Southern blot analysis of HLA-DP gene polymorphisms in Caucasoid rheumatoid arthritis (RA) patients and controls

Association of HLA-DPB1 polymorphisms with rheumatoid arthritis: A systemic review and meta-analysis

BACKGROUND

The current reports on the association between HLA-DPB1 alleles and rheumatoid arthritis (RA) results were controversial. Thus, we conducted a meta-analysis to assess whether DPB1 alleles are associated with increased risk of rheumatoid arthritis.

METHODS

Systematic searches on PubMed, Embase, Elsevier, CNKI (China National Knowledge Infrastructure), Wanfang data and Cochrane Library prior to July 2017 were performed. The pooled odds ratios (ORs) and 95% confidence interval (95% CI) was used to assess the association between frequencies of DPB1 alleles and RA patients.

RESULTS

Eight studies with 592 cases and 935 controls were included in this meta-analysis. Overall, the pooled ORs showed that frequencies of DPB1*0401 and *0601 were higher in the RA group compared with controls (*0401: OR: 1.586, 95%CI: 1.296-1.941, P<0.001; *0601: OR: 1.921, 95%CI: 1.142-3.229, P=0.014). Whereas, the frequencies of DPB1*0101, *0402 and *0501 were lower in the RA control than the controls (*0101: OR: 0.691, 95%CI: 0.481-0.993, P=0.046; *0402: OR: 0.707, 95%CI: 0.555-0.902, P=0.005; *0501: OR: 0.502, 95%CI: 0.329-0.767, P=0.001). No associations were observed for DPB1*0201, *0202, *0301 and *0901 (*0201: OR: 1.129, 95%CI: 0.882-1.446, P = 0.335; *0202: OR: 0.840, 95%CI: 0.940-1.441, P = 0.527; *0301: OR: 0.769, 95%CI: 0.577-1.026, P = 0.074; *0901: OR: 1.221, 95% CI: 0.541-2.755, P = 0.630).

CONCLUSIONS

This meta-analysis demonstrates that high frequency expression of DPB1*0401 and *0601 are significantly associated with susceptibility to RA, it may be a risk factor for occurrence of RA. Low frequency expression of DPB1*0101, *0402 and *0501 may be negatively associated with RA, it may be a protective factor for occurrence of RA.

HLA-DP allele-specific T cell responses to beryllium account for DP-associated susceptibility to chronic beryllium disease

Occupational exposure to small molecules, such as metals, is frequently associated with hypersensitivity reactions. Chronic beryllium (Be) disease (CBD) is a multisystem granulomatous disease that primarily affects the lung, and occurs in approximately 3% of individuals exposed to this element. Immunogenetic studies have demonstrated a strong association between CBD and possession of alleles of HLA-DP containing glutamic acid (Glu) at position 69 in the HLA-DP beta-chain. T cell clones were raised from three patients with CBD in whom exposure occurred 10 and 30 years previously. Of 25 Be-specific clones that were obtained, all were restricted by HLA-DP alleles with Glu at DP beta69. Furthermore, the proliferative responses of the clones were absolutely dependent upon DP beta Glu(69) in that a single amino acid substitution at this position abolished the response. As befits a disease whose pathogenesis involves a delayed type hypersensitivity response, the large majority of Be-specific clones secreted IFN-gamma (Th1) and little or no IL-4 (Th2) cytokines. This study provides insights into the molecular basis of DP2-associated susceptibility to CBD.

Do the HLA-DQ and DP genes play a role in rheumatoid arthritis?

