The authors have declared that no competing interests exist.
To identify the clinical epidemiological characteristics of patients with juvenile idiopathic arthritis (JIA) monitored at the Lucidio Portella Children’s Hospital (HILP) in northeastern Brazil and to ascertain the frequency and forms of presentation, the most affected joints, the most common joint involvement for each form, the frequencies of positive rheumatoid factor (RF+) and positive antinuclear antibodies (ANA+) in the various forms of presentation, and the most common complications.
A study was conducted with 74 medical records of patients with JIA monitored at HILP between January 2010 and January 2013. Descriptive statistics were used for statistical analysis.
JIA was predominant in females with a mean age at onset of 5.2 years and a median disease duration of two years. The most frequent initial form of presentation was oligoarticular (63.5) arthritis, and the most affected joint was the knee (86.4%). The knee was most affected by oligoarticular arthritis, the wrist, knee, and ankle were affected by RF+ polyarticular arthritis, and the knee, ankle, and cervical spine were affected by systemic arthritis. RF+ was observed in 8.5% of the oligoarticular arthritis cases. ANA+ were present in 27.7% of the oligoarticular cases, in 22.2% of the systemic arthritis cases, and in 11.1% of the RF+ polyarticular arthritis . The most common complications were deformities (20.3%) and uveitis (14.9%).
The findings for JIA patients in a referral hospital in northeastern Brazil were consistent with the literature regarding most of the evaluated criteria.
The term juvenile idiopathic arthritis (JIA) represents a heterogeneous group of diseases characterized by arthritis in at least one joint with a minimum of six weeks duration and onset of symptoms up to 16 years of age
Chronic arthritis in children is not rare, but the true frequency is not known
It appears to be worldwide in distribution, but the reported incidence and prevalence vary considerably throughout the world
Santos conducted a study in 72 patients in Belo Horizonte – Brazil, using the ILAR criteria and found the oligoarticular form as most frequent, 44.4% of cases
Oligoarticular form is the most frequent occurring in 50 to 60% of cases of JIA
Systemic Arthritis comprises 10% to 20% of JIA cases. About two-thirds occur in children under 5 years, although it can occur in any age. Genders are involved in same proportion, although there is a slight predominance in females when the onset occurs after 10 years of age
Polyarticular form onset corresponds 30 to 50% of patients with JIA and is characterized by chronic involvement of five or more joints during the first six months of disease. It includes forms with Negative Rheumatoid Factor (RF -) in 20% to 40% of JIA and with Positive Rheumatoid Factor (RF +) in 5% to 10% of JIA
Psoriatic arthritis is inflammatory seronegative arthritis for rheumatoid factor associated with cutaneous psoriasis. It is uncommon in childhood, accounting only 3% of chronic arthritis. Age of onset symptoms is usually between 9 and 12 years. It doesn’t usually have Gender predominance, except specific subtypes with predominance of females in polyarticular form symmetrical and males in spondylithic form
Undifferentiated Arthritis include diseases that some reason do not fills criteria for specific category or fills criteria for more than one
The diagnosis is o exclude other pathologies and identify subtypes of the disease associated with specific immunological and serological markers and to evaluate the degree of inflammation and systemic effects.
According to Bisotto et al
The research objectives were to identify the clinical and epidemiological characteristics of JIA cases in their various forms of presentation, according to the classification of ILAR, and the most common complications, monitored in a Brazilian University Hospital.
The study was based on the medical records of 74 patients diagnosed with JIA according to the ILAR criteria (1997)
The following variables were studied: gender, ethnicity, age at presentation of the first signs/symptoms, disease duration, and form of initial presentation of the disease. The Caucasian and non-Caucasian classification was conducted in accordance with the phenotype of skin color informed by patient self-definition.
Data were also collected regarding the joints most affected, the most common joint involvement in every form, the frequency of RF+ in other forms of presentation (IgM RF+), and the identification of forms of JIA with ANA+.
