Evidence for more than one Parkinson's disease-associated variant within the HLA region.

Parkinson's disease (PD) was recently found to be associated with HLA in a genome-wide association study (GWAS). Follow-up GWAS's replicated the PD-HLA association but their top hits differ. Do the different hits tag the same locus or is there more than one PD-associated variant within HLA? We show that the top GWAS hits are not correlated with each other (0.00≤r(2)≤0.15). Using our GWAS (2000 cases, 1986 controls) we conducted step-wise conditional analysis on 107 SNPs with P<10(-3) for PD-association; 103 dropped-out, four remained significant. Each SNP, when conditioned on the other three, yielded P(SNP1) = 5×10(-4), P(SNP2) = 5×10(-4), P(SNP3) = 4×10(-3) and P(SNP4) = 0.025. The four SNPs were not correlated (0.01≤r(2)≤0.20). Haplotype analysis (excluding rare SNP2) revealed increasing PD risk with increasing risk alleles from OR = 1.27, P = 5×10(-3) for one risk allele to OR = 1.65, P = 4×10(-8) for three. Using additional 843 cases and 856 controls we replicated the independent effects of SNP1 (P(conditioned-on-SNP4) = 0.04) and SNP4 (P(conditioned-on-SNP1) = 0.04); SNP2 and SNP3 could not be replicated. In pooled GWAS and replication, SNP1 had OR(conditioned-on-SNP4) = 1.23, P(conditioned-on-SNP4) = 6×10(-7); SNP4 had OR(conditioned-on-SNP1) = 1.18, P(conditioned-on-SNP1) = 3×10(-3); and the haplotype with both risk alleles had OR = 1.48, P = 2×10(-12). Genotypic OR increased with the number of risk alleles an individual possessed up to OR = 1.94, P = 2×10(-11) for individuals who were homozygous for the risk allele at both SNP1 and SNP4. SNP1 is a variant in HLA-DRA and is associated with HLA-DRA, DRB5 and DQA2 gene expression. SNP4 is correlated (r(2) = 0.95) with variants that are associated with HLA-DQA2 expression, and with the top HLA SNP from the IPDGC GWAS (r(2) = 0.60). Our findings suggest more than one PD-HLA association; either different alleles of the same gene, or separate loci.

Expression of IFNalpha-inducible genes and modulation of HLA-DR and thyroid stimulating hormone receptors in Graves' disease.

Interferon alpha (IFNalpha) plays an important role in the pathogenesis of different autoimmune diseases. IFNalpha is widely used for the treatment of chronic viral infections, particularly chronic hepatitis C virus infection; however, several case reports have emerged describing autoimmune conditions, such as Graves' disease (GD), that have developed in the patients receiving IFNalpha. The mechanism by which IFNalpha is involved in GD remains poorly understood. We investigated the expression of IFNalpha and IFNalpha-inducible genes (IFIGs) in GD and found that IFIGs were overexpressed in 60% of 54 clinical diagnostic GD patients. These elevated IFIGs correlated with serological levels of autoantibody to thyroid stimulating hormone receptor (TSHR). Recombinant human IFNalpha stimulated primary cultured thyrocytes resulted in not only high level expression of IFIGs, but also, more importantly, expression of MHC-II antigens (HLA-DR3 and HLA-DR5) and TSHR in GD subjects. Furthermore, thyroid gland tissues from GD patients over express HLA-DR, TSHR and IFNalpha receptors at both messenger RNA and protein levels. Taken together, these data indicated that in GD patients, IFNalpha can function on thyroid tissue to induce a number of genes, particularly MHC class II molecules which may enhance autoantigen presentation of TSHR on thyrocytes.

Targeting TRAIL death receptors.

The natural occurring tumor necrosis factor related apoptosis-inducing ligand (TRAIL) induces apoptosis following binding to the two TRAIL death receptors (DRs). Its recombinant form and monoclonal antibodies against the TRAIL DRs induce cell death in a wide variety of tumor cell lines and xenografts without causing toxicity to normal cells and are therefore potential attractive anticancer agents. These agents are currently in early clinical development. The phase 1 and 2 studies showed until now limited toxicity and tumor responses have been observed. Ongoing studies focus especially on combination of these agents with other targeted therapies or cytotoxic therapies. In this review, we summarize current knowledge on these agents and highlight their potential role in the intrinsically chemotherapy-resistant glioblastomas. In addition, we discuss the mechanisms to sensitize tumors cells to rhTRAIL by combination with the proteasome inhibitor bortezomib.

