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.

16(th) IHIW: analysis of HLA population data, with updated results for 1996 to 2012 workshop data (AHPD project report).

We present here the results of the Analysis of HLA Population Data (AHPD) project of the 16th International HLA and Immunogenetics Workshop (16IHIW) held in Liverpool in May-June 2012. Thanks to the collaboration of 25 laboratories from 18 different countries, HLA genotypic data for 59 new population samples (either well-defined populations or donor registry samples) were gathered and 55 were analysed statistically following HLA-NET recommendations. The new data included, among others, large sets of well-defined populations from north-east Europe and West Asia, as well as many donor registry data from European countries. The Gene[rate] computer tools were combined to create a Gene[rate] computer pipeline to automatically (i) estimate allele frequencies by an expectation-maximization algorithm accommodating ambiguities, (ii) estimate heterozygosity, (iii) test for Hardy-Weinberg equilibrium (HWE), (iv) test for selective neutrality, (v) generate frequency graphs and summary statistics for each sample at each locus and (vi) plot multidimensional scaling (MDS) analyses comparing the new samples with previous IHIW data. Intrapopulation analyses show that HWE is rarely rejected, while neutrality tests often indicate a significant excess of heterozygotes compared with neutral expectations. The comparison of the 16IHIW AHPD data with data collected during previous workshops (12th-15th) shows that geography is an excellent predictor of HLA genetic differentiations for HLA-A, -B and -DRB1 loci but not for HLA-DQ, whose patterns are probably more influenced by natural selection. In Europe, HLA genetic variation clearly follows a north to south-east axis despite a low level of differentiation between European, North African and West Asian populations. Pacific populations are genetically close to Austronesian-speaking South-East Asian and Taiwanese populations, in agreement with current theories on the peopling of Oceania. Thanks to this project, HLA genetic variation is more clearly defined worldwide and better interpreted in relation to human peopling history and HLA molecular evolution.

Blood group typing in five Afghan populations in the North Hindu-Kush region: implications for blood transfusion practice.

BACKGROUND AND OBJECTIVES: Blood incompatibility arises from individual and ethnic differences in red blood cell (RBC) antigen profiles. This underlines the importance of documenting RBC antigen variability in various ethnic groups. Central Asia is an area with a long and complex migratory history. The purpose of this article is to describe key antigen frequencies of Afghan ethnic groups in the Hindu-Kush region of Afghanistan as a basis for improving blood transfusion practices in that area. MATERIALS AND METHODS: The key ABO, Rh and Kell antigens were investigated in five Afghan populations. In order to depict accurately the blood group gene diversity in the area, DNA from eight additional Pakistani populations were included, and the entire sample set screened using two multiplex polymerase chain reactions sensitive for 17 alleles in 10 blood group genetic systems (MNS, Kell, Duffy, Kidd, Cartwright, Dombrock, Indian, Colton, Diego and Landsteiner-Wiener). RESULTS: Phenotype and allele frequencies fell within the ranges observed in Western European and East Asian populations. Occurrence of DI*01, IN*01, LW*07 and FY*02N.01 and prevalence of ABO*B were consistent with migratory history as well as with putative environmental adaptation in the subtropical environment Hindu-Kush region. CONCLUSION: These findings expand the current knowledge about key antigen frequencies. Regarding occurrence of viral markers, further blood transfusion in the region requires rigorous typing.

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.

Population structure of modern-day Italians reveals patterns of ancient and archaic ancestries in Southern Europe.

European populations display low genetic differentiation as the result of long-term blending of their ancient founding ancestries. However, it is unclear how the combination of ancient ancestries related to early foragers, Neolithic farmers, and Bronze Age nomadic pastoralists can explain the distribution of genetic variation across Europe. Populations in natural crossroads like the Italian peninsula are expected to recapitulate the continental diversity, but have been systematically understudied. Here, we characterize the ancestry profiles of Italian populations using a genome-wide dataset representative of modern and ancient samples from across Italy, Europe, and the rest of the world. Italian genomes capture several ancient signatures, including a non-steppe contribution derived ultimately from the Caucasus. Differences in ancestry composition, as the result of migration and admixture, have generated in Italy the largest degree of population structure detected so far in the continent, as well as shaping the amount of Neanderthal DNA in modern-day populations.

Expression of tpo mRNA in thyroid tumors: quantitative PCR analysis and correlation with alterations of ret, Braf , ras and pax8 genes.

Immunocytochemistry (ICC) of thyroid peroxidase (TPO) using the monoclonal antibody MoAb47 has been used as malignancy marker on thyroid fine needle aspiration. However, little is known about the fate of TPO in thyroid carcinoma. We performed a qualitative PCR (Q-PCR) analysis to measure the expression of variants of tpo mRNA in 13 normal tissue samples, 30 benign tumors (BT), 21 follicular carcinomas (FC), 20 classical papillary carcinomas (PCc), 12 follicular variants of papillary carcinomas (PCfv) and nine oncocytic carcinomas (OC). We also studied mutations involving the ras, Braf, ret or pax8 genes. Results of Q-PCR were closely correlated with those of ICC (P < 0.0001; R = 0.59) and showed that overall tpo expression was lower in all carcinomas than in normal and BT (P < 0.05). The ratio tpo2 or tpo3 to tpo1 was inversed in follicular tumors. Genetic mutations were observed in 90% of PCc, 61.9% of FC, 41.7% of PCfv, 0% of OC and 10% in BT. pax8-ppar gamma1 rearrangement was correlated with qualitative changes in tpo mRNA (P < 0.01). These results confirmed the decrease of TPO expression in 97% of thyroid carcinomas regardless of histological type and the overexpression of shorter splice variants in follicular tumors. Both reduction in quantity of TPO and impairment of its maturation process could account for the atypical immunohistochemical reaction of MoAb47 with TPO.

ret/PTC1 and ret/PTC3 in thyroid tumors from Chernobyl liquidators: comparison with sporadic tumors from Ukrainian and French patients.

