Antigenic Differences between AS03 Adjuvanted Influenza A (H1N1) Pandemic Vaccines: Implications for Pandemrix-Associated Narcolepsy Risk

Background

Narcolepsy results from immune-mediated destruction of hypocretin secreting neurons in hypothalamus, however the triggers and disease mechanisms are poorly understood. Vaccine-attributable risk of narcolepsy reported so far with the AS03 adjuvanted H1N1 vaccination Pandemrix has been manifold compared to the AS03 adjuvanted Arepanrix, which contained differently produced H1N1 viral antigen preparation. Hence, antigenic differences and antibody response to these vaccines were investigated.

Methods and Findings

Increased circulating IgG-antibody levels to Pandemrix H1N1 antigen were found in 47 children with Pandemrix-associated narcolepsy when compared to 57 healthy children vaccinated with Pandemrix. H1N1 antigen of Arepanrix inhibited poorly these antibodies indicating antigenic difference between Arepanrix and Pandemrix. High-resolution gel electrophoresis quantitation and mass spectrometry identification analyses revealed higher amounts of structurally altered viral nucleoprotein (NP) in Pandemrix. Increased antibody levels to hemagglutinin (HA) and NP, particularly to detergent treated NP, was seen in narcolepsy. Higher levels of antibodies to NP were found in children with DQB1*06∶02 risk allele and in DQB1*06∶02 transgenic mice immunized with Pandemrix when compared to controls.

Conclusions

This work identified 1) higher amounts of structurally altered viral NP in Pandemrix than in Arepanrix, 2) detergent-induced antigenic changes of viral NP, that are recognized by antibodies from children with narcolepsy, and 3) increased antibody response to NP in association of DQB1*06∶02 risk allele of narcolepsy. These findings provide a link between Pandemrix and narcolepsy. Although detailed mechanisms of Pandemrix in narcolepsy remain elusive, our results move the focus from adjuvant(s) onto the H1N1 viral proteins.     

HLA‐DRB1 and HLA–DQB1 genes on susceptibility to and protection from allergic bronchopulmonary aspergillosis in patients with cystic fibrosis

Allergic bronchopulmonary aspergillosis (ABPA) is a hypersensitivity pulmonary disease that affects both patients with cystic fibrosis (CF) and those with asthma. HLA‐DRB1 alleles have previously been associated with ABPA–CF susceptibility; however, HLA‐DQB1 allele associations have not been clearly established. The aim of the present study was to investigate HLA class II associations in patients with ABPA–CF and determine their roles in susceptibility or protection. Patients with ABPA–CF, patients with CF without ABPA, patients with asthma without ABPA (AST), and healthy controls were included in this study. DNA was extracted by automatic extractor. HLA‐DRB1 and ‐DQB1 genotyping was performed by the Luminex PCR‐SSOP method (One Lambda, Canoga Park, CA, USA). Allele specific PCR‐SSP was also performed by high‐resolution analysis (One Lambda). Statistical analysis was performed with SSPS and Arlequin software. Both HLA‐DRB1*5:01 and ‐DRB1*11:04 alleles occurred with greater frequency in patients with ABPA–CF than in those with AST and CF and control subjects, corroborating previously published data. On the other hand, analysis of haplotypes revealed that almost all patients with ABPA–CF lacking DRB1*15:01 or DRB1*11:04 carry either DRB1*04, DRB1*11:01, or DRB1*07:01 alleles. In the HLA‐DQB1 region, the HLA‐DQB1*06:02 allele occurred more frequently in patients with ABPA–CF than in those with AST and CF and healthy controls, whereas HLA‐DQB1*02:01 occurred less frequently in patients with ABPA–CF. These data confirm that there is a correlation between HLA‐DRB1*15:01, –DRB1*11:04, DRB1*11:01, –DRB1*04 and –DRB1 * 07:01 alleles and ABPA–CF susceptibility and suggest that HLA‐DQB1*02:01 is an ABPA–CF resistance allele.     