Genetic insights into the disease mechanisms of type II mixed cryoglobulinemia induced by hepatitis C virus.

The ability of the immune system to distinguish between self and non-self is critical to the functioning of the immune response. A breakdown in these mechanisms can lead to the onset of autoimmune disease. Clinical and molecular data suggest that shared immunogenetic mechanisms lead to the autoimmune process. The most studied part of the autoimmune process is the human leukocyte antigen (HLA) region. Recently, progress has been made in narrowing down HLA cluster classifications based on structural and functional features of HLA alleles. Using this approach we have investigated 175 patients with hepatitis C virus (HCV)-induced type II cryoglobulinemia (MC), and compared them to a control group of 14,923 bone marrow donors. Additionally, we investigated the frequency of HLA homozygosity in the same groups of subjects. Our results provide evidence of a role for DR5 and DQ3 HLA class II clusters and a higher frequency of HLA homozygous leading to the clinical outcome of type II mixed cryoglobulinemic autoimmune disease. The DR5 cluster is characterized by a Glu in beta 9 and its polymorphism is connected with preferred anchors at beta 9 of the binding peptide, while the DQ3 cluster is characterized by Glu B86 and Leu B87, which allows the binding of large hydrophobic amino acids at p1 of the binding peptide. The mechanisms by which variations in HLA lead to autoimmunity remain unknown, although they are likely to be mediated by continuous presentation of HCV epitopes to T cells and a genetic background that limits the effective clearance of HCV. The results presented in this paper have increased our knowledge of the mechanism of autoimmune disease and B-cell lymphoproliferation during HCV infection. The work was performed in accordance with the principles of the 1983 Declaration of Helsinki. There is no conflict of interest.

Allergic bronchopulmonary aspergillosis: a US perspective.

PURPOSE OF REVIEW: The present article is an update of allergic bronchopulmonary aspergillosis. Although a rare condition, allergic bronchopulmonary aspergillosis does affect a number of patients with asthma and cystic fibrosis. Prompt recognition and treatment of the disease is critical to improving patient outcomes. RECENT FINDINGS: There is currently much active research being performed in the area of allergic bronchopulmonary aspergillosis. Fascinating insights are being made into the pathophysiology and genetics of the disease. Additionally, research is ongoing on the use of recombinant Aspergillus allergens as an aid to the diagnosis of allergic bronchopulmonary aspergillosis. SUMMARY: These new insights into the genetics and pathophysiology of allergic bronchopulmonary aspergillosis and the development of these new diagnostic techniques could ultimately lead to improved patient treatment. These areas form an important basis for further research.

Studies of HLA associations in male and female patients with Guillain-Barré syndrome (GBS) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP).

HLA associations are found to differ with the gender of the patient in some autoimmune diseases. Here we have investigated whether there are gender-related HLA associations in Guillain-Barré syndrome (GBS) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), both of which occur more frequently in male patients than in females. In GBS, no particular HLA associations were noted, except for a slight negative association in both males and females for carriage of HLA-DR5. In CIDP, the gene frequency and the frequency of individuals positive for HLA-DR2 were greater in female patients than female controls, although this was statistically significant only for the gene frequency. Furthermore more female CIDP patients were homozygous for DR2, than male CIDP patients, or male or female controls and patients with GBS. This suggests that sex-related factors may interact with the risk associated with carriage of HLA-DR2 for development of CIDP.

Identification of two Melan-A CD4+ T cell epitopes presented by frequently expressed MHC class II alleles.

Because of its expression pattern restricted to cells of the melanocytic lineage and to melanoma cells, Melan-A is an important target of immunotherapeutic approaches for the treatment of melanoma. Identification of Melan-A derived sequences recognized by specific T cells is therefore of great interest for the development of these therapeutic strategies. Using circulating CD4(+) T cells from healthy donors, we identified two Melan-A-derived CD4(+) T cell epitopes mapping to the 1-20 and 91-110 regions of the protein and restricted by HLA-DR11 and HLA-DR52 molecules, respectively. CD4(+) T cells specific for the identified epitopes were able to recognize the native antigen when endogenously expressed by antigen presenting cells and tumor cells. In addition, CD4(+) T cells specific for Melan-A 91-110 recognized the epitope after exogenous processing and presentation of Melan-A recombinant protein. Identification of these epitopes will be instrumental for the evaluation of the immune response to Melan-A in cancer patients.

