Type 1A diabetes (T1D) is an autoimmune disorder the risk of which is increased by specific HLA DR͞DQ alleles [e.g., DRB1*03-DQB1*0201 (DR3) or DRB1*04-DQB1*0302 (DR4)]. The genotype associated with the highest risk for T1D is the DR3͞4-DQ8 (DQ8 is DQA1*0301, DQB1*0302) heterozygous genotype. We determined HLA-DR and -DQ genotypes at birth and analyzed DR3͞4-DQ8 siblings of patients with T1D for identical-by-descent HLA haplotype sharing (the number of haplotypes inherited in common between siblings). The children were clinically followed with prospective measurement of anti-islet autoimmunity and for progression to T1D. Risk for islet autoimmunity dramatically increased in DR3͞4-DQ8 siblings who shared both HLA haplotypes with their diabetic proband sibling (63% by age 7, and 85% by age 15) compared with siblings who did not share both HLA haplotypes with their diabetic proband sibling (20% by age 15, P < 0.01). 55% sharing both HLA haplotypes developed diabetes by age 12 versus 5% sharing zero or one haplotype (P ‫؍‬ 0.03). Despite sharing both HLA haplotypes with their proband, siblings without the HLA DR3͞4-DQ8 genotype had only a 25% risk for T1D by age 12. The risk for T1D in the DR3͞4-DQ8 siblings sharing both HLA haplotypes with their proband is remarkable for a complex genetic disorder and provides evidence that T1D is inherited with HLA-DR͞DQ alleles and additional MHC-linked genes both determining major risk. A subset of siblings at extremely high risk for T1D can now be identified at birth for trials to prevent islet autoimmunity.haplotype ͉ human leukocyte antigen ͉ major histocompatibility complex A large body of evidence indicates that type 1A diabetes (T1D) is an autoimmune disorder with important genetic determinants, and it has become one of the most intensively studied complex genetic disorders (1-3). The major histocompatibility complex (MHC) is reported to account for Ϸ40% of the familial aggregation of T1D (4, 5). The HLA-DR and -DQ genes (linked HLA genes in the class II region of the MHC) are well established as being associated with risk for T1D. Although studies have implicated loci other than the HLA-DR and -DQ loci (i.e., HLA-DPB1, HLA-A, HLA-B, and various non-HLA genes) with diabetes risk and earlier age of onset, no loci with contribution to risk equivalent to that of the HLA-DR and -DQ alleles have been identified (6-10).The insulin, PTPN22, and CTLA4 genes are non-HLA diabetes-susceptibility loci with allelic odds ratios of 1.9, 1.7, and 1.2, respectively (11-14). However, even in combination with HLA alleles, none of these identified loci confer a risk Ͼ25% in prospective studies. Nevertheless, a remaining fundamental question is whether there are genetic polymorphisms other than the HLA-DR and -DQ alleles that confer major risk for T1D. If such loci existed, they could be linked to the MHC and would thus be ''hidden'' in most linkage studies by the dramatic influence of the HLA-DR and -DQ alleles.Haplotypes are defined by sets of closely linked genetic variants making chromosom...

