- Email: [email protected]
Epidemiology of Spondyloarthritis in Brazil
SYMPOSIUM ARTICLE
Epidemiology of Spondyloarthritis in Brazil Percival D. Sampaio-Barros, MD, PhD
Abstract: During the period of 2006 to 2007, 28 university centers in Brazil used a standardized protocol of investigation to study the epidemiological, clinical and radiological variables of 1036 consecutive patients with the diagnosis of spondyloarthritis (SpA). Validated translated (Portuguese) versions of the Bath Ankylosing Spondylitis (AS) Disease Activity Index and the Bath AS Functional Index were applied. Patient diagnoses were predominantly AS (72.3%), followed by psoriatic arthritis (13.7%), undifferentiated SpA (6.3%), reactive arthritis (3.6%), juvenile SpA (3.1%) and arthritis related to inflammatory bowel disease (1.0%). There was a predominance of male (73.6%) and white (59.5%) patients. Pure axial disease was observed in 36.7% of the patients, whereas the mixed pattern (axial, peripheral and entheseal) was observed in 47.9%. The most common extra-articular involvement was anterior uveitis (20.2%). HLA-B27 was positive in 69.5% of the tested patients. Key Indexing Terms: Iberoame´rica; Brazil; Spondyloarthritis; Ankylosing spondylitis; Psoriatic arthritis. [Am J Med Sci 2011;341(4):287–288.]
T
he prevalence of spondyloarthritis (SpA) varies around the world. The clinical and radiological picture of SpA in populations of pure genetic background is well known, but there are no large studies analyzing populations of mixed genetic background such as those found in Brazil. Previous studies analyzing series of Brazilian patients with ankylosing spondylitis (AS) have shown that the frequency of HLA-B27 can vary from 64% to 86.7%1,2 and that the most common B27 allele was the HLA-B*2705.3 AS was also the most frequent SpA observed in a Brazilian juvenile cohort.4 Psoriatic arthritis 2 (PsA) more frequently presented the oligoarticular pattern in two Brazilian series.5,6 Undifferentiated SpA (USpA) can affect white and African-Brazilian patients, and HLA-B27 and buttock pain were predictive factors to become a differentiated disease in a long-term follow-up study.7 This report describes the SpA profiles in a large Brazilian series.
METHODS During the period 2006 to 2007, 28 university centers in Brazil used a standardized protocol of investigation to study epidemiological, clinical and radiological variables of 1036 consecutive patient with SpA. This protocol was previously designed by the Spanish Registry of Spondyloarthritis and was also used by approximately 100 centers in 10 other IberoameriFrom the Rheumatology Division, Disciplina de Reumatologia, Faculdade de Medicina, Universidade de Sa˜o Paulo, Sa˜o Paulo, Brasil. Presented at the annual research and education meeting of Spondyloarthritis Research and Treatment Network (SPARTAN), July 23–24, 2010, Houston, Texas. An earlier version of this paper was previously published in Spanish in “Reumatologia Clínica”: PD Sampaio-Barros, CR Gonc¸alves, JA Braga da Silva, et al. Registro Iberoamericano de Espondiloartritis (RESPONDIA): Brasil. Reumatol Clin 2008;4(suppl 4):30 –5. Correspondence: Percival D. Sampaio-Barros, MD, PhD, Rheumatology Division, Disciplina de Reumatologia, Faculdade de Medicina, Universidade de Sa˜o Paulo, Av. Dr. Arnaldo, 455-3° andar-Reumatologia, Sa˜o Paulo, Sa˜o Paulo 01246-903, Brasil (E-mail: [email protected]).
can countries, which constituted the RESPONDIA Group. The general methodology and data analysis was previously published.8 Validated translated (to Portuguese) versions of the Bath AS Disease Activity Index and the Bath AS Functional Index were applied.
