[Hospital infection and its countermove].

Actual activities of Infection Control Team (ICT) in Suzuka General Hospital is reported. Surveillance of hospital infection, feedback of actual information of infection to each fields and ward round by ICT with certified Infection Control Nurse (ICN) can lead good confidence between ICT and other departments. Participation of ICN for ICT is important due to its trans-department activities.

Rapid development of diffuse large B-Cell lymphoma after successful eradication of Helicobacter pylori for gastric MALT lymphoma.

Primary low-grade mucosa-associated lymphoid tissue (MALT) lymphoma of the stomach has a potential to transform to high-grade diffuse large B-cell lymphoma (DLBCL). However, the clonal relation between MALT lymphoma and de novo DLBCL is still controversial. We report here three patients with Helicobacter pylori (H. pylori)-positive gastric MALT lymphoma rapidly progressing to DLBCL at the same site after successful eradication of H. pylori. Although MALT lymphomas in our cases did not possess t(11; 18)(q21;q21), sequence analysis of the rearranged immunoglobulin heavy chain gene showed no clonal relation between preceding MALT lymphoma cells and de novo DLBCL cells at the same site. These findings question the scenario of direct clonal progression of low-grade MALT lymphomas without t(11; 18)(q21;q21) to DLBCL and serve as a reminder of the risk of the progression of DLBCL with a distinct clonality immediately after H. pylori eradication for low-grade MALT lymphoma.

Characteristics of gastric B-cell lymphoma of mucosa-associated lymphoid tissue type involving multiple organs.

BACKGROUND: Mucosa-associated lymphoid tissue (MALT) lymphoma involving multiple organs is not well characterized. METHODS: To obtain a better understanding of gastric MALT lymphoma with multiple organ involvement, we compared Helicobacter pylori infection status; response to eradication therapy; prevalence of genetic abnormality, including t(11;18)(q21;q21); and clonality of tumor cells between patients with gastric MALT lymphoma with and without multiple organ involvement. RESULTS: Of 54 patients with only gastric involvement, 51 were positive for H. pylori (94.4%), whereas only 3 of 9 patients with multiple organ involvement had the infection (33.3%). Among those who received eradication therapy, the remission rate in patients with only gastric involvement was significantly higher than that in patients with multiple organ involvement (71.4% vs 33.3%; P < 0.05). The positive rate of API2-MALT1 fusion transcripts was significantly greater in patients with multiple lesions with either single or multiple organ involvement than in those with a single gastric lesion (71.4% vs 12.5%; P < 0.05), but 2 of 2 patients with multiple gastric lesions had the fusion transcripts. Of 5 patients with multiple organ involvement tested for clonality of the CDR3 region, distinct clones were detected in lymphoma lesions in different organs in 3 patients, whereas the identical clone was present in the different lesions in the remaining 2 patients. CONCLUSIONS: Gastric MALT lymphoma with multiple organ involvement is often associated with API2-MALT1 fusion transcripts. Moreover, H. pylori infection is rare in patients with multiple organ involvement as compared to those with only gastric involvement. Patients with gastric MALT lymphoma with multiple organ involvement who are positive for H. pylori are resistant to eradication therapy.

Immunological and molecular analysis of B lymphocytes in low-grade MALT lymphoma of the stomach. Are there any useful markers for predicting outcome after Helicobacter pylori eradication?

