Common human leukocyte antigen alleles in pemphigus vulgaris and pemphigus foliaceus Italian patients.

Pemphigus refers to a group of autoimmune blistering skin diseases, mainly identified as pemphigus vulgaris and pemphigus foliaceus, both characterized by the presence of autoantibodies against keratinocyte adhesion molecules, leading to loss of cell-cell adhesion with consequent blister formation. Pemphigus vulgaris is reported to be associated with human leukocyte antigen DR4 and/or DR6 whereas no data are available on pemphigus foliaceus, except for the endemic Brazilian form (fogo selvagem), which is reported to be associated with DR1 and DR4. We here report human leukocyte antigen molecular typing on a total of 87 patients, 61 with pemphigus vulgaris and 26 with pemphigus foliaceus, versus 128 healthy matched controls. Generic typing showed an increase of DRB1*04 and DRB1*14 and a decrease of DRB1*07 in both pemphigus vulgaris and pemphigus foliaceus patients. Molecular subtyping of DR4+ and DR14+ subjects showed a highly significant association between the DRB1*1401 and both pemphigus vulgaris (p < 0.0001) and pemphigus foliaceus patients (p < 0.0001) together with a significant increase of the linked DQB1*0503 (pemphigus vulgaris p < 0.0001; pemphigus foliaceus p < 0.0001). Moreover, whereas the association between DRB1*0402 and pemphigus vulgaris (p < 0.0001) has been confirmed, no significant association between a specific allele of the DR4 group and pemphigus foliaceus, has been found. Therefore, at least in Italian patients, pemphigus vulgaris and pemphigus foliaceus share DRB1*1401 and DQB1*0503, as susceptible human leukocyte antigen alleles, whereas DRB1*0402 is only found associated with pemphigus vulgaris. The observation that both diseases, pemphigus vulgaris and pemphigus foliaceus, carry the same susceptible human leukocyte antigen alleles has been interpreted as a common genetic background predisposing to pemphigus as, like in other autoimmune disorders, it is not sufficient to explain the onset of the disease on the basis of the sole aforementioned alleles. Other linked genes and/or environmental factors should play a facilitating role in the outbreak of pemphigus, either pemphigus vulgaris or pemphigus foliaceus.     

The association between HLA DR, DQ antigens, and vulval lichen sclerosus in the UK: HLA DRB112 and its associated DRB112/DQB10301/04/09/010 haplotype confers susceptibility to vulval lichen sclerosus, and HLA DRB10301/04 and its associated DRB10301/04/DQB10201/02/03 haplotype protects from vulval lichen sclerosus

Lichen sclerosus (LS) is considered to have an immunogenetic background. Several small studies, using serological typing, have reported that HLA-DR11, DR12, and DQ7 were increased in LS, with DR17 less frequent. This study aimed to validate and detect new HLA-DR and DQ associations with LS in females and its characteristic clinical parameters. The cases, 187 female LS patients, and 354 healthy controls were all UK North Europeans. PCR-sequence specific primers method was applied to genotype the HLA-DR, DQ polymorphisms that correspond to 17 serologically defined DR and seven DQ antigens. Statistical analysis was performed with two-tailed Fisher's exact test with Bonferroni adjustment (p value after Bonferrroni adjustment, Pc). We found increased frequency of DRB1*12 (DR12) (11.2%vs 2.5%, pc < 0.01) and the haplotype DRB1*12/DQB1*0301/04/09/010 (11.2%vs 2.5%, p < 0.001, pc < 0.05), and a lower frequency of DRB1*0301/04 (DR17) (11.8%vs 25.8%, pc < 0.01) and the haplotype DRB1*03/DQB1*02DRB1*0301/DQB1*0201/02/03 (11.2%vs 24.6%, pc < 0.0001) in patients compared with controls. HLA DR and DQ antigens were not associated with time of onset of disease, site of involvement, structural changes of genitals, and response to treatment with potent topical steroids. In conclusion, HLA-DR and DQ antigens or their haplotypes appear to be involved in both susceptibility to and protection from LS.     

