hydrodynamically injected mice. Recent advances with HCV drug development have revolutionized treatment of the infection. Nevertheless, individuals may be refractory to treatment. Targeting RNA from HCV with CRISPR/Cas isolated from Francisella novicida may have therapeutic utility. Although preclinical work shows that CRISPR/Cas technology has potential to overcome infection with HBV and HCV, significant challenges need to be met. Ensuring specificity for viral targets and efficient delivery of the gene editing sequences to virus-infected cells are particularly important. The field is at an interesting stage and the future of curative antiviral drug regimens, particularly for treatment of chronic HBV infection, may well entail use of combinations that include derivatives of CRISPR/Cas.

The state of gene therapy research in Africa, its significance and implications for the future

Gene therapy has made impressive recent progress and has potential for treating a wide range of diseases, many of which are important to Africa. However, as a result of lack of direct public funding and skilled personnel, direct research on gene therapy in Africa is currently limited and resources to support the endeavor are modest. A strength of the technology is that it is based on principles of rational design, and the tools of gene therapy are now highly versatile. For example gene silencing and gene editing may be used to disable viral genes for therapeutic purposes. Gene therapy may thus lead to cure from infections with HIV-1, hepatitis B virus and Ebola virus, which are of significant public health importance in Africa. Although enthusiasm for gene therapy is justified, significant challenges to implementing the technology remain. These include ensuring efficient delivery of therapeutic nucleic acids to target cells, limiting unintended effects, cost and complexity of treatment regimens. In addition, implementation of effective legislation that will govern gene therapy research will be a challenge. Nevertheless, it is an exciting prospect that gene therapy should soon reach the mainstream of medical management. Participation of African researchers in the exciting developments is currently limited, but their involvement is important to address health problems, develop capacity and enhance economic progress of the continent.