谷本 光音

Reportedly, thyroid mucosa-associated lymphoid tissue (MALT) lymphoma is closely associated with Hashimoto's thyroiditis. However, it remains unknown which antigen is closely associated with thyroid MALT lymphoma. We examined whether B cell response to thyroglobulin (Tg), which is a common thyroid-specific autoantigen, is related etiologically to the pathogenesis of thyroid MALT lymphoma. Expression of human Tg antigens and Cluster of differentiation (CD) 35 was examined immunohistochemically in 15 cases of thyroid MALT lymphoma using paraffin-embedded, formalin-fixed tissue specimens. In all cases of thyroid MALT lymphoma, human Tg was detected immunohistochemically in the follicular epithelial cells and follicular dendritic cells (FDCs). These FDCs were positive by double immunostaining for anti-human Tg rabbit polyclonal antibody (Ab) and for CD35. Results showed that the Tg, a thyroid autoantigen, had immunostained the germinal center of the thyroid MALT lymphoma. The Tg was present in the FDCs, as revealed by the staining pattern of the germinal center;this fact was confirmed by double immunostaining of anti-human Tg mouse monoclonal Ab and anti-CD35 mouse monoclonal Ab. The results of our study suggest that Tg is an autoantigen that is recognized by thyroid MALT lymphoma cells.

Propionibacterium acnes has been implicated as an etiologic agent of sarcoidosis since the isolation of this bacterium from sarcoid lesions. We experimentally produced a murine pulmonary granuloma model using P. acnes with several features that simulate sarcoidosis. Mice were sensitized with heat-killed P. acnes and complete Freund's adjuvant and were subsequently challenged with heat-killed P. acnes at 2-week intervals. P. acnes-challenged mice developed epitheloid cell granulomas in the lungs. These mice showed a pulmonary immune response characterized by an increased number of T-lymphocytes, especially CD4 cells, and the ratio of CD4/CD8 in bronchoalveolar lavage (BAL) fluid also increased. Furthermore, significant elevations in both angiotensin-converting enzyme (ACE) serum levels and antibody titers against P. acnes were observed. Mice sensitized with P. acnes without complete Freund's adjuvant were capable of forming pulmonary granulomas, which appeared to be caused by indigenous P. acnes. The genome of P. acnes was found in the lungs, BAL cells, hilar lymph nodes, liver, and spleen in non-sensitized mice, which were thought to be germ-free. These results suggest that the immune response against indigenous P. acnes may play an important role in the pathogenesis of granuloma formation in a murine model.

We examined the feasibility of triplet chemotherapy using cisplatin, docetaxel, and irinotecan for patients with recurrent or refractory non-small cell lung cancer (NSCLC), retrospectively. Twenty-five patients (21 men and 4 women) with NSCLC and good performance status who were <70 years old were analyzed. The median age was 58 years. Most patients had performance status 1 (16/25), stage IV disease (18/25) and adenocarcinoma-histology (16/25). Cisplatin and docetaxel were given on day 1 and irinotecan on day 2;the cycle was repeated every 3 weeks. The objective response rate was 39.1% (95% confidence interval:18.7-59.5%). The median survival time and actual 2-, 3-, and 5-year survival rates were 14.3 months, 32%, 20%, and 8%, respectively. Of note, only 6 patients were treated with gefitinib at the recurrence after triplet chemotherapy;of these, 4 (67%) achieved a partial response, which might result in favorable survival. Grade 3/4 toxicities consisted of neutropenia (100%), neutropenic fever (56%), nausea/vomiting (40%), and diarrhea (16%);no cases of treatment-related death occurred. Triplet chemotherapy showed impressive survival data in our clinical trial, but proved too toxic for use in treating patients with NSCLC in the clinical practice.