RESULTS The study included 1036 patients, with the diagnosis of AS (72.3%), PsA (13.7%), USpA (6.3%), reactive arthritis (3.6%), juvenile SpA (3.1%) and arthritis related to inflammatory bowel disease (1.0%). There was predominance of male patients (73.6%). With regard to ethnicity, 59.5% were white, 25.9% were African-Brazilians (5.2% pure black and 20.7% Mulattos) and 14.6% were from other origins (mixture of white, black, indigenous and/or East Asians). The mean age was 43.7 ⫾ 12.6 years, and the mean age at onset of disease was 31 ⫾ 13.6 years. Pure axial disease was observed in 36.7% of the patients, whereas pure peripheral involvement was observed in 10.7% and pure entheseal disease in 4.7%; the mixed pattern (axial, peripheral and entheseal) was observed in 47.9% of patients. The most common extra-articular involvement was anterior uveitis, observed in 20.2% of patients. HLA-B27 was positive in 69.5% of the tested patients, and a familial history of a defined SpA was observed in 16.2%. The mean Bath AS Disease Activity Index was 4.12 and the mean Bath AS Functional Index was 4.53. The frequency of the primary demographic and clinical variables in AS, PsA and USpA are summarized on Table 1.
DISCUSSION This is the first epidemiologic study analyzing patients with SpA from all 5 geographic regions in Brazil. The common protocol of investigation was important because it enabled different SpA outpatient clinics around the country to use the same instruments to assess their patients. AS was the most frequent disease observed in the Brazilian series, affecting 72.3% of the patients. Because some patients with psoriatic arthritis plus oligoarticular disease are treated by dermatologists, some patients with enteropathic arthritis are treated by gastroenterologists and many patients with reactive arthritis present mild self-limited symptoms, the low prevalence of these diseases can be explained by a referral bias. The large frequency of male patients with SpA is associated with the predominance of AS in the series. The prevalence of white patients (59.5%) in the study was lower than that observed in European countries, but it was higher than the percentage in the overall Brazilian population (49.9%), while the African-Brazilian SpA percentage (25.9%, with 5.2% pure black and 20.7% Mulattos) was significantly lower than that in the Brazilian population (49.5%, with 6.3% pure black and 43.2% Mulattos). The most striking observation in this large Brazilian series was the high frequency of patients with SpA with a
The American Journal of the Medical Sciences • Volume 341, Number 4, April 2011
287
Sampaio-Barros
TABLE 1. Description of the main variables in AS, PsA and USpA Demographic data Male/female, n (%) Age at onset (yr), mean (SD) Clinical data, mean (SD) Family history SpA Inflammatory low back pain Arthritis, lower limbs Enthesitis Arthritis, upper limbs Cervical pain Hip pain Dactilitis Clinimetrics, mean (SD) BASDAI BASFI VAS pain, last week, night VAS, patient global
AS (n ⴝ 736)
PsA (n ⴝ 139)
USpA (n ⴝ 64)
Pa
570/166 (77/23) 27.7 (11.4)
82/57 (59/41) 39.7 (12.2)
40/24 (62.5/37.5) 30.5 (10.7)
NS 0.000
125 (16.9) 548 (74.4) 278 (37.8) 170 (23.1) 99 (13.5) 260 (35.3) 225 (30.6) 39 (5.3)
21 (17.8) 52 (59.8) 90 (64.7) 26 (18.7) 76 (54.7) 37 (26.6) 25 (18) 27 (19.4)
7 (12.3) 37 (57.8) 42 (65.6) 30 (46.9) 22 (34.4) 17 (26.6) 11 (17.2) 5 (7.8)
NS 0.000 0.000 0.000 0.000 0.066 0.001 0.000
4.6 (3.3) 4.9 (2.7) 4.2 (3.3) 4.8 (2.7)
4.0 (2.5) 4.0 (2.9) 3.3 (3.2) 4.6 (2.9)
4.2 (2.4) 3.2 (2.6) 4.0 (3.3) 4.7 (2.8)
NS 0.000 0.005 NS
a
P determined by analysis of variance (ANOVA). AS, ankylosing spondylitis; BASDAI, Bath AS Disease Activity Index; BASFI, Bath AS Functional Index; NS, not significant; PsA, psoriatic arthritis; SD, standard deviation; USpA, undifferentiated SpA; VAS, visual analog scale.
mixed (axial, peripheric and enthesitic) pattern (47.9%), emphasizing the importance of the peripheral component in the Brazilian patients with SpA. There is a growing interest in SpA in Latin America that is allied with the integration of the different Iberoamerican countries through the RESPONDIA group. The possibility for success with these initiatives and with all research in the field of SpA in Latin America will improve through a more solid cooperation with international societies such as SPARTAN (SpA Research and Treatment Network) and ASAS (Assessment of SpondyloArthritis international Society).