HLA-DR and DQ polymorphisms in bullous pemphigoid from northern China

Bullous pemphigoid (BP) is an autoimmune disease mediated by autoantibodies against hemidesmosome components. This study used PCR-sequence-specific primers to genotype polymorphisms in HLA-DR and DQ in 25 BP patients and 57 normal controls from northern China. We found lower frequencies of DRB1*08 (DR8) and DRB1*08/DQB1*06 (DR8/DQ6) haplotypes in BP patients than in controls (4.08% vs. 15.19% and 1.54% vs. 13.82%, respectively; P < 0.05), suggesting a protective role for DR8 and DR8/DQ6 haplotypes in BP patients from northern China; there were no statistical differences among other alleles tested. This result is strikingly different from previous reports that DQB1*0301 is associated with BP in Caucasian patients and DRB1*1101, DQB1*0302, DRB1*04/DQA1*0301/DQB1*0302 and DRB1*1101/ DQA1*0505/DQB1*0302 with Japanese BP patients. Ethnic differences in the polymorphic composition of the HLA-DR and DQ genes may influence genetic susceptibility to BP.     

Human leukocyte antigens class I and class II in patients with pemphigus in southern Turkey

Background Genetic factors that predispose individuals to pemphigus are considered to play important roles in the development of the disease. Furthermore, population studies of patients with pemphigus have clearly shown that the most prevalent alleles differ across ethnic groups. Objectives This controlled study was designed to detect the distribution of human leukocyte antigen (HLA) class I and II alleles in Turkish patients with pemphigus. Methods Sixty patients diagnosed with pemphigus according to clinical findings, histology, immunofluorescence, and enzyme‐linked immunosorbent assay (ELISA) were enrolled in the study. The control group consisted of 60 healthy adult transplant donors. HLA typing was carried out using a polymerase chain reaction (PCR) with sequence‐specific primers (SSP) method. Results The frequencies of HLAs A*11, CW*01, DRB1*04, DRB1*14, DQB1*05, and DPB1*0401 were found to be statistically significantly higher in the disease group than in controls. By contrast, the frequencies of HLAs B*18, B*50, DRB1*11, DQB1*02, DQB1*06, DPB1*0301, and DPB1*1102 were statistically significantly lower in the pemphigus group than in controls. Linkage dysequilibrium analysis showed that DRB1*14/DQB1*05, A*11/DQB1*05, and A*11/DRB1*14 alleles were detected frequently in pemphigus patients, and DRB1*11/DQB1*05, DRB1*14/DQB1*02, B*50/DQB1*02, and B*50/DPB1*0301 alleles appeared frequently in healthy controls. Conclusions The results suggest that DRB1*04, DRB1*14, DQB1*05, and DPB1*0401 class II HLAs and A*11 and CW*01 class I HLAs are associated with pemphigus in southern Turkey. Observed differences in LD patterns between patients and controls suggest that the coexistence of the respective alleles is strongly determinant of predisposition towards (DRB1*14/DQB1*05 and A*11/DQB1*05) or protection against (B*50/DQB1*02) the disease.     

Genotyping of HLA-I and HLA-II alleles in Chinese patients with paraneoplastic pemphigus

BACKGROUND: Class I and class II HLA genes are thought to play a role in the immunopathogenesis of bullous dermatoses such as pemphigus vulgaris and pemphigus foliaceus, but we know little about the genetic background of paraneoplastic pemphigus (PNP) in Chinese patients. OBJECTIVES: To identify class I and class II HLA alleles by genotyping in Chinese patients with PNP, and to find out the possible association between HLA alleles and disease susceptibility. METHODS: Nineteen Chinese patients with PNP were enrolled in this study. HLA-A, B, C, DRB1 and DQB1 alleles were typed by polymerase chain reaction and a colour-coded sequence-specific oligonucleotide probes method. RESULTS: The frequencies of HLA-B*4002/B*4004, B*51, B*52, Cw*14, DQB1*0301, DRB1*08 and DRB1*11 were relatively prevalent in Chinese Han patients with PNP in comparison with normal controls. After correction for multiple comparisons, Cw*14 remained statistically significant, and the other alleles were unremarkable in these patients. CONCLUSIONS: The genetic background predisposing to PNP may be different in patients from various races and areas. HLA-Cw*14 may be the predisposing allele to PNP in Chinese patients, which is different from the predisposing allele in French patients with PNP and the alleles predisposing to pemphigus vulgaris and pemphigus foliaceus.     

