The LMP2 polymorphism is associated with susceptibility to acute anterior uveitis in HLA-B27 positive juvenile and adult Mexican subjects with ankylosing spondylitis

INTRODUCTION—An association between polymorphism of the HLA linked LMP2 locus and the development of acute anterior uveitis (AAU) has previously been described in B27 positive white subjects with ankylosing spondylitis (AS). This study evaluated LMP2 alleles in two HLA-B27 positive Mexican populations of patients with spondyloarthropathy known to have a different clinical spectrum of disease from white people.
PATIENTS AND METHODS—The study populations consisted of 90 AS patients from Guadalajara with predominantly adult onset disease and 80 AS patients from Mexico City with predominantly juvenile onset disease. LMP2-CfoI amplified fragment length polymorphisms were determined after polymerase chain reaction amplification and digestion with CfoI restriction enzyme.
RESULTS—There was an increased LMP2A allelic frequency in patients who had had AAU in both Guadalajara (31.8%) and Mexico City (33.3%) when compared with non-AAU patients (15.2% and 17.7% of Guadalajara and Mexico City populations, respectively). The odds ratio relating LMP2A allelic frequency and AAU for the combined population, stratified by age at onset of disease, was 2.51 (p=0.01). LMP2 alleles did not influence the age at onset of disease or the development of peripheral arthritis.
CONCLUSIONS—These data support the view that polymorphism at the LMP2 locus is associated with the development of AAU in B27 positive subjects with AS. The requirement for both the less common LMP2 allele and HLA-B27 is consistent with the low prevalence of AAU in Mexican patients with spondyloarthritis.

     

Polymorphism in the LMP2 gene influences susceptibility to extraspinal disease in HLA-B27 positive individuals with ankylosing spondylitis.

OBJECTIVE--To investigate the potential influence of the HLA-linked LMP2 gene on disease susceptibility in HLA-B27 individuals with ankylosing spondylitis (AS). METHODS--A polymorphic CfoI restriction enzyme site in the coding region of the LMP2 gene was evaluated in genomic DNA samples from 193 white and 49 Chinese B27 individuals with well documented AS, 97 of whom had had acute anterior uveitis (AAU) and 97 peripheral arthritis; 42 samples from normal, white, B27 positive blood donors in whom AS was excluded were also evaluated. RESULTS--Analysis of B27 white AS individuals with AAU, peripheral arthritis, or both, revealed significant differences in genotypic distribution of this bi-allelic locus compared with B27 AS patients without extraspinal manifestations (p < 0.005) or B27 controls (p < 0.01). Furthermore, homozygosity for one LMP2 gene allele was significantly more prevalent in AS patients with AAU (71.3%) (p < 0.01) or peripheral arthritis (68.3%) (p < 0.02) than in B27 controls (45.2%). A similar genotypic distribution was noted in B27 Chinese AS individuals with extraspinal manifestations compared with those with axial disease alone. CONCLUSIONS--These findings support the involvement of the HLA linked LMP2 gene in the expression of disease in B27 individuals and represent a novel finding in rheumatic disease.     

Polymorphism of the LMP2 gene and disease phenotype in ankylosing spondylitis: No association with disease severity

Summary Although a number of reports have now described an association between polymorphism of the LMP2 gene and disease phenotype in HLA-B27 positive individuals with ankylosing spondylitis (AS), some describe associations with acute anterior uveitis, others with juvenile onset disease, and one report provides no association. A recent study describes yet a further association with disease severity in patients with juvenile rheumatoid arthritis. We therefore hypothesized that the discrepant findings in adult disease may be a reflection of an underlying association with disease severity. Our study population consisted of 100 HLA-B27 positive Caucasians with AS of ten or more years duration. Clinical assessment of disease severity was based on a metrology index scoring five measurements, the modified health assessment questionnaire for the spondyloarthropathies, and a disease activity index consisting of a visual analog scale to score the amount of pain, stiffness and fatigue. LMP2 genotypes were assigned following polymerase chain reaction amplification from genomic DNA and restriction enzyme digestion with CfoI. Despite confirmation of a significantly higher prevalence of the LMP2 BB genotype in AAU positive (66.0%) versus AAU negative (45.2%) patients (P<0.05), we observed no association between LMP2 genotypes and any of the indices of disease severity. Furthermore, although a significant association was noted between the presence of peripheral synovitis and the functional index score (P<0.05), a history of AAU was not associated with more severe disease. Our data is thus internally consistent in demonstrating no association between LMP2 genotypes and either disease severity or peripheral arthritis, and supports the notion that polymorphism of LMP2 primarily influences the development of AAU and not some other phenotype of AS.     