Allele and haplotype frequencies of human leukocyte antigen-A, -B, -C,-DRB1, and -DQB1 in Chinese patients with hematological diseases

The human leukocyte antigen (HLA) system plays a central role in the immune response to pathogens, as well as in organ and allogenic hematopoietic stem cell transplantation (HSCT). Finding a five-locus (i.e., HLA-A, -B, -C, -DRB1, and -DQB1) matched unrelated donor for a patient awaiting HSCT is a major clinical challenge, due to the lack of HLA-identical sibling donors and the high polymorphism of HLA. To date, most studies providing HLA allele frequencies (AF) and haplotype frequencies (HF) in Chinese populations have focused on donors instead of the recipients and have provided data for three loci (HLA-A, -B, and -DR); however, data from five-locus HLA typing in a large sample of patients, especially those with hematological diseases, remains unavailable. Therefore, this study was designed to determine HLA AF and two-, three-, four- and five-locus HF in a large cohort of Chinese Han patients with hematological diseases. The AF and the HF were determined using high-resolution HLA typing data from 2,878 patients. The total number of HLA-A, -B, -C, -DRB1, and -DQB1 alleles was determined to be 48, 92, 49, 52, and 24, respectively. Hardy-Weinberg equilibrium (HWE) analyses indicated significant deviations from HWE for HLA-A, -C, -DRB1, and -DQB1 AF, but not for HLA-B locus. The three most common alleles at each locus were A*11:01, A*24:02, A*02:01; B*46:01, B*40:01, B*13:02; C*01:02, C*07:02, C*06:02; DRB1*09:01, DRB1*15:01, DRB1*07:01; DQB1*03:01, DQB1*03:03, and DQB1*06:01. Our data may help to determine whether the current bone marrow registry contains sufficient diversity to meet the demand.     

The importance of HLA DQB1*0602 typing in Slovene patients with narcolepsy

The HLA class II region genes DQB1*0602 and DQA1*0102 are currently the best genetic predictors for narcolepsy in humans (1(. The aim of this study was to identify the HLA DQ alleles (DQB1*0602 and DQA1*0102) in Slovene sporadic narcoleptic patients. 11 patients who fulfilled ICSD criteria for narcolepsy entered the study. DRB1*1501 DQB1*0602 was present in all the patients while DQA1*0102 was absent in 2 patients. We propose that DQB1*0602 typing is important in diagnosing narcolepsy in Slovene patients     

HLA-DRB1 and HLA-DQB1 Are Associated with Adult-Onset Immunodeficiency with Acquired Anti-Interferon-Gamma Autoantibodies

Recently a newly identified clinical syndrome of disseminated non-tuberculous mycobacterial diseases (with or without other opportunistic infections in adult patients who were previously healthy, has been recognized in association with an acquired autoantibody to interferon-gamma. This syndrome is emerging as an important cause of morbidity and mortality, especially among people of Asian descent. Trigger for the production of this autoantibody remains unknown, but genetic factors are strongly suspected to be involved. We compared HLA genotyping between 32 patients with this clinical syndrome, and 38 controls. We found that this clinical syndrome was associated with very limited allele polymorphism, with HLA-DRB1 and DQB1 alleles, especially HLA-DRB1*15:01, DRB1*16:02, DQB1*05:01 and DQB1*05:02. Odds ratio of DRB1*15:01, DRB1*16:02, DQB1*05:01 and DQB1*05:02 were 7.03 (95% CI, 2.18–22.69, P<0.0001, 9.06 (95% CI, 2.79–29.46, P<0.0001), 6.68 (95% CI, 2.29–19.52, P = 0.0004), and 6.64 (95% CI, 2.30–19.20, P = 0.0004), respectively. Further investigation is warranted to provide better understanding on pathogenesis of this association.     

IgG Abnormality in Narcolepsy and Idiopathic Hypersomnia

Background

A close association between narcolepsy and the Human Leukocyte Antigen (HLA)-DQB1*0602 allele suggests the involvement of the immune system, or possibly an autoimmune process. We investigated serum IgG levels in narcolepsy.

