RESUMO
Rheumatoid Arthritis (RA) is an autoimmune destructive joint disease affecting 1 % of the general population. In recent years, the benefits of identifying RA at an early stage and initiating therapy before joint damage occurs have been acknowledged. An elevated anti-citrullinated peptide antibody (ACPA) level serves as a marker for the early diagnosis of RA. Often the diagnosis is delayed because conventional methods of antibody detection require referral to a specific laboratory. In the current study, we determined the diagnostic accuracy of a new lateral flow point-of-care kit available for ACPA detection in the rheumatologist office. The presence of ACPA was determined by the visually read, qualitative rapid CCPoint® test (Euro-Diagnostica, Malmö, Sweden) compared to routinely used ELISA assays (Immunoscan CCPlus®-Euro-Diagnostica, Sweden, and QuantLite® CCP3-INOVA Diagnostics Inc., USA), in the sera of 184 patients: early RA(n = 38), established RA (n = 84), inflammatory arthritis(n = 34) and systemic lupus erythematosus (SLE) (n = 28). ACPA was detected in 18/38(47 %), 53/84(63 %), 2/34(6 %) and 2/28(7 %) of patients with early RA, established RA, inflammatory arthritis and SLE, respectively. The sensitivity and specificity, negative and positive predictive values of the CCPoint® test were equivalent to the Immunoscan CCPlus® and Quanta Lite® CCP3 ELISA assays. Correlation between ACPA positive results detected in the different assays was 97 %, while negative agreement reached 98 %. Excellent correlation (100 %) was observed between CCPoint® results obtained using capillary blood versus serum. CCPoint® is a novel technology that allows for a rapid accurate analysis of ACPA and diagnosis during the patient's visit in the rheumatologist office.
Assuntos
Anticorpos Antiproteína Citrulinada/sangue , Artrite Reumatoide/sangue , Testes Imediatos , Adulto , Idoso , Artrite Reumatoide/diagnóstico , Biomarcadores/sangue , Diagnóstico Precoce , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Lúpus Eritematoso Sistêmico/sangue , Masculino , Pessoa de Meia-Idade , Reumatologistas , Sensibilidade e Especificidade , Soro/químicaRESUMO
Vitamin D immune-modulating effects were extensively studied, and low levels have been linked with autoimmune diseases. The associations of vitamin D with autoimmune diseases of the liver, and particularly primary biliary cirrhosis (PBC), are yet to be defined. Hence, in this study, serum levels of vitamin D were determined in 79 patients with PBC and 70 age- and sex-matched controls by the LIAISON chemiluminescent immunoassays (DiaSorin-Italy). Clinical and serological parameters of patients were analyzed with respect to vitamin D status. Mean levels of vitamin D were significantly lower among patients with PBC compared with controls (16.8 ± 9 vs. 22.1 ± 9 ng/ml; p = 0.029), and vitamin D deficiency (≤10 ng/ml) was documented in 33% of patients with PBC versus 7% of controls (p < 0.0001). Vitamin D levels inversely correlated with advanced liver damage and the presence of concomitant autoimmune diseases. In contrast, higher levels of vitamin D were observed among patients with PBC treated with ursodeoxycholic acid (UDCA). In conclusion, low vitamin D levels are common among patients with PBC and correlate with advanced disease, lack of UDCA therapy and autoimmune comorbidity. This alludes to the plausible roles of vitamin D as a prognostic marker of PBC severity, and as a potential player in this disease pathogenesis. While further studies are awaited, monitoring vitamin D in patients with PBC and use of supplements may be advisable.