Two distinctive HLA haplotypes harbor the B27 alleles negatively or positively associated with ankylosing spondylitis in Sardinia: implications for disease pathogenesis

OBJECTIVE: To compare haplotype distribution in HLA-B27-positive patients with ankylosing spondylitis (AS) and healthy control subjects possessing either AS-associated HLA-B27 alleles or the non-AS-associated HLA-B*2709 allele. METHODS: DNA samples from 47 HLA-B27-positive patients with AS and 76 HLA-B27-positive healthy controls (19 positive and 57 negative for B*2709) living in different areas of Sardinia were collected and typed for HLA class I and class II alleles. The third exon of the B27 gene was analyzed for the presence of Asp(116) or His(116), which differentiates B*2709 from the other two B27 subtypes (B*2705 and B*2702) that are mostly found in Sardinia. The parents of 6 subjects positive for B*2709 were also typed for HLA class I and class II alleles. Statistical analysis was performed by Fisher's exact test. RESULTS: In Sardinia, the B27 alleles conferring susceptibility to AS appear to be more frequently carried by a haplotype (A2;B27;Cw2;DR16) that reaches its highest frequency in patients with AS (A2 80.8%, B27 100%, Cw2 83%, and DR16 74.5%). Conversely, the non-AS-associated B*2709 allele is more frequently found together with other HLA alleles whose frequencies are inversely correlated with the disease (A32 or A30, Cw1, and DR12). Familial analysis of 6 subjects positive for HLA-B*2709 confirmed the existence of a "Sardinian" haplotype that is not associated with AS (A32;B*2709;Cw1;DR12). CONCLUSION: In Sardinia, 2 distinct haplotypes harbor the non-AS-associated HLA-B*2709 allele or the AS-associated B27 alleles. Our findings are compatible with the hypothesis that other genes within the HLA region besides HLA-B27 may play some role in conferring susceptibility to AS.     

Effect of HLA-B and HLA-DR genes on susceptibility to and severity of spondyloarthropathies in Mexican patients

OBJECTIVE: To investigate the role of HLA-B and HLA-DR genes as contributors to genetic susceptibility and clinical expression of the spondyloarthropathies (SpA) in the Mexican population. METHODS: The study included 172 patients with SpA (undifferentiated SpA 83, ankylosing spondylitis (AS) 64, and reactive arthritis 25) and 99 healthy controls. The HLA-B and HLA-DR alleles were detected by the polymerase chain reaction with sequence-specific primers technique. Patient assessment included demographic data, diagnostic categories, and disease patterns. Statistical methods included the Mantel-Haenzel chi(2) test, Fisher's exact test, and Woolf method for odds ratio (OR). Differences of continuous variables between HLA allele groups were calculated by Student's t test. RESULTS: Increased frequencies of HLA-B27 (pCh10(-3), OR=28.7), HLA-DR1 (pC=0.045, OR=2.77), and HLA-B15 (p=0.034, pC=NS, OR=2.04) alleles in the whole group were found. HLA-B27 strength of association (OR) was 41.4 in AS; 20.9 in undifferentiated SpA; 27.2 in reactive arthritis. HLA-DR1 and HLA-B15 were increased in undifferentiated SpA (pC=0.045, OR=2.98 and p=0.004, pC=NS, OR=2.75). By analysing 58 HLA-B27 negative patients it was found that HLA-B15 and HLA-DR1 associations with SpA were independent of HLA-B27; increased frequencies of HLA-B15 were found in the whole SpA group and in patients with undifferentiated SpA (pC=0.03, OR=3.09 and pCh0.01, OR=3.77) and of HLA-DR1 in the latter (p=0.04, pC=NS, OR=3.15). HLA-B27 positive patients were younger than HLA-B27 negative patients at onset (p=0.03), but HLA-DR1 positive patients were older than HLA-DR1 negative patients (p=0.03). Bath indices for disease activity and functioning were higher in HLA-B27 positive patients (p=0.006 and p=0.004 v HLA-B27 negative patients). In contrast, neither HLA-DR1 nor HLA-B15 influenced these indices. CONCLUSION: Apart from HLA-B27, there is a significant association of HLA-DR1 and HLA-B15 with SpA in Mexicans which is independent of B27. HLA-B27 is associated with younger age at onset and increased disease severity and HLA-DR1 with older age at onset. The strength of HLA-B15, HLA-B27, and HLA-DR1 associations varied in different forms of SpA.     