Whereas the DRB1 alleles have well-established associations with rheumatoid arthritis (RA), the DQ and DP alleles are of more controversial relevance to RA. Early studies of the DQB1 genes in RA determined the frequencies of the two DQB1*03 subtypes that are in linkage disequilibrium with DR4, DQB1*0301 (DQw7) and *0302 (DQw8). Their results are conflicting and difficult to interpret because molecular biology techniques for determining DR4 specificity polymorphism were not available at the time. None of the more recent studies found compelling evidence that the DQB1 alleles influenced the susceptibility to RA. A few studies suggest that the DQ alleles may influence the clinical or biological expression of the disease, perhaps through a complementary effect of the DRB1 and DQB1 alleles. DR-DQ complementarity has been demonstrated in the DQ8 transgenic mouse model, although this is not necessarily relevant to the human disease. The role of DPB1 remains hypothetical but may involve an influence of some alleles in relatively mild forms of RA. The DQB1 and DPB1 alleles are in strong linkage disequilibrium with the DRB1 alleles, making the elucidation of their independent effects a challenging task. Studies are needed to determine whether these linkage disequilibriums can influence the development of autoimmune diseases.

Relevant residues of DRbeta1 third hypervariable region contributing to the expression and to severity of rheumatoid arthritis (RA) in Mexicans

Rheumatoid arthritis (RA) is a chronic autoimmune disease leading to destruction of the joints. Residues at positions 67-74 of the DRB1 third hypervariable region are involved in susceptibility (S) and resistance (P) to RA. DNA from 83 patients and 175 controls, all of them Mexican Mestizos were oligotyped using PCR-SSOP and PCR-SSP. The (S) alleles are DRB*0404 (p = 0.000004), *0401 (p = 0.007) and *1001 (p = 0.008). Those associated with P are DRB1*0701 (p = 0.0001); *1101 (p = 0.01); *1503 (p = 0.02); *0801 (p = 0.04); *1401 (p = 0.04). Susceptibility/protection are recessive traits; SS genotypes are increased in the patients (p = 0.0003) while PP genotypes are decreased in them (p = 0.00004). The motif at 67-74 and the valine or glycine at position 86 are relevant in the development and severity of RA in Mexicans. The associations suggest that residues 67, 70, 71 are central for susceptibility. The P alleles have D-70 or carry V-86 in the absence of D-70. Thus, susceptibility/protection depends on the combination of basic residues at these positions and a non-polar aa at 86 contributes to resistance. Severity is also HLA influenced. DQA1*03011-DQB1*0302 are associated to severe lesions in the presence of any DR4 subtype. Analyzing different ethnic groups is essential to elucidate the etiopathogenesis of RA.

The role of HLA-DR-DR and HLA-DR-DP interactions in genetic susceptibility to rheumatoid arthritis

In order to analyze the relationships between the DR and DP loci in the genetic susceptibility to RA, HLA-DRB1 and -DPB1 polymorphism was studied in 155 RA patients compared to 150 controls, using a reverse dot-blot analysis. Our data were consistent with the involvement of the amino acid in position 71 of the third hypervariable region of the DR beta 1 chain in susceptibility to the disease. The higher risk for RA was observed in patients who carried the association of a lysine (K), characterizing the DRB1* 0401 susceptibility allele, with an arginine (R), observed in all the other DRB1* susceptibility alleles (21.9% vs 0.6%, p(c) < 10(-6), OR = 42) In the absence of arginine, the presence of lysine was still associated with the disease (33% vs 19%, p(c) < 0.03, OR = 2). In contrast, in the absence of lysine, the frequency of arginine in position 71 was similar in patients and controls (30% vs 26%, p = NS). On another hand, the analysis of the HLA-DPB1 locus showed that the DPB1 *0401 allele frequency was significantly increased in the RA patient group (n = 47) who expressed only arginine at the position 71 of the beta 1 chain (82% vs 56% in controls, p < 0.008), with role of HLA-DR--DR and -DR-DP interactions in the genetic susceptibility to RA.

The presence of the HLA class II allele DPB1*0501 in ethnic Thais correlates with an enhanced vaccine-induced antibody response to a malaria sporozoite antigen

In this study, we examined the correlation between the frequency of allelic variants of the class II human leukocyte antigen (HLA) DR, DQ and DP gene loci and the quantitative humoral immune response observed in 71 Thai volunteers, subsequent to vaccination with a conjugated subunit vaccine. This vaccine was designed to induce antibodies directed against the immunodominant repeat region of the Plasmodium falciparum circumsporozoite (CS) protein. The presence of the DPB1*0501, a relatively common allele in Asian populations, was found to be associated with high vaccine-induced CS repeat-specific antibody responses in the volunteers. Given the increasing focus on the use of subunit vaccines in the control of infectious diseases, consideration of the influence of class II allele frequencies in ethnically diverse recipient populations may be important.

