RESUMEN
OBJECTIVES: To determine TCR excision circle (TREC) levels, a marker of recent thymic emigrants, in the peripheral lymphocyte pool of rheumatoid factor-negative (RFØ) polyarticular juvenile idiopathic arthritis (JIA) children. METHODS: We studied TREC levels in peripheral blood mononuclear cells (PBMC) in 30 RFØ polyarticular JIA children with active disease and in 30 age- and gender-matched healthy controls. Signal-joint TREC concentration was determined by real-time quantitative-PCR as the number of TREC copies/microg PBMC DNA gauged by a standard curve with known number of TREC-containing plasmids. RESULTS: TREC levels in PBMC were significantly lower in JIA (4.90 +/- 3.86 x 104 TRECs/microg DNA) as compared to controls (10.45 +/- 8.45 x 104 TRECs/microg DNA, p=0.001). There was an inverse correlation between age and TREC levels in healthy children (r=-0.438, p=0.016) but not in JIA. No clinical association was observed between TREC levels and disease activity and use of oral steroids and methotrexate. CONCLUSIONS: The finding of decreased PBMC TREC levels in RFØ polyarticular JIA children is consistent with a low proportion of recent thymus emigrants. This may interfere with the equilibrium between populations of polyclonal and naïve T cells versus oligoclonal memory auto-reactive T cells and, therefore, may hinder the maintenance of immune tolerance in this disease.
Asunto(s)
Artritis Juvenil/inmunología , Artritis Juvenil/patología , Reordenamiento Génico de Linfocito T/genética , Linfocitos T/patología , Timo/patología , Adolescente , Antirreumáticos/uso terapéutico , Artritis Juvenil/tratamiento farmacológico , Movimiento Celular/inmunología , Niño , Femenino , Reordenamiento Génico de Linfocito T/inmunología , Humanos , Tolerancia Inmunológica/genética , Tolerancia Inmunológica/inmunología , Memoria Inmunológica/genética , Memoria Inmunológica/inmunología , Recuento de Linfocitos , Masculino , Metotrexato/uso terapéutico , Plásmidos/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factor Reumatoide/metabolismo , Esteroides/uso terapéutico , Linfocitos T/fisiologíaRESUMEN
We aim to evaluate the prevalence of vitamin D deficiency in patients with systemic lupus erythematosus (SLE) and investigate the association between total, free and bioavailable vitamin D serum concentrations and disease activity. Patients with SLE (ACR 1997) consecutively seen at UNIFESP's outpatient's clinics had disease activity measured after clinical and laboratory evaluation using SLEDAI (Systemic Lupus Erythematosus Disease Activity Index). 25-hydroxyvitamin D (25(OH)D) serum concentrations measured by chemiluminescence and vitamin D binding protein (DBP) measured by ELISA were used to calculate free and bioavailable vitamin D. Healthy blood donors were used as controls. A total of 142 patients (71.4%) had 25(OH)D serum concentrations below 30 ng/mL. Total 25(OH)D serum concentration was associated with disease activity categorized in 5 continuous groups of SLEDAI. 25(OH)D serum concentrations were higher among patients with SLEDAI 1-5 and lower in those with severe activity (SLEDAI≥20) (p <0.05). On the other hand, no statistically significant difference was observed for DBP, free and bioavailable vitamin D measurements in the disease activity subgroups evaluated. Vitamin D deficiency is highly prevalent among patients with SLE and was associated with higher disease activity. DBP serum level and calculation of free and bioavailable vitamin D were not associated with SLE disease activity.