DR antigens influence graft outcome and HCV recurrence after liver transplantation.

Hepatitis C (HCV) recurrence following liver transplantation is universal. However, the severity of recurrence is highly variable between patients. We speculated that recipient DR antigens or the level of DR mismatching between the recipient and the donor might affect the severity of HCV recurrence and allograft survival. Clinical outcome was compared between HCV+ recipients with DR2, DR3, or DR5 versus HCV+ recipients with all other DR antigens. Recipients with DR3 had reduced allograft survival (P < .02), a higher rate of HCV recurrence (P < .05), and more severe liver disease (P < .05). Recipients with DR5 had superior allograft survival (P < .05), low rates of HCV recurrence (P < .05), and benign liver disease (P < .05). Clinical outcome of recipients with DR2 was equivalent (P = Ns) to the non-DR2, -3, -5 recipients. The incidence of acute rejection was equivalent (P = Ns) in all groups. The level of DR mismatching between donor and recipient did not affect HCV recurrence or severity. However, allograft survival was better (P < .05) in recipients with zero DR mismatches. The data show that host genetic factors play an important role in HCV recurrence and allograft outcome after liver transplantation. In addition, identification of DR antigens may help predict an HCV+ patient's relative risk for severe HCV recurrence.

Different contribution of class II HLA in fulminant and typical autoimmune type 1 diabetes mellitus.

AIMS/HYPOTHESIS: Fulminant type 1 diabetes, which is characterised by a markedly acute onset of diabetes and an absence of islet-related autoantibodies, accounts for 20% of type 1 diabetes in Japan. We aimed to clarify the contribution of the HLA subtype to fulminant type 1 diabetes in Japanese. METHODS: We determined the serological subtypes of HLA-A, -DR and -DQ in 115 patients with fulminant type 1 diabetes, 98 patients with typical type 1A diabetes and 190 normal control subjects. RESULTS: The frequency of HLA-DR4, but not DR9, was significantly higher in fulminant type 1 diabetes, while those of HLA-DR1, DR2, DR5 and DR8 were significantly lower than those in controls. In contrast, DR9 but not DR4 was more frequent and DR2 was extremely rare in typical type 1A diabetes. Haplotype analysis revealed that DR4-DQ4 was significantly more frequent, and both DR2-DQ1 and DR8-DQ1 were less frequent in fulminant diabetes. In type 1A diabetes, DR2-DQ1 was extremely rare while DR9-DQ3 was significantly more frequent. In the combination analysis, the homozygotes of DR4-DQ4 in fulminant type 1 diabetes and DR9-DQ3 in typical type 1A diabetes indicated high odds ratios (13.3 and 13.3, respectively). CONCLUSIONS/INTERPRETATION: Our results suggest that class II HLA contributes to the development of fulminant type 1 diabetes. Susceptibility and resistance of the HLA subtype to type 1 diabetes are distinct between fulminant and typical autoimmune type 1 diabetes.

Expression of TRAIL, DR4, and DR5 in kidney and serum from patients receiving renal transplantation.

Renal transplantation is the best treatment of some end-stage renal diseases. Unfortunately, not every transplant is successful due to the rejection or dysfunction of the transplanted kidney. Many cytokines participate in rejection by inducing inflammation or apoptosis. In this study, the expressions of TRAIL, DR4, and DR5 in rejected renal tissue and of serum soluble TRAIL (sTRAIL) in patients with kidney rejection were investigated by immunohistochemical staining and sandwich enzyme-linked immunosorbent assay, respectively. The results showed that the expression of TRAIL, DR4 and DR5, and serum sTRAIL levels were markedly upregulated among renal transplant patients. Since both membrane and soluble forms of TRAIL can induce apoptosis of DR4/DR5-expressing cells via recruiting FADD and caspase 8, elevated TRAIL and its receptors may participate in renal graft rejection.

