Comparing HLA Shared Epitopes in French Caucasian Patients with Scleroderma

Although many studies have analyzed HLA allele frequencies in several ethnic groups in patients with scleroderma (SSc), none has been done in French Caucasian patients and none has evaluated which one of the common amino acid sequences, 67FLEDR71, shared by HLA-DRB susceptibility alleles, or 71TRAELDT77, shared by HLA-DQB1 susceptibility alleles in SSc, was the most important to develop the disease. HLA-DRB and DQB typing was performed for a total of 468 healthy controls and 282 patients with SSc allowing FLEDR and TRAELDT analyses. Results were stratified according to patient’s clinical subtypes and autoantibody status. Moreover, standardized HLA-DRß1 and DRß5 reverse transcriptase Taqman PCR assays were developed to quantify ß1 and ß5 mRNA in 20 subjects with HLA-DRB1*15 and/or DRB1*11 haplotypes. FLEDR motif is highly associated with diffuse SSc (χ2 = 28.4, p<10−6) and with anti-topoisomerase antibody (ATA) production (χ2 = 43.9, p<10−9) whereas TRAELDT association is weaker in both subgroups (χ2 = 7.2, p = 0.027 and χ2 = 14.6, p = 0.0007 respectively). Moreover, FLEDR motif- association among patients with diffuse SSc remains significant only in ATA subgroup. The risk to develop ATA positive SSc is higher with double dose FLEDR than single dose with respectively, adjusted standardised residuals of 5.1 and 2.6. The increase in FLEDR motif is mostly due to the higher frequency of HLA-DRB1*11 and DRB1*15 haplotypes. Furthermore, FLEDR is always carried by the most abundantly expressed ß chain: ß1 in HLA DRB1*11 haplotypes and ß5 in HLA-DRB1*15 haplotypes

Male Microchimerism at High Levels in Peripheral Blood Mononuclear Cells from Women with End Stage Renal Disease before Kidney Transplantation

Patients with end stage renal diseases (ESRD) are generally tested for donor chimerism after kidney transplantation for tolerance mechanism purposes. But, to our knowledge, no data are available on natural and/or iatrogenic microchimerism (Mc), deriving from pregnancy and/or blood transfusion, acquired prior to transplantation. In this context, we tested the prevalence of male Mc using a real time PCR assay for DYS14, a Y-chromosome specific sequence, in peripheral blood mononuclear cells (PBMC) from 55 women with ESRD, prior to their first kidney transplantation, and compared them with results from 82 healthy women. Male Mc was also quantified in 5 native kidney biopsies obtained two to four years prior to blood testing and in PBMC from 8 women collected after female kidney transplantation, several years after the initial blood testing. Women with ESRD showed statistically higher frequencies (62%) and quantities (98 genome equivalent cells per million of host cells, gEq/M) of male Mc in their PBMC than healthy women (16% and 0.3 gEq/M, p<0.00001 and p = 0.0005 respectively). Male Mc was increased in women with ESRD whether they had or not a history of male pregnancy and/or of blood transfusion. Three out of five renal biopsies obtained a few years prior to the blood test also contained Mc, but no correlation could be established between earlier Mc in a kidney and later presence in PBMC. Finally, several years after female kidney transplantation, male Mc was totally cleared from PBMC in all women tested but one. This intriguing and striking initial result of natural and iatrogenic male Mc persistence in peripheral blood from women with ESRD raises several hypotheses for the possible role of these cells in renal diseases. Further studies are needed to elucidate mechanisms of recruitment and persistence of Mc in women with ESRD

Analyzing HLA-G polymorphisms in children from women with scleroderma.