RF was evaluated using the latex agglutination and Waaler-Rose tests with a value of 1:16. RF+ is associated with an aggressive disease progression including joint deformities, joint-space narrowing, and joint erosion
A continuous line of human tumor cells (HEP-2) were used to perform the ANA analysis. Titers between 1:80 and 1:160 were considered to be low, titers between 1:160 and 1:640 were considered to be medium, and titers above 1:640 were considered to be high. ANA is usually positive in low titers (less than 1:640) in 65% to 85% of children with oligoarticular JIA and in girls with uveitis
All the patients underwent a routine clinical rheumatologic examination. Complications included deformities, uveitis, and macrophage activation syndrome. The deformities are diagnostic for clinical manifestations in joints. The deformities that develop at the hands include ulnar drift at the wrists and the metacarpal phalangeal (MCP) joints and boutonniere and swan neck deformities at the fingers. The deformities that develop at the feet include hallux valgus deformities at the first MTP joints, hammertoe, and cock-up toe deformities. The deformities that develop at the knee include flexion contracture, epiphyseal enlargement, and hypoplasia of the menisci
All of the patients diagnosed with JIA underwent an ophthalmological slit lamp examination. Ocular involvement was considered when the ophthalmologist diagnosed uveitis based on the criteria established by the International Uveitis Study Group 3 adapted by the SUN2, according to the anatomical classification, considering previous, uveitis in which the primary site of inflammation was in the anterior chamber (iritis, anterior cyclites and iridocyclites)
Macrophage activation syndrome, which is the most serious complication of systemic JIA, was diagnosed using a symptomatology of sudden onset of fever, generalized lymphadenopathy, hepatosplenomegaly, and coagulation disorders and was confirmed by the presence of histiocytic phagocytosing hemocytes or platelets in the bone marrow, lymph nodes, liver, or spleen, low ESR, and pancytopenia.
Data were collected on a sheet, tabulated, and processed using the Statistical Package for the Social Sciences 17.0 (SPSS) program, and the results are presented in tables and graphs.
For the statistical analysis, frequencies were calculated for the categorical qualitative variables. For the quantitative variables, the central tendency was determined using the mean and median, and the dispersion was determined using the standard deviation.
Of the total 74 patients studied, 47 (63.5 %) were female and 27 (36.5%) were male, 51 were non-Caucasian (69.2%), and 23 were Caucasian (38.8%).
The mean age at presentation of the first signs/symptoms was 5.2 years (SD = 3.3 years) with a minimum age at the first signs/symptoms of one year and a maximum of 12 years.
The median disease duration was two years, the minimum duration was six months, and the maximum duration was 11 years.
Oligoarticular arthritis represented the most frequent presentation (47; 63.5%) followed by systemic (11; 14.8%) and RF+ polyarticular (9; 12.2%) arthritis. RF- polyarticular (4; 5.4%) and psoriatic arthritis were present in three cases (4.1%). There were no cases related to enthesitis-related arthritis or undifferentiated arthritis (
Initial | Sex | Age onset (year) | Disease duration (year) | |||
form n % | Male Female n % n % | Mean (Sd) Median | Mean(Sd) Median | |||
Oligo (47; 63.5) | 15 31.9 | 32 68.1 | 4 (±3) | 3 | 3 (±2) 2 | |
Systemic (11; 14.8) | 6 54.5 | 5 45.5 | 6 (±2) | 7 | - | 0.5 |
RF+ Poly (9; 12.2 ) | 1 11.1 | 8 8.9 | 7 (±3) | 8 | 5 (±3) | 1 |
RF- Poly (4; 5.4) | 4 100 | - - | 7 (±4) | 8 | 1 (±0.5) | 0.5 |
Psoriatic (3; 4,1) | 1 33.3 | 2 66.7 | 11 (±4) | 9 | - | 2 |
Sd:Std deviation
Oligoarticular arthritis was most commonly observed in the knee. RF+ polyarticular arthritis was frequently observed in the wrist, knee, and ankle. RF- polyarticular arthritis was observed to the same extent in the knee, ankle, wrist, and cervical spine. The systemic form most frequently involved the knee and ankle joints followed by the cervical spine. The knee joint was involved in most of the psoriatic arthritis cases (
Forms | OOligoart ((n=47) | Polyartic.FR+ (n=9) | Polyartic.FR- (n=4 ) | Systemic Psorias Total (n=11) (n=3) (n=74) | |