Methodology/Principal Findings

We measured the serum total IgG levels in 159 Japanese narcolepsy-cataplexy patients positive for the HLA-DQB1*0602 allele, 28 idiopathic hypersomnia patients with long sleep time, and 123 healthy controls (the HLA-DQB1*0602 allele present in 45 subjects). The serum levels of each IgG subclass were subsequently measured. The distribution of serum IgG was significantly different among healthy controls negative for the HLA-DQB1*0602 allele (11.66±3.55 mg/ml), healthy controls positive for the HLA-DQB1*0602 allele (11.45±3.43), narcolepsy patients (9.67±3.38), and idiopathic hypersomnia patients (13.81±3.80). None of the following clinical variables, age, disease duration, Epworth Sleepiness Scale, smoking habit and BMI at the time of blood sampling, were associated with IgG levels in narcolepsy or idiopathic hypersomnia. Furthermore we found the decrease in IgG1 and IgG2 levels, stable expression of IgG3, and the increase in the proportion of IgG4 in narcolepsy patients with abnormally low IgG levels. The increase in the proportion of IgG4 levels was also found in narcolepsy patients with normal serum total IgG levels. Idiopathic hypersomnia patients showed a different pattern of IgG subclass distribution with high IgG3 and IgG4 level, low IgG2 level, and IgG1/IgG2 imbalance.

Conclusions/Significance

Our study is the first to determine IgG abnormalities in narcolepsy and idiopathic hypersomnia by measuring the serum IgG levels in a large number of hypersomnia patients. The observed IgG abnormalities indicate humoral immune alterations in narcolepsy and idiopathic hypersomnia. Different IgG profiles suggest immunological differences between narcolepsy and idiopathic hypersomnia.     

Associations of <Emphasis Type="Italic">CTLA4</Emphasis> +49 A/G Dimorphism and HLA-DRB1*/DQB1* Alleles With Type 1 Diabetes from South India

The aim of present study was to elucidate the association of CTLA4 +49 A/G and HLA-DRB1*/DQB1* gene polymorphism in south Indian T1DM patients. The patients and controls (n?=?196 each) were enrolled for CTLA4 and HLA-DRB1*/DQB1* genotyping by RFLP/PCR-SSP methods. The increased frequencies of CTLA4 ‘AG’ (OR?=?1.99; p?=?0.001), ‘GG’ (OR?=?3.94; p?=?0.001) genotypes, and ‘G’ allele (OR?=?2.42; p?=?9.26?×?10^?8) were observed in patients. Reduced frequencies of ‘AA’ (OR?=?0.35; p?=?7.19?×?10^?7) and ‘A’ (OR?=?0.41; p?=?9.26?×?10^?8) in patients revealed protective association. Among HLA-DRB1*/DQB1* alleles, DRB1*04 (OR?=?3.29; p?=?1.0?×?10^?5), DRB1*03 (OR?=?2.81; p?=?1.9?×?10^?6), DQB1*02:01 (OR?=?2.93; p?=?1.65?×?10^?5), DQB1*02:02 (OR?=?3.38; p?=?0.0003), and DQB1*03:02 (OR?=?7.72; p?=?0.0003) were in susceptible association. Decreased frequencies of alleles, DRB1*15 (OR?=?0.32; p?=?2.55?×?10^?7), DRB1*10 (OR?=?0.45; p?=?0.002), DQB1*06:01 (OR?=?0.43; p?=?0.0001), and DQB1*05:02 (OR?=?0.28; p?=?2.1?×?10^?4) in patients were suggested protective association. The combination of DRB1*03+AG (OR?=?5.21; p?=?1.4?×?10^?6), DRB1*04+AG (OR?=?2.14; p?=?0.053), DRB1*04+GG (OR?=?5.21; p?=?0.036), DQB1*02:01+AG (OR?=?4.44; p?=?3.6?×?10^?5), DQB1*02:02+AG (OR?=?20.9; p?=?9.5?×?10^?4), and DQB1*02:02+GG (OR?=?4.06; p?=?0.036) revealed susceptible association. However, the combination of DRB1*10+AA (OR?=?0.35; p?=?0.003), DRB1*15+AA (OR?=?0.22; p?=?5.3?×?10^?7), DQB1*05:01+AA (OR?=?0.45; p?=?0.007), DQB1*05:02+AA (OR?=?0.17; p?=?1.7?×?10^?4), DQB1*06:01+AA (OR?=?0.40; p?=?0.002), and DQB1*06:02+AG (OR?=?0.34; p?=?0.001) showed decreased frequency in patients, suggesting protective association. In conclusion, CTLA4/HLA-DR/DQ genotypic combinations revealed strong susceptible/protective association toward T1DM in south India. A female preponderance in disease associations was also documented.     