MICA gene triplet repeat polymorphism in patients with HLA-B27 positive and negative ankylosing spondylitis from Sardinia

OBJECTIVE: We investigated the distribution of MICA triplet repeat polymorphism in a random population and in patients with seronegative spondyloarthritis from Sardinia compared to continental Italy. METHODS: We analyzed the distribution of MICA triplet repeat polymorphism in HLA-B*2709 [not associated with ankylosing spondylitis (AS)] and B*2705 (associated with AS) haplotypes, to verify whether the strong association of MICA-A4 with HLA-B27 reported in other populations is maintained in Sardinia, and compared the distribution of MICA-A alleles in HLA-B27 negative versus HLA-B27+ patients with AS. RESULTS: We found that the frequency of MICA-A4 triplet repeat allele in a random Sardinia population is higher (53.2%) than in other Caucasian populations (around 20%); this allele is strongly associated with both HLA-B*2709 and B*2705. No significant difference between HLA-B27+ patients with AS and healthy controls was found: the MICA-A4 allele was present in more than 90% of subjects. MICA-A4 was found in 16 out of 20 HLA-B27 negative Sardinian patients with AS, with a frequency (80%) more similar to that of the HLA-B27+ group of patients than that of controls. CONCLUSION: The high frequency of MICA-A4 allele in HLA-B27 negative patients with AS from Sardinia, suggests the presence within the HLA region of a susceptibility factor other and certainly weaker than B27. This factor is likely to be more easily found by analyzing genetically homogeneous populations like the Sardinian, characterized by a small number of very frequent haplotypes.     

Hla–dr8 and acute anterior uveitis in ankylosing spondylitis

Objective. To identify possible factors in the development of acute anterior uveitis (AUU) in patients with ankylosing spondylitis (AS). Methods. We investigated HLA antigens serologically, and HLA–DRB1^*08 alleles by polymerase chain reaction–restriction fragment length polymorphism, in 42 Japanese AS patients with and without AAU. Results. Thirty-six of the AS patients (85.7%) had HLA–B27. Thirteen (65%) of the 20 patients with AAU had HLA–DR8, whereas only 1 (4.5%) of the 22 patients without AAU had DR8. The difference was statistically significant (P_corr < 0.001). Conclusion. Our data suggest that HLA–B27 is strongly associated with AS in Japanese patients and that HLA–DR8 is important for the development of AAU in Japanese patients with AS.     

LMP2与LMP7基因多态性与强直性脊柱炎并发虹睫炎易感性关系的研究

目的研究ＬＭＰ基因多态性与强直性脊柱炎并发虹睫炎发病的关系。方法应用ＰＣＲ对正常人和病人进行ＨＬＡＢ２７检测以及ＬＭＰ２和ＬＭＰ７扩增。ＣｆｏＩ进行限制性酶切图谱分析。结果强直性脊柱炎有虹睫炎（ＡＳ＋ＡＡＵ）病史以及单纯虹睫炎（ＡＡＵ）患者ＬＭＰ２基因ＢＢ纯合型较正常人以及强直性脊柱炎（ＡＳ）患者明显增高（Ｐ＜００５）,ＡＳ＋ＡＡＵ患者ＢＢ型ＯＲ＝３６,ＡＡＵ患者ＢＢ型ＯＲ＝５８３。ＬＭＰ７基因多态性无明显差别。结论在我国汉人中,ＬＭＰ２基因多态性与ＡＳ＋ＡＡＵ以及ＡＡＵ发病存在明显相关关系。     

The role of HLA genes in familial spondyloarthropathy: a comprehensive study of 70 multiplex families