Like children exposed to Chernobyl fallout, the workers who cleaned up after the accident, also known as liquidators, have exhibited an increased incidence of thyroid cancer. A high prevalence of ret/PTC3 rearrangement has been found in pediatric post-Chernobyl thyroid tumors, but this feature has not been investigated in liquidator thyroid tumors. In this study we analyzed the prevalence of ret/PTC1 and ret/PTC3 in thyroid tumors from 21 liquidators, 31 nonirradiated adult Ukrainian patients, and 34 nonirradiated adult French patients. ret rearrangements in carcinomas were found in 83.3% of liquidators, 64.7% of Ukrainian patients, and 42.9% of French patients. The prevalence of ret/PTC1 was statistically similar in the three groups. The prevalence of ret/PTC3 was significantly higher in liquidators than in French patients (P = 0.03) but it was also high in nonirradiated Ukrainian patients who exhibited values intermediate between liquidators and French patients. In adenomas the prevalence of rearrangement was significantly higher in all Ukrainians than in French patients (P = 0.004). Like children exposed to Chernobyl fallout, liquidators showed a high prevalence of ret/PTC3. This finding suggests that irradiation had the same effect regardless of age. However, given the high rate of ret/PTC3 in nonirradiated adult Ukrainians, the possibility of genetic susceptibility or low-level exposure to radiation in that group cannot be excluded.

Cord blood collection and banking from a population with highly diverse geographic origins increase HLA diversity in the registry and do not lower the proportion of validated cord blood units: experience of the Marseille Cord Blood Bank.

Several Cord Blood (CB) Bank studies suggested that ethnicity impaired CB unit (CBU) qualification. The Bone Marrow Donors Worldwide registries present an over-representation of unrelated donors (UD) from Northwestern European descent. This raises the question of equality of access to hematopoietic stem cells transplant, especially in the Mediterranean zone, which has taken in many waves of immigration. The aim of our study is to address whether, in the Marseille CB Bank, CBU qualification rate is impaired by geographic origin. The study compared biological characteristics of 106 CBU disqualified for total nucleated cell (TNC) count (dCBU) and 136 qualified CBU in relation to registry enrichment and haplotype origin. A high proportion (>80%) of both dCBU and CBU had at least one non-European haplotype and enrich CB and UD registries to a higher extent than those with two European haplotypes (P<0.001). No difference was observed between TNC count and volume according to geographic origin. Our study shows that diverse Mediterranean origins do not have an impact on the CBU qualification rate. Partnership with Mediterranean birth clinics with highly trained staff is a reasonable option to increase the HLA diversity of CB Bank inventories and to improve the representation of minorities.

Specific pattern of RAS oncogene mutations in follicular thyroid tumors.

The prevalence of H-RAS, K-RAS, and N-RAS gene mutations in thyroid tumors according to malignancy and histology is controversial. Differences in methodology and histological classifications may explain discrepant results. To address this issue, we first performed a pooled analysis of 269 mutations garnered from 39 previous studies. Mutations proved significantly less frequent when detected with direct sequencing than without (12.3% vs. 17%). The rate of mutation involving N-RAS exon 1 (N1) and K-RAS exon 2 (K2) was less than 1%. Mutations of codon 61 of N-RAS (N2) were significantly more frequent in follicular tumors (19%) than in papillary cancers (5%) and significantly more frequent in malignant (25%) than in benign (14%) tumors. H-RAS mutations in codons 12/13 (H1) were found in 2-3% of all types of tumors, but H-RAS mutations in codon 61 (H2) were observed in only 1.4% of tumors, and almost all of them were malignant. K-RAS mutations in exon 1 were found more often in papillary than follicular cancers (2.7% vs. 1.6%) and were sometimes correlated with special epidemiological circumstances. The second part of this study involved analysis of 80 follicular tumors from patients living in Marseille (France) and Kiev (Ukraine). We used direct sequencing after PCR amplification of exons 1 and 2 of the three RAS genes. Common and atypical adenomas were separated using strict cytological criteria. Mutations of H1-RAS were found in 12.5% of common adenomas and one follicular carcinoma (2.9%). Mutations of N2-RAS occurred in 23.3% and 17.6% of atypical adenomas and follicular carcinomas, respectively. These results confirm the predominance of N2-RAS mutations in thyroid follicular tumors and their correlation with malignancy. They support the implication of N2-RAS mutations in the malignant progression of thyroid follicular tumors and the assumption that some atypical adenomas are precursors of follicular carcinomas.