Complex HLA-DR and -DQ interactions confer risk of narcolepsy-cataplexy in three ethnic groups

Human narcolepsy-cataplexy, a sleep disorder associated with a centrally mediated hypocretin (orexin) deficiency, is tightly associated with HLA-DQB1*0602. Few studies have investigated the influence that additional HLA class II alleles have on susceptibility to this disease. In this work, 1,087 control subjects and 420 narcoleptic subjects with cataplexy, from three ethnic groups, were HLA typed, and the effects of HLA-DRB1, -DQA1, and -DQB1 were analyzed. As reported elsewhere, almost all narcoleptic subjects were positive for both HLA-DQA1*0102 and -DQB1*0602. A strong predisposing effect was observed in DQB1*0602 homozygotes, across all ethnic groups. Relative risks for narcolepsy were next calculated for heterozygous DQB1*0602/other HLA class II allelic combinations. Nine HLA class II alleles carried in trans with DQB1*0602 were found to influence disease predisposition. Significantly higher relative risks were observed for heterozygote combinations including DQB1*0301, DQA1*06, DRB1*04, DRB1*08, DRB1*11, and DRB1*12. Three alleles-DQB1*0601, DQB1*0501, and DQA1*01 (non-DQA1*0102)-were found to be protective. The genetic contribution of HLA-DQ to narcolepsy susceptibility was also estimated by use of lambda statistics. Results indicate that complex HLA-DR and -DQ interactions contribute to the genetic predisposition to human narcolepsy but that additional susceptibility loci are also most likely involved. Together with the recent hypocretin discoveries, these findings are consistent with an immunologically mediated destruction of hypocretin-containing cells in human narcolepsy-cataplexy.     

Study of the HLA class II allele polymorphism and phylogenetic analysis in Vojvodina population

The polymorphism at the HLA DRB1 and DQB1 loci in the population of Vojvodina was studied by PCR-SSP method. A total of 13 DRB1 and 5 DQB1 specificities displaying population-specific frequency distribution pattern were described. The most frequent HLA Class II alleles in Vojvodina population were: HLA-DRB1*11 (af = 0.30), −DRB1*04 (af = 0.28), −DRB1*07 (af = 0.21), −DRB1*13 and −DRB1*16 (af = 0.18), −DQB1*03 (af = 0.64), −DQB1*05 (af = 0.39) and −DQB1*02 (af = 0.35). The haplotypes with high frequencies (≥0.02) included HLA DRB1*11 DQB1*03 (0.0825), DRB1*04DQB1*03 (0.0725), DRB1*07DQB1*02 (0.0475). The allele DRB1*07 showed the strongest association with DQB1*02 (Δ = 0.0261, gC² = 4.437) and DRB1*13 allele with DQB1*06 (Δ = 0.0222, gC² = 4.247). The allelic frequencies and populations distance dendrogram revealed the closest relationship of Vojvodina population with Hungarians, Croat, and Greeks which can be the result of turbulent migration within this region and admixture with neighbour populations during the history.     

