Ethnic influence in clinical and functional measures of Brazilian patients with spondyloarthritis.

OBJECTIVE: Spondyloarthritides (SpA) can present different disease spectra according to ethnic background. The Brazilian Registry of Spondyloarthritis (RBE) is a nationwide registry that comprises a large databank on clinical, functional, and treatment data on Brazilian patients with SpA. The aim of our study was to analyze the influence of ethnic background in SpA disease patterns in a large series of Brazilian patients. METHODS: A common protocol of investigation was prospectively applied to 1318 SpA patients in 29 centers distributed through the main geographical regions in Brazil. The group comprised whites (65%), African Brazilians (31.3%), and people of mixed origins (3.7%). Clinical and demographic variables and various disease index scores were compiled. Ankylosing spondylitis (AS) was the most frequent disease in the group (65.1%); others were psoriatic arthritis (18.3%), undifferentiated SpA (6.8%), enteropathic arthritis (3.7%), and reactive arthritis (3.4%). RESULTS: White patients were significantly associated with psoriasis (p = 0.002), positive HLA-B27 (p = 0.014), and use of corticosteroids (p < 0.0001). Hip involvement (p = 0.02), axial inflammatory pain (p = 0.04), and radiographic sacroiliitis (p = 0.025) were associated with African Brazilian descent. Sex distribution, family history, and presence of peripheral arthritis, uveitis, dactylitis, urethritis, and inflammatory bowel disease were similar in the 3 groups, as well as age at disease onset, time from first symptom until diagnosis, and use of anti-tumor necrosis factor-α agents (p > 0.05). Schober test and thoracic expansion were similar in the 3 groups, whereas African Brazilians had higher Maastricht Ankylosing Spondylitis Enthesitis Scores (p = 0.005) and decreased lateral lumbar flexion (p = 0.003), while whites had a higher occiput-to-wall distance (p = 0.02). African Brazilians reported a worse patient global assessment of disease (p = 0.011). Other index scores and prevalence of work incapacity were similar in the 3 groups, although African Brazilians had worse performance in the Ankylosing Spondylitis Quality of Life questionnaire (p < 0.001). CONCLUSION: Ethnic background is associated with distinct clinical aspects of SpA in Brazilian patients. African Brazilian patients with SpA have a poorer quality of life and report worse disease compared to whites.

Influence of HLA-B*5703 and HLA-B*1403 on susceptibility to spondyloarthropathies in the Zambian population.

OBJECTIVE: To analyze the distribution of HLA-B alleles and to investigate their contribution in the susceptibility to spondyloarthropathies (SpA) in a sample population from Zambia, in order to determine a relationship between some HLA-B alleles and development of ankylosing spondylitis (AS), reactive arthritis (ReA), or undifferentiated SpA (uSpA). METHODS: . We selected 72 patients with SpA and found that 46 had uSpA, 23 ReA, and 3 AS. We also selected 92 matched controls; 55 of these had human immunodeficiency virus type I (HIV-I) infection. RESULTS: We found a significant increase in the rate of uSpA and ReA with features of Reiter's syndrome (RS) in HIV-positive individuals who carried the HLA-B*5703 allele (pc < 0.0001 and pc < 0.001, respectively). Among the significant new findings identified were the presence of B*1403 in 2 of the 3 AS patients (pc < 0.05, OR 47), confirming previous data in the Togolese population. CONCLUSION: The presence of B*5703 and HIV infection may not affect susceptibility to AS and ReA, but they do show an important influence in uSpA and RS. Our findings confirm that HLA-B*1403 is the only factor to increase the risk of AS in a sub-Saharan African population, whereas HLA-B27 was virtually absent in patients with AS.

Rheumatic disease and the Australian aborigine.

OBJECTIVE: To document the frequency and disease phenotype of various rheumatic diseases in the Australian Aborigine. METHODS: A comprehensive review was performed of the archaeological, ethnohistorical, and contemporary literature relating to rheumatic diseases in these indigenous people. RESULTS: No evidence was found to suggest that rheumatoid arthritis (RA), ankylosing spondylitis (AS), or gout occurred in Aborigines before or during the early stages of white settlement of Australia. Part of the explanation for the absence of these disorders in this indigenous group may relate to the scarcity of predisposing genetic elements, for example, shared rheumatoid epitope for RA, B27 antigen for AS. In contrast, osteoarthritis appeared to be common particularly involving the temporomandibular joint, right elbow and knees and, most probably, was related to excessive joint loading in their hunter gatherer lifestyle. Since white settlement, high frequency rates for rheumatic fever, systemic lupus erythematosus, and pyogenic arthritis have been observed and there are now scanty reports of the emergence of RA and gout in these original Australians. CONCLUSION: The occurrence and phenotype of various rheumatic disorders in Australian Aborigines is distinctive but with recent changes in diet, lifestyle, and continuing genetic admixture may be undergoing change. An examination of rheumatic diseases in Australian Aborigines and its changing phenotype may lead to a greater understanding of the aetiopathogenesis of these disorders.

Spondylarthropathic diseases in indigenous circumpolar populations of Russia and Alaska.

