Association of the calcitonin gene (CA) polymorphism with osteoarthritis of the knee in a Mexican mestizo population.

Osteoarthritis (OA) is the most common form of destructive joint disease that is characterized by the degeneration of the articular cartilage, synovial membrane, joint capsule, and subchondral bone. The knee is a joint commonly affected for OA. Calcitonin (CT) has been suggested to have chondroprotective effects; therefore, could play a role in the pathogenesis of OA of the knee. Genetic variations in or adjacent to the CT gene may be associated with primary OA development. We conducted a case-control association study in which we examined the correlation between a dinucleotide (cytosine-adenine, CA) repeat polymorphism at the CT locus and OA of the knee in 88 patients with OA and in 111 control subjects from the Mexican mestizo population. Allele A and genotype AG frequencies were significantly higher in patients with OA than in control subjects (56.3 vs. 43.2%; p<0.001 and 40.9 vs. 26.1%; p=0.027, respectively), and were associated with the presence of OA of the knee (odds ratio [OR], 2.62; 95% confidence interval [95% CI], 1.30-5.27, and OR, 1.93; 95% CI, 1.04-3.58, respectively) using a logistic regression model adjusted for gender, age and Body mass index (BMI). The GG genotype was associated with a lower risk of OA development of the knee; thus, it may constitute a protective factor against this disease (OR, 0.40; 95% CI, 0.16-0.98). In summary, we conclude that the dinucleotide CA polymorphism in the CT gene may become a useful marker for genetic studies of OA of the knee in Mexican population.

Factors affecting survival in juvenile systemic sclerosis.

OBJECTIVES: To determine whether demographic, clinical and immunological features may predict the outcome in juvenile SSc (JSSc). METHODS: Clinical and laboratory characteristics of patients with JSSc collected from paediatric rheumatology centres worldwide were analysed. First, univariate tests identified those features significantly related with fatal outcome, and then multivariate logistic regression analysis was applied to determine the predictors of mortality. RESULTS: One hundred and thirty-four patients from 40 centres were eligible for the analysis. Sixteen patients died and a rapidly fatal course was observed in most of them: 4/16 died within 1 yr after diagnosis and 10/16 within 5 yrs. At the moment of diagnosis, patients with poor outcome showed a significantly higher frequency of internal organ involvement, particularly cardiac, respiratory and gastrointestinal systems. No significant difference emerged for entity of skin, vascular and musculo-skeletal involvement, nor for auto-antibodies profile and laboratory tests. Multivariate analysis showed the following factors to be significant predictors of mortality: fibrosis on chest X-rays [odds ratio (OR) 11.2], raised creatinine levels (OR 22.7) and pericarditis (OR 41.3), while a short disease duration at diagnosis conferred protection (OR 0.3). CONCLUSIONS: All patients with JSSc and fatal outcome were affected by the diffuse form of the disease, and most of them showed a very rapid progression and early signs of internal organ involvement. This suggests that, in children, SSc may have two possible courses: a rapid development of internal organ failure leading to severe disability and eventually to death, or a slow course of the disease with lower mortality.

Disability impact on quality of life in Mexican adults with juvenile idiopathic arthritis and juvenile ankylosing spondylitis.

OBJECTIVE: Our aim was to determine the disability impact on quality of life (QOL) in Mexican adults with juvenile idiopathic arthritis polyarticular course (JIAPA) and juvenile ankylosing spondylitis (JAS). METHODS: A cross-sectional study was performed on 32 adult patients with juvenile idiopathic arthritis. Functional outcome was evaluated using Global Functional Status (GFS) according to American College of Rheumatology (ACR) and Spanish Health Assessment Questionnaire-Disability Index (HAQ-DI) arthritis-specific measurements for functional disability in patients with polyarticular course and Bath Ankylosing Spondylitis Functional Index (BASFI) for those who developed JAS. Quality of life (QOL) was assessed using SF-36 and EuroQol 5D (EQ-5D). Descriptive statistics and associations among clinical, functional, and QOL measurements were examined using Spearman's correlation test. Multiple regression analysis was used to estimate predictor factors for impaired QOL. Differences between groups were evaluated by Fisher exact and Mann-Whitney U tests, and p values of <0.05 were considered statistically significant. RESULTS: JIAPA and JAS had GFS III/IV in 65 and 50%, respectively. A HAQ-DI score of > 1.5 was found in 35% of JIAPA, and a BASFI score of > 5 in 92% of JAS. Patients with JIAPA and JAS reported lower scores for all physical domains and for mental domains (physical role, social functioning, and emotional role) compared with Mexican population scores (p < 0.005). Health status between both groups studied does not show significant differences (p > 0.05). EQ-5D showed impairment in all five dimensions for both groups studied. Multiple regression analysis showed that GFS was the only variable that affects QOL assessed by SF36. CONCLUSIONS: In our study population, JIAPA and JAS exhibited a great disability impact on QOL and poor functional outcome during the patients' adult life. GFS has a significant impact on quality of life.

Reliability of the articular examination in children with juvenile rheumatoid arthritis: interobserver agreement and sources of disagreement.

OBJECTIVE: To assess the interobserver agreement of articular examination in children with juvenile rheumatoid arthritis (JRA) and identify sources of disagreement. METHODS: Four rheumatologists graded tenderness/pain on motion, swelling, and limitation of motion in the joints of 10 children with JRA, as recommended by the Pediatric Rheumatology Collaborative Study Group, and 17 different joint indices were computed. Agreement was measured by kappa (kappa) and intraclass correlation coefficients (Ri). RESULTS: All 4 observers detected tenderness in 15.7% of the joints, but they disagreed (2 vs 2) on 4.2% (kappa = 0.71). They detected swelling in 5.2% but disagreed on 6.2% (kappa = 0.47). They found limitation in 4.9%, but disagreed on 8.1% (kappa = 0.54). The tender joint count, and the American Rheumatism Association cooperating clinics and Hart modified Ritchie indices were the most reliable (Ri > 0.93); the swelling severity index fared the worst (Ri = 0.40). There were differences in examination maneuvers and judgment among examiners. Discrepancies were larger in metacarpophalangeal joints and in patients with many involved joints. CONCLUSION: There was low agreement in the assessment of joint swelling and limitation of motion. Differences in examiners' techniques, patients with severe disease, and the small hand joints were important sources of disagreement.