International audienceEmbryos during pregnancy and organs during transplantation, express high levels of soluble HLA-G (sHLA-G) molecules for successful implantation and protection against maternal immune cells or recipient's cells. We and others have shown that women with scleroderma (SSc) carry cells/DNA arising from pregnancy, so-called fetal microchimerism (Mc) more often and in higher quantities than healthy women decades after delivery. We hypothesized that high levels of fetal Mc were the consequence of a fetus with a high sHLA-G profile, therefore that children from women with SSc would have this profile more often than children from healthy women. High sHLA-G secretor profile is influenced by at least two variations in the HLA-G 3' untranslated region (UTR): a 14 bp deletion in exon 8 and the presence of cysteine (C) in position +3142 and by one variation in the 5' Upstream Regulatory Region (URR) at position -725. By a previously developed three-step multiplex PCR SNaPshot method, we evaluated 16 HLA-G polymorphisms in DNA samples from the first-born children of 39 women with SSc and 32 healthy women. Contrary to expectations, children from women with SSc did not have a high sHLA-G profile, but rather the opposite. We discuss possible reasons for this result and future orientations for HLA-G studies in SSc

1.65 Copy number variation of TLR7 and TLR8 genes is age and sex biased: which role in autoimmunity?

International audienceBACKGROUND AND OBJECTIVES: Women, having two X chromosomes, are more predisposed than men to autoimmune diseases. The X chromosome contains many genes linked to immunity which may contribute to this gender bias. In a mouse model, a duplication of the innate immunity X-linked toll like receptor 7 (Tlr7) gene has been shown to potentiate autoimmunity in males. We then proposed to investigate whether TLR7 gene and its neighboring paralog TLR8 could have variations in their copy numbers, contributing to the pathogenesis of rheumatoid arthritis (RA) in men. METHODS: A real-time quantitative PCR protocol was developed to assess copy number variation (CNV) of TLR7 and TLR8 gene, using sensitive and optimised ΔΔCt and standard curve methods, in DNA from peripheral blood mononuclear cells of 60 patients with RA (including 49 men) and 64 healthy controls (including 42 men). Among them, 31 men with RA and 18 healthy men were further screened for TLR7/8 CNV in 4 subpopulations: B cells, T cells, granulocytes and the depleted fraction of the former 3. RESULTS: TLR7/8 copy numbers significantly increased with age in PBMCs from all men (P < 0.0001, Spearman's rank correlation test), whether they had RA or not. The increase had mean amplitude of 20%, spanning from the age of 20 until 80, according to the linear-regression-curve's best fit. This age-dependent and disease-independent CNV increase was also observed in all cell subsets. Interestingly, such increase was not observed in women, healthy or with RA, but rather an opposite trend. CONCLUSION AND PERSPECTIVES: For the first time we showed an increased CNV in TLR7 and TLR8 genes which is age and sex-mediated. Several hypotheses could explain such phenomenon. For example, somatically acquired duplications can affect some cells over time and result in an increase with age in men. In parallel, X chromosome monosomy, previously described in aging women could account for the opposite trend in those. Another explanation for men can be due to the presence of feminine microchimerism, arising from feto-maternal or twin sister exchange during in utero life, as previously described. Such cells would carry 2 X chromosomes and contribute to the increased pool of X-linked genes among XY host cells. Investigating these hypotheses would provide better understanding of age-associated X-linked genetic modifications and the role of the X chromosome in gender differences in health and disease. Abstract topicOther

Characteristics from healthy women and women with ESRD.

a<p>pregnancy and transfusion information was incomplete for one healthy woman. ns: not significant.</p

Quantification of male Mc in PBMC from 8 women with ESRD after female kidney transplantation.

*<p>GFR: glomerular filtration rate.</p><p>All patients from this table are different from patients presented <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0032248#pone-0032248-t003" target="_blank">table 3</a>, except Patient 4 who is Patient 1 in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0032248#pone-0032248-t003" target="_blank">Table 3</a>.</p

Male Mc in women with ESRD and healthy women according to pregnancy and transfusion history.

<p>TSF+: women who had received at least one blood transfusion; TSF−: women who had never received a blood transfusion; S+: women who had given birth to at least one son; S−: women who had never given birth to a son (S−);</p>*<p>no stats: statistical analyses were not done due to small numbers.</p

Male Mc quantities in PBMC from women with ESRD and healthy women.

<p>Male Mc quantities in PBMC from women with ESRD and healthy women.</p

Quantification of Mc in kidney biopsies prior to transplantation from five women with ESRD.

*<p>ANCA: antineutrophil cytoplasmic antibodies, SLE: systemic lupus erythematosus; HUS: hemolytic-uremic syndrome, FSGS: Focal segmental glomerulosclerosis.</p