AIMS: To compare the nature and frequency of spondylarthropathy in geographically separated but genetically related populations with a high prevalence of HLA-B27. METHODS: Using a common questionnaire and disease criteria, cases were ascertained through cross-sectional community surveys in Russia and by examination and study of possible cases identified through rheumatic disease registries and the Native Health Service's computerized patient care data system in Alaska. RESULTS: Similar overall prevalences of spondyloarthropathy (2.0-3.4%) and a similar spectrum of disease were found, including reactive arthritis, ankylosing spondylitis and undifferentiated spondylarthropathy. Psoriatic arthritis was very rare. CONCLUSION: No predisposition to one particular form of spondyloarthropathy was observed; genetic and microbial settings for a spectrum of disease were present. Among adults positive for the presence of HLA-B27 the prevalence of all types of spondylarthropathies was estimated to be 4.5%, all populations combined, and the prevalence of AS was estimated to be 1.6%.

Prevalence of spondyloarthropathies and HLA-B27 in the native population of Chukotka, Russia.

OBJECTIVE: We sought to determine the prevalence and nature of spondyloarthropathies (SPA) and the prevalence of HLA-B27 in the native selected circumpolar population of Chukotka, Russia. METHODS: We conducted a cross sectional study that included medical examinations and interviews of 355 of 498 (71.3%) native residents of 2 Eastern Chukotka settlements, Enmelen and Nunligran. RESULTS: Among them were 268 Chukchas, 7 Eskimos, and 80 subjects of mixed race. There were 9 subjects (2.5%) with SPA, 3 of 7 Chukchas had ankylosing spondylitis (AS) (1.1%), 2 reactive arthritis (ReA), 2 with undifferentiated SPA. Among the mixed race persons one Chukcha-Eskimo had AS, one Eskimo-Russian had psoriatic arthritis (PsA). We found a high percentage of HLA-B27 antigen in the population, 34% in Chukcha natives and 25% in mixed race. CONCLUSION: Our data complement other studies of circumpolar populations and reinforce the reported high prevalences of SPA and HLA-B27 among those populations.

[The epidemiology of spondyloarthropathies among the native inhabitants of Chukotka. 2. The prevalence of HLA-B27 in the population and among spondyloarthropathy patients]. / Epidemiologiia spondiloartropatii sredi korennykh zhitelei Chukotki. Soobshchenie 2. Raspredelenie HLA-B27 v populiatsii i sredi bol'nykh spondiloartropatiiami.

To establish the incidence of HLA-B27 among the indigenous population of Chukot Peninsula, a one-stage cross-sectional study was made of all the natives of the two settlements of eastern Chukot Peninsula (Sireniki and Novo-Chaplino). At the moment of examination altogether 640 natives lived in both settlements. Of these, 464 persons (72.5%) could be examined clinically; HLA typing could be performed in 439 persons (68.6%). Among the 439 natives examined, antigen B27 was identified in 141 cases (32.1%). Among Eskimos, the number of HLA-B27-positive individuals amounted to 39.7%, among Chukchi to 18.9% (p = 0.0005). Half-breeds occupied an intermediate position between the two groups. The frequency of NLA-B27-positive cases was 29.7% among them. 7 patients were diagnosed to have diseases belonging to the group of spondyloarthropathies. 2 persons presented with ankylosing spondyloarthritis, 2 with Reiter's syndrome, 2 with undifferentiated spondyloarthropathies and 1 with juvenile chronic arthritis. All the patients with ankylosing spondyloarthritis and Reiter's syndrome appeared HLA-B27-positive.

[The epidemiology of spondylarthropathies among the native inhabitants of Chukotka (Eskimos and Chukchi). 1. The prevalence of spondylarthropathies among the Eskimos and the coast Chukchi]. / Epidemiologiia spondiloartropatii sredi korennykh zhitelei Chukotki (éskimosov i chukhei). Soobshchenie 1. Rasprostranennost' spondiloartropatii sredi éskimosov i beregovykh chukchei.

To establish the prevalence of spondyloarthropathies among the indigenous population of Chukot Peninsula, a one-stage cross-sectional study was made with a direct medical examination of the natives of the two settlements of Eastern Chukot Peninsula: Sireniki and Novo-Chaplino where the main part of Eskimos live. During expedition, 640 natives aged over 6 years lived in both settlements (382 and 258 respectively). 464 persons (72.5%) were examined. Of these, 7 persons (1.5%) were diagnosed to suffer from diseases belonging to the group of spondyloarthropathies: 2 persons (0.4%) had ankylosing spondyloarthritis, 2 (0.4%) Reiter's syndrome, 2 undifferentiated spondyloarthropathies, and 1 juvenile chronic arthritis. Of the 7 patients, 4 were Eskimos, 2 half-breeds and 1 was a Chukchi man. The incidence of ankylosing spondyloarthritis among Eskimos amounted to 0.9%, Reiter's syndrome to 0.5%, and undifferentiated spondyloarthropathies to 0.5%. Thus the one-stage expedition examination of the indigenous population of Chukotka Peninsula (Eskimos and Chukchi) has shown that diseases belonging to the group of spondyloarthropathies are widely prevalent among Eskimos.