HLA association with nasopharyngeal carcinoma in southern Tunisia

In order to study the association of HLA-A, -B and/or DRB1, DQB1 and the nasopharyngeal carcinoma (NPC), 141 patients affected with NPC were typed for the HLA class I by serology method of microlymphocytotoxicity. Among these patients 101 were genotyped for HLA class II system by the PCR-SSP technique. HLA typing results were compared to those of 116 controls. We found that the HLA-A31 and -A33 antigens were significantly more expressed in patients than in the controls (P = 0.016 and 0.010, respectively) and the HLA-A19 antigen, was significantly more frequent in patients when compared to the controls (P = 0.007). The HLA-DRB1*03 and DRB1*13 alleles were significantly more frequent in patients as compared to the controls. The DRB1*01 allele was expressed with a frequency of 20.69% in the controls whereas it was only detected in 3.96% of the NPC patients. Furthermore, the DQB1*05 allele was expressed at a frequency which was significantly less important in affected patient (P = 0.03), whereas, the DQB1*02 allele was more frequent in patients (P = 0.643 × 10⁻⁴). Thus our study revealed a significant increase of HLA-A31, A33, A19, B16, B53 and DRB1*03, DRB1*13 and DQB1*02 alleles in our patients. These markers could play a predisposing role in the development of NPC. In contrast, a decrease of HLA-B14, -B35 and DRB1*01 and DQB1*05 alleles was found suggesting a likely protective effect.     

Analysis of extended HLA haplotypes in multiple sclerosis and narcolepsy families confirms a predisposing effect for the class I region in Tasmanian MS patients

Human leucocyte antigen (HLA)-DRB1*15 is associated with predisposition to multiple sclerosis (MS), although conjecture surrounds the possible involvement of an alternate risk locus in the class I region of the HLA complex. We have shown previously that an alternate MS risk allele(s) may be encompassed by the telomerically extended DRB1*15 haplotype, and here, we have attempted to map the putative variant. Thirteen microsatellite markers encompassing a 6.79-megabase (D6S2236-G51152) region, and the DRB1 and DQB1 genes, were genotyped in 166 MS simplex families and 104 control families from the Australian State of Tasmania and 153 narcolepsy simplex families (trios) from the USA. Complementary approaches were used to investigate residual predisposing effects of microsatellite alleles comprising the extended DRB1*15 haplotype taking into account the strong predisposing effect of DRB1*15: (1) Disease association of the extended DRB1*15 haplotype was compared for MS and narcolepsy families--predisposing effects were observed for extended class I microsatellite marker alleles in MS families, but not narcolepsy families; (2) disease association of the extended DRB1*15 haplotype was investigated after conditioning MS and control haplotypes on the absence of DRB1*15--a significant predisposing effect was observed for a 627-kb haplotype (D6S258 allele 8-MOGCA allele 4; MOG, myelin oligodendrocyte glycoprotein) spanning the extended class I region. MOGCA allele 4 displayed the strongest predisposing effect in DRB1*15-conditioned haplotypes (p = 0.0006; OR 2.83 [1.54-5.19]). Together, these data confirm that an alternate MS risk locus exists in the extended class I region in Tasmanian MS patients independent of DRB1*15.     

HLA alleles associated with the adaptive immune response to smallpox vaccine: a replication study

