DR Alleles Research Articles

Factors associated with the presence of glutamic acid decarboxylase and islet antigen-2 autoantibodies in patients with long-standing type 1 diabetes

AimGlutamic acid decarboxylase (GAD) and/or islet antigen-2 (IA-2) autoantibodies (ab) are present in 90% of patients at the onset of type 1 diabetes (T1D). Few studies have shown that they may persist in the long-term. We analysed the frequency of GADab and IA-2ab and the factors associated with their persistency in patients with long-lasting T1D. MethodsThis cross-sectional study included 430 adult patients with T1D of at least 10-year duration, consecutively seen over one year. GADab and IA-2ab were determined by radio-binding assays. Autoantibodies to thyroperoxydase, gastric parietal cells and transglutaminase were assessed in 418 patients, and HLA DRB1 genotyping in 359. Parameters associated with the persistency of antibodies were studied by multivariate analysis. ResultsMedian age at diagnosis of T1D was 12 years, and median diabetes duration was 19 years. Extrapancreatic autoimmunity was present in 38% of the patients, and associated autoimmune diseases in 21%. GADab and/or IA-2ab were found in 56% of the patients, and in 32% in those with more than 25-year diabetes duration. GADab were more frequent than IA-2ab. Female sex, an older age at diagnosis, and a shorter duration of diabetes were independently associated with the presence of ab. The same factors and the DR3 allele were associated with GADab, while only diabetes duration and the DR4 allele were associated with IA-2ab. ConclusionIn a large proportion of the patients with T1D, the long-term persistency of diabetes-associated antibodies allows aetiological diagnosis, even far from the onset of hyperglycaemia.

HLA DR and DQ alleles and haplotypes associated with clinical response to glatiramer acetate in multiple sclerosis

ObjectiveClinical response to immunomodulatory therapies in multiple sclerosis (MS) is variable among patients. Currently, there are no validated biomarkers of clinical response to any of the approved treatments for MS. The objective of this study was to determine if HLA-class II alleles predict the clinical response to glatiramer acetate (GA). MethodsThis was a prospective study of 64 MS patients with relapsing-remitting disease. Patients were HLA-typed and classified as GA-responders or non-responders after 2 years of treatment based on a clinical criterion. Statistical models were used to determine whether HLA-DR and DQ alleles and haplotypes predict the clinical response to GA. ResultsTests of association of response singled out four alleles and two haplotypes with nominal p<0.01. The presence of alleles DR15 or DQ6 or the absence of DR17 and DQ2 alleles was associated with favorable clinical response. The presence of the DR15−DQ6 haplotype and the absence of the DR17–DQ2 haplotype were also associated with favorable treatment response. A best fitting two-haplotype model resulted in the identification of three prognostic categories (good, neutral, and poor). A DR15-DQ6 positive but DR17-DQ2 negative combination was strongly predictive of a favorable clinical response (71%). Conversely, a DR15-DQ6 negative but DR17-DQ2 positive combination was strongly predictive of poor clinical response to GA (17%). ConclusionHLA-DR and DQ typing may prove to be useful biomarkers of predicting response to GA in MS and may help select patients appropriate for this treatment.

The PTPN22 1858T allele but not variants in the proximal promoter region ofIL-21gene is associated with the susceptibility to type 1 diabetes and the presence of autoantibodies in a Brazilian cohort

Interleukin (IL)-21 and protein tyrosine phosphatase non-receptor 22 (PTPN22) regulate lymphocyte function and have been implicated in the pathogenesis of autoimmune diabetes. We sequenced the proximal promoter of the IL-21 gene for the first time and analysed the PTPN22 1858T polymorphism in type 1A diabetes (T1AD) patients and healthy controls (HC). We correlated the frequencies of islet and extra-pancreatic autoantibodies with genotypes from both loci. The case series comprised 612 T1AD patients and 792 HC. Genotyping of PTPN22 C1858T was performed on 434 T1AD patients and 689 HC. The -448 to +83 base pairs (bp) region of the IL-21 gene was sequenced in 309 Brazilian T1AD and 189 HC subjects. We also evaluated human leucocyte antigen (HLA) DR3/DR4 alleles. The frequencies of glutamic acid decarboxylase (GAD65), tyrosine phosphatase-like protein (IA)-2, anti-nuclear antibody (ANA), thyroid peroxidase (TPO), thyroglobulin (TG), thyrotrophin receptor autoantibody (TRAb), anti-smooth muscle (ASM) and 21-hydroxylase (21-OH) autoantibodies were higher in T1AD patients than in HC. The PTPN22 1858T allele was associated with an increased risk for developing T1AD [odds ratio (OR) = 1·94; P < 0·001], particularly in patients of European ancestry, and with a higher frequency of GAD65 and TG autoantibodies. HLA-DR3/DR4 alleles predominated in T1AD patients. A heterozygous allelic IL-21 gene variant (g.-241 T > A) was found in only one patient. In conclusion, only PTPN22 C1858T polymorphism and HLA-DR3 and/or DR4 alleles, but not allelic variants in the 5'-proximal region of the IL-21 gene were associated with T1AD risk. Patients with T1AD had increased frequencies of anti-islet-cell, anti-thyroid, anti-nuclear, anti-smooth muscle and anti-21-OH autoantibodies. The C1858T PTPN22 polymorphism was also associated with a higher frequency of GAD65 and TG autoantibodies.