Molecular analysis of HLA DP and DQ genes associated with dermatitis herpetiformis

HLA class II DQ and DP genes from dermatitis herpetiformis patients were amplified and analyzed using molecular probes and compared to those from celiac disease patients and to an HLA and ethnically matched control group. In dermatitis herpetiformis, as in celiac disease, the strongest association of disease was with the DQ subregion alleles DQB1*0201 and DQA1*0501 that are linked to the DRB1*0301 allele. DQB1*0201 determines the DQw2 serologic marker whereas DRB1*0301 determines the DRw17 serologic marker (formerly termed DR3). A DP subregion allele DPB1*0301 was increased and a constellation of DPB1 alleles that included DPB1*0202, *0901, and *1301 was decreased in dermatitis herpetiformis. DPB1*0101, an allele reported to be increased in celiac disease, was not increased in dermatitis herpetiformis. DP beta chains that lack a negatively charged amino acid residue at position 69 of the DP beta chain are significantly over-represented both in dermatitis herpetiformis and celiac disease patients with the DRw17, DQw2 haplotype, compared to healthy controls with that haplotype. These data favor a multigenic model for the contribution of HLA class II D region genes to dermatitis herpetiformis susceptibility. Further, they indicate that a specific DQ molecule, when present in combination with the product of one of several different DPB1 alleles, may contribute to susceptibility to the intestinal lesion, which is common to dermatitis herpetiformis and celiac disease.     

Human leucocyte antigen class II associations in chronic idiopathic urticaria

The major histocompatibility complex (MHC) acts as a marker for self during T-cell ontogeny and is associated with the pathogenesis of many autoimmune diseases. Recent investigations have shown about 30% of patients with chronic idiopathic urticaria (CIU) have IgG autoantibodies against the high-affinity IgE receptor, FcepsilonRI, or IgE. A link between MHC class II alleles and CIU has not been reported previously. DNA was extracted from blood of 100 Caucasian patients with CIU, and the MHC class II type determined using the polymerase chain reaction with sequence-specific primers, testing for DRB and DQB1 alleles. The frequency of alleles in CIU patients was compared with that found in 603 controls. Further human leucocyte antigen (HLA) typing on patient subsets, classified by the patients' responses to intradermal injection of autologous serum and their serum-induced histamine release from basophil leucocytes of healthy donors, was undertaken. HLA DRB1*04 (DR4) and its associated allele, DQB1*0302 (DQ8), are raised in CIU patients compared with a control population (P = 2 x 10-5 and P = 2 x 10-4, respectively). HLA DRB1*15 (DR15) and its associated allele, DQB1*06 (DQ6), are significantly less frequently associated with CIU. The HLA DRB1*04 association is particularly strong (corrected P = 3.6 x 10-6) for patients whose serum has in vivo and in vitro histamine-releasing activity. HLA class II typing is consistent with the concept that CIU is a heterogeneous disease, and supports an autoimmune pathogenesis in a subset of patients.     

HLA class II alleles in patients with alopecia areata

Our purpose was to determine which HLA class II alleles are associated with Turkish alopecia areata patients. Also we investigated whether there was a relationship between the age of onset and severity of disease and HLA alleles or not. Sixty-five patients with alopecia areata were included in this study, and 50 healthy transplant donors were used as a control group. The total group of alopecia areata patients as well as various subgroups according to scalp hair loss were compared to the control group. HLA DNA typing was performed by polymerase chain reaction/sequence specific primer method. The frequency of DQB1*03 allele was 86.1% in all patients compared to 62.0% in controls (P = 0.005). While the frequency of DQB1*03 was significantly increased, the frequency of DRB1*03 was decreased in the all patients group (4.6% versus 22.0%, P = 0.01). In the group of scalp hair loss less than 25%; the frequency of DRB1*03 was decreased (3.2%, P = 0.02). The group of patients with 25-75% scalp hair loss was compared to control group; the frequencies of DRB1*04 (66.7% versus 28.0%, P = 0.02) was increased. When the alopecia totalis, alopecia universalis or alopecia totalis/alopecia universalis group was compared to control group; DQB1*03 was associated with an increased frequency in this group versus control group (90.9%, P = 0.03). There were no significant differences for the other DQ alleles and the DR alleles tested in the patients and in the controls. When patients with early onset were compared to patients with late onset; no significant allele differences were found. Our findings suggested that DQB1*03 allele is a marker for general susceptibility to alopecia areata and may also serve as special genetic marker for susceptibility for the severe form of alopecia areata in our population. However, this association is not related to age at onset of the disease.     

