ABSTRACT
A 61-year-old woman, hospitalized for a persistent cough and dyspnea, had no history of bronchial asthma, but was undergoing chemotherapy for methotrexate-related lymphoproliferative disorder due to rheumatoid arthritis. Her peripheral blood eosinophil count was significantly increased, and chest CT revealed left lower lobe atelectasis and high-attenuation mucus. Bronchoscopy revealed mucous plugs and pathological examination revealed numerous eosinophils and filamentous fungi. Allergic bronchopulmonary mycosis (ABPM) caused by Scedosporium apiospermum was diagnosed using culture and genetic analyses. Treatment with corticosteroids and antifungal drugs led to improvement. ABPM caused by S. apiospermum is extremely rare, emphasizing the importance of species identification.
ABSTRACT
BACKGROUND Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a form of vasculitis predominantly affecting small blood vessels and systemic organs, including the lungs and kidneys. The serum ANCA is an important diagnostic marker for AAV. However, ANCA levels can be nonspecifically elevated in autoimmune diseases like rheumatoid arthritis (RA) and some infectious diseases. Furthermore, RA and AAV can occur together. Therefore, when ANCA is detected in patients with RA, interpretation of the results is often difficult. CASE REPORT A 71-year-old woman with a 15-year history of RA was admitted to our hospital with a fever and anorexia. She was treated with prednisolone 5 mg/day and iguratimod 50 mg/day for the RA. She presented with bilateral frosted glass shadows in the lungs, acute kidney injury, positive myeloperoxidase (MPO)-ANCA results, and elevated ß-D-glucan levels, suggesting AAV or pneumocystis pneumonia. A renal biopsy and bronchoalveolar lavage ruled out AAV. A polymerase chain reaction of the bronchoalveolar lavage fluid was positive for Pneumocystis jirovecii DNA, leading to a diagnosis of pneumocystis pneumonia. After admission, the patient continued to receive intravenous supplemental fluids, and renal function improved. Based on her pathological test results and clinical course, acute kidney injury was diagnosed as prerenal failure due to dehydration in the background of chronic kidney disease. CONCLUSIONS Even if MPO-ANCA is positive in patients with RA, it is important to consider the possibility of a false-positive result and perform a thorough and aggressive examination.