OBJECTIVES: To investigate whether HLA alleles, other than HLA-B27, influence predisposition to spondyloarthropathy (SpA) in multiplex families. METHODS: Seventy French families with at least two affected SpA members were recruited. Patients, and their first degree relatives were typed for HLA-A, B, C, and DR, and extended HLA haplotypes were determined. The distribution of HLA-A, C, and DR alleles carried on HLA-B27+ haplotypes in SpA families was compared with the distribution of these alleles among HLA-B27+ haplotypes in the French general population. Contribution to SpA susceptibility of HLA-A, B, C, and DR alleles, other than HLA-B27, was tested by transmission disequilibrium test. The contribution of HLA alleles to specific presentation features of SpA was examined. RESULTS: Frequencies of HLA-A, C, and DR alleles carried on HLA-B27+ haplotypes from SpA families were comparable with those seen in the French population, except for DR13 which was overrepresented among patients (pcorr<0.001). Most interestingly, the HLA-DR4 allele was transmitted in excess to patients with SpA, independently of linkage to HLA-B27 (pcorr=0.05), and in a direction opposite to that for HLA-B27+ unaffected siblings (pcorr=0.01). Finally, the distribution of HLA alleles was not related to the presentation feature of SpA. CONCLUSION: HLA predisposition to familial SpA appears not to be limited to HLA-B27, but some HLA-DR alleles also have a significant influence. In particular, HLA-DR4 contributes significantly to a genetic predisposition to SpA, which may have implications in our understanding of SpA pathogenesis.     

TNF-238A promoter polymorphism contributes to susceptibility to ankylosing spondylitis in HLA-B27 negative patients.

OBJECTIVE: To investigate the relative contribution of MHC loci in their susceptibility to primary ankylosing spondylitis (AS) in HLA-B27 negative patients and to compare the clinical features and genetic factors with those of HLA-B27 positive AS. METHODS: DNA from patients with B27 negative primary AS (n = 28), B27 positive primary AS (n = 77), and matched healthy controls (B27-, n = 100; B27+, n = 70) were analyzed to investigate whether HLA genes determine the disease susceptibility, or whether other closely linked loci might play a role in disease development. HLA typing was carried out by serology and PCR/SSP (HLA-B, -DR), MICA-TM polymorphism in the transmembrane region by radioactive PCR, and tumor necrosis factor-alpha (TNF-alpha) promoter polymorphism at positions -238 and -308 by PCR-RFLP. RESULTS: Subtle clinical differences were found for primary AS, the B27 negative patients being less frequently complicated by acute anterior uveitis and more associated with peripheral arthritis than B27 positive. Differences were found in the distribution of TNF-alpha -238 genotypes among patients with primary AS (B27- vs B27+). The TNF-alpha -238(A) polymorphism was present in 50% of the B27 negative patients carrying the -238 G/A and A/A genotypes and was significantly increased compared with B27 positive AS (odds ratio 4.3) and with the B27 negative control group (OR 5.9). The TNF-alpha genotypes were equally prevalent in B27 positive AS and healthy matched B27 positive controls. No significant HLA and MICA typing differences were found between the populations under study. CONCLUSION: Our results indicate that the polymorphism variation in the TNF-alpha promoter -238.2(A) influences disease susceptibility in B27 negative primary AS but had no effect in our B27 positive AS population.     

HLA antigens and juvenile onset spondyloarthritides: negative association with non-B27 alleles

OBJECTIVE: To describe the association between HLA-B and HLA-DR genes and juvenile onset spondyloarthritides (SpA) in Mexicans. METHODS: The study included 66 consecutive patients with SpA (45 with ankylosing spondylitis (AS) and 21 with undifferentiated SpA) and 99 non-related healthy controls. The HLA-A, -B and DR alleles were detected by the polymerase chain reaction with the sequence-specific primers technique. Statistical methods included the Mantel-Haenzel chi2 test, Fisher's exact test, and Woolf method for odds ratio (OR). RESULTS: The frequency of HLA-B27 was significantly increased in the whole group (pC < 10(-3), OR = 53.0, aetiological fraction = 51%), particularly in AS (pC < 10(-3), OR = 67.42, aetiological fraction 57%). In contrast, the frequencies of HLA-B44, and HLA-B14 were significantly decreased. Also, a weak negative association HLA-DR5 (p < 0.05) was found. CONCLUSION: Apart from an expected significant association between HLA-B27 and juvenile-onset SpA, particularly AS, we found negative associations with HLA-B44, B14, and DR5. There was also a trend for HLA-B15 and DR1 associations with SpA.     