3. Conde RA, Sampaio-Barros PD, Donadi EA, et al. Frequency of the HLA-B27 alleles in Brazilian patients with AS. J Rheumatol 2003;30: 2511–2.
REFERENCES
7. Sampaio-Barros PD, Bortoluzzo AB, Conde RA, et al. Undifferentiated spondyloarthritis: a longterm followup. J Rheumatol 2010;37: 1195–9.
1. Sampaio-Barros PD, Gonc¸alves CR, Braga da Silva JA, et al. Registro Iberoamericano de Espondiloartritis (RESPONDIA): Brasil. Reumatol Clin 2008;4(suppl 4):30 –5. 2. Sampaio-Barros PD, Bertolo MB, Kraemer MH, et al. Primary ankylosing spondylitis: patterns of disease in a Brazilian population of 147 patients. J Rheumatol 2001;28:560 –5.
288
4. Faustino PC, Terreri MT, Andrade CT, et al. Características clínicas das espondiloartropatias na infaˆncia: ana´lise de 26 pacientes. Rev Ass Med Brasil 2001;47:216 –20. 5. Aslanian FM, Lisboa FF, Iwamoto A, et al. Clinical and epidemiological evaluation of psoriasis: clinical variants and articular manifestations. J Eur Acad Dermatol Venereol 2005;19:141–2. 6. Bonfiglioli R, Conde RA, Sampaio-Barros PD, et al. Frequency of HLA-B27 alleles in Brazilian patients with psoriatic arthritis. Clin Rheumatol 2008;27:709 –12.
8. Va´zquez-Mellado J, Font-Ugalde P, Mun˜oz-Goma´riz E, et al. Registro Iberoamericano de Espondiloartritis (RESPONDIA): que es, como surgio´, quie´nes somos y que hacemos? Metodologia general. Reumatol Clin 2008 2008;4(suppl 4):S17–32.
Volume 341, Number 4, April 2011
Epidemiology of Spondyloarthritis in Brazil Percival D. Sampaio-Barros, MD, PhD
Abstract: During the period of 2006 to 2007, 28 university centers in Brazil used a standardized protocol of investigation to study the epidemiological, clinical and radiological variables of 1036 consecutive patients with the diagnosis of spondyloarthritis (SpA). Validated translated (Portuguese) versions of the Bath Ankylosing Spondylitis (AS) Disease Activity Index and the Bath AS Functional Index were applied. Patient diagnoses were predominantly AS (72.3%), followed by psoriatic arthritis (13.7%), undifferentiated SpA (6.3%), reactive arthritis (3.6%), juvenile SpA (3.1%) and arthritis related to inflammatory bowel disease (1.0%). There was a predominance of male (73.6%) and white (59.5%) patients. Pure axial disease was observed in 36.7% of the patients, whereas the mixed pattern (axial, peripheral and entheseal) was observed in 47.9%. The most common extra-articular involvement was anterior uveitis (20.2%). HLA-B27 was positive in 69.5% of the tested patients. Key Indexing Terms: Iberoame´rica; Brazil; Spondyloarthritis; Ankylosing spondylitis; Psoriatic arthritis. [Am J Med Sci 2011;341(4):287–288.]
T
he prevalence of spondyloarthritis (SpA) varies around the world. The clinical and radiological picture of SpA in populations of pure genetic background is well known, but there are no large studies analyzing populations of mixed genetic background such as those found in Brazil. Previous studies analyzing series of Brazilian patients with ankylosing spondylitis (AS) have shown that the frequency of HLA-B27 can vary from 64% to 86.7%1,2 and that the most common B27 allele was the HLA-B*2705.3 AS was also the most frequent SpA observed in a Brazilian juvenile cohort.4 Psoriatic arthritis 2 (PsA) more frequently presented the oligoarticular pattern in two Brazilian series.5,6 Undifferentiated SpA (USpA) can affect white and African-Brazilian patients, and HLA-B27 and buttock pain were predictive factors to become a differentiated disease in a long-term follow-up study.7 This report describes the SpA profiles in a large Brazilian series.
