淋巴滤泡形成与幽门螺杆菌致病——313例青年志愿者病理研究报告

作者调查了313例青年志愿者胃内HP感染状态与胃粘膜淋巴滤泡形成的关系。通过内镜普查,细菌和病理学诊断发现螺杆菌感染率为58.5％(183/313),淋巴滤泡形成率为28.4％(52/183),通过研究HP的感染量与淋巴滤泡大小证实了二者的正相关关系,并发现淋巴滤泡形成与内镜诊断无关,结合国外的报道提出了淋巴滤泡形成可能是HP感染致胃MALT发生过程中的一个重要步骤。     

Decreased frequency of HLA-B35 in patients with gastric MALT lymphoma

Persistent infection with Helicobacter pylori has been shown to be strongly associated with the development of low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma. However, the prevalence of H. pylori infection exceeds the incidence of MALT lymphoma by far. This discrepancy might at least partially be explained on a genomic basis of the host. To evaluate the association between HLA type and MALT lymphoma, we investigated 46 patients with MALT lymphoma recruited in a prospective multicenter study from October 1998 to March 2001. Over 13,000 voluntary stem cell donors from over 40 German blood banks represented the control group. Exploratory statistical analysis using Fishers exact test showed significantly decreased frequency of HLA-B35 in the MALT lymphoma group compared to the control group. Our data suggest a negative association between HLA-B35 and MALT lymphoma; however, larger studies are necessary to confirm a protective role of this HLA antigen.     

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: 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. Received: January 5, 2001 / Accepted: November 2, 2001     

Extranodal Marginal Zone B-Cell Lymphoma of Mucosa-Associated Lymphoid Tissue (MALT lymphoma) in Ulcerative Colitis

Extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) occurring in inflammatory bowel diseases, including ulcerative colitis (UC) and Crohn''s disease, has been reported, although it is extremely rare. An 18-year-old man with a two-years history of UC underwent colon endoscopy, and was found to have active total UC ranging from anus to cecum. Six biopsies were obtained. The microscopic examinations showed severe infiltrations of atypical small lymphocytes. They showed hyperchromatic nuclei and increased nucleocytoplasmic ratio and scattered immunoblastic cells. Centrocyte-like atypical lymphocytes, monocytoid cells, and plasma cells were seen in some places. Vague germinal centers were present, and apparent lymphoepithelial lesions were seen. No crypt abscesses were seen, and there were few neutrophils. No apparent other findings of UC were seen. Immunohistochemically, the atypical lymphocytes were positive for vimentin, CD45, CD20, CD79α, CD138, κ-chain, λ-chain, and p53 and Ki-67 antigen (labeling index = 63%). They were also positive for CD45RO, CD3, and CD15, but these positive cells were very scant compared with CD20 and CD79α. They were negative for CD10, CD30, CD56, cytokeratin (CK) AE1/3, CK CAM5.2, CK34BE12, CK5, CK6, CK7, CK8, CK14, CK18, CK19, CK20, EMA, chromogranin, synaptophysin, NSE, S100 protein, CEA, CA19-9, p63, and HMB45. Without clinical information, the appearances are those of MALT lymphoma. However, with clinical information, making the diagnosis of MALT lymphoma was hesitated. It is only mentioned herein that atypical lymphocytic infiltrations indistinguishable from MALT lymphoma occurred in an 18-year-old male patient with a two-year history of UC.     

Prevalence of Achromobacter xylosoxidans in pulmonary mucosa‐associated lymphoid tissue lymphoma in different regions of Europe

Extranodal marginal zone lymphoma of mucosa‐associated lymphoid tissue (MALT lymphoma) comprises 7–8% of B‐cell lymphomas and commonly originates from a background of long‐standing chronic inflammation. An association with distinct bacteria species has been confirmed for several anatomical sites of MALT lymphoma. For pulmonary MALT lymphoma, however, a clear link with an infectious agent or autoimmune disorder has not yet been reported. Using a 16S rRNA gene–based approach, we have recently identified Achromobacter (Alcaligenes) xylosoxidans in eight of nine cases of pulmonary MALT lymphoma. A. xylosoxidans is a gram‐negative betaproteobacterium with low virulence, but high resistance to antibiotic treatment. To further examine a potential association with A. xylosoxidans, 124 cases of pulmonary MALT lymphoma and 82 control tissues from six European countries were analysed using a specific nested PCR. Although prevalence rates for A. xylosoxidans varied significantly from country to country, they were consistently higher for MALT lymphoma as compared to controls. Overall, 57/124 (46%) pulmonary MALT lymphomas and 15/82 (18%) control tissues were positive for A. xylosoxidans (P = 0·004). Whether the significant association of A. xylosoxidans with pulmonary MALT lymphoma demonstrated in our study points to a potential causal role in the pathogenesis of this lymphoma will require further studies.     

