New insights into the pathogenesis of anti-Ro antibody associated congenital complete heart block

Antithymocyte Globuline Therapy and Bradycardia in Children

In antithymocyte globulin (ATG) treated patients occasionally bradycardia has been noticed. Therefore, we retrospectively analyzed the occurrence of bradycardia in ATG-treated children. Using medical records between 2007 and 2012 we identified children undergoing a combined therapy with ATG and glucocorticoids (ATG group, n = 22). The incidence of bradycardia was compared to that registered in children treated with glucocorticoids alone (glucocorticoid alone group, n = 21). Heart rates (HR) were registered before and on days 0-3, 4-7 and 8-14 after the ATG or steroid administration. The rate of bradycardic episodes was higher during ATG therapy than in the steroid alone group, while severe bradycardia occurred only in the ATG group (97 versus 32, p = 0.0037, and 13 versus 0, p = 0.0029, respectively). There was an interaction between the time and treatment group on HR (p = 0.046). Heart rates in ATG and steroid alone groups differed significantly on day 0-3 and day 4-7 (p = 0.046, p = 0.006, respectively). Within the ATG group HR was lower on days 4-7 compared to the days before and the days 8-14 values (p < 0.001, 95%CI: 0.020-0.074). These findings indicate that transient asymptomatic bradycardia is probably more common with ATG therapy than previously reported. HR should be closely monitored during and after ATG therapy.

Autoantibodies Associated with Rheumatic Diseases

The identification of circulating autoantibodies contributes to the correct diagnosis as well as to the follow-up of rheumatic diseases. Some autoantibodies are even included in diagnostic and classification criteria for these types of autoimmune diseases. There are several relatively specific screening and identification methods for the measurement of autoantibodies available. The type of assay crucially influences the diagnostic value of the parameters. In general, routine laboratories should prefer enzyme immunoassays (ELISA) using well characterized antigens, although ELISA tests tend to produce more false-positive and true weakly positive results, which reduce their positive predictive value. Therefore one should be aware that laboratory results can only be properly interpreted when there is a correlation with the clinical situation and when the limitations of the technologies used for autoantibody identification have been taken into consideration. A diagnostic algorithm consisting of screening and identification steps should be established by each laboratory in order to create a rational, evidence-based and cost-effective basis for the diagnosis of rheumatic diseases.