Polymorphisms of HLA-DR and -DQ genes in Japanese patients with bullous pemphigoid

Bullous pemphigoid (BP), an autoimmune skin disease of the elderly, is mediated by autoantibodies that bind to hemidesmosomes of epidermal basal cells. This study investigated BP-associated HLA-DR and -DQ genes among Japanese patients. We analyzed HLA-DR and -DQ genes among 23 Japanese BP patients based on the polymerase chain reaction-restriction fragment length polymorphism. Eighteen of these 23 patients (78%) carried at least one allele of HLA-DRB1*04 or DRB1*1101, with significant increases in HLA-DRB1*04 (*0403, *0406)/DQA1*0301/DQB1*0302 and DRB1*1101/DQA1*0505/DQB1*0302 haplotypes as well as the individual alleles DRB1*1101 and DQB1*0302 (corrected p < 0.05 for each comparison), when compared to control subjects. These data differ from the accepted DQB1*0301 (DQ7) association with the same disease among Caucasians. These findings indicate that different HLA class II haplotypes genetically influence susceptibility to BP among different ethnic groups. Our findings, together with previous reports on Caucasian patients with the pemphigoid group of bullous diseases, suggest that HLA-DRB1 molecules might participate in the regulation of autoimmune responses to BP antigens.     

Multiple basal cell carcinomas: no association with HLA-DRB, HLA-DQAI or HLA-DQBI in Swedish patients

Summary Many diseases with autoimmune features are associated with alleles of the human leucocyte antigen (HLA). However, few if any malignant disorders have reproducibly been shown to be HLA-associated. In three independent studies, using serological tissue typing techniques, an increase of the HLA class II specificity DR1 has been found in patients with multiple basal cell carcinomas. These observations prompted us to determine the frequencies of DRB1, DQA1, and DQB1 alleles by high-resolution genomic tissue-typing methods, including subdivision of the serological DR 1 specificity in the four sequence-defined alleles, DRB1*0101 to DRB1*0104, in 50 unrelated Swedish patients with a history of four or more basal cell carcinomas and 250 healthy controls. The frequency of DR1 was the same in patients and controls (18%). All DR1-positive patients and controls carried the DQA1* 0101 and DQBI*0501 alleles. Six of the nine DR1-positive patients were DRB1*0101-positive. one DRB1*0102 and two carried the DRB1*0103 allele. This distribution of DRB1*01 alleles did not differ from the one found in the controls. We conclude that genetic factors associated with the HLA class II region do not contribute significantly to the aetiology of multiple basal cell carcinomas.     

汉族红斑型天疱疮与HLA-Ⅱ类基因的相关性研究

目的 探讨HLA-DR、DQB1位点基因在红斑型天疱疮（PE）易感性中的作用。方法 用聚合酶链反应-序列特异性引物（PCR-SSP）方法，对37例红斑型天疱疮患者进行了HLA-DR、DQB1等位基因的分型，并分别与57例和53例作了对照。结果 与正常对照组比较，PE患者组DR4（DRB1*0406）、DRB1*14、DQB1*0302、DQB1*0503基因频率比对照组显著增高。结论 HLA-DRB1*14、DQB1*0503可能是汉族PE患者易感的单倍型。     