Association between HLA-DQB1*03:01 and Bullous pemphigoid in Iranian patients.

A common Human Leukocyte Antigen (HLA) class II allele, DQβ1*03:01, seems to be associated with Bullous pemphigoid (BP) in Caucasians whereas previous studies in other ethnic groups showed other HLA class II alleles as genetic predisposing factors for BP. To investigate the association of HLA class II alleles and haplotypes with BP in Iranian population. Fifty patients with Bullous pemphigoid and 180 geographically matched, healthy individuals as control group enrolled into this study. HLA typing of class II (DR and DQ alleles) was carried out using polymerase chain reaction based on sequence-specific primers method. Class II DQA1 and DQB1 typing showed a significantly higher frequency of HLA-DQA1*05:01 (45% vs. 33%, p=0.03), HLA-DQB1*03:01 (36% vs. 23.6%, p=0.02) and HLA-DQB1*04:01 (4% vs. 1.6%, p=0.04) in the BP patients compared with controls. For DRB1 allele frequencies, there were no significant disease associations. The frequency of DRB1*08:01/DQA1*05:01/DQB1*03:01 (3% vs. 0%, p=0.02) haplotype showed an increase among patients compared with controls. Our data suggest that Iranian patients with BP present the same genetic predisposition linked to HLA-DQB1*03:01 previously reported in Caucasians.

Association of Epstein–Barr virus infection with multiple sclerosis in India

ObjectivesEpstein–Barr virus (EBV) seroprevalence is high from early childhood in Indian populations, though multiple sclerosis (MS) is uncommon. The present study aims to evaluate the association of EBV infection with MS in Indian patients. MethodIn this study 140 MS patients and equal number of matched controls were included. Estimation of serum Immunoglobin G (IgG) for EBV Nuclear antigen 1 (EBNA1), viral capsid antigen (EBV-VCA) and early antigen (EB-EA) were obtained by quantitative enzyme linked immunosorbent assay (ELISA). Patients and controls were genotyped for the human leukocyte antigen (HLA) DRB1*1501 allele. ResultsA modest difference was observed for EBNA1 (p=0.02) and EBV-VCA (p=0.03) titres in MS patients as compared to healthy controls. There was no association between EBNA1 titres and MS. High EBNA1 titre (>99.75U/l) was significantly associated with HLA DRBI*15:01 (OR=4.92. CI=1.07–22.57) status in MS patients but not in healthy controls (OR=1.19, CI=0.53–2.63). ConclusionEvidence for a strong association with remote EBV infection was lacking in this study of Indian patients with MS. Patients who are carriers of HLA DR15 allele may have high EBNA1 titres. These preliminary results need to be reproduced in an independent and larger dataset.

Autoimmune Polyglandular Syndrome III in a Patient with Idiopathic Portal Hypertension

A 42-year-old woman with a history of idiopathic portal hypertension (IPH) developed type 1A diabetes and was found to have chronic thyroiditis. The concurrence of IPH and type 1A diabetes has been previously reported in only one case. This is the second known case, and our patient was classified as having autoimmune polyglandular syndrome (APS) III. The patient's HLA DR and DQ alleles were determined to be susceptible to autoimmune thyroid diseases but resistant to type 1A diabetes.

