Search PubMed⌕ Search

Biomedical subjects

Valérie Dubois

Publications and source records attributed to Valérie Dubois.

3 recordsLinked to original sources

Donor HLA Class I Evolutionary Divergence and Late Allograft Rejection After Liver Transplantation in Children: An Emulated Target Trial.

HLA evolutionary divergence (HED), a continuous metric quantifying the differences between each amino acid of two homologous HLA alleles, reflects the importance of the immunopeptidome presented to T lymphocytes. It has been associated with rejection after liver transplantation. This retrospective cohort study aimed to analyse the potential effect of donor or recipient HED on liver transplant rejection in a new series of patients transplanted during childhood and followed in adulthood. The study included 120 children who had been transplanted between 1991 and 2010 and were followed by routine biopsies and histological evaluations with a median of 14.1 years post-LT. Liver biopsies were performed routinely 1, 5, 10 and 20 years after transplantation and in the event of liver dysfunction. HED was calculated using the physicochemical Grantham distance for donor and recipient Class I (HLA-A, -B, -C) and Class II (HLA-DRB1, -DQB1) alleles. The influence of HED on rejection was analysed using inverse probability weighting (IPW) and target trial emulation using the g method. Based on the IPW score, donor HED class I was correlated with the occurrence of late (> 90 days) rejection (HR, 1.19, 95% CI: 1.01-1.40) independently of HLA mismatches, donor age and initial induction. The emulated target trial confirmed that donor HED Class I has a causal effect on liver graft rejection and this relationship was observed long-term.

Humans↗

Guidelines From the French-Speaking Society for Histocompatibility and Immunogenetics (SFHI) for Harmonisation of HLA Genotyping in Autoimmune Diseases, Drug Hypersensitivity and Pharmacogenetics.

HLA molecules play a central role in the adaptive immune response. Their high polymorphism influences individual susceptibility to various autoimmune diseases and certain drug-induced hypersensitivities. In France, HLA genotyping is classified as a medical genetics procedure and is strictly regulated. The Société Francophone d'Histocompatibilité et d'Immunogénétique (SFHI) has established national guidelines outlining clinically validated indications, required resolution levels and interpretation criteria based on robust data. These guidelines are particularly relevant for common clinical contexts, including autoimmune diseases and pharmacogenetic testing. Well-established associations include HLA-DQB1*02/DQA1*05 (DQ2) and HLA-DQB1*03:02/DQA1*05 (DQ8) with celiac disease, HLA-B*27 with spondyloarthritis, HLA-DQB1*06:02 with type 1 narcolepsy, HLA-A*29 with Birdshot chorioretinopathy and several pharmacogenetic risk alleles such as HLA-B*57:01 (abacavir), HLA-B*15:02 and HLA-A*31:01 (carbamazepine) and HLA-B*58:01 (allopurinol). In immunotherapy, the efficacy of tebentafusp has been shown to depend on HLA-A*02:01 positivity. HLA alleles must be interpreted as relative risk factors, not absolute predictors. Critical analysis of HLA-related scientific literature requires consideration of the genotyping technique, typing resolution, allele frequencies within the studied population and environmental factors. High-resolution typing is essential in pharmacogenetics and recommended in selected autoimmune disorders. Interpretation should be conducted by qualified medical biologists, integrating clinical context, allelic diversity and recent technological advances, particularly next-generation sequencing. HLA genotyping represents a valuable tool in diagnosis and risk assessment, with increasing importance in the era of personalised medicine.

Humans↗