Class II MHC typing in pemphigoid gestationis

Pemphigoid gestationis (PG) is a rare, autoimmune skin disease associated with pregnancy or the immediate postpartum period, previously shown to be associated with the HLA class II antigens DR3 and DR 4. Advances in molecular analytical techniques now allow the identification of HLA alleles previously difficult to define by serological assays. Unsuspected polymorphism within the HLA-DR 3 and DR 4 classes can, therefore, be identified. The aim of our study was to apply these newer techniques to the question of genetic predisposition in PG by re-evaluating the association with DR 3 and by studying a possible link with DQ. We have investigated by restriction fragment length polymorphism, the DQA, and by sequence specified oligonucleotide probing the DQB and DRB 1 (HLA DR) specificities of 41 women with immunofluorescence-confirmed PG. The principal finding of this study is that there is an association between PG and DRB 1*0301 (DR3) and DRB 1*0401/040X (DR4). Although there is also an increase (P= 0.06) in the concurrent presence of both antigens, this appears to be due to the association with either antigen alone. We also found an increase in the frequency of DQA1*2 (P= 0.016 vs. control) and a decrease in frequency of DQB 1*0201 (P= 0.022 vs. controls) and DQB1*0602 (P= 0.026 vs. controls).     

Human leukocyte antigen genotypes and antibody profiles associated with familial pemphigus in Japanese

Previous population-based, genetic studies have shown that human leukocyte antigen (HLA) class II loci such as HLA-DR4 (DRB1*04) and HLA-DR14 (DRB1*14) alleles are consistently associated with the occurrence of pemphigus vulgaris (PV) in Japanese as well as other ethnic populations. Among PV-related HLA-DRB1 alleles (*0406, *1401, *1405, *1406) in Japan, HLA DRB1*1405 and DRB1*0406 were found to be associated with both PV and pemphigus foliaceus (PF) phenotypes. We report four familial cases of pemphigus in two unrelated families, together with analysis of their HLA-DR and -DQ alleles, and their antibody profiles. One family comprised a woman with PF and her mother with PV: both patients shared a HLA haplotype of A31(19), B54(22), CW1 and DRB1*1405. Another family included two sisters with PF and PV, respectively: both of these patients shared a DRB1*1405-DQA1*0104-DQB1*0503 haplotype. Clinicopathological and serological monitoring revealed that the elder sister with PF presented with a PV phenotype later, and gained anti-desmoglein (Dsg)3 antibodies in addition to having a low titer of anti-Dsg1 antibodies. Conversely, the younger sister with PV developed PF with only anti-Dsg1 antibody detected. These results indicate that an HLA-DRB1*1405 (DQB1*0503) haplotype may confer susceptibility to both PV and PF, and that genetic susceptibility alone is not always responsible for the clinical phenotype and autoantibody profile.     

Mycosis fungoides: HLA class II associations among Ashkenazi and non-Ashkenazi Jewish patients

BACKGROUND: An immunogenetic mechanism has been suggested to play a role in the pathogenesis of mycosis fungoides (MF). While results of studies on HLA class I associations haveproved inconsistent, two previous studies showed that certain HLA class II alleles were significantly increased among North American caucasian patients with MF: HLA-DRB1*11 and DQB1*03. OBJECTIVES: To investigate the possible HLA class I and class II associations with MF among Jewish patients. METHODS: The patient group comprised 68 Jewish patients with MF: 38 Ashkenazi and 30 non-Ashkenazi. The control group comprised 252 healthy Jewish volunteers: 132 Ashkenazi and 120 non-Ashkenazi. Tissue typing for HLA class I (A and B) was performed using the National Institutes of Health microlymphocytotoxicity technique. DNA-based low-medium resolution analysis for DRB1* and DQB1* alleles was performed using polymerase chain reaction (PCR) amplification with sequence-specific primers. For those alleles found to have significantly increased frequency, high-resolution analysis was done by means of PCR sequence-specific oligotyping. RESULTS: The allele frequency of HLA-DRB1*11 was found to be significantly increased but only among Ashkenazi patients with MF (30% vs. 19% in the controls; P = 0.034). High-resolution analysis for DRB1*11, not previously performed, suggested that its greater frequency is due to the increased number of Ashkenazi MF patients with the DRB1*1104 allele (P corrected = 0.036). Analysed together, DQB1*03 alleles (DQB1*0301-0304) had a significantly greater frequency in MF as a group as compared with controls (47% vs. 33%, P = 0.003). DQB1*0301 was demonstrated to be the specific allele associated with MF in Jewish patients (allele frequency of 36% vs. 23% in controls; P corrected = 0.0068), which was not the case for North American caucasian patients with MF. No greater frequencies of any of the HLA class I A or B antigens were found. CONCLUSIONS: Our findings further demonstrate the 'universality' of MF HLA class II susceptibility alleles, i.e. HLA-DRB1*11 and HLA-DQB1*03, suggesting that HLA polymorphism is likely to be important in the pathogenesis of MF in Jewish patients, as it is in North American caucasian patients. Not previously reported is our finding that HLA-DRB1*1104 is the specific allele more prevalent among patients with MF. Our study also underscores some differences in HLA profiles between non-Jewish and Jewish patients with MF and between Ashkenazi and non-Ashkenazi Jewish patients, indicating the possibility of diverse HLA disease associations in populations with different genetic backgrounds. Our study provides further evidence for the lack of association between HLA class I and MF.     