We previously reported HLA allelic associations with vaccinia virus (VACV)-induced adaptive immune responses in a cohort of healthy individuals (n = 1,071 subjects) after a single dose of the licensed smallpox (Dryvax) vaccine. This study demonstrated that specific HLA alleles were significantly associated with VACV-induced neutralizing antibody (NA) titers (HLA-B*13:02, *38:02, *44:03, *48:01, and HLA-DQB1*03:02, *06:04) and cytokine (HLA-DRB1*01:03, *03:01, *10:01, *13:01, *15:01) immune responses. We undertook an independent study of 1,053 healthy individuals and examined associations between HLA alleles and measures of adaptive immunity after a single dose of Dryvax-derived ACAM2000 vaccine to evaluate previously discovered HLA allelic associations from the Dryvax study and determine if these associations are replicated with ACAM2000. Females had significantly higher NA titers than male subjects in both study cohorts [median ID50 discovery cohort 159 (93, 256) vs. 125 (75, 186), p < 0.001; replication cohort 144 (82, 204) vs. 110 (61, 189), p = 0.024]. The association between the DQB1*03:02 allele (median ID₅₀ discovery cohort 152, p = 0.015; replication cohort 134, p = 0.010) and higher NA titers was replicated. Two HLA associations of comparable magnitudes were consistently found between DRB1*04:03 and DRB1*08:01 alleles and IFN-γ ELISPOT responses. The association between the DRB1*15:01 allele with IFN-γ secretion was also replicated (median pg/mL discovery cohort 182, p = 0.052; replication cohort 203, p = 0.014). Our results suggest that smallpox vaccine-induced adaptive immune responses are significantly influenced by HLA gene polymorphisms. These data provide information for functional studies and design of novel candidate smallpox vaccines.     

The HLA-DRB4 gene is present in half of the Spanish HLA-DQ2-negative celiac patients

We studied nine consecutive DQ2-negative celiacs [from a group of 186 consecutive celiac disease (CD) patients] for the presence of the HLA-DQB1, DRB1, and DRBx alleles. HLA-DR53 was present in only 5 out of 9 (55%) of DQ2-negative patients. DRB4 (DR53) positivity -39% of chromosomes--among Spanish DQ2-negative CD patients is due to both DR4- and DR7-positive cases. Spanish DQ2-positive patients show a high frequency of DR7/DR11 heterozygous carriers of DRB4 (DR53). One-third of our DQ2-negative celiac patients have DRB1*04 (DR4). Six patients are DR4 negative: at least one of the DQ2 alleles (DQA1*0501/DQB1*02) is present in four cases, but none of the alleles of risk, including DR53, were found in the remaining two cases, both of whom carry DQB1*06 alleles (*0602/3 and 0604). The fact that half of our DQ2-negative patients lack DRB4 (DR53) leads us to believe that this gene is not an essential factor to confer CD susceptibility.     

No Serological Evidence of Influenza A H1N1pdm09 Virus Infection as a Contributing Factor in Childhood Narcolepsy after Pandemrix Vaccination Campaign in Finland

Background

Narcolepsy cataplexy syndrome, characterised by excessive daytime sleepiness and cataplexy, is strongly associated with a genetic marker, human leukocyte antigen (HLA) DQB1*06:02. A sudden increase in the incidence of childhood narcolepsy was observed after vaccination with AS03-adjuvanted Pandemrix influenza vaccine in Finland at the beginning of 2010. Here, we analysed whether the coinciding influenza A H1N1pdm pandemic contributed, together with the Pandemrix vaccination, to the increased incidence of childhood narcolepsy in 2010. The analysis was based on the presence or absence of antibody response against non-structural protein 1 (NS1) from H1N1pdm09 virus, which was not a component of Pandemrix vaccine.

Methods

Non-structural (NS) 1 proteins from recombinant influenza A/Udorn/72 (H3N2) and influenza A/Finland/554/09 (H1N1pdm09) viruses were purified and used in Western blot analysis to determine specific antibody responses in human sera. The sera were obtained from 45 patients who fell ill with narcolepsy after vaccination with AS03-adjuvanted Pandemrix at the end of 2009, and from controls.

Findings

Based on quantitative Western blot analysis, only two of the 45 (4.4%) Pandemrix-vaccinated narcoleptic patients showed specific antibody response against the NS1 protein from the H1N1pdm09 virus, indicating past infection with the H1N1pdm09 virus. Instead, paired serum samples from patients, who suffered from a laboratory confirmed H1N1pdm09 infection, showed high levels or diagnostic rises (96%) in H1N1pdm virus NS1-specific antibodies and very high cross-reactivity to H3N2 subtype influenza A virus NS1 protein.

