M. Mantovani

A prospective policy development to increase split-liver transplantation for 2 adult recipients: Results of a 12-year multicenter collaborative study

Objective:To analyze in a multicenter study the potential benefit of a new prospective policy development to increase split-liver procedures for 2 adult recipients. Background:Split-liver transplantation is an important means of overcoming organ shortages. Division of the donor liver for 1 adult and 1 pediatric recipient has reduced the mortality of children waiting for liver transplantation but the benefits or disadvantages to survival when the liver is divided for 2 adults (adult-to-adult split-liver transplant, AASLT) compared with recipients of a whole graft have not been fully investigated. Methods:We developed a computerized algorithm in selected donors for 2 adult recipients and applied it prospectively over a 12-year period among 7 collaborative centers. Patient and graft outcomes of this cohort receiving AASLT either as full right grafts or full left grafts were analyzed and retrospectively compared with a matched cohort of adults who received a conventional whole-liver transplant (WLT). Univariate and multivariate analysis was done for selected clinical variables in the AASLT group to assess the impact on the patient outcome. Results:Sixty-four patients who received the AASLT had a high postoperative complication rate (64.1% grade III and IV) and a lower 5-year survival rate than recipients of a WLT (63.3% and 83.1%) Conclusions:AASLT should be considered a surgical option for selected smaller-sized adults only in experimental clinical studies in experienced centers.

Interaction between calcineurin inhibitors and IL-28B rs12979860 C>T polymorphism and response to treatment for post-transplant recurrent hepatitis C

BACKGROUND The impact of calcineurin inhibitors on achievement of sustained virological response to antiviral therapy for post-transplant recurrent hepatitis C is controversial. This study aimed at investigating the interactions between calcineurin inhibitors and interleukin-28B (IL-28B) gene polymorphisms and sustained virological response. METHODS Retrospective study of 147 liver transplant recipients with recurrent hepatitis C, who received 48 weeks of peg-interferon-α (N=113) or standard interferon (N=34), in association with ribavirin. Cyclosporine and tacrolimus were administered in 68 and 79 patients, respectively. IL-28B rs12979860 allele frequency was assessed in both donors and recipients. RESULTS Overall, 57 patients (38.8%) obtained sustained virological response; no difference was found between cyclosporine and tacrolimus-treated patients (42.6% vs. 35.4%, p=0.371). Recipient and donor IL-28B genotypic frequencies were C/C=30.6%, C/T=51.7%, T/T=17.7% and C/C=44.9%, C/T=50.3%, T/T=4.8%, respectively. Combining donor and recipient alleles, response rates decreased from cyclosporine-treated patients carrying ≤ 1 T allele (56.1%) to tacrolimus-treated patients carrying ≤ 1 T allele (44.7%) to patients carrying ≥ 2 T alleles (25.0%, p=0.0009). CONCLUSIONS Donor and recipient rs12979860 alleles synergistically influence sustained virological response rate to antiviral treatment for recurrent hepatitis C. In patients carrying <2 T alleles cyclosporine favours a better response than tacrolimus, while no difference was found in the presence of ≥ 2 T alleles.

A new approach to safely type for HLA the HIV infected people eligible to abacavir therapy: saliva or buccal swab as reliable DNA sources.

