Anti-Ro, anti-La, anti-RNP antibodies and PR interval in adult patients with systemic lupus erythematosus

Background: Children born from mothers with anti-Ro, La or RNP autoantibodies may develop neonatal lupus. One of the manifestations of neonatal lupus is congenital atrio ventricular block. Objective: To study EKG PR interval in adult systemic lupus erythematosus (SLE) patients with anti-Ro, anti-La and anti-RNP autoantibodies. Methods: PR intervals and the presence of anti-Ro, La and RNP antibodies were studied in 61 SLE patients and compared with 61 controls. Results: 36.6% of SLE patients were anti-Ro positive, 20% were anti-La and 22.9% were anti-RNP positive. All studied PR intervals were within normal limits (upper limit of 0.2 sec). We did not find any association between PR interval length and the presence of anti-Ro (p=0.54), anti-La (p=0.45) or anti-RNP autoantibodies (p=0.36). Conclusion: The presence of anti-Ro, La and RNP autoantibodies does not influence PR interval in adult SLE patients.