Conclusion

Based on our findings, it is unlikely that H1N1pdm09 virus infection contributed to a sudden increase in the incidence of childhood narcolepsy observed in Finland in 2010 after AS03-adjuvanted Pandemrix vaccination.     

HLA-DQ primarily confers protection and HLA-DR susceptibility in type I (insulin-dependent) diabetes studied in population-based affected families and controls.

The association between HLA-DR and -DQ and insulin-dependent diabetes mellitus (IDDM) in a defined high-incidence area was analyzed in a total of 58 population-based patients, representing 77% of IDDM patients with age at onset below 16 years, and in 92 unrelated parents in control families without IDDM. HLA haplotypes were confirmed by analyzing first-degree relatives in both groups. Seven different methods were used to analyze risk: (1) odds ratio, (2) absolute risk, (3) haplotype relative risk, (4) transcomplementation relative risk, (5) relative predisposing effects, (6) stratification analysis, and (7) test of predisposing allele on haplotype. DQB1*0302 indicated somewhat higher risk than did DR4, while DR3 had a higher risk than DQB1*0201; however, the 95% confidence intervals of the risk estimates overlapped. The positive association between IDDM and the DQB1*0201-DQA1*0501-DR3 haplotype seems to be due to DR3 or to an unknown linked gene. More important, DQA1*0301 was present among 93% of the patients, and this allele in various transcomplementation combinations with DQB1 alleles showed closer association to IDDM than did any other alleles. The strong negative association of the DQB1*0602 allele also in the presence of either DR4 or DQB1*0302 or both suggests that, in a high-risk population for IDDM, HLA-DQ primarily confers protection, perhaps by induction of tolerance. Consistent with known functions, HLA-DR may primarily confer susceptibility, perhaps by induction of autoreactive T lymphocytes.     

Gluten-specific T cells cross-react between HLA-DQ8 and the HLA-DQ2α/DQ8β transdimer

Because susceptibility to celiac disease is associated strongly with HLA-DQ2 (DQA1*05/DQB1*02) and weakly with HLA-DQ8 (DQA1*03/DQB1*03), a subset of patients carries both HLA-DQ2 and HLA-DQ8. As a result, these patients may express two types of mixed HLA-DQ2/8 transdimers (encoded by DQA1*05/DQB1*03 and DQA1*03/DQB1*02) in addition to HLA-DQ2 and HLA-DQ8. Using T cells from a celiac disease patient expressing HLA-DQ8trans (encoded by DQA*0501/DQB*0302), but neither HLA-DQ2 nor HLA-DQ8, we demonstrate that this transdimer is expressed on the cell surface and can present multiple gluten peptides to T cell clones isolated from the duodenum of this patient. Furthermore, T cell clones derived from this patient and HLA-DQ2/8 heterozygous celiac disease patients respond to gluten peptides presented by HLA-DQ8trans, as well as HLA-DQ8, in a similar fashion. Finally, one gluten peptide is recognized better when presented by HLA-DQ8trans, which correlates with preferential binding of this peptide to HLA-DQ8trans. These results implicate HLA-DQ8trans in celiac disease pathogenesis and demonstrate extensive T cell cross-reactivity between HLA-DQ8 and HLA-DQ8trans. Because type 1 diabetes is strongly associated with the presence of HLA-DQ8trans, our findings may bear relevance to this disease as well.     

The Prevalence and Characteristics of Primary Headache and Dream-Enacting Behaviour in Japanese Patients with Narcolepsy or Idiopathic Hypersomnia: A Multi-Centre Cross-Sectional Study

Background

Because the prevalence and characteristics of primary headache have yet to be thoroughly studied in patients with hypersomnia disorders, including narcolepsy and idiopathic hypersomnia, we examined these parameters in the Japanese population.

Methods

In a multicentre cross-sectional survey, among 576 consecutive outpatients with sleep disorders, 68 narcolepsy patients and 35 idiopathic hypersomnia patients were included. Additionally, 61 healthy control subjects participated. Semi-structured headache questionnaires were administered to all participants.

