Recurrent hepatitis C virus infection post liver transplantation: impact of choice of calcineurin inhibitor

Repurposable drugs for SARS-CoV-2 and influenza sepsis with scRNA-seq data targeting post-transcription modifications

Coronavirus disease 2019 (COVID-19) has impacted almost every part of human life worldwide, posing a massive threat to human health. The lack of time for new drug discovery and the urgent need for rapid disease control to reduce mortality have led to a search for quick and effective alternatives to novel therapeutics, for example drug repurposing. To identify potentially repurposable drugs, we employed a systematic approach to mine candidates from U.S. FDA-approved drugs and preclinical small-molecule compounds by integrating gene expression perturbation data for chemicals from the Library of Integrated Network-Based Cellular Signatures project with a publicly available single-cell RNA sequencing dataset from patients with mild and severe COVID-19 (GEO: GSE145926, public data available and accessed on 22 April 2020). We identified 281 FDA-approved drugs that have the potential to be effective against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, 16 of which are currently undergoing clinical trials to evaluate their efficacy against COVID-19. We experimentally tested and demonstrated the inhibitory effects of tyrphostin-AG-1478 and brefeldin-a, two chemical inhibitors of glycosylation (a post-translational modification) on the replication of the single-stranded ribonucleic acid (ssRNA) virus influenza A virus as well as on the transcription and translation of host cell cytokines and their regulators (IFNs and ISGs). In conclusion, we have identified and experimentally validated repurposable anti-SARS-CoV-2 and IAV drugs using a systems biology approach, which may have the potential for treating these viral infections and their complications (sepsis).

Effect of Calcineurin Inhibitors and Mammalian Target of Rapamycin Inhibitors on the Course of COVID-19 in Kidney Transplant Recipients

Coronavirus disease 19 (COVID-19) has been an ongoing pandemic since December 2019. Unfortunately, kidney transplant recipients are a high-risk group during the disease course, and scientific data are still limited in this patient group. Beyond the dosage of immunosuppressive drugs, pharmacological immunosuppression may also alter the infection response in the COVID-19 course. The effects of immunosuppressive agents on the development and process of infection should not be decided only by determining how potent they are and how much they suppress the immune system; it is also thought that the direct effect of the virus, increased oxidative stress, and cytokine storm play a role in the pathogenesis of COVID-19 disease. There are data about immunosuppressive drugs like calcineurin inhibitors (CNI) or mammalian target of rapamycin inhibitors (mTORi) therapy related to their beneficial effects during any infection course. Limited data suggest that the use of CNI or mTORi may have beneficial effects on the process. In this hypothetical review, the probable impacts of CNI and mTORi on the pathogenesis of the COVID-19 were investigated.

Cyclosporine A impairs bone repair in critical defects filled with different osteoconductive bone substitutes

The aim of this study was to assess the influence of cyclosporine administration on the repair of critical-sized calvaria defects (CSDs) in rat calvaria filled with diverse biomaterials. Sixty animals were divided into two groups: the control (CTR) group (saline solution) and the cyclosporine (CCP) group (cyclosporine, 10 mg/kg/day). These medications were administered daily by gavage, beginning 15 days before the surgical procedure and lasting until the day the animals were euthanized. A CSD (5 mm Ø) was made in the calvaria of each animal, which was allocated to one of 3 subgroups, according to the biomaterial used to fill the defect: coagulum (COA), deproteinized bovine bone (DBB), or biphasic calcium phosphate ceramics of hydroxyapatite and β-phosphate tricalcium (HA/TCP). Euthanasia of the animals was performed 15 and 60 days after the surgical procedure (n = 5 animals/period/subgroup). Bone repair (formation) assessment was performed through microtomography and histometry, while the analyses of the expression of the BMP2, Osteocalcin, and TGFβ1 proteins were performed using immunohistochemistry. The CSDs not filled with biomaterials demonstrated lower bone formation in the CCP group. At 15 days, less bone formation was observed in the CSDs filled with DBB, a smaller volume of mineralized tissue was observed in the CSDs filled with HA/TCP, and the expression levels of BMP2 and osteocalcin were lower in the CCP group compared to the CTR group. The use of cyclosporine impaired bone repair in CSD, and this effect can be partially explained by the suppression of BMP2 and osteocalcin expression.

Effect of cyclosporine A versus tacrolimus on the response to antiviral therapy after hepatitis C genotype-4 recurrence post-liver transplantation: A prospective cohort trial

WHAT IS KNOWN AND OBJECTIVE

The influence of immunosuppression on the response to antiviral therapy (AVT) for recurrent hepatitis C virus (HCV) infection in liver transplant (LT) recipients remains controversial, especially for the rarely investigated genotype 4. This study aims to compare the effects of the two widely used calcineurin inhibitors (CNIs) (cyclosporine A (CsA) and tacrolimus (Tac)) on the therapeutic response to different AVT regimens.

