The frequencies of myeloperoxidase (MPO)-ANCA and proteinase 3-ANCA positivity in patients with HP were equivalent, while MPO-ANCA positivity was obviously dominant in patients without HP.
They were characterized as follows: (1) disease onset with initial signs/symptoms due to intractable otitis media with effusion or granulation, which did not respond to ordinary treatments such as antibiotics and insertion of tympanic ventilation tubes, followed by progressive hearing loss; (2) predominantly female (73%) and older (median age: 68 years); (3) predominantly myeloperoxidase (MPO)-ANCA-positive (60%), followed by proteinase 3 (PR3)-ANCA-positive (19%) and both ANCAs-negative (16%); (4) frequently observed accompanying facial palsy (36%) and hypertrophic pachymeningitis (28%); and (5) disease often involving lung (35%) and kidney (26%) lesions.