Macrophage involvement in mitral valve pathology in mucopolysaccharidosis type VI (Maroteaux-Lamy syndrome).
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.
Center for Lysosomal and Metabolic Diseases, Departments of Pediatrics and Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, the Netherlands.
Marion
M
Brands
Jorine
J
Roelants
Ronald
R
de Krijger
Ad
A
Bogers
Arnold
A
Reuser
Ans
A
van der Ploeg
Wim
W
Helbing
D001706:Biopsy; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008264:Macrophages / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008943:Mitral Valve / Q000473:pathology*; D009087:Mucopolysaccharidosis VI / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D016896:Treatment Outcome
CD14; CD68; heart valve pathology; lysosomal storage disorder; mitral valve replacement; mucopolysaccharidosis