[Two cases of silicosis exhibiting MPO-ANCA associated disorder]

We reported two cases of silicosis exhibiting MPO-ANCA associated disorder. Case 1 was a 69 year-old man with silicosis and chronic interstitial pneumonia. He was admitted because of fever, dry cough, left chest pain, dyspnea and body weight loss. He was diagnosed as acute exacerbation of interstitial pneumonia, pericarditis and gastrointestinal bleeding. Case 2 was a 67 year-old man with silicosis. He repeated attack of fever, hoarseness, dysphagia and headache. The cell counts of cerebrospinal fluid increased and the thickness of cerebellar tent and left dura mater was observed in the brain MRI. Therefore, he was diagnosed as pachymeningitis and neuropathy of cranial nerves. Both cases were complicated by silicosis and the laboratory findings showed high serum levels of P-ANCA, ANA and rheumatoid factor and inflammatory responses, indicating they were suspected vasculitis. The two cases were treated by steroid and immunosuppressive therapy and had good clinical response. Silicosis may affect multiple organ involvement associated with P-ANCA.