Myelin basic protein gene is associated with MS in DR4- and DR5-positive Italians and Russians.

BACKGROUND: The myelin basic protein (MBP) gene may confer genetic susceptibility to multiple sclerosis (MS). The association of MS with alleles of the (TGGA)n variable number tandem repeat (VNTR) 5' to the MBP gene is the subject of conflicting reports. OBJECTIVE: To study possible MS association with VNTR alleles of MBP gene in ethnic Italians and ethnic Russians. METHODS: Two hundred sixty-nine unrelated patients with definite MS and 385 unrelated healthy control subjects from Italy and Russia were genotyped for the MBP VNTR region and for the human leukocyte antigen (HLA) class II DRB1 gene. The phenotype, allele, and genotype frequencies for two groups of MBP alleles were determined. Patients and control subjects were stratified according to HLA-DRB1 phenotypes. RESULTS: The distribution of MBP alleles and genotypes in the two ethnic groups, including both MS patients and control subjects, was very similar. When MS patients and healthy control subjects were stratified according to HLA-DRB1 phenotypes, a significant association of MS with MBP alleles was found only in the DR4- and DR5-positive subgroups. A significant association with MBP alleles was also observed in the nonstratified groups, owing mainly to the contribution of the DR4- and DR5-positive individuals. CONCLUSION: Polymorphism of the MBP or another gene in its vicinity appears to contribute to the etiology of MS for the subgroups of DR4- and DR5-positive Italians and Russians.

T-cell receptor bias in patients with allergic bronchopulmonary aspergillosis.

CD4(+) Th2 helper cell mediated immune responses have been shown to play a crucial role in the pathogenesis of ABPA. HLA and TCR are the candidate genes, which can influence the specificity of these responses. We have previously established a strong association of HLA DR2/5 in ABPA susceptibility. The study was designed to determine whether allergen specific T cell express a limited usage of T cell receptor (TCR) Vbeta gene repertoire in ABPA and to find an association of susceptible HLA-DR determinants with the identified TCR gene segments. TCR Vbeta typing was performed on antigen specific T cell lines from 14 ABPA and 12 nonABPA patients. The majority of ABPA patients (86%) expressed allergen specific T cells with Vbeta13 genes indicating its role in susceptibility, whereas in nonABPA controls, Vbeta1 genes T cell repertoires were predominantly expressed. The unrestricted pattern of Vbeta gene amplification seen before antigen stimulation suggests an oligoclonal expansion of a specific T cell population in response to the allergen Asp f 1 in ABPA and nonABPA patients. The increased usage of Vbeta13 in ABPA and Vbeta1 in nonABPA indicates their importance in susceptibility and resistance, respectively.

New DR5 sequences: a novel DRB1*11122 allele identified in Paiwan tribe members of Taiwan and a corrected sequence for the DRB1*1201 allele.

We report herein the identification of a new DRB1 allele using sequence-based typing (SBT). This novel allele, HLA-DRB1*11122, was found in an aboriginal individual (SWP71) from the Paiwan tribe in the southern part of Taiwan. This individual was typed by SBT method as having an HLA genotype of HLA-A*24021/24021, HLA-B*4001/4002, HLA-DRB1*11122/15011, HLA-DRB3*0202, and HLA-DRB5*01011. This new allele differs from DRB1*1112 in the polymorphic exon 2 only at codon 34 (CAA-->CAG; both specify glutamine) and from DRB1*1110 in the exon 2 sequence only at codon 32 (CAT-->TAT; H32T). The most likely candidate allele which is found in the aboriginal populations of Taiwan and which may mutate into this new allele is DRB1*11011. DRB1*11122 allele differs from DRB1*11011 allele in the polymorphic exon 2 at both codon 34 (CAA-->CAG) and codon 37 (TAC-->TTC; T37F). This novel HLA-DRB1*11122 allele was also found in another aboriginal individual (SWP90) from the same Paiwan tribe. This SWP90 individual was typed by SBT method as having an HLA genotype of HLA-A*24021/24021, HLA-B*4002/5502, HLA-DRB1*11122/1201, and HLA-DRB3*01011/0202. However, the original DRB1*1201 sequence from HERLUFF was found to be erroneously reported and the corrected sequence from SWP90 is now presented herein.

