[HLA-B58.01 and allopurinol hypersensitivity renal vasculitis in a Chinese patient]. / HLA-B58.01 et vascularite rénale d'hypersensibilité à l'allopurinol chez un patient chinois.

INTRODUCTION: Allopurinol, widely used in the treatment of hyperuricemia and gout, has been shown to cause severe cutaneous reactions, including Stevens-Johnson syndrome and toxic epidermal necrolysis, as well as systemic reactions such as DRESS (Drug Reaction with Eosinophilia and Systemic Symptoms). The HLA-B*5801 allele is known to be a risk factor for severe cutaneous manifestations of hypersensitivity to allopurinol, mostly in Asian populations. OBSERVATION: We report the observation of a 47-year-old Chinese patient, with no previous medical history, carrying the HLA-B*5801 allele, who developed an isolated allopurinol hypersensitivity necrotizing renal vasculitis without cutaneous manifestations. DISCUSSION: . The identification of this allele should be proposed before prescribing allopurinol in patients originating from certain regions of Asia, and the imputability of allopurinol should be evoked in case of necrotizing renal vasculitis, even without associated cutaneous involvement.

HLA-G*01:04∼UTR3 Recipient Correlates With Lower Survival and Higher Frequency of Chronic Rejection After Lung Transplantation.

Lung transplantation (LTx) is a valid therapeutic option for selected patients with end-stage lung disease. Soluble HLA-G (sHLA-G) has been associated with increased graft survival and decreased rejection episodes in solid organ transplantation. HLA-G haplotypes named UTRs, defined by SNPs from both the 5'URR and 3'UTR, have been reported to reliably predict sHLA-G level. The aim of this retrospective study was to determine the impact of HLA-G alleles and UTR polymorphism from LTx recipients on anti-HLA allo-immunization risk, overall survival and chronic rejection (CLAD). HLA-G SNPs were genotyped in 124 recipients who underwent LTx from 1996 to 2010 in Marseille, 123 healthy individuals and 26 cystic fibrosis patients not requiring LTx. sHLA-G levels were measured for 38 LTx patients at D0, M3 and M12 and for 123 healthy donors. HLA-G*01:06∼UTR2 was associated with a worse evolution of cystic fibrosis (p = 0.005) but not of long-term survival post-LTx. HLA-G*01:04∼UTR3 haplotype was associated with lower levels of sHLA-G at D0 and M3 (p = 0.03), impaired long-term survival (p = 0.001), increased CLAD occurrence (p = 0.03) and the production of de novo donor-specific antibodies (DSA) at M3 (p = 0.01). This study is the first to show the deleterious association of different HLA-G alleles and UTRs in LTx.

[Platelet allo-antibodies identification strategies for preventing and managing platelet refractoriness]. / Stratégies d'exploration de l'allo-immunisation plaquettaire pour la prévention et la prise en charge des inefficacités transfusionnelles plaquettaires.

Platelet refractoriness is a serious complication for patients receiving recurrent platelet transfusions, which can be explained by non-immune and immune causes. Human Leukocyte Antigens (HLA) allo-immunization, especially against HLA class I, is the major cause for immune platelet refractoriness. To a lesser extent, allo-antibodies against specific Human Platelet Antigen (HPA) are also involved. Pregnancy, transplantation and previous transfusions can lead to allo-immune reaction against platelet antigens. After transfusion, platelet count is decreased by accelerated platelet destruction related to antibodies fixation on incompatible platelet antigens. New laboratory tests for allo-antibodies identification were developed to improve sensibility and specificity, especially with the LUMINEX(®) technology. The good use and interpretation of these antibodies assays can improve strategies for platelet refractoriness prevention and management with a patient adapted response. Compatible platelets units can be selected according to their identity with recipient typing or immune compatibility regarding HLA or HPA antibodies or HLA epitope compatibility. Prospective studies are needed to further confirm the clinical benefit of new allo-antibodies identification methods and consensus strategies for immune platelet refractoriness management.

Linkage disequilibrium between HLA-G*0104 and HLA-E*0103 alleles in Tswa Pygmies.