BACKGROUND Increasing the safety in Immunogenetics Labs, in the era of antiretroviral pharmacogenomics, represents an imperative goal. To this purpose, we tested saliva and buccal cells as biological sources of DNA, alternative to peripheral blood, for HLA-B*57:01 genomic typing of HIV positive patients eligible to treatment with abacavir. METHODS Blood, saliva and buccal cells of 20 voluntary donors and 20 HIV positive patients were collected. DNA was extracted with a manual commercial kit and an automated platform. Quality and quantity of DNA was evaluated with different procedures. The suitability and reliability of DNAs for HLA-B*57:01 genotyping was checked at low and high resolution level, using PCR-SSP (sequence specific primers PCR), revPCR-SSO (reverse sequence specific oligonucleotides PCR), bead array and SBT (sequence based typing) techniques. RESULTS DNA concentrations were qualitatively very good and quantitatively comparable in all the specimens tested with an inferior yield for cotton swabs. Comparing the results of HLA typing with different methodologies, the 100% of reproducibility was achieved. CONCLUSIONS The viral load of buccal epithelial cells or saliva is extremely low. Here we demonstrated that the DNA from these alternative sources is appropriate for HLA-B*57:01 typing. We strongly recommend the use of this procedure to increase the safety in the lab when dealing with infectious samples.

Description of the new allele HLA-DQB1*04:03:02.

A new variant of HLA‐DQB1*04:03 allele officially designated as HLA‐DQB1*04:03:02 was detected in two unrelated Caucasoid individuals by polymerase chain reaction‐sequence‐specific primers and SBT. The new allele nucleotide sequence differs from HLA‐DQB1*04:03:01 for a single silent point mutation in exon 2 at position 159, codon 21.

Three novel alleles at the HLA-DRB1 locus identified by sequence-based typing.

We describe here the sequences of 3 new HLA-DRB1 variants officially named DRB1*03:05:03, DRB1*11:10:02, and DRB1*14:86. These novel alleles have been detected in 3 Caucasoid individuals by sequence-based typing. The first and second alleles are the result of a silent mutation, which does not imply any amino acid change. The sequence of DRB1*14:86 exhibits a single nucleotide difference with the allele DRB1*14:01:01 at position 239.

Description and molecular modeling of a novel human leukocyte antigen allele: A*32:22

We describe here the sequence and the molecular modeling of a new variant of HLA-A*32 allele officially named A*32:22. This novel allele has been detected in an Italian cord blood sample by sequence-based typing (SBT). The mutation (CAT →CGT), which has occurred at codon 151, at nucleotide position 524, implies an amino acidic change from Histidine to Arginine. Residue 151 is located on top of the molecule inside the region contacted by T cell receptor (TCR) and it is possibly involved in docking TCR. A positively charged residue is maintained on this position determining a slight change of electrostatic potential on the molecular surface. This suggests a limited functional relevance of the amino acid substitution encoded by A*32:22.

Molecular modelling of HLA-B*35:132.

Here we describe the molecular modelling of the new variant HLA‐B*35:132. This allele shows one mismatch with B*35:01:01:01 in exon 3 at position 575 where a T is substituted by a C, which implies an amino acidic change from Leucine to Proline. This seems not to alter the molecular structure and not to compromise the HLA complex and T‐cell receptor interaction.

Two novel alleles at HLA-B locus identified in two volunteer bone marrow donors by sequence-based typing.

Two novel human leucocyte antigen (HLA) class I alleles have been identified in two Italian individuals. HLA‐B*27:07:02 is identical to HLA‐B*27:07:01 except for a nucleotide substitution at position 846 (A‐>G) resulting in a silent mutation. HLA‐B*35:206 differs from the most similar allele, HLA‐B*35:08:01, because of a single base mutation at position 149 (G‐>C) causing an aminoacidic change at codon 26 from Gly to Ala.

Identification of two novel HLA‐A alleles: A*24:199 and A*02:324

Here, we describe two new HLA‐A alleles: A*24:199 and A*02:324. The two new variants are attributed to a single nucleotide mutation namely A→C for A*24:199 and G→A for A*02:324. Both point mutations are responsible for a change in translated amino acids.

Description of the novel HLA-DPB1*137:01 allele found in an Italian subject

In this report, we describe the identification and sequencing of a novel HLA‐DPB1 allele, found in an Italian haematological patient. This allele is identical to DPB1*17:01 except for a single nucleotide substitution (GAC→GAG) at position 57, which changes the encoded amino acid from Asp to Glu.