Complementarity of Binding Motifs is a General Property of HLA-A and HLA-B Molecules and Does Not Seem to Effect HLA Haplotype Composition

Different human leukocyte antigen (HLA) haplotypes (i.e., the specific combinations of HLA-A, -B, -DR alleles inherited together from one parent) are observed in different frequencies in human populations. Some haplotypes, like HLA-A1-B8, are very frequent, reaching up to 10% in the Caucasian population, while others are very rare. Numerous studies have identified associations between HLA haplotypes and diseases, and differences in haplotype frequencies can in part be explained by these associations: the stronger the association with a severe (autoimmune) disease, the lower the expected HLA haplotype frequency. The peptide repertoires of the HLA molecules composing a haplotype can also influence the frequency of a haplotype. For example, it would seem advantageous to have HLA molecules with non-overlapping binding specificities within a haplotype, as individuals expressing such an haplotype would present a diverse set of peptides from viruses and pathogenic bacteria on the cell surface. To test this hypothesis, we collect the proteome data from a set of common viruses, and estimate the total ligand repertoire of HLA class I haplotypes (HLA-A-B) using in silico predictions. We compare the size of these repertoires to the HLA haplotype frequencies reported in the National Marrow Donor Program (NMDP). We find that in most HLA-A and HLA-B pairs have fairly distinct binding motifs, and that the observed haplotypes do not contain HLA-A and -B molecules with more distinct binding motifs than random HLA-A and HLA-B pairs. In addition, the population frequency of a haplotype is not correlated to the distinctness of its HLA-A and HLA-B peptide binding motifs. These results suggest that there is a not a strong selection pressure on the haplotype level favoring haplotypes having HLA molecules with distinct binding motifs, which would result the largest possible presented peptide repertoires in the context of infectious diseases.

Positivity for HLA DR1 is associated with basal cell carcinoma in renal transplant patients in southern Brazil

Renal transplant patients have a higher incidence of non-melanoma skin cancer (NMSC). Previous studies hypothesized that human leukocyte antigen (HLA), especially types DR1, DR4, and DR7, may influence the incidence of these tumors. This study investigates the association between NMSC and the presence of HLA DR1, DR4, and DR7 in renal transplant patients in southern Brazil. In a historical cohort study, 1032 patients who underwent renal transplantation during the period from January 1993 to December 2006 were examined to identify occurrences of NMSC and HLA status prior to transplant. Of the 1032 patients examined, 59 (5.71%) developed NMSC (squamous cell carcinoma [SCC]: 2.42%; basal cell carcinoma [BCC]: 1.74%; both: 1.55%). The presence of HLA DR1 was associated with a higher probability of developing any NMSC and particularly with developing BCC (P < 0.05). There was no statistically significant association between the presence of HLA DR4 or DR7 and the occurrence of NMSC in this sample. HLA DR1 appears to be associated with the development of BCC, as well as with the higher number of NMSC lesions in renal transplant patients. This study supports the trend to associate the DR1 allele with BCC and not with SCC.

Engineered Antigen- Presenting Cells Expressing Human HLA Class-II DR Alleles Support Efficient Enrichment and Expansion of Antigen Specific Th1 CD4[+] T-Cells Which Are Functionally Augmented by IL-15Rα/IL-15 Complexes