METHODS

A prospective, dual-centre, cohort study of 126 Egyptian living donor liver transplant (LDLT) recipients with recurrent HCV genotype 4 infection, who were categorized into three groups according to the AVT used. Group I received pegylated interferon (Peg-IFN-α 2a) plus ribavirin (RBV) (n = 44), group II received the direct antiviral agent (DAA) sofosbuvir plus RBV (n = 52) and group III received daclatasvir and sofosbuvir (also DAAs) plus RBV (n = 30). Each group was further subdivided according to the primary immunosuppression (CsA or Tac). The sustained virological response (SVR) and relapse rates were considered the primary therapeutic outcomes of AVT.

RESULTS

No significant intergroup differences were observed in the achievement of primary and secondary outcomes. SVR rates in the IFN-based regimen were 75% and 66.7% in CsA and Tac users and 81.2% and 83% in DAAs, respectively. Relapse rates in the IFN-based regimen were 10% and 16.7% in CsA and Tac users and 12.5% and 14.9% in DAAs, respectively.

WHAT IS NEW AND CONCLUSION

Within the limitations of a relatively small study, CsA did not offer an advantage over Tac regarding the response to AVT after HCV genotype 4 recurrence in LDLT recipients.

Characterization of Remitting and Relapsing Hyperglycemia in Post-Renal-Transplant Recipients

Background

Hyperglycemia following solid organ transplant is common among patients without pre-existing diabetes mellitus (DM). Post-transplant hyperglycemia can occur once or multiple times, which if continued, causes new-onset diabetes after transplantation (NODAT).

Objective

To study if the first and recurrent incidence of hyperglycemia are affected differently by immunosuppressive regimens, demographic and medical-related risk factors, and inpatient hyperglycemic conditions (i.e., an emphasis on the time course of post-transplant complications).

Methods

We conducted a retrospective analysis of 407 patients who underwent kidney transplantation at Mayo Clinic Arizona. Among these, there were 292 patients with no signs of DM prior to transplant. For this category of patients, we evaluated the impact of (1) immunosuppressive drugs (e.g., tacrolimus, sirolimus, and steroid), (2) demographic and medical-related risk factors, and (3) inpatient hyperglycemic conditions on the first and recurrent incidence of hyperglycemia in one year post-transplant. We employed two versions of Cox regression analyses: (1) a time-dependent model to analyze the recurrent cases of hyperglycemia and (2) a time-independent model to analyze the first incidence of hyperglycemia.

Results

Age (P = 0.018), HDL cholesterol (P = 0.010), and the average trough level of tacrolimus (P<0.0001) are significant risk factors associated with the first incidence of hyperglycemia, while age (P<0.0001), non-White race (P = 0.002), BMI (P = 0.002), HDL cholesterol (P = 0.003), uric acid (P = 0.012), and using steroid (P = 0.007) are the significant risk factors for the recurrent cases of hyperglycemia.

Discussion

This study draws attention to the importance of analyzing the risk factors associated with a disease (specially a chronic one) with respect to both its first and recurrent incidence, as well as carefully differentiating these two perspectives: a fact that is currently overlooked in the literature.

Review on immunosuppression in liver transplantation

The optimal level of immunosuppression in solid organ transplantation, in particular for the liver, is a delicate balance between the benefit of preventing rejection and the adverse side effects of immunosuppression. There is uncertainty about when this level is achieved in any individual recipient. Immunosuppression regimens vary between individual centers and changes with time as new agents and data are available. Presently concerns about the adverse side effects of calcineurin inhibitor, the main class of immunosuppressive agents used in liver transplantation (LT), has led to consideration of the use of antibody induction therapies for patients at higher risk of developing adverse side effects. The longevity of the transplanted organ is potentially improved by better management of rejection episodes and special consideration for tailoring of immunosuppression to the individual with viral hepatitis C, hepatocellular carcinoma or pregnancy. This review provides an overview of the current strategies for post LT immunosuppression and discusses modifications to consider for special patient populations.

Hepatitis C: New challenges in liver transplantation

In an era of great achievements in liver transplantation, hepatitis C viral infection (HCV) remains an unsolved problem. As a leading indication for liver transplantation in Western countries, HCV poses a significant burden both before and after transplantation. Post-transplant disease recurrence occurs in nearly all patients with detectable pretransplant viremia, compromising the lifesaving significance of transplantation. Many factors involving the donor, recipient and virus have been evaluated throughout the literature, although few have been fully elucidated and implemented in actual clinical practice. Antiviral therapy has been recognized as a cornerstone of HCV infection control; however, experience and success are diminished following transplantation in a challenging cohort of patients with liver cirrhosis. Current therapeutic protocols surpass those used previously, both in sustained viral response and side-effect profile. In this article we review the most relevant and contemporary scientific evidence regarding hepatitis C infection and liver transplantation, with special attention dedicated to novel, more efficient and safer antiviral regimens.

