Specificity and effector mechanisms of autoantibodies in congenital heart block.

Abstract

Complete congenital atrio-ventricular (AV) heart block develops in 2-5% of fetuses of Ro/SSA and La/SSB autoantibody-positive pregnant women. During pregnancy, the Ro/SSA and La/SSB antibodies are transported across the placenta and affect the fetus. Emerging data suggest that this happens by a two-stage process. In the first step, maternal autoantibodies bind fetal cardiomyocytes, dysregulate calcium homestasis and induce apoptosis in affected cells. This step might clinically correspond to a first-degree heart block, and be reversible. La/SSB antibodies can bind apoptotic cardiomyocytes and thus increase Ig deposition in the heart. The tissue damage could, as a second step, lead to spread of inflammation in genetically pre-disposed fetuses, progressing to fibrosis and calcification of the AV-node and subsequent complete congenital heart block. Early intrauterine treatment of an incomplete AV-block with fluorinated steroids has been shown to prevent progression of the heart block, making it clinically important to find specific markers to identify the high-risk pregnancies.

• Authors: Marie Wahren-Herlenius, Sven-Erik Sonesson
• Journal: Current opinion in immunology (Curr Opin Immunol) Vol. 18 Issue 6 Pg. 690-6 (Dec 2006) ISSN: 0952-7915 [Print] England
• PMID: 17011766 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Review)

Chemical References

• Autoantibodies
• Autoantigens
• Steroids, Fluorinated

Topics

• Animals
• Autoantibodies (immunology)
• Autoantigens (immunology)
• Female
• Fetal Diseases (immunology)
• Fetal Therapies
• Heart Block (congenital, immunology, prevention & control)
• Humans
• Myocytes, Cardiac (immunology, pathology)
• Pregnancy
• Steroids, Fluorinated (therapeutic use)