Deciphering the genetic landscape of Alzheimer disease (AD) is essential to define the pathophysiological pathways involved and to successfully translate genomics to potential tailored medical care. To generate the most complete knowledge of the AD genetics, we developed through the European Alzheimer Disease BioBank (EADB) consortium a discovery meta-analysis of genome-wide association studies (GWAS) based on a new large case-control study and previous GWAS (in total 39,106 clinically diagnosed cases, 46,828 proxy-AD cases and 401,577 controls) with the most promising signals followed-up in independent samples (18,063 cases and 23,207 controls). In addition to 34 known AD loci, we report here the genome-wide significant association of 31 new loci with the risk of AD. Pathway-enrichment analyses strongly indicated the involvement of gene sets related to amyloid and Tau, but also highlighted microglia, in which increased gene expression corresponds to more significant AD risk. In addition, we successfully prioritized candidate genes in the majority of our new loci, with nine being primarily expressed in microglia. Finally, we observed that a polygenic risk score generated from this new genetic landscape was strongly associated with the risk of progression from mild cognitive impairment (MCI) to dementia (4,609 MCI cases of whom 1,532 converted to dementia), independently of age and the APOE e4 allele.

Maxwell GL, Risinger JI, Shaw H, Alvarez A, Barrett JC, Futreal A, Berchuck A. Mutations in the PTEN tumor suppressor gene in cervical carcinomas. Int J Gynecol Cancer 1998; 8: 489–493. To elucidate further the molecular pathogenesis of cervical cancer we sought to determine whether mutations in the PTEN tumor suppressor gene are a feature of these cancers. Genomic DNA was extracted from 67 primary cervical cancers and 9 immortalized cervical cancer cell lines. Using the polymerase chain reaction, the nine exons and intronic splice sites of the PTEN gene were amplified using 11 primer pairs. Single strand conformation polymorphism analysis was used to screen for mutations in the PTEN gene and variant bands were subjected to DNA sequencing. The primary cancers were also tested for the presence of HPV DNA. Mutations in the PTEN gene were not detected in any of the immortalized cell lines, but sequence alterations were noted in 4/67 (6%) primary cervical cancers. Three mutations resulted in frameshifts that predict truncated protein products, including two cases in which we found an identical 4‐base‐pair deletion in codons 318–319. In addition, a one‐base‐pair insertion in codon 320 was seen in another case. Finally, a missense mutation (G143 A) was observed immediately adjacent to the catalytic site of the phosphatase domain in exon 5. In two cases with PTEN mutations in which corresponding normal DNA was available, loss of the wild type allele was demonstrated. There was no apparent relationship between the presence of a PTEN mutation and pathologic features or the presence of human papillomavirus DNA. Although mutations in the PTEN gene are found in only a small fraction of cervical cancers, alterations of this tumor suppressor gene may play a role in the development of some of these cancers.

Our objective was to examine the association between myocardial infarction (MI) and two DNA-polymorphisms at the proinflammatory chemokine receptors CCR2 (I64V) and CCR5 (32 bp deletion, (Delta)ccr5), defining if these polymorphisms influence the age for the onset of MI. A total of 214 patients with an age at the first MI episode <55 years, 96 patients that suffered the first MI episode when older than 60 years, and 360 population controls were polymerase chain reaction genotyped for the CCR2-V64I and CCR5-Delta32/wt polymorphisms. Patients and controls were male from the same Caucasian population (Asturias, northern Spain). The frequency of the Deltaccr5 allele was significantly higher in controls compared to patients <55 years (P = 0.004), or in patients >60 years compared to patients <55 years (P = 0.002). Taking the patients >60 years as the reference group, non-carriers of the (Delta)ccr5-allele would have a three-fold higher risk of suffering an episode of MI at <55 years of age (OR = 3.06; 95% CI = 1.46-6.42). Gene and genotype frequencies for the CCR2 polymorphism did not differ between patients <55 years and controls or patients >60 years. Our data suggest that the variation at the CCR5 gene could modulate the age at the onset of MI. Patients carrying the (Delta)ccr5-allele would be protected against an early episode of MI. CCR5 and the CCR5-ligands are expressed by cells in the arteriosclerotic plaque. Thus, the protective role of (Delta)ccr5 could be a consequence of an attenuated inflammatory response, that would determine a slower progression of the arteriosclerotic lesion among (Delta)ccr5-carriers. Our work suggests that the pharmacological blockade of CCR5 could be a valuable therapy in the treatment of MI.

The diagnosis of HEV infection is technically challenging and should be made simultaneously with RT-PCR methods, viral load quantification and serological markers. In immunosuppressed children who develop chronic hepatitis, the prevalence of HEV is high and could explain the chronic liver inflammation potentially leading to cirrhosis. Re-infection by different HEV strains from zoonotic transmission can result in progressive liver disease in immunocompromised children.