Technology has become available to cost-effectively analyze thousands of single nucleotide polymorphisms (SNPs). We recently confirmed by genotyping a small series of class I alleles and microsatellite markers that the extended haplotype HLA-A1-B8-DR3 (8.1 AH) at the major histocompatibility complex (MHC) is a common and conserved haplotype. To further evaluate the region of conservation of the DR3 haplotypes, we genotyped 31 8. M ore than 20 years ago, analysis of polymorphisms of complement genes, such as the 21-hydroxylase gene and alleles of class I and II major histocompatibility complex (MHC) genes, identified a number of MHC haplotypes that were termed "conserved extended haplotypes" or "ancestral haplotypes" (1-4). A Basque haplotype studied in U.S. French-Canadian populations with the HLA A30, Cw5, B18, BfF1, C4F, C4s°, DR3 haplotype was associated with diabetes susceptibility, and more recent studies have confirmed increased risk associated with this haplotype (5). The HLA-A1-B8-DR3 haplotype (8.1 AH) is one of the most common extended DR3 haplotypes, with a northernEuropean frequency of ϳ10%. The 8.1 AH consists of the HLA-A1, HLA-Cw7, HLA-B8, MICA-5.1, DR3, and DQ2 alleles (6) and has been sequenced by Stewart et al. (7). It has been associated with multiple immunological diseases, such as type 1 diabetes, celiac disease, systemic lupus erythematosus, common variable immunodeficiency, myasthenia gravis, and accelerated HIV disease (8 -10). However, a recent study has reported that the 8.1 AH is not more diabetogenic compared with other DR3 haplotypes (6).With the sequencing of the genome, the development of single nucleotide polymorphism (SNP) databases and haplotype maps, software to analyze haplotype blocks, and finally development of cost-effective large-scale SNP typing reagents, detailed multi-SNP analysis of the MHC region is now feasible. In this study, the analysis of multiple SNPs was necessary to describe the amount of conservation of the 8.1 AH or the proportion of alleles that were identical between 8.1 AHs. The basic scientific question we explored was how long and how conserved is the extended 8.1 AH? With our analysis of 656 SNPs of 31 8.1 AHs, we describe the 8.1 AH as having a remarkably long region (2.9 Mb) of Ͼ99.9% conservation. RESEARCH DESIGN AND METHODSIn the ongoing prospective Diabetes Autoimmunity Study of the Young (DAISY), participants (most with Caucasian and Hispanic ancestry) were HLA typed and stratified into groups by family history of type 1A diabetes. Subgroups of DAISY children were enrolled for prospective follow-up of development of anti-islet autoantibodies and diabetes. DNA samples from DAISY families, including children and parents with and without type 1 diabetes, were genotyped at the HLA-A, -B, -DRB1, and -DQB1 loci with sequence-specific oligonucleotide genotyping as previously described (11). The MICA microsatellite marker was genotyped using fluorescence-based methods as previously described (12). DNA from 45 of these families (143 individuals) was analy...

(DR3/4-DQ8) siblings who share both major histocompatibility complex (MHC) haplotypes identical-by-descent with their proband siblings have a higher risk for type 1A diabetes than DR3/4-DQ8 siblings who do not share both MHC haplotypes identical-bydescent. Our goal was to search for non-DR/DQ MHC genetic determinants that cause the additional risk in the DR3/4-DQ8 siblings who share both MHC haplotypes. RESEARCH DESIGN AND METHODS-We completed an extensive single nucleotide polymorphism (SNP) analysis of the extended MHC in 237 families with type 1A diabetes from the U.S. and 1,240 families from the Type 1 Diabetes Genetics Consortium.RESULTS-We found evidence for an association with type 1A diabetes (rs1233478, P ϭ 1.6 ϫ 10 Ϫ23 , allelic odds ratio 2.0) in the UBD/MAS1L region, telomeric of the classic MHC. We also observed over 99% conservation for up to 9 million nucleotides between chromosomes containing a common haplotype with the HLA-DRB1*03, HLA-B*08, and HLA-A*01 alleles, termed the "8.1 haplotype." The diabetes association in the UBD/MAS1L region remained significant both after chromosomes with the 8.1 haplotype were removed (rs1233478, P ϭ 1.4 ϫ 10 Ϫ12 ) and after adjustment for known HLA risk factors HLA-DRB1, HLA-DQB1, HLA-B, and HLA-A (P ϭ 0.01). CONCLUSIONS-Polymorphisms

Inflammatory oncotaxis, the phenomenon in which mechanically injured tissues are predisposed to cancer metastases, has been reported for a number of tumor types, but not previously for histologically proven lung cancer. We review clinical and experimental evidence and mechanisms that may underlie inflammatory oncotaxis, and provide illustrative examples of two patients with squamous cell carcinoma of the lung who developed distant, localized metastatic disease at sites of recent physical trauma. Trauma may predispose to metastasis through two distinct, but not mutually exclusive, mechanisms: (1) physical trauma induces tissue damage and local inflammation, creating a favorable environment that is permissive for seeding of metastatic cells from distant sites; and/or (2) micrometastatic foci are already present at the time of physical injury, and trauma initiates changes in the microenvironment that stimulate the proliferation of the metastatic cells. Further exploration of post-traumatic inflammatory oncotaxis may elucidate fundamental mechanisms of metastasis and could provide novel strategies to prevent cancer metastasis.