HLA-DPB1 polymorphism in the Thais of Southeast Asia

In this study we examined DPB1 allele frequencies in five ethnic Thai populations resident in different regions of Thailand and neighboring countries. In contrast to other Asian and Pacific populations such as the Japanese, Chinese, Korean, and Papua New Guineans, where DPB1*0501 has consistently been shown to be the most frequent allele, NE Thais and Thai-Khmers demonstrate a prevalence of DPB1*1301. Comparison of DPB1 allele frequencies in the Thais of SE Asia, with known frequencies in the Chinese and Japanese populations of E Asia, would appear to confirm previous calculations of genetic divergence between these Oriental populations.

Frequency of HLA-DPB1 alleles in a Spanish population: their contribution to rheumatoid arthritis susceptibility

HLA-DPB1 allele frequencies in 181 unrelated control individuals and 70 rheumatoid factor-positive RA patients from Seville (Spain) were determined using oligonucleotide typing methods. All frequencies shown concern the percentage of individuals positive for a certain allele. HLA-DPB1*0401 was the most common DPB1 allele in the healthy individuals, possessed by 65.7% of them. In addition to HLA-DPB1*0401, only the following alleles were found in normal subjects at frequencies greater than 10%: DPB1*0101 (15.5%), DPB1*0201 (12.2%), DPB1*0301 (16.6), and DPB1*0402 (29.3%). When HLA-DPB1 allelic frequencies were compared between seropositive RA patients and controls, a negative association for DPB1*0301 and DPB1*0401 was found in RA patients, although it failed to reach statistical significance after correction for the number of comparisons made. The other DPB1 alleles exhibited almost identical frequencies in both groups. However, when only DR4+ patients and controls were considered, the decrease in the frequency of the DPB1*0301 and DPB1*0401 alleles lacked statistical significance. On the other hand, when DR4- RA patients and controls were compared, the frequency of DPB1*0301 was found decreased significantly again, even more than in the whole group of patients.

A shared HLA-DRB1 sequence confers RA susceptibility in Greeks

Previous serological studies of Greek rheumatoid arthritis (RA) patients have failed to demonstrate an association with DR4. Using sequence specific oligonucleotide typing we have identified the DRB1 alleles in panels of Greek RA patients and controls. When patient and control HLA-DRB1 frequencies were compared, significantly higher frequencies of DRB1*0101 (23.3% vs. 7.0%, odds ratio [OR] 4.0, 95% confidence intervals [CI] 1.4-12.0) and DRB1*1001 (20.9% vs. 5.8%, OR 4.3, 95% CI 1.3-13.7) were found in RA patients compared with controls. No association of DRB1*04 with RA was observed (20.9% vs. 14.0% in controls) confirming earlier reports. However DRB1*04 subtyping demonstrated a small but significant increase of DRB1*0405 in patients (14.0% vs. 3.5%, OR 4.5, 95% CI 1.1-18.9). When the frequency of individuals carrying the shared RA susceptibility epitope was compared between patients and controls it was found to be significantly higher in RA patients (60.5% vs. 22.1%, OR 5.4, 95% CI 2.4-12.0). We conclude that the shared epitope is significantly associated with RA in this population, but that it is predominantly accounted for by DRB1*0101 and DRB1*1001. Previous studies of UK RA patients have demonstrated a negative association of DR2 with disease and articular erosions. HLA-DR2 variants, DRB1*1501 and *1502 are not at reduced frequency in Greek RA patients (DRB1*1501, 14.0% in patients vs. 7.0% in controls; DRB1*1502, 7.0% in patients vs. 7.0% in controls). Genes conferring RA resistance may be in linkage disequilibrium with DR2 in UK patients. This does not appear to be the case in Greek RA patients. No association was seen between RA and HLA-DPB1 type.