AbstractAbstract 1905Previous studies have affirmed the therapeutic efficacy of adoptively transferred antigen specific CD8+ and CD4+ T-cells (TC) against viral infections and tumors. A major challenge in optimizing this approach is to develop strategies to permit generation of CD4+ and long lived CD8+ TC of defined antigen specificity.We previously described a panel of NIH 3T3 based artifical antigen presenting cells (AAPC) for the immediate generation of HLA class-I restricted CMVpp65 specific CD8+ TC. We now describe a panel of NIH 3T3 based AAPC, each transduced to express a shared HLA DRA 0101 alpha chain and one of the following β chains of the human HLA class-II alleles DRB1 0301, 0701, 1501, 0401 and 1101. At least one of these alleles is inherited by 61% and 59% of caucasians and blacks respectively. These AAPCs were also transduced to co-express the human TC costimulatory molecules B7.1, ICAM-1 and LFA-3. Sensitization of TC from seropositive donors in the presence of IL-2 with AAPCs sharing one of these alleles, either loaded with a CMVpp65 peptide pool or transduced to express the CMV pp65 protein, resulted in 33–71 fold expansion of CMVpp65 specific CD4+ TC that exhibited a Th1 cytokine profile, producing TNF-α and IFNγ in response to the same CMVpp65 epitopes. These TC were also cytotoxic against peptide loaded HLA class-II sharing targets. Epitope mapping demonstrated that the HLA DRB1 0301 restricted TC responded to a CMVpp65 epitope known to be presented by this allele QEFFWDANDIY (aa 509–527) and to an unreported epitope DVEEDLTMTRN (aa 245–263). The DRB1 0701 restricted CD4+ TC responded to 4 different epitopes. Two of these also included nonamer peptide sequences previously reported to be presented by HLA class-I alleles; Q IFLEV QAIRE and PQYSEH PTFTS presented by HLA B44, and a third AGILARNLVPM, contained an epitope presented by HLA B0801. The fourth epitope, KYQEFFWDANDIY is known to be also presented by HLA DRB1 0301. The DRB1 1501 restricted CD4+ TC were also responsive to a known class-II epitope LLQTGIHVRVS (aa 37–55) as well as a new epitope LVSQYTPDSTP (aa 53–71). CD4+ TC from 3 donors also responded to CMVpp65 when sensitized with autologous DCs loaded with CMVpp65 peptide pool, and each recognized the same epitopes as TC sensitized with the class-II AAPCs.Supplementation of TC cultures with soluble IL-15Rα/ IL-15 complexes markedly augmented the proportion of IFNg+ CD4+ TC, while increasing concentrations of IL-2 resulted in generation of Th2 type CD4+ TC generating IL-4, IL-5 and IL-2 in response to re-stimulation with CMVpp65 peptides. This system can therefore be harnessed by cytokine modulation to selectively generate CD4+ TC with a Th1, or Th2 cytokine profile.The fact that the class-II AAPC transduced to express the full sequence of CMVpp65 are able to process and present antigenic epitopes on the surface of the expressed HLA class-II allele in the absence of the human invariant chain and HLA-DM suggests that the mouse 3T3 cells contain sufficiently homologous proteins to permit the transfer of processed peptides to human Class-II alleles for presentation. Alternatively, invariant chain independent pathways could permit delivery of certain immunogenic epitopes to the expressed class II HLA alleles. The repertoire of epitopes presented by the Class-II AAPCs with or without the invariant chain is currently under study.Our results suggest that the panel of AAPCs expressing these HLA DRB1 alleles provides a novel and rapid approach for the generation of Th1 CD4+ virus-specific TC of desired HLA class-II restriction for adoptive therapy of CMV disease to foster lasting immunity with co-infused CMVpp65-specific CD8+ TC. Class-II AAPCs used with different concentrations or types of cytokines may also be useful to generate other functional subsets of CD4+ TC to promote tolerance or enhance tumor- specific immunity. Disclosures:No relevant conflicts of interest to declare.

Human leukocyte antigens and Gaucher disease

Gaucher disease (GD) is caused by the reduced activity of lysosomal enzyme glucocerebrosidase, which leads to the accumulation of glucocerebroside in macrophages and a chronic stimulation of the immune system. GD is divided into 3 main types according to the presence or absence of neurological involvement and to its presentation (acute or chronic). Gaucher cells show an increase in their expression of HLA-DR antigens on their surface, and there is an increase in levels of antigen-presenting molecules. Over 100 diseases have already been associated to HLA antigens; however, this association has never been studied in GD. To analyze the variability of HLA genes in a Southern Brazilian sample of GD patients, to compare it with controls, and to look for associations with clinical manifestations. Thirty-one GD patients (24 mild, 4 moderate, and 3 severe) were included in the study. They were typed for HLA A, B, and DR and compared to 250 healthy controls. The clinical data were obtained from the review of medical records. There was a significant difference in the frequency of B37 allele among patients when compared to controls (p=0.011, OR 13.28). An association was found between DR11 (p=0.008) and DR13 (p=0.011) alleles and the severity of the disease. DR11 allele seems to be associated to neurologic compromise, while DR13 seems to be associated to osteonecrosis. Our data suggest a possible association of HLA variants and GD. The HLA variants must be further studied, for they seem to be a phenotype-modifier factor for GD.