Anti-liver-kidney microsome type-1 antibodies (LKM1), present in sera from a group of patients with autoimmune hepatitis, are directed against P450IID6. Previous work, using cDNA constructions spanning most of the P450IID6 protein defined the main immunogenic site between the amino acids (aa), 254-271 and predicted the presence of other putative immunogenic sites in the molecule. Fusion proteins from new cDNA constructions, spanning so-far-untested regions between aa 1-125 and 431-522, were not recognized by LKM1-positive sera. Synthetic peptides, representing sequences from putative immunogenic regions or previously untested regions, allowed a precise definition of four antigenic sites located between peptides 257-269, 321-351, 373-389 and 410-429, which were recognized, respectively, by 14, 8, 1 and 2 out of 15 LKM1-positive sera tested. The minimal sequence of the main antigenic site (peptide 257-269) recognized by the autoantibody was established to be WDPAQPPRD (peptide 262-270). In addition, deletion and replacement experiments showed that aa 263 (Asp) was essential for the binding of the autoantibody to peptide 262-270. Analysis of the second most frequently recognized peptide between aa 321-351, was performed using peptides 321-339 and 340-351 in competitive inhibition studies. Complete elimination of antibody binding to peptide 321-351 obtained by absorption of both shorter peptides indicated that peptide 321-351 is a discontinuous antigenic site. LKM1-positive sera reacting against peptide 321-351 recognized either both the shorter peptides or just one of them preferentially. Results of the present study suggest that the production of LKM1 antibodies is an antigen-driven, poly- or oligoclonal B cell response. The identification of antigenic sites will allow: (i) the development of specific diagnostic tests and (ii) further studies on the pathogenic value of LKM1 antibodies in autoimmune hepatitis.

Autoimmune hepatitis (AIH) is characterized by a loss of immunological tolerance to hepatocytes. Patients respond well to immunosuppression but progression to endstage liver disease occurs in 10%-20% of cases, leading to liver transplantation. Using a murine model of type 2 AIH, we identified susceptibility factors for autoimmune hepatitis and attempted to restore immunological tolerance to liver autoantigens. An increased ectopic expression of a liver autoantigen (FTCD) in the thymus leading to reduced numbers of circulating autoreactive T cells was sufficient to prevent development of AIH in mice. However, in the presence of a reduced central tolerance to FTCD, a strong regulatory T-cell response was able to inhibit proliferation of liver-specific autoreactive T cells and prevent AIH. Development of a severe AIH stemmed from reduced numbers of functional regulatory T cell (Tregs) leading to an increased proliferation of FTCD-specific autoreactive T and B cells. Adoptive transfer of ex vivo expanded CXCR31 Tregs in mice with AIH efficiently targeted the inflamed liver, restored peripheral tolerance to FTCD, and induced remission of AIH. Conclusion: Peripheral tolerance to liver autoantigens in AIH is paramount. Autologous infusion of ex vivo expanded CXCR31 Tregs in AIH patients could be an effective therapeutic approach to restore peripheral tolerance and induce remission of AIH. (HEPATOLOGY 2013;57:217-227)

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Chemokines are critical for the inflammatory process in autoimmune diseases such as rheumatoid arthritis (RA). The chemokine receptor-5 (CCR5) mediates chemotaxis by CC-chemokines and is expressed by lymphocytes with the Th1 phenotype and monocyte/macrophages. A 32 bp deletion in the CCR5 (CCR5-⌬32 allele) abolishes receptor expression in homozygotes, while CCR5-⌬32 carriers would express less receptor than wild-type homozygotes. This polymorphism is related to the resistance to HIV-1 infection and progression towards AIDS. We hypothesized that the CCR5-⌬32 allele may modulate the severity of disease in RA. A total of 160 RA-patients (71 and 89 with severe and non-severe phenotypes, respectively) and 500 healthy individuals from the same Caucasian population (Asturias, northern Spain) were genotyped. Carriers of the CCR5-⌬32 allele were at a significantly higher frequency (P = 0.012) in non-severe compared to severe patients (17% vs 4%). Our results suggest that the CCR5-⌬32 polymorphism is a genetic marker related to the severity of RA. Genes and Immunity (2000) 1, 288-289.Keywords: chemokines; CCR5-⌬32 allele; rheumatoid arthritis; disease severity Rheumatoid arthritis (RA) is a systemic chronic inflammatory disease of the joints characterized by the infiltration of the synovial membrane with T lymphocytes and macrophages, and pannus formation over the underlying cartilage and bone. The inflammatory process observed in RA is mediated by chemotactic factors released by the inflamed tissues. Chemokines display a potent chemotactic activity for cells of the immune system, playing an important role in both the destructive and the fibrovasculoproliferative phases of RA.1 The chemokine receptor-5 (CCR5) mediates chemotaxis by the CC-chemokines RANTES, MIP-1␣ and MIP-1␤. This receptor is expressed by lymphocytes exhibiting the Th1-phenotype and by monocytes/macrophages. 2In addition to its role in inflammation, CCR5 also acts as an HIV-1 coreceptor to mediate the first step in cell entry:fusion of the viral envelope with the membrane in the the target CD4 + cell. A 32 bp deletion at the coding region of the CCR5 gene, the CCR5-⌬32 mutation, leads to the expression of reduced amounts of the CCR5 protein in heterozygous individuals.3 CCR5-⌬32 homozygotes do not express the receptor and have nearly complete resistence to HIV-1 infection despite repeated exposure, while heterozygotes progress slowly towards AIDS compared to wild-type homozygotes. 4 The CCR5-