METHODS During the period 2006 to 2007, 28 university centers in Brazil used a standardized protocol of investigation to study epidemiological, clinical and radiological variables of 1036 consecutive patient with SpA. This protocol was previously designed by the Spanish Registry of Spondyloarthritis and was also used by approximately 100 centers in 10 other IberoameriFrom the Rheumatology Division, Disciplina de Reumatologia, Faculdade de Medicina, Universidade de Sa˜o Paulo, Sa˜o Paulo, Brasil. Presented at the annual research and education meeting of Spondyloarthritis Research and Treatment Network (SPARTAN), July 23–24, 2010, Houston, Texas. An earlier version of this paper was previously published in Spanish in “Reumatologia Clínica”: PD Sampaio-Barros, CR Gonc¸alves, JA Braga da Silva, et al. Registro Iberoamericano de Espondiloartritis (RESPONDIA): Brasil. Reumatol Clin 2008;4(suppl 4):30 –5. Correspondence: Percival D. Sampaio-Barros, MD, PhD, Rheumatology Division, Disciplina de Reumatologia, Faculdade de Medicina, Universidade de Sa˜o Paulo, Av. Dr. Arnaldo, 455-3° andar-Reumatologia, Sa˜o Paulo, Sa˜o Paulo 01246-903, Brasil (E-mail: [email protected]).
can countries, which constituted the RESPONDIA Group. The general methodology and data analysis was previously published.8 Validated translated (to Portuguese) versions of the Bath AS Disease Activity Index and the Bath AS Functional Index were applied.
RESULTS The study included 1036 patients, with the diagnosis of AS (72.3%), PsA (13.7%), USpA (6.3%), reactive arthritis (3.6%), juvenile SpA (3.1%) and arthritis related to inflammatory bowel disease (1.0%). There was predominance of male patients (73.6%). With regard to ethnicity, 59.5% were white, 25.9% were African-Brazilians (5.2% pure black and 20.7% Mulattos) and 14.6% were from other origins (mixture of white, black, indigenous and/or East Asians). The mean age was 43.7 ⫾ 12.6 years, and the mean age at onset of disease was 31 ⫾ 13.6 years. Pure axial disease was observed in 36.7% of the patients, whereas pure peripheral involvement was observed in 10.7% and pure entheseal disease in 4.7%; the mixed pattern (axial, peripheral and entheseal) was observed in 47.9% of patients. The most common extra-articular involvement was anterior uveitis, observed in 20.2% of patients. HLA-B27 was positive in 69.5% of the tested patients, and a familial history of a defined SpA was observed in 16.2%. The mean Bath AS Disease Activity Index was 4.12 and the mean Bath AS Functional Index was 4.53. The frequency of the primary demographic and clinical variables in AS, PsA and USpA are summarized on Table 1.
DISCUSSION This is the first epidemiologic study analyzing patients with SpA from all 5 geographic regions in Brazil. The common protocol of investigation was important because it enabled different SpA outpatient clinics around the country to use the same instruments to assess their patients. AS was the most frequent disease observed in the Brazilian series, affecting 72.3% of the patients. Because some patients with psoriatic arthritis plus oligoarticular disease are treated by dermatologists, some patients with enteropathic arthritis are treated by gastroenterologists and many patients with reactive arthritis present mild self-limited symptoms, the low prevalence of these diseases can be explained by a referral bias. The large frequency of male patients with SpA is associated with the predominance of AS in the series. The prevalence of white patients (59.5%) in the study was lower than that observed in European countries, but it was higher than the percentage in the overall Brazilian population (49.9%), while the African-Brazilian SpA percentage (25.9%, with 5.2% pure black and 20.7% Mulattos) was significantly lower than that in the Brazilian population (49.5%, with 6.3% pure black and 43.2% Mulattos). The most striking observation in this large Brazilian series was the high frequency of patients with SpA with a