Interactions between virus-related factors and post-transplant ascites in patients with hepatitis C and no cirrhosis: role of cryoglobulinemia

Refractory ascites may appear in liver transplant recipients with recurrence of hepatitis C virus infection, even in the absence of advanced fibrosis. The mechanisms are unclear. The aim was to determine whether post-transplant cryoglobulinemia could be a predisposing factor for ascites in this population. Retrospective data of 82 liver transplant recipients with HCV recurrence surviving more than 1 year were collected. Cryoglobulinemia was systematically tested after transplantation. All patients had 1-year protocol biopsy with assessment of sinusoidal distension, perisinusoidal fibrosis, and centrolobular necrosis. Additional biopsies were performed when needed. Fourteen of 82 patients (17%) developed refractory ascites. When ascites appeared, fibrosis was stage F0-F1 in 36% and F2-F3 in 57%. Factors independently associated with post-transplant ascites were pretransplant refractory ascites (P = 0.001), fibrosis ≥stage 2 at 1 year (P = 0.002), perisinusoidal fibrosis at 1 year (P = 0.02), and positive cryoglobulinemia (P = 0.02). Patients with ascites had a significantly worse prognosis compared to those without ascites. Refractory ascites may occur in liver transplant recipients with HCV recurrence in the absence of advanced fibrosis. The finding that both positive cryoglobulinemia and perisinusoidal fibrosis at 1 year were significantly associated with ascites suggests that liver microangiopathy is involved in the mechanisms of HCV-related ascites.

Aspirin may reduce liver fibrosis progression: Evidence from a multicenter retrospective study of recurrent hepatitis C after liver transplantation

BACKGROUND AND AIMS

There is evidence for an association between thrombosis in the hepatic microcirculation and liver fibrosis. The aim of this study was to evaluate the role of daily low-dose aspirin (75 or 100mg, given for prevention of hepatic artery thrombosis) in fibrosis progression to ≥ F2 fibrosis score in liver-transplant recipients with recurrent hepatitis C virus (HCV).

METHODS

All HCV-positive patients who had undergone liver transplantation (LT) between 2000 and 2010 were included. Exclusion criteria were negative HCV RNA, previous LT or death within a year of LT. Liver fibrosis was assessed by histological evaluation. Data were censored at the date of the last histological evaluation before starting anti HCV therapy. Progression to fibrosis F ≥ 2 was analyzed with a multistate model with time-dependent covariables.

RESULTS

One hundred and eighty-eight patients were included. In univariate analysis, older recipient and donor age, male donor gender, activity score ≥ A2 after LT, number of steroid boluses and aspirin intake (HR: 0.75 [0.57-0.97]; P=0.03) influenced the risk of progression to fibrosis ≥ F2. In multivariate analysis, adjusted on site, older donor age, male donor gender, activity score ≥ A2 and number of steroids boluses, remained independent predictors of fibrosis progression, while younger recipient age and aspirin intake (HR: 0.65 [0.47-0.91]; P=0.01) were associated with a slower fibrosis progression.

CONCLUSION

Low-dose aspirin treatment might be associated with a lower risk of liver fibrosis progression in patients with HCV recurrence after LT.

REFINE: a randomized trial comparing cyclosporine A and tacrolimus on fibrosis after liver transplantation for hepatitis C

REFINE was a 12-month, prospective, open-label study in 356 patients receiving de novo liver transplantation for hepatitis C virus (HCV) cirrhosis, randomized to cyclosporine A (CsA) or tacrolimus with (i) no steroids, IL-2 receptor antibody induction and mycophenolic acid, or (ii) slow steroid tapering. The primary analysis population based on availability of liver biopsies comprised 165 patients (88 CsA, 77 tacrolimus). There was no difference in the primary endpoint, fibrosis stage ≥2 at 12 months, which occurred in 63/88 CsA-treated patients (71.6%) and 52/77 tacrolimus-treated patients (67.5%) (odds ratio [OR] 1.11; 95% CI 0.56, 2.21; p = 0.759). Similarly, no significant between-group difference occurred at month 24 (OR 1.15; 95% CI 0.47, 2.80; p = 0.767). Among steroid-free patients, fibrosis score ≥2 was significantly less frequent with CsA versus tacrolimus at month 12 (7/37 [18.9%] vs. 16/38 [42.1%]; p = 0.029). HCV viral load was similar in both the tacrolimus- and CsA-treated cohorts. Mean blood glucose was significantly higher with tacrolimus from day 15 onward. Biopsy-proven acute rejection, graft loss and death were similar. These results showed no differences in posttransplant HCV-induced liver fibrosis between patients treated with CsA or tacrolimus in steroid-containing regimens, whereas CsA in steroid-free protocols was associated with reduced severity of fibrosis progression at 1 year posttransplant.