Mucous membrane pemphigoid: HLA-DQB1*0301 is associated with all clinical sites of involvement and may be linked to antibasement membrane IgG production

BACKGROUND: Class I human leucocyte antigens (HLA) -A, -B, -Cw and class II HLA-DRB1, -DQB1 alleles were determined in 131 British Caucasian patients with mucous membrane pemphigoid (MMP) using serological and DNA-based methods. OBJECTIVES: To analyse the class I and II alleles expressed in well-defined clinical and immunopathological subgroups of MMP, in order to establish whether specific alleles or haplotypes might in part explain disease susceptibility, clinical sites of involvement or disease severity. METHODS: Subgroups of patients were analysed according to the following clinical criteria: age of onset, sex, sites of clinical involvement (oral, ocular, skin, nasal, genital, pharyngeal, oesophageal, laryngeal, perianal), disease severity and history of autoimmune disease. Subgroups were also analysed according to the following immunopathological criteria: autoantibody profile, the presence of circulating antibasement membrane IgG or IgA antibodies and the detection of target basement membrane zone (BMZ) antigens (BP230 and BP180) by IgG autoantibodies. RESULTS: Class I HLA typing showed no significant disease or subgroup associations. Class II DRB1 typing showed a significantly increased allelic frequency in MMP vs. controls for DRB1*11 (RR = 2.08, Pc < 0.0000056). For DQB1, MMP vs. controls, there was a significantly increased allelic frequency for DQB1*0301 (Pc < 0.00000028) in both males and females; all clinical sites of involvement, with the exception of laryngeal, oesophageal and perianal sites and in patients with detectable circulating anti-BMZ IgG compared with those negative for IgG (P < 0.0096, Pc < 0.019). A positive trend was noted in patients with ocular involvement compared with no ocular involvement and in patients with a clinical score > or = 10 compared with < 10. We found no difference in DQB1*0301 allele frequency between subgroups with or without BP180 or BP230 target antigens. Haplotype frequencies showed an increase in DRB1*04, DQB1*0301 (Pc < 0.000066) and DRB1*11, DQB1*0301 (Pc < 0.000002) among patients compared with controls. CONCLUSIONS: The DQB1*0301 allele confers a predisposition to all subgroups of MMP and may have a role in T-cell recognition of basement membrane antigens, resulting in the production of anti-BMZ IgG autoantibodies. The positive trend between increased allelic expression of DQB1*0301 in patients with ocular disease and in those with a higher clinical score, further suggests a role for this allele in disease severity.     

Simultaneous onset of pemphigus vulgaris in two Turkish siblings

The etiology of pemphigus vulgaris is still unknown. Reported familial cases are indicators of a genetic aspect of the disease. We report a brother and sister with simultaneous onset of pemphigus vulgaris. The class II antigens, HLA DRB1*04 and DQB1*03 were detected in both patients. The oral mucosa was affected in one them. Elevation of transaminase levels due to azathioprine therapy was observed in these two cases.     

