Desquamative interstitial pneumonitis accompanied by a variety of autoimmune abnormalities in an individual with a history of asbestos exposure

: A 75-year-old-man who had been occupationally exposed to asbestos over several decades was admitted complaining of dry cough and mild exertional dyspnea. Chest X-ray films revealed the presence of bilateral infiltrates. An open biopsy showed the lung pathology to be desquamative interstitial pneumonitis (DIP), and detected a calcified plaque of the left parietal pleura at cost-phrenic sulcus, which on microscopic inspection demonstrated thin needle-like structures suggestive of asbestos particles. A hormonal examination showed decreased levels of tri-iodothyronine and tetraiodothyronine and an increased level of thyroid stimulating hormone. Additionally, a positive microsome test indicated autoimmune hypothyroidism. A serological study was positive for anti-nuclear antibody and direct Coombs, and showed heightened levels of IgG. The patient was placed on oral prednisolone therapy; one month later, his symptoms had subsided, and his lung function and chest x-ray findings had improved significantly. In addition, the abnormal values for autoimmune and thyroid function eventually returned to normal ranges. These findings suggest that DIP and humoral immune dysfunction were caused by asbestos exposure, and responded well to steroid treatment.