Reticulin and endomysial antibodies in bullous diseases. Comparison of specificity and sensitivity

Reticulin antibodies of IgG- and IgA-class and endomysial antibodies, which are of the IgA class, were studied by indirect immunofluorescence in 30 normal subjects, and in 45 patients with dermatitis herpetiformis (DH), 31 with pemphigoid, and 30 with pemphigus. Endomysial antibodies were present in 65% of patients with DH maintained on a normal diet and were absent in those on a gluten-free diet and in those with other diseases and in normal controls. Reticulin antibodies of the IgA class were disease specific for DH and occurred in only 25% of such patients. IgG-class reticulin antibodies, on the other hand, were not specific for DH, as they occurred in similar frequencies in patients with pemphigoid and pemphigus and in normal subjects. IgA-class reticulin antibodies occurred primarily in those patients with DH who had high titers of endomysial antibodies. None of the 20 such patients who were negative for endomysial antibodies had IgA-class reticulin antibodies. These studies indicate the high degree of specificity and sensitivity of endomysial antibodies.