Post-liver transplantation graft biopsies should not be used to assess the IL28B donor genotype in HCV recipients
Authors: Maria Francesca Donato, Enrico Galmozzi, Cristina Rigamonti, Alessio Aghemo
Journal: Journal of Hepatology (2012)

Determination of IL28B polymorphisms in liver biopsies obtained after liver transplantationJournal of HepatologyVol. 56Issue 2PreviewRecipient and donor IL28B polymorphisms seem to play an important role in the response to hepatitis C treatment after liver transplantation (LT). Since donor peripheral blood mononuclear cells (PBMC) are not always available, the aim of our study was to assess whether follow-up biopsies obtained after LT could be used to determine donor IL28B genotype. Full-Text PDF We read with interest the article by Coto-Llerena et al. [[1]Coto-Llerena M. Crespo G. Gonzalez P. Koutsoudakis G. Miquel R. Navasa M. et al.Determination of IL28B polymorphisms in liver biopsies obtained after liver transplantation.J Hepatol. 2012; 56: 355-358Abstract Full Text Full Text PDF PubMed Scopus (17) Google Scholar] showing that the determination of the donor interleukin 28B (IL28B) genotype on post-liver transplantation (LT) graft biopsies carries a high risk of misclassification, as it adds to the current debate on the clinical role of this test in LT patients. Indeed, following LT it is still somewhat unclear whether the donor, the recipient or the combination of the two IL28B genotypes is actually associated with the achievement of a sustained virological response (SVR) after interferon (IFN)-based treatment in HCV patients [2Fukuhara T. Taketomi A. Motomura T. Okano S. Ninomiya A. Abe T. et al.Variants in IL28B in liver recipients and donors correlate with response to peg-interferon and ribavirin therapy for recurrent hepatitis C.Gastroenterology. 2010; 139: 1577-1585Abstract Full Text Full Text PDF PubMed Scopus (197) Google Scholar, 3Charlton M.R. Thompson A. Veldt B.J. Watt K. Tillmann H. Poterucha J.J. et al.Interleukin-28B polymorphisms are associated with histological recurrence and treatment response following liver transplantation in patients with hepatitis C virus infection.Hepatology. 2011; 53: 317-324Crossref PubMed Scopus (198) Google Scholar, 4Lange C.M. Moradpour D. Doehring A. Lehr H.A. Müllhaupt B. Bibert S. et al.Impact of donor and recipient IL28B rs 12979860 genotypes on hepatitis C virus liver graft reinfection.J Hepatol. 2011; 55: 322-327Abstract Full Text Full Text PDF PubMed Scopus (110) Google Scholar, 5Coto-Llerena M. Perez-del-Pulgar S. Crespo G. Carrión J.A. Martínez S.M. Sánchez-Tapias J.M. et al.Donor and recipients IL28B polymorphisms in HCV-infected patients undergoing antiviral therapy before and after liver transplantation.Am J Transplant. 2011; 11: 1051-1057Crossref PubMed Scopus (83) Google Scholar, 6Eurich D. Boas-Knoop S. Ruehl M. Schulz M. Carrillo E.D. Berg T. et al.Relationship between the Interleuchin-28B gene polymorphism and the histological severity hepatitis C virus-induced graft inflammation and the response to antiviral therapy after liver transplantation.Liver Transpl. 2011; 17: 289-298Crossref PubMed Scopus (65) Google Scholar]. Clearing this matter would have important clinical implications, especially since IL28B genotyping of the recipient can be easily performed by DNA extraction from the blood, while on the other hand, given that donor blood is not always routinely available for clinical use, donor DNA needs to be extracted from formalin-fixed paraffin embedded (FFPE) liver tissue specimens obtained before, during or after LT. Although this is feasible from a technical standpoint, no study has shown whether the IL28B genotype obtained matches that obtained from peripheral blood mononuclear cells (PBMC). For this matter, the authors analyzed the IL28B rs12979860 donor genotype, by TaqMan real-time PCR and direct sequencing, in 56 HCV-infected LT recipients and their donors, in PBMCs and/or liver biopsies obtained at the moment of LT (reperfusion) or at any time during post-transplant follow-up. Overall, IL28B rs12979860 genotyping was successful in up to 98% of samples. The authors report a 100% match in IL28B genotype between donor PBMC and reperfusion biopsies in 36 out of 56 patients studied, while, they found a high rate of discordant results between IL28B genotype in donor PBMC or reperfusion liver biopsies compared to post-transplant liver biopsy specimens. To externally validate these findings, we analyzed the IL28B genotype of 39 liver donors by comparing DNA extracted from donor PBMC and FFPE or snap frozen post-transplant follow-up liver biopsies. IL28B rs12979860 genotyping was performed by TaqMan real-time PCR, and confirmed by Tetra-primers Amplification Refractory Mutation System (T-ARMS) PCR [[7]Galmozzi E. Del Menico B. Rametta R. Dongiovanni P. Fracanzani A.L. Benedan L. et al.A tetra-primer amplification refractory mutation system polymerase chain reaction for evaluation of rs12979860 IL28B genotype.J Viral Hepat. 2011; 9: 628-630Crossref Scopus (26) Google Scholar]. As shown in Fig. 1, we replicate Coto-Llerena’s findings, since overall in 39% of cases there was a mismatch between IL28B genotype obtained in PBMCs and post-LT liver biopsies. Moreover, similar mismatch rates were found when IL28B genotype was tested from DNA extracted from snap frozen or FFPE follow-up liver biopsies (36% vs. 45%, p = 0.55). Our data therefore show that, independently from the source used to extract DNA, the use of follow-up biopsies should be discouraged as a routine test to determine donor IL28B genotype due to an extremely high mismatch rate. The authors declared that they do not have anything to disclose regarding funding or conflict of interest with respect to this manuscript. The authors thank the Nord Italian Transplant Program (NITp) for the donor blood samples.