affected joint | n % | n % | n % | n % n % n % | |
Cervical spine | - - | 5 55.5 | 1 25.0 | 7 63,3 - - 13 17.6 | |
Mandibular | - - | - - | - - | 3 27.3 - - 3 4.0 | |
temporo | |||||
Shoulder | - - | - - | - - | 1 9.0 - - 1 1.5 | |
Elbow | 2 5.5 | 5 55.5 | - - | 4 36.5 - - 11 14.8 | |
Wrist | 5 11.1 | 9 100.0 | 3 75.0 | 6 54.5 1 33.3 24 32.4 | |
Hand | 4 8.3 | 7 77.7 | 1 25.0 | 1 9.0 1 33.3 14 18.9 | |
Coxo-femoral | 2 5.5 | 1 11,1 | 1 25.0 | 4 36.5 - - 8 10.8 | |
Knee | 40 86,1 | 9 100,0 | 4 100.0 | 8 72.7 3 100.0 64 86.4 | |
Ankle | 13 27.7 | 9 100.0 | 3 75.0 | 8 72.7 1 33.3 34 45.9 | |
Foot | - - | 3 33.3 | - - | - - - - 3 4.0 |
The frequency of serological characteristics and most commonly observed complications are shown in
Disease Forms | O Oligoart ((n=47) n % | Polyartic.FR+ (n=9) n % | Polyartic.FR- (n=4 ) n % | Systemic Psorias Total (n=11) n% (n=3) n% (n=74) n% |
Serological characteristics | ||||
FR+ | 4 8.5 | 9 100.0 | - - | - - - - 13 17.5 |
FAN+ | 16 34,0 | 2 22,2 | - - | 2 18,2 - - 20 27,0 |
Complicações | ||||
Deformities | 9 19.1 | 6 66.6 | - - | - - - - 15 20.3 |
Uveitis | 11 23,4 | - - | - - | - - - - 11 14,9 |
Macrophage | - - | - - | - - | 1 9.1 - - 1 1,3 |
activation | ||||
syndrome |
This study showed that JIA most commonly affects female non-Caucasian children. Santos
A higher frequency of JIA was observed in non-Caucasian patients. The classification was performed regarding the self-defined phenotype of skin color. Brazil represents a mixed population with a relatively large percentage of immigrants, especially in the Northeast, which prevents an exact determination of patient ethnicity difficult.
In a multicenter study conducted in 13 Brazilian pediatric rheumatology referral centers, 780 children with JIA were treated during a one-year period. In the Pediatric Rheumatology Outpatient Unit of the Department of Childcare and Pediatrics, School of Medicine of Ribeirão Preto - Brazil, an average of 14 new cases of JIA per year were treated over the past five years
Two peaks of a higher incidence of disease onset were determined: children under five, who belong predominantly to the oligoarticular group, and adolescents, who belong to the RF+ and enthesitis-related arthritis groups
The most frequently affected joint was the knee followed by the heel, wrist, hand, and cervical spine (
Oligoarticular arthritis (63.5%) was the most frequently observed initial presentation of JIA in the sample, which is consistent with the literature. In Europe and North America, oligoarticular arthritis is the most frequent form of JIA and represented approximately 50% of the cases in a large case study series conducted in 1997 by Chalom et al
Forms | Piauí Brazil Pires et al, 2014 | BeloHorizonte Brazil Santos, 2006 | Turkey Yilmazet al, 2008 | India Kunjir et al, 2010 | South of África, Weakley et al, 2012 | United Kingdom Thomson et al, 2002 | Spain Merino et al, 2001 | Alsace, France Danner et al, 2006 | Italy Ravelli, 2007 |
Systemic | 14,9 | 31,9 | 15,3 | 8,0 | 7,7 | 14,5 | 14,4 | 8,9 | 4 - 17 |
Oligo | 63,5 | 34,7 | 34,1 | 21,0 | 26,8 | 45,6 | 37,6 | 40,3 | 27 -56 |
Poly FR- | 5,4 | 18,1 | 30,6 | 17,0 | 26,9 | 19,6 | 22,4 | 20,4 | 28-Nov |
Poly FR+ | 12,2 | 4,2 | 6,6 | 12,0 | 14,0 | 7,1 | 1,6 | - | 2 - 7 |
Psoriat A | 4,0 | 4,2 | 1,0 | 1,0 | 1,3 | 7,1 | 1,6 | 4,5 | 11-Feb |
ERA | _ | 5,6 | 10,3 | 36,0 | 23,0 | 6,5 | 7,2 | 17,9 | 11-Mar |
others | _ | 1,4 | 2,5 | 5,0 | - | - | 15,2 | 6,0 | 21-Nov |
RF+ polyarticular arthritis was the third most frequently observed disease presentation with 9 cases (12.2%), which is also higher than values reported in the literature (
Psoriatic arthritis was found in a small number of cases (3; 4.0%) and more often in females. Skin lesions were manifested before joint involvement. In male patients, skin involvement occurred at the same time as joint involvement and was severe. Psoriatic arthritis was both RF- and ANA-. Statistics have shown that 6-42% of psoriasis patients develop some type of joint involvement
Enthesitis-associated arthritis and undifferentiated arthritis, which are commonly under-diagnosed and exhibit unspecific forms of clinical presentation, were not detected in this study (