Clinical patterns and characteristics of ankylosing spondylitis in China

The study aimed to determine whether unique clinical patterns of AS may exist in China, specifically to explore the different clinical manifestations caused by gender, HLA-B27 status, and age at disease onset. The multicenter cross-sectional survey was conducted and 1251 patients were enrolled across China, representing a broad spectrum of Chinese AS patients. The mean age at onset and diagnosis were 29.2 (11.4) and 33.5 (12.6) years, respectively. The male/female ratio was 2.7:1. Acute anterior uveitis (AAU) was experienced in 10.3% of AS patients and 9.1% patients had juvenile-onset AS (JoAS). Men were significantly younger at onset and diagnosis and showed a higher frequency of HLA-B27 positivity, JoAS, and AAU than women. HLA-B27-positive patients had a younger age of onset than HLA-B27-negative patients. HLA-B27-positive patients were nearly three times as likely to develop AAU than negative patients (P = 0.04). JoAS patients had a family history of AS more often than adult-onset AS (AoAS) patients, and 4.9% of JoAS patients underwent surgical treatments, a rate more than six times that of AoAS patients (P = 0.01). Men had higher levels of C-reactive protein than women, as did HLA-B27 positives compared to negative patients, and JoAS compared to AoAS (all P < 0.05). The clinical patterns of our AS patients were similar to those in other studies in non-Chinese cohort: (1) the age at onset was 29.2 (11.4) years, which was older than found in other studies; (2) men were more likely be HLA-B27 carriers than women; and (3) AAU was less common in Chinese patients.     

Susceptibility to ankylosing spondylitis in twins the role of genes,HLA, and the environment

Objective. To determine the relative effects of genetic and environmental factors in susceptibility to ankylosing spondylitis (AS). Methods. Twins with AS were identified from the Royal National Hospital for Rheumatic Diseases database. Clinical and radiographic examinations were performed to establish diagnoses, and disease severity was assessed using a combination of validated scoring systems. HLA typing for HLA-B27, HLA-B60, and HLA-DR1 was performed by polymerase chain reaction with sequence-specific primers, and zygosity was assessed using microsatellite markers. Genetic and environmental variance components were assessed with the program Mx, using data from this and previous studies of twins with AS. Results. Six of 8 monozygotic (MZ) twin pairs were disease concordant, compared with 4 of 15 B27-positive dizygotic (DZ) twin pairs (27%) and 4 of 32 DZ twin pairs overall (12.5%). Nonsignificant increases in similarity with regard to age at disease onset and all of the disease severity scores assessed were noted in disease-concordant MZ twins compared with concordant DZ twins. HLA-B27 and B60 were associated with the disease in probands, and the rate of disease concordance was significantly increased among DZ twin pairs in which the co-twin was positive for both B27 and DR1. Additive genetic effects were estimated to contribute 97% of the population variance. Conclusion. Susceptibility to AS is largely genetically determined, and the environmental trigger for the disease is probably ubiquitous. HLA-B27 accounts for a minority of the overall genetic susceptibility to AS.     

Immunogenetic differences between patients with familial and non-familial rheumatoid arthritis

OBJECTIVE: To search for possible immunogenetic differencies between the patients with familial and non-familial rheumatoid arthritis (RA). METHODS: The study compared 129 familial RA patients with 217 non-familial patients for the frequencies of HLA-DR antigens including DR4 subtypes, DR4-DQB1*0301 and DR4-DQB1*0302 haplotypes and HLA-B27 antigen as well as the age of disease onset and existence of rheumatoid factor or joint erosions. RESULTS: Two major differences between familial and non-familial groups were found: firstly, familial RA patients had increased frequency of HLA-DR4 as compared with the non-familial RA group (68.2 v. 54.8%; p = 0.019). Secondly, the mean age at onset of RA was significantly lower in the familial than in the sporadic RA patients (42.0 v. 46.5 years; p = 0.0020) and the difference still remained when the DR4 positive and negative subgroups were compared separately. CONCLUSION: These results confirm the more prominent association with HLA-DR4 in familial than in the non-familial cases and suggest that accumulation of HLA risk genes may, at least partly, explain the familial occurrence of the disease. Other susceptibility genes may also be concentrated in multiplex case families as suggested by an earlier age at the onset of RA in both HLA-DR4 positive and negative familial patients.     

