Although OATP1B1 is not expressed in the kidney, polymorphisms in SLCO1B1 have been associated with methotrexate clearance or toxicity. This unexpected pharmacogenetic association may reflect remote communication between liver and kidney transporters. This study confirms the pharmacogenetic association with methotrexate toxicity in adult patients with hematological malignancies. Using a targeted urinary metabolomics approach, we identified 38 and 34 metabolites which were differentially excreted between wildtype and carriers of the c.388A>G or c.521T>C variant alleles, respectively, half of them being associated with methotrexate toxicity. These metabolites mainly consisted of fatty acid derivatives and microbiota catabolites, including glycine conjugates and other uremic toxins, all known OATs substrates. These results suggest that dysfunction of a transporter affects the excretion profile of endogenous or exogenous substrates, possibly through metabolite-mediated interactions involving other transport systems, even in distant organs. This opens the way for better comprehension of complex pharmacokinetics and transporter-mediated drug-drug or nutrient-drug interactions.

We report 4 bloodstream infections associated with CC9 agr type II Staphylococcus aureus in individuals without animal exposure. We demonstrate, by microarray analysis, the presence of egc cluster, fnbA, cap operon, lukS, set2, set12, splE, splD, sak, epiD, and can, genomic features associated with a high virulence potential in humans.

Patients with an inherited autosomal-dominant disorder, capillary malformation-arteriovenous malformation (CM-AVM), frequently have mutations in Ras P21 protein activator 1 (RASA1). The aims of this study were to determine the prevalence of germline RASA1 variants in a French multicentre national cohort of children, age range 2-12 years, with sporadic occurrence of capillary malformation (CM) of the legs, whatever the associated abnormalities, and to identify genotype-phenotype correlates. DNA was extracted from leukocytes in blood samples, purified and amplified, and all exons of the RASA1 gene were analysed. Among 113 children analysed, 7 had heterozygous variants (6.1%). Four different variants were identified; 2 were new. In children with RASA1 variants, CMs were more frequently bilateral and multifocal. In conclusion, RASA1 variants are rarely found in children with sporadic CM of lower limbs without CM-AVM syndrome. CMs in this study were heterogeneous, and no disease-causing relationship could be proven.