HLA‐A, ‐B, ‐DR allele group frequencies in 7007 kidney transplant list patients in 27 UK centres

This observational study aims to determine the HLA specificity frequencies of patients on the UK renal transplant list, which can be used as a resource for those laboratories that support the UK renal transplant programme. Whilst the HLA specificity frequencies may differ from that of the general population, it is the individuals on the transplant list who are in need of a new kidney, which has to be provided from the general population. Any differences in protein allele frequencies between this patient population and the general population are likely to be minimal because of the very large number of patients included. The HLA-A, -B and -DR allele group frequencies from 7007 patients on the UK kidney transplant list (August, 2009) were analysed. HLA types had been submitted to NHSBT to register patients on the UK deceased donor kidney waiting list. The data were submitted from 27 different registering centres throughout the UK. Within this data set, 25 different HLA-A, 50 HLA-B and 18 HLA-DR allele groups were present. The most common allele groups at each locus were -A2 (phenotype frequency 42.6%), -B44 (phenotype frequency 23.3%) and -DR4 (phenotype frequency 29.8%). The least common allele groups at each locus were -A19, - A43, -B16, -B21, -B22, -B83 and -DR5. Reports of HLA frequency (protein allotype) data from populations as large as this are not readily available adding value to this observational study.

158-P

Aim We recently identified a patient carrying an HLA DR4 allele without having any allele of the DR53-expressed group or the common null allele DRB4∗01:03NDR53. The type was obtained using our routine typing method of SSP with Invitrogen reagents and software. It was then confirmed using the Olerup SSP typing tray and software. We then referred the specimen to the HLA laboratory at Stanford University, where the typing was repeated using several SSOP and SSP tests with a variety of reagents. The compound interpretation of all tests showed the DRB genotype would be DRB1∗13:01, DRB1∗04:01, DRB3∗01:01, DRB4∗03:01N. The allele DRB4∗03:01N lacks exon-2(full deletion)of DRB and carries an intact exon-3. This gene does not encode any functional histocompatibility antigen. The finding intriguing in itself since DRB4∗03:01N has been described previously in a haplotype carrying DRB1∗07:01-DRB4∗03:01N-DQB1∗02:02. In this case, the haplotype has DRB1∗04:01. Therefore this is a new independent mechanism for the generation of DRB4∗03:01N. It is not surprising since it is only the loss of an exon. We do not have all the details that both alleles would be the same since intron sequencing would be required to show similarities or differences. Methods SSP and SSOP typing. Results See body of abstract. Conclusions The case illustrates the point that DR53 needs to be typed for and not assumed because of the presence of DR4.

West Nile Virus T-Cell Ligand Sequences Shared with Other Flaviviruses: a Multitude of Variant Sequences as Potential Altered Peptide Ligands

Phylogenetic relatedness and cocirculation of several major human pathogen flaviviruses are recognized as a possible cause of deleterious immune responses to mixed infection or immunization and call for a greater understanding of the inter-Flavivirus protein homologies. This study focused on the identification of human leukocyte antigen (HLA)-restricted West Nile virus (WNV) T-cell ligands and characterization of their distribution in reported sequence data of WNV and other flaviviruses. H-2-deficient mice transgenic for either A2, A24, B7, DR2, DR3, or DR4 HLA alleles were immunized with overlapping peptides of the WNV proteome, and peptide-specific T-cell activation was measured by gamma interferon (IFN-γ) enzyme-linked immunosorbent spot (ELISpot) assays. Approximately 30% (137) of the WNV proteome peptides were identified as HLA-restricted T-cell ligands. The majority of these ligands were conserved in ∼≥88% of analyzed WNV sequences. Notably, only 51 were WNV specific, and the remaining 86, chiefly of E, NS3, and NS5, shared an identity of nine or more consecutive amino acids with sequences of 64 other flaviviruses, including several major human pathogens. Many of the shared ligands had an incidence of >50% in the analyzed sequences of one or more of six major flaviviruses. The multitude of WNV sequences shared with other flaviviruses as interspecies variants highlights the possible hazard of defective T-cell activation by altered peptide ligands in the event of dual exposure to WNV and other flaviviruses, by either infection or immunization. The data suggest the possible preferred use of sequences that are pathogen specific with minimum interspecies sequence homology for the design of Flavivirus vaccines.

