title: Is there a linear IgM dermatosis? Significance of linear IgM junctional staining in cutaneous immunopathology.
abstract: A linear IgM staining of the basal membrane zone (BMZ) is difficult to classify as denoting any known dermatological disorder. In a group of 2,771 persons biopsied for routine immunofluorescence microscopy, 25 cases (0.9%) with this phenomenon were found, whereas the incidences of bullous pemphigoid and linear IgA dermatosis in this group were resp. 1.2% and 0.01%. The IF patterns, serological data and clinical pictures of the linear IgM group were reviewed for a common denominator. One patient had bullous pemphigoid. The others showed a variety of symptoms and diagnoses. In the majority of cases the linear IgM deposits were monoclonal, a feature not understood. Immunoelectronmicroscopy performed in one patient proved IgM deposits below the basal lamina. It is concluded that there is no such entity as a linear IgM dermatosis and furthermore, that linear IgM staining at the BMZ has to be distinguished from related patterns such as the granular BMZ deposits ('lupus band') in SLE.
mesh_terms: D000328:Adult; D000368:Aged; D001485:Basement Membrane / Q000276:immunology / Q000473:pathology; D002648:Child; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D007075:Immunoglobulin M / Q000032:analysis*; D007223:Infant; D008297:Male; D008875:Middle Aged; D012867:Skin / Q000276:immunology* / Q000648:ultrastructure; D012871:Skin Diseases / Q000276:immunology* / Q000473:pathology
chemical_list: D007075:Immunoglobulin M