The American Journal of the Medical Sciences • Volume 341, Number 4, April 2011
287
Sampaio-Barros
TABLE 1. Description of the main variables in AS, PsA and USpA Demographic data Male/female, n (%) Age at onset (yr), mean (SD) Clinical data, mean (SD) Family history SpA Inflammatory low back pain Arthritis, lower limbs Enthesitis Arthritis, upper limbs Cervical pain Hip pain Dactilitis Clinimetrics, mean (SD) BASDAI BASFI VAS pain, last week, night VAS, patient global
AS (n ⴝ 736)
PsA (n ⴝ 139)
USpA (n ⴝ 64)
Pa
570/166 (77/23) 27.7 (11.4)
82/57 (59/41) 39.7 (12.2)
40/24 (62.5/37.5) 30.5 (10.7)
NS 0.000
125 (16.9) 548 (74.4) 278 (37.8) 170 (23.1) 99 (13.5) 260 (35.3) 225 (30.6) 39 (5.3)
21 (17.8) 52 (59.8) 90 (64.7) 26 (18.7) 76 (54.7) 37 (26.6) 25 (18) 27 (19.4)
7 (12.3) 37 (57.8) 42 (65.6) 30 (46.9) 22 (34.4) 17 (26.6) 11 (17.2) 5 (7.8)
NS 0.000 0.000 0.000 0.000 0.066 0.001 0.000
4.6 (3.3) 4.9 (2.7) 4.2 (3.3) 4.8 (2.7)
4.0 (2.5) 4.0 (2.9) 3.3 (3.2) 4.6 (2.9)
4.2 (2.4) 3.2 (2.6) 4.0 (3.3) 4.7 (2.8)
NS 0.000 0.005 NS
a
P determined by analysis of variance (ANOVA). AS, ankylosing spondylitis; BASDAI, Bath AS Disease Activity Index; BASFI, Bath AS Functional Index; NS, not significant; PsA, psoriatic arthritis; SD, standard deviation; USpA, undifferentiated SpA; VAS, visual analog scale.
mixed (axial, peripheric and enthesitic) pattern (47.9%), emphasizing the importance of the peripheral component in the Brazilian patients with SpA. There is a growing interest in SpA in Latin America that is allied with the integration of the different Iberoamerican countries through the RESPONDIA group. The possibility for success with these initiatives and with all research in the field of SpA in Latin America will improve through a more solid cooperation with international societies such as SPARTAN (SpA Research and Treatment Network) and ASAS (Assessment of SpondyloArthritis international Society).
3. Conde RA, Sampaio-Barros PD, Donadi EA, et al. Frequency of the HLA-B27 alleles in Brazilian patients with AS. J Rheumatol 2003;30: 2511–2.
REFERENCES
7. Sampaio-Barros PD, Bortoluzzo AB, Conde RA, et al. Undifferentiated spondyloarthritis: a longterm followup. J Rheumatol 2010;37: 1195–9.
1. Sampaio-Barros PD, Gonc¸alves CR, Braga da Silva JA, et al. Registro Iberoamericano de Espondiloartritis (RESPONDIA): Brasil. Reumatol Clin 2008;4(suppl 4):30 –5. 2. Sampaio-Barros PD, Bertolo MB, Kraemer MH, et al. Primary ankylosing spondylitis: patterns of disease in a Brazilian population of 147 patients. J Rheumatol 2001;28:560 –5.
288
4. Faustino PC, Terreri MT, Andrade CT, et al. Características clínicas das espondiloartropatias na infaˆncia: ana´lise de 26 pacientes. Rev Ass Med Brasil 2001;47:216 –20. 5. Aslanian FM, Lisboa FF, Iwamoto A, et al. Clinical and epidemiological evaluation of psoriasis: clinical variants and articular manifestations. J Eur Acad Dermatol Venereol 2005;19:141–2. 6. Bonfiglioli R, Conde RA, Sampaio-Barros PD, et al. Frequency of HLA-B27 alleles in Brazilian patients with psoriatic arthritis. Clin Rheumatol 2008;27:709 –12.
8. Va´zquez-Mellado J, Font-Ugalde P, Mun˜oz-Goma´riz E, et al. Registro Iberoamericano de Espondiloartritis (RESPONDIA): que es, como surgio´, quie´nes somos y que hacemos? Metodologia general. Reumatol Clin 2008 2008;4(suppl 4):S17–32.
Volume 341, Number 4, April 2011