SLE患者抗U1 RNP抗体与HLA-Ⅱ类基因的相关性分析

目的 探讨云南汉族系统性红斑狼疮（SLE）患者抗U1RNP抗体与HLA－DRB1、DQA1、DQB1等3位基因及单体型的相关性。方法 采用多聚酶链反应－序列特异性引物（PCR－SSP）技术对63例云南汉族SLE患者进行DRB1、DQA1、DQB1基因分型。结果 抗U1RNP抗体阳性的SLE病人中DQA1＊0101及DR15－DQA1＊0102－DQB1＊0601单体型频率亦显著增高（P＝0．040，P＝0．000）。结论 云南汉族SLE抗U1RNP抗体的产生与DQA1＊0101等位基因及DR15－DQA1＊0102－DQB1＊0601单体型相关。     

Correlation between HLA and pityriasis rosea susceptibility in Brazilian blacks

Objectives The human leucocyte antigen (HLA) has been related to susceptibility factors in several diseases. This study aimed to determine the potential genetic susceptibility of patients with pityriasis rosea (PR) through HLA molecular typing analysis. Methods The method of choice was polymerase chain reaction with sequence‐specific primers (PCR‐SSP) using low‐resolution typing kits, with determination of the alleles class I (HLA‐A, HLA‐B and HLA‐C) and class II (HLA‐DRB1, DRB3, DRB4, DRB5 and DQB1) performed in 30 Afro‐Brazilian PR‐diagnosed patients and 45 healthy individuals as the control group (PR‐C). Results Analysis of the HLA typing results showed that the relative risk (RR) of 4.00 [95% confidence interval (95% CI) 1.20–13.28, two‐tailed P = 0.018] for allele HLA‐DQB1*04 class II, detected in 33.3% of PR patients, was significant. By contrast, in the control group only 11.1% of subjects had that allele. Three out of six B*51 alleles and three out of six B*53 alleles detected in PR patients were found, together with the allele DQB1*04. Conclusion We suggest that alleles DQB1*04 may be involved in the genetic susceptibility of PR based on the significant predominance of those alleles observed in the black PR patients. We also recommend that more studies are conducted on populations of other ethnic origins, preferentially with higher resolution techniques of DNA typing.     

Molecular genetic analysis of HLA-DR and -DQ alleles in Spanish patients with melanoma

Controversial data have been reported about HLA alleles and susceptibility to melanoma. The relationship between distribution of HLA alleles in patients with melanoma and susceptibility to tumour was analysed, to study the possible correlation between HLA class II DQA1, DQB1 and DRBI genes and melanoma in a Spanish population. Genomic DNA from 82 patients with melanoma and 367 random healthy donors, from the same geographic area, were typed by PCR-SSP (sequence specific primers). The patients were also divided into different groups according to the age and presence of cancer relatives, and compared with the controls. None of these HLA class II alleles showed significant positive or negative associations with either the overall population of patients with melanoma or the considered subgroups. Moreover, values for relative risk of DQB1*0301, DQB1*0302, DQB1*0303, DQB*05, DQA1*0401, DQA1*0101/0104 and DRB*08, which have been reported to be increased or decreased in patients with melanoma, were very low and of no statistical significance. Our results indicate that HLA class II alleles may not contribute to a strong susceptibility to melanoma in the Spanish population, although further studies on larger series are needed to corroborate this. Key words:     

The genetic basis of alopecia areata: HLA associations with patchy alopecia areata versus alopecia totalis and alopecia universalis

Many diseases, notably those having a strong autoimmune component, have been shown to have an association with specific human leukocyte antigens (HLA). The molecular basis for this genetic association with disease is the fact that HLA bind and present peptides derived from self and foreign protein antigens to the immune system for recognition and activation of the immune response. Previous studies with heterogeneous groups of alopecia areata (AA) patients have suggested associations with some HLA class I and class II antigens. For this study we selected only patients with long-standing disease and stratified them into two groups by strict definitions of duration and extent of disease: those with patchy AA and those with either alopecia totalis (AT) or alopecia universalis (AU). The patients were tissue typed for HLA class II antigens by biomolecular methods that provided antigen discrimination at an allele level. More than 80% of all of the AA patients typed were positive for the antigen DQB1*03 (DQ3), suggesting that this antigen is a marker for general susceptibility to AA. In addition, two other antigens were found significantly increased in frequency only in the group of AT/AU patients, DRB1*0401 (DR4) and DQB1*0301(DQ7). This strongly suggests that the two clinical types of AA, namely patchy AA versus AT/AU, can be distinguished by a genetically based predisposition to extent of disease.