Gastrointestinal lymphoproliferative disorders

Malignant lymphomas can be first detected in some patients in endoscopic biopsies of the gastrointestinal (GI) tract. However, their recognition and accurate classification often pose problems for the pathologist for several reasons. First, the small sampling size limits pattern recognition and the number of ancillary studies which can be performed. Second, the immune system of the GI tract is capable of intense hyperplastic responses which may mimic lymphoma. Third, in a fashion similar to cutaneous lesions, those in the alimentary tract may be visualized and biopsied at a very early phase in their development when differentiation into neoplasia may be incomplete. Some forms of immune response actually pass through a poorly defined transition into lymphoma. Examples of such 'dysplasia' of the gut immune system include Helicobacter gastritis, coeliac disease and multicentric lymphoid hyperplasia associated with underlying immunodeficiency. With ever increasing endoscopic scrutiny of the gut by gastroenterologists, it is not surprising that the frequency of these indeterminate cases seems to be growing. In combination with careful clinical correlation and conventional microscopic analysis, selective immunohistochemical studies currently constitute the most powerful ancillary method in the pathologist's effort to recognize and classify GI lymphomas accurately.     

眼黏膜相关淋巴瘤并骨髓侵犯一例伴文献分析

目的观察眼附属器黏膜相关淋巴瘤的临床特点。方法报告1例双眼同时起病的眼附属器黏膜相关样淋巴组织（MALT）结外边缘区B细胞淋巴瘤（OAML）并骨髓侵犯一例,结合文献对该类型淋巴瘤病因、临床表现、免疫组化、分子生物学改变、治疗进行探讨。结果OAML大部分为局限性病变,单侧多见,晚期播散型少见。结论OAML为惰性过程,相关至死率低,对于IE可给予放疗,加用免疫化学治疗可降低复发,对于IVE期患者需全身化疗,总体预后良好。     

Immunomodulatory treatment for mucosa-associated lymphoid tissue lymphoma (MALT lymphoma)

The pathogenesis of mucosa-associated lymphoid tissue (MALT) lymphoma has been characterized as a dynamic process driven by lymphoma cell dependency on T-cell signaling, chronic antigenic stimulation of marginal zone B-cells and activation of the nuclear factor-kappa B signaling pathway. This concept is underlined by the strong causal connection of chronic Helicobacter pylori associated gastritis and MALT lymphoma development based on perpetual auto-antigenic stimulation of Helicobacter pylori-specific T-cells, but also its association with further potential infectious triggers and autoimmune disorders for extragastric lymphoma sites. Thus, given the dependency of MALT lymphoma cells on the tumor microenvironment, this specific entity appears highly suitable for immunomodulatory treatment strategies. Several approaches have been assessed in the last years including promising data on immunomodulatory agents “IMiDs” thalidomide and lenalidomide, macrolide antibiotics and antibodies. The aim of the present review is to discuss rationales for immunomodulatory therapies in MALT lymphoma and to present the statu quo on immunomodulatory and therefore chemotherapy-free treatment strategies for these patients.     

Prevalence of hepatitis C virus infection in B-cell non-Hodgkin's lymphoma: systematic review and meta-analysis

BACKGROUND & AIMS: The aim of our study was to conduct a systematic review of studies evaluating prevalence of hepatitis C virus (HCV) infection in B-cell non-Hodgkin's lymphoma (B-NHL) and to perform a meta-analysis of case-control studies comparing this prevalence with that of a reference group. METHODS: Data sources: Electronic databases and the Cochrane Controlled Trials Register. Study selection: Studies evaluating prevalence of HCV infection in patients with B-NHL. Studies comparing HCV prevalence in B-NHL (cases) and in a reference group (controls) were included in the meta-analysis. Data extraction: Author/country, diagnostic method (serology/PCR), control type, matching/design, and VHC prevalence. Data synthesis: Prevalence of HCV infection and meta-analysis combining the odds ratios (OR). RESULTS: Forty-eight studies (5542 patients) were identified. Mean HCV infection prevalence was 13% (95% CI: 12%-14%), which was higher in Italy (20%) and Japan (14%). Ten studies compared HCV prevalence in B-NHL (17%) and healthy controls (1.5%) (OR: 10.8; 95% CI: 7.4-16), results being homogeneous; OR increased up to 14.1 when only Italian studies were considered. Sixteen studies compared HCV prevalence in B-NHL (13%) and in other hematologic malignancies (2.9%) (OR: 4.2; 95% CI: 2.5-7), also with homogeneous results; OR increased up to 7.8 when subanalysis included only Italian studies. CONCLUSIONS: HCV prevalence in patients with B-NHL is approximately 15%, higher than that reported not only in general population (1.5%) but also in patients with other hematologic malignancies (2.9%), suggesting a role of HCV in the etiology of B-NHL. The striking geographic variation in this association suggests that genetic and/or environmental factors are also involved in the pathogenesis of this disorder.