BACKGROUND: Although Helicobacter pylori eradication is effective in treating low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma, the condition in some patients deteriorates even after the eradication. Therefore, it is important to predict the disease outcome before starting H. pylori eradication. We investigated the usefulness of flow cytometry, quantifying CD19- and CD20-positive B lymphocytes in MALT lymphoma tissue, for predicting the disease outcome after H. pylori eradication. METHODS: Tissue specimens from 14 patients with H. pylori-positive low-grade gastric MALT lymphoma were examined by histology, Southern blotting, and flow cytometry before therapy. Serum levels of soluble interleukin (IL)-2 receptor were also measured. The relationship between the data and the prognosis after H. pylori eradication was analyzed. RESULTS: Remission occurred in 10 of the 14 patients. The condition in the 4 remaining patients deteriorated even after H. pylori eradication. The percentages of CD19- and CD20-positive cells in MALT lymphoma tissue from the patients in remission were both significantly lower than those in the tissue from patients not in remission. Indeed, 4 of the 5 patients in whom both CD19- and CD20-positive cells accounted for more than 50% of the total number of lymphocytes had gastrectomy, whereas all patients in whom both CD19- and CD20-positive cells accounted for less than 50% of the total number of lymphocytes achieved remission. Although immunoglobulin gene rearrangement was present in all patients operated on, there were also 6 patients whose MALT lymphoma was ameliorated in spite of the presence of gene rearrangement. The serum level of soluble IL-2 receptor was in the normal range in all patients tested. CONCLUSIONS: Analysis of mature B-cell markers in MALT lymphoma tissue is more useful than the examination of immunoglobulin gene rearrangement or serum levels of soluble IL-2 receptor in predicting the outcome of low-grade gastric MALT lymphoma after H. pylori eradication.

Regression of MALT lymphomas coexisting in the duodenal bulb and the stomach by eradication of Helicobacter pylori.

We report the regression of coexisting mucosa-associated lymphoid tissue (MALT) lymphomas in the duodenal bulb and gastric corpus brought about by Helicobacter pylori eradication. During an endoscopic examination, multiple polyps in the duodenal bulb were observed in a 62-year-old woman. The pathology of the duodenal polyps was low-grade B-cell MALT lymphoma. Gastric MALT lymphoma was also detected in biopsies of rough mucosa from the gastric corpus. Southern blot analysis showed rearranged bands of DNA immunoglobulin heavy chain J portion (IgH-J) in both lesions, but the positions of these bands were different in the two lesions. H. pylori was recognized in the gastric mucosa by positive serum H. pylori antibody and urease tests, while bacterial bodies were not found in the duodenal bulb. With 1 year after the successful eradication of H. pylori, both the lesions, that in the duodenal bulb and that in the gastric corpus, had disappeared. Furthermore, positive rearrangement of IgH-J was not found at either of the lesion sites. In May 2000, 3 years after the treatment, endoscopic surveillance failed to find any recurrence of these malignant lymphomas.

Experimental immune-mediated pancreatitis in neonatally thymectomized mice immunized with carbonic anhydrase II and lactoferrin.

We previously reported that autoantibodies against carbonic anhydrase II and lactoferrin are frequently identified in patients with autoimmune-related pancreatitis. To clarify the role of carbonic anhydrase II and lactoferrin, we created animal models of autoimmune pancreatitis by immunizing neonatally thymectomized mice with carbonic anhydrase II and lactoferrin and also by transferring immunized spleen cells to nude mice. Neonatally thymectomized BALB/c mice were immunized with carbonic anhydrase II or lactoferrin followed by three booster injections (n = 10 in each group). We transferred whole, CD4+, or CD8+ spleen cells prepared from immunized neonatally thymectomized mice to nude mice (n = 5 in each group). Gene expression of IFN-gamma and IL-4 was investigated using semiquantitative reverse transcription-polymerase chain reaction. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling staining was used to examine apoptosis. In immunized neonatally thymectomized mice, the prevalence of inflammation was significantly higher in the pancreas. Inflammation was present in all mice receiving whole or CD4+ cells. There was no change in any of the mice receiving CD8+ cells or nonimmunized spleen cells. Carbonic anhydrase II or lactoferrin-immunized mice had apoptotic duct cells or acinar cells, respectively. Expression of the IFN-gamma gene was up-regulated in each group. Similar findings were observed in the salivary glands and liver. An immunologic mechanism against carbonic anhydrase II or lactoferrin is involved in the pathogenesis of these pancreatitis models, in which the effector cells are Th1-type CD4+ T cells.