Macrophage involvement in mitral valve pathology in mucopolysaccharidosis type VI (Maroteaux–lamy syndrome)

Authors

  • Marion Brands,

    1. Center for Lysosomal and Metabolic Diseases, Departments of Pediatrics and Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, the Netherlands
    Search for more papers by this author
  • Jorine Roelants,

    1. Center for Lysosomal and Metabolic Diseases, Departments of Pediatrics and Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, the Netherlands
    Search for more papers by this author
  • Ronald de Krijger,

    1. Department of Pathology, Josephine Nefkens Institute, Erasmus MC University Medical Center, Rotterdam, the Netherlands
    Search for more papers by this author
  • Ad Bogers,

    1. Department of Cardiology, Thoraxcenter Erasmus MC University Medical Center, Rotterdam, the Netherlands
    Search for more papers by this author
  • Arnold Reuser,

    Corresponding author
    1. Center for Lysosomal and Metabolic Diseases, Departments of Pediatrics and Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, the Netherlands
    • Correspondence to:

      Dr. Arnold J.J. Reuser, Ph.D., Molewaterplein 50, 3015 GE Rotterdam, The Netherlands.

      E-mail: a.reuser@erasmusmc.nl

    Search for more papers by this author
  • Ans van der Ploeg,

    1. Center for Lysosomal and Metabolic Diseases, Departments of Pediatrics and Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, the Netherlands
    Search for more papers by this author
  • Wim Helbing

    1. Division of Pediatric Cardiology, Department of Pediatrics, Erasmus MC University Medical Center, Rotterdam, the Netherlands
    Search for more papers by this author

  • Conflict of interest: none.

Abstract

Maroteaux–Lamy syndrome (mucopolysaccharidosis type VI) is a rare lysosomal storage disorder in which the pathologic storage of glycosaminoglycans in various tissues can lead to severe symptoms, including cardiomyopathy. We report on a child with Maroteaux–Lamy syndrome whose cardiac condition deteriorated and eventually led to cardiac failure at the age of 7 years due to severe mitral regurgitation. She received a mitral valve replacement and tricuspid repair with successful outcome. Histologic examination of the mitral valve showed abundant “clear” cells in both the leaflets and chordae tendineae. In Hurler disease (MPS I), similar cells have been identified as activated valvular interstitial cells (VICs, a myofibroblast like cell type). Here we report that the “clear” cells are CD68 positive, a frequently used marker of macrophage lineage. The “clear” cells remained unstained with the more specific macrophage marker CD14 while persistent staining of other cells demonstrated macrophage infiltration. From these observations, we infer that macrophages are involved in mitral valve pathology in MPS VI. © 2013 Wiley Periodicals, Inc.

Ancillary