In Vitro and In Vivo Proof of Tolerance After Two-Step Haploidentical Bone Marrow and Kidney Transplantation of the Same Donor

In Vitro and In Vivo Proof of Tolerance After Two-Step Haploidentical Bone Marrow and Kidney Transplantation of the Same Donor

Autoantibodies and High-Risk HLA Susceptibility Markers in First-Degree Relatives of Brazilian Patients with Type 1 Diabetes Mellitus: A Progression to Disease Based Study

The objective of this study was to determine the frequencies of autoantibodies to heterogeneous islet-cell cytoplasmic antigens (ICA), glutamic acid decarboxylase(65) (GAD(65)A), insulinoma-associated antigen-2 (IA-2A) and insulin (IAA)-and human leukocyte antigen (HLA) class II markers (HLA-DR and -DQ) in first degree relatives of heterogeneous Brazilian patients with type I diabetes (T1DM). A major focus of this study was to determine the influence of age, gender, proband characteristics and ancestry on the prevalence of autoantibodies and HLA-DR and -DQ alleles on disease progression and genetic predisposition to T1DM among the first-degree relatives. IAA, ICA, GAD(65)A, IA-2A and HLA- class II alleles were determined in 546 first-degree-relatives, 244 siblings, 55 offspring and 233 parents of 178 Brazilian patients with T1DM. Overall, 8.9% of the relatives were positive for one or more autoantibodies. IAA was the only antibody detected in parents. GAD(65) was the most prevalent antibody in offspring and siblings as compared to parents and it was the sole antibody detected in offspring. Five siblings were positive for the IA-2 antibody. A significant number (62.1%) of siblings had 1 or 2 high risk HLA haplotypes. During a 4-year follow-up study, 5 siblings (expressing HLA-DR3 or -DR4 alleles) and 1 offspring positive for GAD(65)A progressed to diabetes. The data indicated that the GAD(65) and IA-2 antibodies were the strongest predictors of T1DM in our study population. The high risk HLA haplotypes alone were not predictive of progression to overt diabetes.

Characterization of colon cancer–associated antigens that would be key therapeutic targets in the prevention of disease relapse or progression.

594 Background: Colon cancer (CRC) is an immunogenic tumor and adaptive immunity may play a role in inhibiting disease relapse. A vaccine to boost cellular immunity in CRC patients could prevent disease recurrence, but there have been few defined immunogenic proteins identified as vaccine candidates. TVG has shown that overexpressed tumor associated proteins, abundant in the cancer state but expressed at basal levels in normal cells, can be immunogenic. We hypothesized that ideal candidate antigens would be ones already validated as prognostic markers in multivariate analysis. Methods: From a directed literature review we selected antigens based on (1) incidence of expression, (2) independent predictor of poor prognosis or early disease recurrence, and (3) known biologic function in CRC pathogenesis. We identified peptides that were predicted to be high affinity binders across multiple HLA DR alleles. We evaluated immunogenicity of peptides with IFN-g ELISPOT assays in CRC and control patients. We then evaluated the efficacy of vaccination in reducing tumors in the AOM mouse model. We evaluated immunogenicity of peptides with IFN-g ELISPOT assays using vaccinated mice splenocytes. We quantified antigen protein expression in AOM tumors. Results: The eight proteins are: CDC25B, COX-2, EBAG9, EGFR, Fascin-1, IGF-1R, PRL-3 and VCP. For all candidate antigens there was a greater IFN-g response in CRC patients than in controls. Four antigens (COX-2 p&lt;.0001, CDC25B p&lt;.0002, and EGFR p=.01, Fascin-1 p=.05) demonstrated a statistically significant reduction in the development of colon tumors compared to vaccination with adjuvant alone. Conclusions: We conclude that: 1. biologically relevant CRC associated proteins can be identified that are associated with prognosis, 2. epitopes predicted to bind multiple DR alleles, derived from candidate antigens, elicit T cell responses greater in CRC patients than in normal controls, 3. vaccination with peptides derived from four antigens resulted in a statistically significant reduction in the development of colon tumors in a mouse model, and 4. these antigens may represent novel immunologic targets for CRC.

Relationship betweenHLA-DRgene polymorphisms and outcomes of hepatitis B viral infections: A meta-analysis

