[A case of spontaneous remission of paragonimiasis miyazakii]

A 52-year-old man was admitted with fever and chest pain. Chest X-ray showed a soft infiltration in the right lung and bilateral pleural effusions. A strong tuberculin reaction was elicited. Significant laboratory findings included eosinophilia (37% in peripheral blood and 78% in pleural fluid) and elevated IgE levels (577 IU/ml in sera and 6700 IU/ml in pleural fluid). Adenosine deaminase activity in the pleural fluid was high. No helminth eggs were detected after repeated examination of the pleural fluid and sputum. No definitive diagnosis was made. Three months of chemotherapy with INH and rifampicin resulted in little improvement. Corticosteroid was then administered orally under a tentative diagnosis of idiopathic eosinophilic pleurisy, which proved to be a successful treatment and resulted in a marked reduction of pleural fluid volume. Two years after discharge, the patient's chest X-ray was normal and laboratory findings were normal including the eosinophil count and IgE level. The pleural fluid obtained at the first admission and kept frozen was subjected to immunological analysis for anti-parasite antibody activity. The pleural fluid showed an unexpectedly high titer of antibody activity (x6400 dilution) against Paragonimus miyazakii antigen assayed by double diffusion Ouchterlony method. Examination of the sera obtained from the patient two years after discharge, however, revealed no detectable antibody activity against the parasite antigens assayed either by Ouchterlony or ELISA method. We concluded from the clinical as well as laboratory findings that the patient had recovered from Paragonimiasis miyazakii without specific intervention for the disease.