Lymphocytic infiltrations in the lung of two autopsy cases with HTLV-I-associated myelopathy

Pulmonary involvement in two autopsy cases with HTLV-I-associated myelopathy (HAM) was observed histopathologically and immunohistochemically. Case 1 was a 59-year-old woman who fell ill after having a blood transfusion, and died immediately of acute heart failure. Case 2, a 55-year-old man, died of pelvic tumor after a long period of steroid medication for the myelopathy. Histologically, in case 1, the submucosal stroma of bronchioles was thickened with T-lymphocyte infiltration. In addition, clusters of B-lymphocytes were aggregated beneath the epithelial layer of respiratory bronchiole; the alveolar septum was infiltrated with a few T-lymphocytes. Furthermore, many B-lymphocytes were aggregated in the submucosal stroma of large bronchi. On the other hand, obvious pathological changes were not seen in the lung tissues of case 2. The long period of steroid medication may account for the fewer findings in case 2. These results present the possibility that latent inflammatory changes develop in the lung of HAM patients, although clinical manifestations are not obvious, and that steroid therapy can modify those inflammatory changes.