DPB1 polymorphism in rheumatoid arthritis: evidence of an association with allele DPB1 0401

HLA-DP polymorphism was examined in 71 rheumatoid arthritis patients and 148 controls, using dot-blot analysis with 14 synthetic oligonucleotide probes specific for the variable region of the DPB1 second exon. The DPB1 0401 allele was found to be significantly more frequent in RA patients than in controls (77.46% vs 55.40%, p less than 0.002, pc less than 0.03, relative risk value: 2.74). An association between DPB1 0401 and seropositivity for rhumatoid factors was also observed: 44 of the 55 seropositive RA patients were DPB1 0401 (p less than 0.001). Analyzing the HLA DPB1 alleles frequencies in 57 HLA-DR-typed RA patients did not show any linkage between the DPB1 0401 and the DR4 specificities. Furthermore, the DPB1 0401 homozygous frequency was increased in DR4-negative RA patients. Our findings suggest an independent role of the DPB1 0401 allele in the genetic susceptibility to RA.

Frequency of DPB1*0401 is significantly decreased in patients with allergic asthma in a mulatto population

Allergic asthma (AA) is a multifactorial disease in which the IgE hyperresponsiveness to mite allergens is determinant for its pathogenesis and clinical picture. We have reported previously that IgE responsiveness to mite allergens in AA patients is linked to HLA and possibly controlled by a dominant suppression (Is) gene of that region. The present population study was done to detect alleles involved in the genetic control of mite IgE response that accompanies AA, using polymerase chain reaction and oligonucleotide DNA typing of DP locus. Instead of finding any significant positive association with AA, in this study we found that the allele DPB1*0401 is present mainly in the nonallergic control population and strikingly absent in patients (p less than 0.008), suggesting that this gene could confer resistance to AA and other atopic diseases. Our results add more evidence regarding the existence of Is genes in the HLA region involved in the control of IgE immune response to environmental allergens. Furthermore, they suggest that genes of HLA are important genetic components involved in the etiology of AA.

Analysis of HLA-DR and -DQ gene polymorphisms in Sudanese patients with type 1 (insulin-dependent) diabetes

In this study we report for the first time, the molecular analysis of HLA-DR and -DQ gene frequencies in a large cohort of well characterized type 1 (insulin-dependent) diabetes mellitus (IDDM) patients (n = 72), and ethnically matched controls (n = 59) collected in sub-Saharan Africa. High molecular mass DNA was prepared and analyzed in Southern blots with DRB1, DQA1, and DQB1 probes. By identifying DR and DQ allele-specific restriction fragment length polymorphisms (RFLPs), we have shown a strong positive association between IDDM and the Asp 57- DQB1 allele *0201 (DQw2). A rare DR4, DQw2 haplotype was also identified at high frequency in the IDDM cohort. We can now confirm that the association between Asp 57-DQB1 alleles and IDDM, previously reported in ethnically diverse cohorts collected in Western Europe, North America, and South Asia, is also present in an IDDM cohort collected in Africa.

HLA-DPB1*0301 is a major risk factor for rheumatoid factor-negative adult rheumatoid arthritis

HLA-DPB1 alleles were determined using the polymerase chain reaction and allele-specific oligonucleotide probes in Caucasoid patients with rheumatoid arthritis (RA) and in healthy controls. DPB1*0301 was found to be increased in seronegative patients (50.0% versus 10.8% in controls; relative risk = 8.3, P less than 0.0001). With our previous finding that DPB1*0301 is increased in seronegative children with polyarticular-onset arthritis, the results suggest a relationship between this disease and seronegative RA in adults.

HLA DPB1 alleles and susceptibility to rheumatoid arthritis

HLA-DPB1 genotypic and phenotypic frequencies were investigated in a series of 35 adult rheumatoid arthritis (RA) patients and 42 controls. No significant associations between DPB1 alleles and susceptibility to RA were demonstrated, although some non-significant differences in DPB1*0301 and 0401 allele frequencies between patients and controls were observed.