Nonclassical human leukocyte antigen (HLA)-G and -E loci are separated by approximately 660 kb on the short arm of chromosome 6. Interestingly, some functional and expression characteristics are relatively identical or associated for both molecules. For example, expression of HLA-E on the cell surface has been linked to preferential binding of nonameric leader peptides derived from the signal sequence of HLA-G. It has been suggested that these two molecules act synergistically in modulating susceptibility to infectious or chronic inflammatory diseases. A possible explanation for these observations is that HLA-E and HLA-G are evolving under analogous selective pressures and have functions that place them under selective regimes differing from classical HLA genes. The purpose of this study was to investigate the consistency of this hypothesis based on the characterization of the molecular polymorphism of these two genes and their linkage disequilibrium (LD) in three populations, i.e. Southeastern French (n = 57), Teke Congolese (n = 84) and Tswa Pygmies (n = 74). Allelic frequencies observed for HLA-G and HLA-E and for 14-bp ins/del polymorphism in the three populations were similar to those observed in the literature for populations from corresponding geographic areas. Only one of the recently described HLA-G polymorphisms (HLA-G*01:07-01:16) was found, i.e. HLA-G*01:15 in one individual from Congo. We showed that two haplotypes in Tswa Pygmies, i.e. HLA-G*01:04-E*01:03:01 and G*01:04-E*01:01, exhibited highly significant positive and negative D' values respectively. Although these LD could have functional implications, it is more likely because of the genetic drift as the two other populations did not display any significant LD.

A hierarchical analysis of transcriptome alterations in intrauterine growth restriction (IUGR) reveals common pathophysiological pathways in mammals.

Intra-uterine growth restriction (IUGR) is a frequent disease, affecting up to 10% of human pregnancies and responsible for increased perinatal morbidity and mortality. Moreover, low birth weight is an important cause of the metabolic syndrome in the adult. Protein depletion during the gestation of rat females has been widely used as a model for human IUGR. By transcriptome analysis of control and protein-deprived rat placentas, we were able to identify 2543 transcripts modified more than 2.5 fold (1347 induced and 1196 repressed). Automatic functional classification enabled us to identify clusters of induced genes affecting chromosome structure, transcription, intracellular transport, protein modifications and apoptosis. In particular, we suggest the existence of a complex balance regulating apoptosis. Among repressed genes, we noted several groups of genes involved in immunity, signalling and degradation of noxious chemicals. These observations suggest that IUGR placentas have a decreased resistance to external aggression. The promoters of the most induced and most repressed genes were contrasted for their composition in putative transcription factor binding sites. There was an over-representation of Zn finger (ZNF) proteins and Pdx1 (pancreatic and duodenal homeobox protein 1) putative binding sites. Consistently, Pdx1 and a high proportion of ZNF genes were induced at the transcriptional level. A similar analysis of ZNF promoters showed an increased presence of putative binding sites for the Tata box binding protein (Tbp). Consistently again, we showed that the Tbp and TBP-associated factors (Tafs) were up-regulated in IUGR placentas. Also, samples of human IUGR and control placentas showed that human orthologous ZNFs and PDX1 were transcriptionally induced, especially in non-vascular IUGR. Immunohistochemistry revealed increased expression of PDX1 in IUGR human placentas. In conclusion, our approach permitted the proposition of hypotheses on a hierarchy of gene inductions/repressions leading to massive transcriptional alterations in the IUGR placenta, in humans and in rodents.

The imbalance between circulating endothelial cells and progenitors in cardiovascular diseases: a mirror of disrupted endothelial integrity.

The disruption of endothelial integrity is at the crossroads of the initiation and progression of multiple cardiovascular diseases pathophysiology. During these last years, it has been evidenced that endothelium is a highly dynamic tissue in equilibrium with a circulating compartment composed of various sub-populations offering important opportunities for a non-invasive exploration. Among these, circulating endothelial cells (CEC) are mature cells detached from injured vessels. Rarely found in blood in the health, CEC number is raised in a wide variety of pathological conditions associated with profound vascular insult. An additional population are the endothelial progenitor cells derived from bone marrow and characterised by their ability to participate in endothelial repair. Reduced number and impaired function of EPC have been related to situations with increased cardiovascular risk or to clinical atherosclerotic diseases. This review will focus on present data concerning CEC and endothelial cells and progenitors (PEC) in the setting of cardiovascular diseases. Particular emphasis will be given on the clinical value of these endothelial biomarkers to monitor endothelial homeostasis depending on the balance between endothelial injury and repair.