Kaushik Agarwal

Chronic ductopenic rejection in patients with recurrent hepatitis C virus treated with pegylated interferon alfa-2a and ribavirin

Background. Interferon use for post liver transplantation (LT) recurrent hepatitis C (HCV) has not consistently been associated with acute cellular rejection (ACR). We examined the incidence of chronic ductopenic rejection (CR) in patients receiving pegylated interferon alfa-2a and ribavirin (PEG) to treat recurrent HCV. Methods. A chart review of 12 patients developing CR while receiving an escalating dose regimen of PEG with protocol liver biopsies every 6 months was conducted. Values are shown as median (range). Results. Twelve of the 70 patients treated with PEG developed CR. Median age at LT was 53 (37–63) years; immunosuppression consisted of tacrolimus or cyclosporine with prednisone. PEG was started at 3.6 (0.2–13.5) years after LT. Two patients had one episode of ACR before PEG. Four patients had first ACR while receiving PEG. CR was diagnosed after 12 (4–17) months of PEG; by then 8 patients had undetectable HCV-RNA. Tacrolimus and cyclosporine levels (ng/mL) were 7.9 (3.2–18.9) and 76 (71–93) before PEG, and 6.9 (3.7–9.7) and 130 (81–153) at CR. Six patients were treated more than 1 year with PEG; three had undetectable HCV-RNA when CR was diagnosed. Five patients are being treated for CR; one has been listed for LT; two patients were retransplanted. Five patients died as a result of sepsis partially related to CR. Conclusions. Treatment with pegylated-interferon alpha-2a and ribavirin may trigger rapidly progressive CR in patients with therapeutic immunosuppressive trough levels, with or without first inducing ACR.

Polymorphisms in the T cell regulatory gene cytotoxic T lymphocyte antigen 4 influence the rate of acute rejection after liver transplantation

Background: The cytotoxic T lymphocyte antigen 4 (CTLA-4) gene encodes for a membrane bound (mCTLA-4) and a soluble (sCTLA-4) isoform, which are both involved in regulation of T cell function. The CTLA-4 +49A/G single nucleotide polymorphism (SNP) influences expression of mCTLA-4; +6230G/A SNP affects the production of sCTLA-4. Aim: To examine whether these functional SNPs influence the rate of rejection after liver transplantation. Patients and methods: Liver graft recipients (n = 483) were genotyped for both SNPs, and haplotypes were reconstructed. Association with rejection was tested by the log rank test using the Kaplan-Meier method with time to the first acute rejection episode as outcome. Multiple analysis of SNPs together with demographic factors was performed by Cox regression. Results: Three haplotypes were observed in the cohort: +49A/+6230A, +49A/+6230G, and +49G/+6230G. The +49A/+6230G haplotype was significantly and dose dependently associated with acute rejection (p = 0.01). Of the demographic factors tested, only underlying liver disease was significantly associated with rejection. Adjusted for underlying liver disease, each additional +49A/+6230G haplotype allele resulted in a significantly higher risk of acute rejection (risk ratio 1.34 (95% confidence interval 1.04–1.72); p = 0.02). Patients who lacked this haplotype had the lowest, carriers an intermediate, and homozygotes the highest risk of acute rejection. Conclusion: The CTLA-4 +49A/+6230G haplotype, which encodes for normal mCTLA-4 expression but reduced sCTLA-4 production, is a co-dominant risk allele for acute rejection after clinical liver transplantation. This implies that even under immunosuppression, CTLA-4 is critically involved in the regulation of the human immune response to allogeneic grafts.

Immunohistochemical assessment of hepatitis C virus antigen in cholestatic hepatitis after liver transplantation

Background: Patients with common variable immunodeficiency may exhibit rapidly progressive hepatitis when infected with hepatitis C virus (HCV), leading to cirrhosis and liver failure. Liver transplantation in these patients may result in a cholestatic form of HCV reinfection with exceptionally high virus loads. Aims: To report an immunohistochemical investigation of the pretransplant and post-transplant liver of one such patient. Methods/Results: On immunohistochemical staining of frozen sections with anti-HCV core monoclonal antibody or fluorescein labelled human polyclonal anti-HCV IgG, no HCV antigens were demonstrated in the native cirrhotic liver removed at transplant, despite a viral load of 106.4 genomes/g. The transplanted liver, collected six weeks post-transplant, exhibited cholestatic recurrent hepatitis, had an HCV virus load of 1010 genomes/g of liver, and revealed HCV antigen in the cytoplasm of most hepatocytes, with a pronounced periportal distribution. No virus antigen was demonstrable in other cell types. The core antigen was also detected in paraffin wax embedded, formaldehyde fixed tissue of this liver after high temperature antigen retrieval, but not in the native cirrhotic liver or a selection of HCV positive livers collected pretransplant from immunocompetent patients. Attempts to delineate the distribution of E1, NS3, and NS4 antigens were unsuccessful because monoclonal antibodies to these antigens produced “false positive” staining of foci of hepatocytes in the post-transplant livers of HCV seronegative patients with cholestasis. Conclusion: This case provided an opportunity to study the natural development of HCV during acute infection in the absence of an immune response, and may help to elucidate the pathogenesis of HCV recurrence in liver allografts.

The use of drotrecogin alfa (activated) in a patient with recent orthotopic liver transplant

Drotrecogin alfa has been shown to reduce mortality in severe sepsis. However, it remains unlicensed for use in patients with previous liver transplantation. We report its use in such a case. Prior to administration a risk benefit analysis was performed in line with General Medical Council recommendations. This included being satisfied that no appropriately licensed alternative would better serve the patients needs and that sufficient evidence existed to demonstrate the safety and efficacy of the drug. Responsibility was taken for prescription, monitoring and follow up. The process was carefully documented and the patient recovered fully with no adverse effects. To date the only published data on the use of drotrecogin alpha in transplant recipients is a case series of three patients. Further published data may encourage review of the licence.