HLA-DR and DQ DNA genotyping in multiple sclerosis patients in Northern Ireland

DNA from multiple sclerosis (MS) patients and healthy control individuals from the Northern Ireland population, was assessed by restriction fragment length polymorphism (RFLP) analysis to look for disease-associated polymorphisms. HLA-DR and -DQ allogenotyping was performed using a single enzyme (TaqI)/Multiple probe system. The TaqI/DR beta RFLPs correlate well with serologically defined specificities and in addition detect further subtypes of these associated with DQ or Dw specificities. The results confirm an association of MS with DR beta 15 and show a decreased frequency of DR beta 4 in the patients. An increased frequency of DR beta 17 in patients negative for DR beta 15 was also found. There is a decrease in the frequency of the TaqI/DQ beta 3 (TA10 + ve) RFLP and the TaqI/DQ alpha 2LL genotype in the MS patients, these not being associated with DR beta 15. In addition RFLP analysis of the DPA1 and DPB1 genes reveals an MspI/DP beta 3.0-kb fragment which occurs at a higher frequency in the patients than in the controls.

Rheumatoid arthritis may be primarily associated with HLA-DR4 molecules sharing a particular sequence at residues 67-74

Genomic typing of in vitro amplified DNA with sequence-specific oligonucleotide (SSO) probes was performed for DRB1, DQA1, DQB1, DPA1 and DPB1 alleles in 54 random Norwegian rheumatoid arthritis (RA) patients and 181 healthy controls. DRB1 alleles encoding the serological specificity DR4 were found in 80% of the patients, compared to 34% of the controls (relative risk = 7.9, p less than 0.0001). All DR4-positive RA patients carried either DRB1*0401 (Dw4), 0404 (Dw14), or 0405 (Dw15), while no patients were found to carry DRB1*0402 (Dw10) or 0403 (Dw13). The frequency of the DRB1*0101 allele encoding DR1 was not increased, even among DR4-negative RA patients, and we were unable to detect any sharing of other class II alleles among DR4-negative patients. No contribution of any DQA1, DQB1, DPA1 or DPB1 alleles to RA susceptibility could be detected. The results suggest that in the Norwegian population RA is primarily associated with a shared sequence at residues 67-74 of the DR beta 1 chain, but only when this sequence is expressed on DR4 molecules.

Evaluation of HLA-class II identity between unrelated individuals by serological typing, DNA-RFLP method, and mixed lymphocyte reaction

Seven groups, each consisting of two to nine unrelated HLA-A, -B, and -DR serologically identical individuals, were analyzed by DNA-restriction fragment length polymorphism (RFLP) and mixed lymphocyte reactions (MLR) in order to evaluate HLA-class II identity between unrelated individuals and to assess the importance of HLA-class II incompatibilities detected by DNA-RFLP in the allogeneic reactions. It is clear that DNA-RFLP represents a powerful typing method for HLA-DR, -DQ, and -DP since the combinations of the RFLP band patterns define all the serological specificities and most of the cellular specificities to give a highly accurate typing. This report shows that an HLA-DP incompatibility induces proliferation in primary mixed lymphocyte culture (MLC) between unrelated HLA-A, -B, -DR, -DQ, and -DW identical individuals, which may suggest the importance of this molecule as a transplantation antigen, especially for unrelated bone marrow transplantations. Still, an isolated HLA-DPw4/HLA-DP a disparity did not induce any proliferation in MLC. Moreover, our results show that DQw7 (w3)/DQw8 (w3) disparity associated with HLA-DR4 represents a nonfunctional incompatibility in MLR. The HLA-Dw subtypes of HLA-DR specificities can induce a high proliferative response in MLC. The HLA-Dw subtypes of HLA-DR specificities can induce a high proliferative response in MLC. Finally, DNA-RFLP typing represents a reliable method for the selection of histocompatible donor-recipient pairs and could potentially reduce many logistic problems and delays in live-donor transplantation, especially for unrelated bone marrow transplantation.