[Double balloon endoscopy as a useful tool for the diagnosis and treatment of four cases of primary small intestinal lymphoma].

Primary small intestinal lymphoma (PSIL) is a relatively rare form of non-Hodgkin lymphoma, often complicated by bleeding, obstruction, or perforation of the intestine during the clinical course. The initial diagnosis and management of these complications are often difficult in PSIL, because the small intestine is usually inaccessible in routine endoscopy. Recently, total enteroscopy with a double-balloon method, called double balloon endoscopy (DBE), has been developed for the diagnosis and treatment of small intestinal disorders. We report herein on 4 cases of PSIL (2 diffuse large B-cell lymphomas and 2 follicular lymphomas [FLs]). In these cases, DBE was useful in the diagnosis, decision to perform surgery after assessment of bleeding lesion, and treatment of the intestinal stenosis using enteroscopic balloon dilatation. Combination chemotherapy consisting of anthracycline, cyclophosphamide, vincristine, and prednisolone with rituximab was administered in 3 cases, and all achieved complete remission. One patient with FL of the duodenum was treated with rituximab alone, but with little effect. We conclude that DBE is useful in the management of PSIL. More PSIL cases must be analyzed to establish the optimal management of patients with this form of lymphoma.

Increased apoptosis of circulating T cells in myelodysplastic syndromes.

The mechanism of T cell lymphopenia in myelodysplastic syndromes (MDS) is unknown. We investigated apoptosis in freshly isolated and cultured lymphocytes; the latter were used to detect cells not yet apoptotic but destined for apoptosis. Apoptosis increased in both fresh and cultured T cells in MDS compared with those from healthy controls. Furthermore, in lymphopenic MDS patients the lymphocyte count correlated negatively with the degree of T cell apoptosis. MDS T cells showed increased Fas expression. However, in MDS but not in controls, the degree of T cell apoptosis was independent of the Fas expression level, and exogenous anti-Fas antibodies did not modulate T cell apoptosis. Mechanisms other than the Fas-Fas ligand pathway may induce T cell apoptosis in MDS.

Expression of functional B7-H2 and B7.2 costimulatory molecules and their prognostic implications in de novo acute myeloid leukemia.

PURPOSE: The B7 family molecules have been shown to regulate immune responses in both positive and negative fashions. Their roles in the progression of human cancers, however, are not well established. The aim of this study was to examine whether leukemic cells of acute myeloid leukemia express functional B7 family molecules and, if so, whether such expression has any clinical significance. EXPERIMENTAL DESIGN: The expression of four B7 family molecules, B7.1, B7.2, B7-H1, and B7-H2, on leukemic cells from acute myeloid leukemia patients was analyzed by flow cytometry. The function of the expressed molecules was examined by the allogeneic mixed lymphocyte-leukemic cell reaction, and their relationship to the clinical data and survival was analyzed. RESULTS: Although B7.1 and B7-H1 expressions were rare, the cells from a substantial number of acute myeloid leukemia cases expressed B7.2 and B7-H2 molecules [mean percentages of B7.2- and B7-H2-positive cells were 28.9% (n = 58) and 15.3% (n = 59), respectively]. Patients in whom >25% of leukemic cells expressed B7-H2 had significantly shorter survival, and this B7-H2 positivity had the strongest prognostic value when B7-H2 and other prognostic factors were analyzed together by multivariate analysis (P = 0.0108). Furthermore, B7.2 expression was associated with hyperleukocytosis (P = 0.026). Consistent with this finding, acute myeloid leukemia cells expressing B7.2 and B7-H2 induced allogeneic CD4+ T cells to proliferate and secrete interleukin-4 and interleukin-10 in vitro, effects that were partially blocked by antibodies against B7.2 and B7-H2. CONCLUSIONS: Our results indicate the expression of functional B7.2 and B7-H2 molecules, and these molecules may facilitate progression of acute myeloid leukemia.