are at the highest risk of developing type 1 diabetes. We sought to find an inexpensive, rapid test to identify DR3/4-DQ8 subjects using two single nucleotide polymorphisms (SNPs).RESEARCH DESIGN AND METHODS-SNPs rs2040410 and rs7454108 were associated with DR3-DQB1*0201 and DR4-DQB1*0302. We correlated these SNPs with HLA genotypes and with publicly available data on 5,019 subjects from the Type 1 Diabetes Genetic Consortium (T1DGC). Additionally, we analyzed these SNPs in samples from 143 HLA-typed children who participated in the Diabetes Autoimmunity Study of the Young (DAISY) using Taqman probes (rs7454108) and restriction digest analysis (rs2040410).RESULTS-With a simple combinatorial rule, the SNPs of interest identified the presence or absence of the DR3/4-DQ8 genotype. A wide variety of genotypes were tested for both SNPs. In T1DGC samples, the two SNPs were 98.5% (1,173 of 1,191) sensitive and 99.7% (3,815 of 3,828) specific for DR3/4-DQ8. In the DAISY population, the test was 100% (69 of 69) sensitive and 100% (74 of 74) specific. Overall, the sensitivity and specificity for the test were 98.57 and 99.67%, respectively. CONCLUSIONS-

OBJECTIVE-A major goal in genetic studies of type 1A diabetes is prediction of anti-islet autoimmunity and subsequent diabetes in the general population, as Ͼ85% of patients do not have a first-degree relative with type 1A diabetes. Given prior association studies, we hypothesized that the strongest candidates for enhancing diabetes risk among DR3-DQB1*0201/DR4-DQB1*0302 individuals would be alleles of DP and DRB1*04 subtypes and, in particular, the absence of reportedly protective alleles DPB1*0402 and/or DRB1*0403. RESEARCH DESIGN AND METHODS-We genotyped 457DR3-DQB1*0201/DR4-DQB1*0302 Diabetes Autoimmunity Study of the Young (DAISY) children (358 general population and 99 siblings/offspring of type 1 diabetic patients) at the DPB1, DQB1, and DRB1 loci using linear arrays of immobilized sequencespecific oligonucleotides, with direct sequencing to differentiate DRB1*04 subtypes.RESULTS-By survival curve analysis of DAISY children, the risk of persistently expressing anti-islet autoantibodies is ϳ55% for relatives (children with a parent or sibling with type 1 diabetes) in the absence of these two protective alleles vs. 0% (P ϭ 0.02) with either protective allele, and the risk is 20 vs. 2% (P ϭ 0.004) for general population children. Even when the population analyzed is limited to DR3-DQB1*0201/DR4-DQB1*0302 children with DRB1*0401 (the most common DRB1*04 subtype), DPB1*0402 influences development of anti-islet autoantibodies.CONCLUSIONS-The ability to identify a major group of general population newborns with a 20% risk of anti-islet autoimmunity should enhance both studies of the environmental determinants of type 1A diabetes and the design of trials for the primary prevention of anti-islet autoimmunity.

The major susceptibility locus for type 1 diabetes mellitus (T1D) maps to the human lymphocyte antigen (HLA) class II region in the major histocompatibility complex on chromosome 6p21. In southern European populations, like the Basques, the greatest risk to T1D is associated with DR3 homo-and heterozygosity and is comparable to that of DR3/DR4, the highest risk genotype in northern European populations. Celiac disease (CD) is another DR3-associated autoimmune disorder showing certain overlap with T1D that has been explained by the involvement of common genetic determinants, a situation more frequent in DR3-rich populations, like the Basques. As both T1D-and CD-associated HLA alleles are part of conserved extended haplotypes (CEH), we compared DR3-homozygous T1D and CD patients to determine whether CEHs were equally distributed between both disorders or there was a differential contribution of different haplotypes. We observed a very pronounced distribution bias (Po10 À5 ) of the two major DR3 CEHs, with DR3-B18 predominating in T1D and DR3-B8 in CD. Additionally, high-density single nucleotide polymorphism (SNP) analysis of the complete CEH [A*30-B*18-MICA*4-F1C30-DRB1*0301-DQB1*0201-DPB1*0202] revealed extraordinary conservation throughout the 4.9 Mbp analyzed supporting the existence of additional diabetogenic variants (other than HLA-DRB1*0301-DQB1*0201), conserved within the DR3-B18 CEH (but not in other DR3 haplotypes) that could explain its enhanced diabetogenicity.

No abstract