HLA-B60 and B61 are strongly associated with ankylosing spondylitis in HLA-B27-negative Taiwan Chinese patients

OBJECTIVES: Carriage of HLA-B60 has been shown to increase the risk of ankylosing spondylitis (AS) in B27-positive Caucasian patients, but the association in B27-negative cases is less certain. This study assessed HLA class I gene associations in Chinese HLA-B27-negative AS patients. METHODS: Forty-one Chinese HLA-B27-negative AS patients fulfilling the modified New York diagnostic criteria for AS were recruited, and 11 383 HLA-B27-negative blood donors were used for comparison. HLA-A and -B typing was done with the microlymphocytotoxicity assay. RESULTS: Among the B27-negative AS patients, 21 were male and 20 were female. Of HLA-B alleles, only B60 and B61 significantly increased susceptibility to AS in HLA-B27-negative patients (P<0.001). CONCLUSIONS: In Taiwan Chinese, carriage of B60 is increased in HLA-B27-negative AS patients. The association between B61 and HLA-B27-negative AS patients has not been reported previously. Whether the gene involved is HLA-B60 or B61 or another gene in linkage disequilibrium with these genes is unknown.     

HLA haplotypes in non-familial rheumatoid arthritis.

The frequencies of HLA-A, B, C, DR, and BF haplotypes in 44 unrelated Caucasian patients with definite seropositive rheumatoid arthritis (RA) were compared with haplotype frequencies in controls. Overall, the patients had an increased risk for HLA-DR4, DR3, and DR2 antigens, but frequencies of certain DR4 or DR3 haplotypes were not increased, suggesting the importance of other HLA loci for the evaluation of risk. The presence of DR4 alone was not found to produce an increased risk for RA since the frequencies of certain DR4 haplotypes were similar in patients and controls. Increased frequencies of HLA-B18, DR4, HLA-B15, DR4, and HLA-A1, B8, Cw7, DR3 haplotypes were found in patients. RA susceptibility has been found to be associated with the last two haplotypes in some studies of multiple case families, suggesting that similar genetic mechanisms may underlie the disease in familial and sporadic forms.     

GRAVES' DISEASE AND HLA: CLINICAL AND EPIDEMIOLOGIC ASSOCIATIONS

Correlation between clinical and epidemiological features of Graves' disease and HLA were sought in 175 patients, eighty-three of whom were typed for HLA DR antigens. The relative risks (x) conferred by HLA-B8 and DR3 were 3.1 and 5–7 respectively ( P <0.0005 uncorrected). The disease occurred at an earlier age in HLA-DR3 positive patients compared to negative patients ( P <0.005 in females> and <30-years-old). Eighty-four out of ninety-two patients could specify the season of onset of hyperthyroidism; an excess of HLA-B8 positive patients in the summer and a lack of these in the spring and autumn was found. No associations between B8 and exophthalmos and/or soft tissue eye changes were observed. However, significant associations between exophthalmos and either exophthalmos and/or soft tissue changes were found with DR3 (x=3.6 and 3.8 respectively). HLA-DR3 positive patients were found to be more resistant to radioiodine therapy than patients negative for these antigens. No heterogeneity in the distribution of HLA antigens was found when the following indices were examined: sex, goitre size, severity of disease, pretibial myxoedema, antecedent psychological disorder, consumption of oral contraceptives, family history of Graves' disease or thyroid antibody titre. HLA does not appear to distinguish subvariants of Graves' disease, rather it influences the susceptibility to disease and its persistence once it becomes clinically manifest.     

HLA class I associations of ankylosing spondylitis in the white population in the United Kingdom.

