[Assessment of serum IgG activity correlation against cyclic citrullinated peptide antibodies, topoisomerase I and centromere proteins in Mexican patients with progressive systemic sclerosis]. / Evaluación de la correlación de la actividad de IgG sérica contra péptido citrulinado cíclico, topoisomerasa I y proteínas de centrómero en pacientes mexicanos con esclerosis sistémica progresiva.

OBJECTIVE: To evaluate sera titers for antibodies anti-cyclic citrullinated peptide and their correlation against sera levels of anti-topoisomerase I and anti-centromere antibodies in Mexican patients with systemic sclerosis. PATIENTS AND METHODS: Consecutive outpatients with systemic sclerosis who attending to rheumatology clinic at a second level hospital facility. The antibodies anti-cyclic citrullinated peptide, anti-topoisomerase I and anti-centromere were determined by enzymatic immunoassay (ELISA). STATISTICAL ANALYSIS: Spearman for correlation between numerical variables with nonparametric distribution. Fisher exact test or chi2 to compare proportions and Student t test for dimensional variables. RESULTS: Thirty female patients were included; aged 53 +/- 13, the disease duration at the time of the study was 10 +/- 9. Twenty-three patients (77%) exhibited diffuse disease. Anti-centromere, anti-topoisomerase I, and anti-cyclic citrullinated peptide were detected in nine, nine and three patients respectively. The correlation analysis showed the independence of autoantibodies anti-centromere and anti-topoisomerase I with respect to the levels of anti-cyclic citrullinated peptide. CONCLUSIONS: This study confirms the low frequency of anti-cyclic citrullinated peptide antibodies in patients with systemic sclerosis. A lack of correlation between autoantibodies considered as "mutually excluded" anti-topoisomerase I and anti-centromere, indicating that the analysis of the relevance for anti-cyclic citrullinated peptide in systemic sclerosis must include other clinical and serological variables.

Circulating leptin and bone mineral density in rheumatoid arthritis.

OBJECTIVE: To evaluate the association between circulating leptin and bone mineral density (BMD) in patients with rheumatoid arthritis (RA). METHODS: One-hundred thirty postmenopausal women with RA were assessed for body mass index (BMI), disease characteristics, history of drug use, rheumatoid factor, and erythrocyte sedimentation rate (ESR). BMD (g/cm(2)) was determined in the hip and spine by DEXA. Serum leptin concentrations were measured by ELISA. Spearman's correlation coefficients (rho) were determined between BMD and leptin and other variables. A multiple regression analysis was used to adjust for confounders. RESULTS: Patients' serum leptin levels varied widely (range 2-128 ng/ml). Thirty-three patients (25%) had osteoporosis. Higher levels of leptin correlated significantly with BMD in the lumbar spine (rho = 0.17, p = 0.04) and total hip (rho = 0.21, p = 0.01). The variables that were negatively correlated with BMD were age, duration of menopause, and ESR. After adjustment for confounders, leptin was no longer associated with BMD. In the multivariate model, factors that remained associated with BMD in the total hip were age (p = 0.021) and BMI (p = 0.003); and the factors that remained associated with BMD in the lumbar spine were BMI (p = 0.03) and ESR (p = 0.01). CONCLUSION: No relevant association was found between circulating leptin levels and BMD in patients with RA in this cross-sectional study. Followup studies are needed to evaluate whether abnormal leptin levels confer a risk for fractures due to osteoporosis.

Circulating E-selectin and tumor necrosis factor-alpha in extraarticular involvement and joint disease activity in rheumatoid arthritis.

In this cross-sectional study, we assessed the relationship between circulating TNF-alpha and E-selectin (sE-selectin) with extraarticular involvement and severity of joint disease in RA. We compared 56 patients who had RA and extraarticular involvement (ExRA) with a group of 84 patients with only articular involvement (non-ExRA). ExRA had higher circulating TNF-alpha than non-ExRA (32 +/- 9 vs. 28 +/- 6 pg/mL, P = 0.002). sE-selectin levels did not differ between both groups. sE-selectin correlated with tender joint count (rho = 0.19, P = 0.03), morning stiffness (rho = 0.19, P = 0.03), severity of pain (rho = 0.21, P = 0.02), disease activity (assessed by the patient) (rho = 0.21, P = 0.02), HAQ-DI (rho = 0.29, P = 0.004), and rheumatoid factor titers (rho = 0.31, P = <0.001). Circulating TNF-alpha had no correlation with sE-selectin or disease activity. We concluded that sE-selectin correlated with severity of joint disease, further follow-up studies should evaluate if sE-selectin is useful as prognosis marker for progression of articular damage.

Hyperhomocysteinemia in ankylosing spondylitis: prevalence and association with clinical variables.

We evaluated the prevalence and characteristics associated with hyperhomocysteinemia in ankylosing spondylitis (AS). Ninety-seven patients with AS were compared with 97 controls. The assessment included clinical characteristics, disease activity (BASDAI), functioning (BASFI), history of drugs, and erythrocyte sedimentation rate (ESR). Total serum homocysteine (tHcy) was determined by fluorescence polarization immunoassay. A higher frequency of hyperhomocysteinemia (>15 micromol/L) was observed in AS (12 vs. 1%, P = 0.002). In the multivariate analysis the risk for hyperhomocysteinemia was increased in patients with higher score of HAQ-S (OR = 5.27, 95% CI: 1.29-21.44) and higher ESR (OR = 1.09, 95% CI: 1.02-1.18). No statistical associations was observed between hyperhomocysteinemia with other variables including methotrexate or sulfasalazine utilization. In conclusion, this study found a significant prevalence of hyperhomocysteinemia in Mexican patients with AS mainly associated to a worst functional impairment. Further follow-up studies are required to evaluate the risk of cardiovascular disease in these patients.