Polymorphism in the MHC-encoded LMP7 gene: association with JRA without functional significance for immunoproteasome assembly.

OBJECTIVE: To determine if a polymorphism in the immunoproteasome subunit LMP7 was associated with juvenile rheumatoid arthritis (JRA) and had functional significance. METHODS: The frequency of LMP7QQ+ vs QQ- (QK and KK genotypes) among 207 patients with JRA and 50 controls was determined. JRA subtypes were pauciarticular (53%), polyarticular (33%), and systemic (14%). Onset was before age 6 (early onset) in 60% of patients. The functional significance of the LMP7 polymorphism was determined by comparing incorporation of LMP7Q vs LMP7K into proteasomes. RESULTS: There was an increased frequency of LMP7QQ in patients vs controls (73 vs 56%; p = 0.016), mainly due to the pauciarticular and systemic JRA subtypes (p = 0.037), and more pronounced in early onset disease (77 vs 56%; p = 0.006). The association persisted with stratification for HLA-DR5(11) and -DPB 1 *0201 (p = 0.002 and 0.013). We found no difference in the relative incorporation of LMP7Q and LMP7K into proteasomes. CONCLUSIONS: These results support an association between LMP7QQ homozygosity and JRA, particularly early onset disease. The difference persists with stratification, at least for DR5(11) and DPB1*0201, suggesting that this effect is unlikely to be due to linkage disequilibrium with HLA alleles known to be associated with early onset pauciarticular JRA. Importantly, as there does not appear to be functional significance associated with the LMP7 polymorphism, this may be a marker for another as yet unidentified susceptibility locus.

Persistent polyclonal B-cell lymphocytosis: further evidence for a genetic disorder associated with B-cell abnormalities.

Persistent polyclonal B-cell lymphocytosis (PPBL) is an intriguing disorder diagnosed predominantly in women, usually cigarette smokers, characterized by an increase in the number of polyclonal B lymphocytes. Abnormality of the B-cell population is also evidenced by the presence of multiple bcl-2/Ig gene rearrangements and the finding of an additional long arm chromosome 3q+ (i3)(q10) within a significant proportion of B cells. The physiopathology of PPBL is unknown but its association with the HLA DR7 phenotype suggests a possible genetic disorder. To further determine whether PPBL has a genetic predisposition, we have undertaken an extensive study in a large family of a patient diagnosed with PPBL. Three individuals among the first-degree relatives presented all the criteria for a diagnosis of PPBL. A slight increase in serum IgM without evidence of B-cell proliferation was shown in two additional siblings. Multiple bcl-2/Ig gene rearrangements, a typical feature of PPBL, were identified in 8/10 individuals among first-degree relatives. A statistically significant association was found between the presence of these rearrangements and of a paternal HLA haplotype. We conclude that PPBL has a familial occurrence suggesting an underlying genetic defect. The development of the complete syndrome probably relies on unidentified additional co-factors.

Additive effect of Apo2L/TRAIL and Adeno-p53 in the induction of apoptosis in myeloma cell lines.

OBJECTIVE: We have previously shown that Adenovirus-p53 (Ad-p53) is a potent inducer of apoptosis in myeloma cells expressing nonfunctional p53 and low levels of bcl-2 and that Apo2L/TRAIL is a potent inducer of apoptosis, independent of bcl-2. A study was designed to test the synergy between Ad-p53 and Apo2L/TRAIL in the induction of apoptosis in relation to the expression of DR4/DR5 and DcR1, in cells undergoing Ad-p53-induced apoptosis. METHODS: Replication deficient Ad-p53 and human recombinant Apo2L/TRAIL were used. Myeloma cells with mutated/w.t. p53 and varying expression of bcl-2 were used to test the effect of Ad-p53, Apo2L/TRAIL, or both, on apoptosis, measured by annexin V. RESULTS: Treatment with Ad-p53 resulted in a dose-dependent apoptosis concomitant with a dose-dependent increase in the expression of DR4/DR5 and a decrease in the expression of DcR1, in Ad-p53-sensitive cell lines. In these cells, addition of Apo2L/TRAIL to cells treated with Ad-p53 resulted in a dose-dependent increase in apoptosis. Myeloma cells resistant to Ad-p53 had high levels of DR4/DR5 and high levels of DcR1 and treatment with Ad-p53 did not reduce the expression of DcR1. Also, addition of Apo2L/TRAIL to Ad-p53 did not affect the level of apoptosis beyond the level of apoptosis observed with Apo2L/TRAIL alone. CONCLUSIONS: 1) Cotreatment with Ad-p53 and Apo2L/TRAIL resulted in additive apoptosis in myeloma cells expressing nonfunctional p53 and low levels of bcl-2. 2) Resistance to Ad-p53 or to the combination of Ad-p53 and Apo2L/TRAIL was not due to the lack of adenovirus receptor (CAR) or low expression of DR4/DR5 but rather due to the relatively high expression of DcR1 receptor.