OBJECTIVE: To investigate the HLA class I associations of ankylosing spondylitis (AS) in the white population, with particular reference to HLA-B27 subtypes. METHODS: HLA-B27 and -B60 typing was performed in 284 white patients with AS. Allele frequencies of HLA-B27 and HLA-B60 from 5926 white bone marrow donors were used for comparison. HLA-B27 subtyping was performed by single strand conformation polymorphism (SSCP) in all HLA-B27 positive AS patients, and 154 HLA-B27 positive ethnically matched blood donors. RESULTS: The strong association of HLA-B27 and AS was confirmed (odds ratio (OR) 171, 95% confidence interval (CI) 135 to 218; p < 10(-99)). The association of HLA-B60 with AS was confirmed in HLA-B27 positive cases (OR 3.6, 95% CI 2.1 to 6.3; p < 5 x 10(-5)), and a similar association was demonstrated in HLA-B27 negative AS (OR 3.5, 95% CI 1.1 to 11.4; p < 0.05). No significant difference was observed in the frequencies of HLA-B27 allelic subtypes in patients and controls (HLA-B*2702, three of 172 patients v five of 154 controls; HLA-B*2705, 169 of 172 patients v 147 of 154 controls; HLA-B*2708, none of 172 patients v two of 154 controls), and no novel HLA-B27 alleles were detected. CONCLUSION: HLA-B27 and -B60 are associated with susceptibility to AS, but differences in HLA-B27 subtype do not affect susceptibility to AS in this white population.     

Acute anterior uveitis,arthritides and enteric antigens

Summary One hundred and fourteen patients with acute anterior uveitis were studied for the presence of the HLA-B27 tissue type, the prevalence of spondylitis and arthritis and the occurrence of gastro-intestinal and urogenital infections or diarrhoeal illness in the history. Eighty-seven (76%) were B27+ and 27 (24%) B27-. Forty-two (48%) of the B27+group had ankylosing spondylitis (AS); 13 (30%) of them were females. Sacroilitis (SI) with no spinal involvement was present in 21 patients (24%), 13 (61%) males and 8 (38%) females. Peripheral arthritis occurred in 6 patients. Thus, 68 (78%) of the HLA-B27+positive patients had inflammatory spinal and/or joint disease, compared with 1 (4%) of the HLA-B27-group (p<0.001). The AS diagnosis was unknown previous to our examination in 31% of the males and 54% of the females, and SI was undiscovered in 61% of the males and 62% of the females. The occurrence of acute enteric infections was significantly increased in the B27+AAU group, compared with the B27-patients and the patients reported exacerbation of AAU in connection with episodes of diarrhoea. An increased occurrence of urogenital infections was shown only in cocomparison with the males of the B-27+AAU group. Thirty-three out of 47 AAU patients assayed by enzyme immuno-assay (EIA) for the quantification of IgM, IgA and IgG antibodies against Klebsiella pneumoniae, E coli, and Proteus mirabilis had significantly raised antibody titres against one or more of the antibodies studied, as compared to 62 healthy controls. Though there was no statistically significant difference between the B27+group and the B27-group suggesting that these antigens may also play a part in the pathogenesis of B27 negative AAU. These results confirm the previous findings that gut infections are important in the aetiology of AAU and AS, but other mechanisms than the immunological cross-reactivity with enteric bacteria require further examination.     

The HLA association with Graves' disease is sex-specific in Hong Kong Chinese subjects

OBJECTIVE Graves' disease is associated with different HLA genes in Caucasians and the Chinese, in whom the HLA associations may be stronger in males than females. Common HLA-associated susceptibility in both races may occur at the HLA-DQ loci. The aims of this study were to examine the HLA-A, B, DR and DQ associations with Graves' disease in a Hong Kong Chinese population and to determine whether the HLA associations differ between the sexes and between subjects with and without thyrotoxic periodic paralysis. DESIGN HLA-A, B and DR types were determined by serological typing and DQA1 and DQB1 alleles by oligonucleotide probing of the respective enzymatically amplified gene. PATIENTS Ninety-seven Chinese patients with Graves' disease (31 males with, 35 males without and 31 females without thyrotoxic periodic paralysis) and 105 racially matched healthy controls. MEASUREMENTS Frequencies of HLA types/alleles at each locus were compared between patients and controls and between the Graves' subgroups using the χ² test. RESULTS HLA-B46, DR9 and DQB1*0303 were associated with Graves' disease in males only; these associations were weaker in males with thyrotoxic periodic paralysis. DR12, DQA1*0401 and DQB1*0301 were protective, regardless of sex or the presence of thyrotoxic periodic paralysis. The positive HLA associations in the Hong Kong Chinese were distinct from those in Caucasians whereas the protective haplotype was similar to that described in Caucasians. CONCLUSIONS These findings call in question the role of HLA genes in disease susceptibility but suggest a role for HLA in protection from Graves' disease.