To assess the rigorous relationship between human leukocyte antigens (HLA)-DR alleles and outcomes of hepatitis B virus (HBV) infections by means of meta-analysis. Medline/PubMed, EMBASE, CNKI and VIP were searched to identify relevant studies. Study quality was evaluated using the Newcastle-Ottawa Scale. Odds ratios (OR) and 95% confidence interval (95% CI) were pooled using Stata 11.0. Subgroup analyses were performed by ethnicity. Heterogeneity and publication bias analyses were performed to validate the credibility. A total of 2609 patients with chronic hepatitis B and 2606 controls spontaneously recovering from prior HBV infection were included. Meta-analysis showed that HLA-DR*04 (OR = 0.72, 95% CI: 0.60-0.85) and DR*13 (OR = 0.27, 95% CI: 0.19-0.37) alleles were significantly associated with HBV clearance while patients carrying HLA-DR*03 (OR = 1.47, 95% CI: 1.16-1.87) or DR*07 (OR = 1.59, 95% CI: 1.24-2.03) alleles had a significantly increased risk of chronic HBV persistence. For the HLA-DR*01 polymorphism, a significantly association with HBV clearance was found in Chinese Han group (OR = 0.48, 95% CI: 0.26-0.86), but not found in other ethnic groups (P = 0.191). For other polymorphisms, no association with the HBV infection outcome was found. HLA-DR*04 and DR*13 alleles may be the protective factors for HBV clearance and HLA-DR*03, and DR*07 alleles may be the risk factors for HBV persistence.

Type 1 diabetes is increasing in very young children, but is the real reason referable only to environmental factors?

In spite of intensive research in recent decades, the causative factors of type 1 diabetes remain unknown. To some extent the disease is genetically influenced, and mostly by certain MHC types. However, 90% of patients with type 1 diabetes have no first-degree relatives, and the pairwise concordance rate for monozygotic twins is \30% [1]. In any event, type 1 diabetes is a disease in which the environment plays a major role [2]. So far, the real factor(s) involved are still unknown, but many are put forward from time to time. In this issue of the journal, you can read the paper by McNamee et al. [3], which found weak evidence of increased risk of type 1 diabetes in children who had neonatal jaundice (OR 1.14; 95% CI 0.99–1.32; P = 0.07), with some evidence of heterogeneity (I = 53%, P = 0.01). The authors conclude that jaundice caused by blood group incompatibility or requiring phototherapy may be associated with a greater increase in type 1 diabetes risk and deserves further study. Several papers have been published on this topic (neonatal factors associated with an increased risk of type 1 diabetes), most of which have been evaluated by two metaanalyses [4, 5]. The first found that increased birth weight is associated with childhood onset, equivalent to a 7% increase in risk for every 1,000 g in weight [4], and the second reported that caesarean section increases the risk by around 20% [5]. A more recent paper provides formal confirmation that the risk of childhood onset diabetes increases with maternal age: 5% for each 5 years of age [6]. Why should neonatal jaundice influence the risk of diabetes in children? There is much speculation, but the main explanation is that blood group incompatibility may be the most important factor, together with the practice of phototherapy, used to treat the more severe cases of jaundice, which may itself be a risk factor. An increased frequency of the DR3 allele was observed also in patients with AB0 incompatibility when compared to healthy controls [7]. In their study, Berzina et al. [7] observed that patients with type 1 diabetes had a significantly higher frequency of DR3, DQ2, DR4 and DQ8 alleles when compared to healthy controls, while no significant difference was observed in frequency of DR3 between AB0 blood group incompatibility and type 1 diabetes patients, leading to the conclusion that DR3 is associated with both the development of type 1 diabetes and ABO incompatibility. This might be the reason for increased risk of childhood diabetes in patients with neonatal jaundice, often due to AB0 incompatibility. The truth is that the rise of childhood type 1 diabetes remains largely unexplained [8, 9], and possibly, it is not the only kind of diabetes affecting young patients. Indeed, we are accustomed to diagnosing type 1 diabetes whenever we treat a child with ‘high blood sugar levels’, as if hyperglycaemia in children always means type 1 diabetes, overlooking the existence of many other forms of diabetes that do not require insulin, for example, monogenic diabetes, mitochondrial diabetes or type 2 diabetes in adolescents [10]. For many years, a differential diagnosis of hyperglycaemia in children has been difficult because of the lack of suitable diagnostic tools: specific autoantibodies, molecular biology techniques, genetic mapping, etc. In the last two decades, an explanation of the pathogenic mechanisms of most forms of hyperglycaemia in children clearly demonstrated that not all of them are due to type 1 diabetes. We have attempted to better define differential diagnosis. On the one hand, papers like the one by McNamee A. E. Scaramuzza (&) G. V. Zuccotti Department of Paediatrics, University of Milano, ‘‘Luigi Sacco Hospital’’, via G.B. Grassi 74, 20157 Milan, Italy e-mail: scaramuzza.andrea@hsacco.it

Gene CNVs and protein levels of complement C4A and C4B as novel biomarkers for partial disease remissions in new-onset type 1 diabetes patients