Protective and susceptible HLA polymorphisms in IgA nephropathy patients with end-stage renal failure.

Idiopathic immunoglobulin A (IgA) nephropathy is characterised by an extreme variability in clinical course, leading to end-stage renal failure in 15-20% of adults. This subgroup of patients with IgA nephropathy is usually included in the waiting lists of organ exchange organisations. The frequency of HLA-A,B,DR antigens of this subset of IgA nephropathy patients was calculated and compared to controls. The antigens HLA-B35 and DR5 were significantly increased in the patients with relative risk values of 1.385 and 1.487, respectively. The antigens HLA-B7, B8, DR2, and DR3 were found in a significantly lower frequency in the patients as compared to the controls. The relative risk (RR) values ranged between 0.695 and 0.727. Consequently, the haplotypes HLA-A1, B8, DR3, HLA-A3, B7, DR2, HLA-A2, B7, DR2 together with HLA-A1, B15, DR4, HLA-A9, B12, DR7, and HLA-A10, B18, DR2 were found to be protective with RR values ranging from 0.309 to 0.587. The only susceptible haplotype observed was HLA-A2-B5, DR5 (RR=2.990).

Hashimoto's disease during interferon-alpha therapy in a patient with pre-treatment negative anti-thyroid autoantibodies and with the specific genetic susceptibility to the thyroid disease.

OBJECTIVES: The authors described a case of Hashimoto's disease during interferon-alpha (IFN-alpha) treatment for chronic viral C hepatitis in a patient with the specific genetic susceptibility associated with the thyroid disease. RESULTS: A 60-year-old woman with chronic active viral C hepatitis (HCV genotype = 3a) started IFN-alpha therapy in November '96. Before treatment thyroid function tests were normal and anti-thyroid (anti-thyroglobulin and anti-thyroid peroxidase) Abs were negative. During IFN therapy, serum aminotransferases fell within the normal range and viremia (serum HCV-RNA) became negative after one year. After 20 months, the patient presented clinical features of primary hypothyroidism. Anti-thyroid Abs were found positive. Hormonal, ultrasonographic, radioiodine scanning and fine needle aspiration findings were consistent with the diagnosis of Hashimoto's thyroiditis. The tissutal typing of the patient showed the presence of Human Leukocyte Antigen (HLA) DRB1*11 gene (corresponding to DR5 antigen). IFN-alpha therapy was suspended and a treatment with l-T4 started. Chronic viral infection relapsed after the suspension of the IFN-alpha therapy. CONCLUSIONS: This case report showed that the clinical appearance of Hashimoto's disease after IFN-alpha therapy for chronic C hepatitis in our patient was associated with a specific genetic predisposition (DR5) for this pathology. Further studies are necessary to evaluate whether the study of HLA antigens may be a very useful tool to detect the patients with a predisposition to develop autoimmune thyroiditis, in order to make a early diagnosis of thyroid disorders during the IFN-alpha treatment.

A common HLA phenotype in slipped capital femoral epiphysis?

Studies from three different countries have linked the HLA B12 and DR4 antigens with slipped capital femoral epiphysis (SCFE). We questioned whether our patients shared in common either of these antigens. HLA phenotype was determined in 7 patients with SCFE, two of whom were brothers with almost identical haplotypes. The B12 antigen was found in none of our patients and the DR4 in only 3. Neither of the 2 brothers held the DR4 antigen. The commonest antigens (also shared by the 2 brothers) were B35, present in 5 and DR52 in 4 of 7 patients. We conclude that neither the previously described B12 nor the DR4 antigen can reliably serve as genetic markers for SCFE in our region.