The most commonly affected joint was the knee (86.4%), which is inconsistent with the literature, followed by the ankle (45.9%), wrist (32.4%), hand (18.9%), cervical spine (17.6%), elbow (14.8%), and coxofemoral joint (10.8%). Arthritis can involve any joint. The initial phase most frequently involves oligoarticular arthritis, which can progress to polyarthritis
The study revealed that the knee and ankle were equally affected in the systemic form of arthritis (72.7% of cases). The joints of the cervical spine and wrist were affected more than half the cases. According to Petty and Cassidy
The wrist, knee, ankle and metacarpophalangeal joints were most affected by RF+ polyarticular arthritis, which is consistent with previous studies. In RF+ polyarticular arthritis, the small and large joints of the upper and lower extremities are affected to the greatest extent along with the cervical spine and temporomandibular joint. The characteristic pattern is symmetrical arthritis, which mainly affects the metacarpophalangeal, metatarsophalangeal, and wrist joints.
The knee, wrist and ankle spine joints were most affected in cases of RF- polyarticular arthritis. According to Petty and Cassidy
RF+ arthritis was present in 17.5% of the surveyed sample, in all the cases of RF+ polyarticular arthritis, and in 8.5% of the oligoarticular arthritis cases. RF+ has been shown to occur in 7-10% of children with JIA using latex agglutination and Waaler-Rose tests. Using an enzyme-linked immunosorbent assay (ELISA), the values increase to 22%-35%. RF+ is usually present in female children with polyarticular JIA and indicates a severe and erosive disease
ANA + were present in 27.0% of the total sample surveyed, in 34.0% of cases of the oligoarticular arthritis cases, 18.2% of the systemic arthritis cases, and 22.2% of the RF + polyarticular arthritis cases. Probably, difference between results found in the study and other studies is due to number of the sample searched. Possibly, the expansion the studied population may show results closer to those in literature. In Brazil, researches between FAN and JIA are strongly associated with the presence of uveitis. Previous studies have shown that ANA are usually positive in 40% to 85% of cases with early oligoarticular arthritis. Several researches have revealed strong association between positive ANA with oligoarticular JIA and uveitis in a female child
Deformities were observed in 20.3% of the cases and were distributed in 19.1% of the oligoarticular arthritis cases and 66.6% of the RF+ polyarticular arthritis cases. RF+ polyarticular arthritis presents several clinical, immunogenic, and developmental similarities with rheumatoid arthritis (RA) in adults. Synovitis persisting for months or years may cause irreversible consequences such as subluxations, fusions, or osteoarticular destruction and may evolve into functional incapacity with important implications for the quality of life of individuals and their families
Uveitis was observed in 14.9% of the cases. The frequency of chronic uveitis has varied considerably in a series of reports of children with chronic arthritis: a rate of 2% was found in Costa Rica
Uveitis exhibits an insidious and asymptomatic onset in most cases. Untreated uveitis can evolve with sequels ranging from posterior synechiae to cataracts, glaucoma, and blindness
Macrophage activation syndrome occurred in only one case (1.3%) in the present study. This is the most serious complication of systemic JIA. It is considered a form of hemophagocytic lymphohistiocytic syndrome and is associated with serious morbidity. Macrophage activation syndrome occurs in 7% of cases during the course of the disease. Early recognition and appropriate treatment of this complication are essential for survival of the patient
This study draws attention to the early age of onset, prolonged disease duration, affected joints, and severe and disabling complications of JIA in a phase of life where health is essential for proper growth and development in northeastern Brazil. The importance of early diagnosis, proper treatment, and regular monitoring with free access to health services must be emphasized. Due to the importance of the topic, the scarcity of Brazilian scientific studies on the topic, and the serious consequences for the health of children, further studies of this disease are necessary.