To determine the roles of complement C4A and C4B gene copy-number variations and their plasma protein concentrations in residual insulin secretion and loss of pancreatic β-cell function in new-onset type 1 diabetes (T1D) patients. We studied 34 patients of European ancestry with new-onset T1D, aged between 3 and 17 yr (10.7 ± 3.45), at Nationwide Children's Hospital in Columbus, Ohio. Gene copy-number and size variations of complement C4A and C4B were determined by genomic Southern blot analyses. C4A and C4B protein phenotypes were elucidated by immunofixation and radial immunodiffusion. Two-digit human leukocyte antigen (HLA)-DRB1 genotypes were determined by sequence-specific polymerase chain reaction. At 1- and 9-month post diagnosis, stimulated C-peptide levels were measured after a standardized mixed-meal tolerance test. The diploid gene copy-numbers of C4A varied from 0 to 4, and those of C4B from 0 to 3. Patients with higher copy-number of C4A or higher C4A plasma protein concentrations at diagnosis had higher C-peptide levels at 1-month post diagnosis (p = 0.008; p = 0.008). When controlled by the Z-score of body mass index, C4A copy-numbers, C4A protein concentrations, the age of disease onset, and the number of HLA-DR3 but not DR4 alleles were significant parameters in determining C-peptide levels. At 9-month post diagnosis, 42.3% of patients remained in partial remission, and these patients were characterized by lower total C4B copy-numbers or lower C4B protein concentrations (p = 0.02; p = 0.0004). C4A appears to associate with the protection of residual β-cell function in new-onset T1D; C4B is correlated with the end of disease remission at 9-month post diagnosis.

Abstract PR-9: Characterization of colon cancer associated antigens which would be key therapeutic targets in the prevention of disease relapse or progression.

Abstract Colon cancer (CRC) is an immunogenic tumor and adaptive immunity may play a role in inhibiting disease relapse. A vaccine to boost cellular immunity in CRC patients could prevent disease recurrence, but there have been few defined immunogenic proteins identified as vaccine candidates. TVG has shown that overexpressed tumor associated proteins, abundant in the cancer state but expressed at basal levels in normal cells, can be immunogenic. We hypothesized that ideal candidate antigens would be ones already validated as prognostic markers in multivariate analysis. We performed a directed literature review using search words e.g. colon cancer, prognosis, biomarker, multivariate analysis. We selected a panel of eight proteins based on (1) incidence of expression, (2) independent predictor of poor prognosis, (3) independent predictor of early disease recurrence, and (4) known biologic function in CRC pathogenesis. Using a web based algorithm program developed by TVG, we identified peptides that were predicted to be high affinity binders across multiple HLA DR alleles. We selected and synthesized 19 peptides predicted to be the highest binders. We evaluated the potential immunogenicity of peptides with IFN-g ELISPOT assays using PBMC from CRC patients and normal controls. The eight proteins are: CDC25B, COX-2, EBAG9, EGFR, Fascin-1, IGF-1R, PRL-3 and VCP. Two of the eight proteins had already been shown to be human tumor antigens. For all candidate antigens there was a greater IFN-g response in CRC patients than in controls; for three proteins, this difference reached statistical significance. We then evaluated the efficacy of vaccination in reducing tumor formation in a mouse model of carcinogen induced CRC. FVB mice were vaccinated with PBS alone, adjuvant alone, or adjuvant plus peptide vaccine. Seven days after final immunization, mice were treated with AOM for 6 weeks, and all mice sacrificed at 25 weeks of age. Four antigens (COX-2 p&amp;lt;.0001, CDC25B p&amp;lt;.0002, and EGFR p=.01, Fascin-1 p=.05) demonstrated a statistically significant reduction in the development of colon tumors compared to vaccination with adjuvant alone. We evaluated the potential immunogenicity of peptides with IFN-g ELISPOT assays using splenocytes from vaccinated mice. We quantified antigen protein expression in AOM tumors. We conclude that: 1. biologically relevant CRC associated proteins can be identified that are associated with prognosis, 2. epitopes predicted to bind multiple DR alleles, derived from candidate antigens, elicit T cell responses greater in CRC patients than in normal controls, 3. vaccination with peptides derived from four antigens resulted in a statistically significant reduction in the development of colon tumors in a mouse model, and 4. these antigens may represent novel immunologic targets for CRC. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr PR-9.