Results

The patients with narcolepsy (52.9%) and idiopathic hypersomnia (77.1%) more frequently experienced headache than the healthy controls (24.6%; p<0.0001). The prevalence rates were 23.5%, 41.2% and 4.9% for migraine (p<0.0001) and 16.2%, 23.5% and 14.8% (p = 0.58) for tension-type headache among the narcolepsy patients, the idiopathic hypersomnia patients and the control subjects, respectively. Those who experienced migraine more frequently experienced excessive daytime sleepiness, defined as an Epworth Sleepiness Scale score of ≥10, than those who did not experience headache among the patients with narcolepsy (93.8% vs. 65.6%, p = 0.040) and idiopathic hypersomnia (86.7% vs. 37.5%, p = 0.026). Dream-enacting behaviour (DEB), as evaluated by the rapid eye movement sleep disorders questionnaire, was more frequently observed in the narcolepsy patients than in the idiopathic hypersomnia patients and the control subjects. An increased DEB frequency was observed in the narcolepsy patients with migraines compared to those without headache.

Conclusions

Migraines were frequently observed in patients with narcolepsy and idiopathic hypersomnia. DEB is a characteristic of narcolepsy patients. Further studies are required to assess the factors that contribute to migraines in narcolepsy and idiopathic hypersomnia patients.     

HLA-C, DRB1 and DQB1 alleles involved in genetic predisposition to psoriasis vulgaris in the Slovak population

Psoriasis vulgaris is a complex chronic skin disease with immunological and genetic background. The most important predisposing genetic factors in psoriasis are genes of the human leukocyte antigen (HLA) region. Accumulative evidence has shown that several HLA alleles are closely associated with psoriasis; however, they tend to vary in different racial and ethnic backgrounds. One hundred forty-seven unrelated Slovak patients with psoriasis vulgaris (average age at onset 28?±?14 years) were genotyped for the HLA-C, DQB1 and DRB1 alleles by the polymerase chain reaction using sequence-specific primers. Allele frequencies observed in the group of psoriatic patients were compared to those obtained in the ethnically matched control group comprising 194 subjects with no history of psoriasis. Susceptibility to psoriasis vulgaris in our study group is significantly associated with HLA-C*06 (odds ratio (OR)?=?3.85), DRB1*07 (OR?=?2.56) and DQB1*02 (OR?=?1.09), respectively, whereas DRB*01 (OR?=?0.05) is associated negatively. Hereby, we provide the first report on the association of HLA-C, DRB1 and DQB1 alleles with psoriasis in the Slovak population. Our findings confirm HLA-C*06 and DRB1*07 as the most important genetic risk factors for psoriasis. However, the role of HLA genes as causative in the pathogenesis of the disease remains unclear. Identification of genetic factors that increase the risk of psoriasis is a precondition that helps to elucidate the pathogenesis of this troubling disease and identify targets for a more specific and effective therapy.     

Linkage of human narcolepsy with HLA association to chromosome 4p13-q21

Although narcolepsy is highly associated with human leukocyte antigen (HLA) DQ6/DQB1*0602 and/or DR2/DRB1*1501, most individuals with the HLA haplotype are free of narcolepsy. This indicates that HLA alone makes a relatively small contribution to the development of narcolepsy and that a non-HLA gene(s) can contribute to the genetic predisposition even in narcoleptic cases with HLA association. We conducted a genome-wide linkage search for narcolepsy in eight Japanese families with 21 DR2-positive patients (14 narcoleptic cases with cataplexy and 7 cases with an incomplete form of narcolepsy). A lod score of 3.09 suggested linkage to chromosome 4p13-q21. A lod score of 1.53 was obtained at the HLA-DRB1 locus, though this lod score may be biased since all the affected patients and many of the family members were DR2-positive. No other loci including hypocretin, hypocretin receptor 1, and hypocretin receptor 2 had lod scores greater than 1.0. The present study suggests that chromosome 4p13-q21 contains a second locus for HLA-associated human narcolepsy.