Therapy-related acute myeloid leukemia and myelodysplastic syndrome after hematopoietic cell transplantation for lymphoma.

Therapy-related acute myeloid leukemia and myelodysplastic syndrome (t-AML/MDS) represent severe late effects in patients receiving hematopoietic cell transplantation (HCT) for lymphoma. The choice between high-dose therapy with autologous HCT and allogeneic HCT with reduced-intensity conditioning remains controversial in patients with relapsed lymphoma. We retrospectively analyzed incidence and risk factors for the development of t-AML/MDS in lymphoma patients treated with autologous or allogeneic HCT. A total of 13 810 lymphoma patients who received autologous (n=9963) or allogeneic (n=3847) HCT between 1985 and 2012 were considered. At a median overall survival (OS) of 52 and 46 months in autologous and allogeneic HCT groups, respectively, lymphoma patients receiving autologous HCT (1.38% at 3 years after autologous HCT) had a significant risk for developing t-AML/MDS compared to allogeneic HCT (0.37% at 3 years after allogeneic HCT, P<0.001). Significant risk factors for the development of t-AML/MDS after autologous and allogeneic HCT were high-stage risk at HCT (P=0.04) or secondary malignancies (P<0.001) and receiving cord blood stem cell (P=0.03) or involved field radiotherapy (P=0.002), respectively. Strategies that carefully select lymphoma patients for autologous HCT, by excluding lymphoma patients with high-stage risk at HCT, may allow the identification of individual lymphoma patients at particular high risk for t-AML/MDS.

Extranodal natural killer/T-cell lymphoma from skin or soft tissue: suggestion of treatment from multinational retrospective analysis.

BACKGROUND: Clinical features and outcomes of extranodal natural killer/T-cell lymphoma (ENKL) arising from extranasal sites are not fully understood. The purpose of this study was to study the prognosis and treatment outcome of skin/soft tissue primary ENKL. PATIENTS AND METHODS: This multicenter retrospective study included 48 patients with skin/soft tissue primary ENKL diagnosed from 1993 to 2010. RESULTS: Patients with Ann Arbor stage I, T1-2N0M0 by International Society for Cutaneous Lymphomas-European Organization of Research and Treatment of Cancer TNM (tumour-node-metastasis) stage, International prognostic index score of 0-1, and a Korean prognostic index (KPI) score of 0-1 were associated with better survival. Four of five patients with T1-2N0M0 disease achieved complete response with radiation alone. In disseminated disease, only 6 of 13 patients responded to anthracycline-containing chemotherapy, and all the two patients receiving SMILE showed response. CONCLUSION: In conclusion, we identified the prognostic value of KPI, and we suggest a treatment recommendation according to the TNM (tumour-node-metastasis) stage. Radiotherapy with/without chemotherapy seemed to be optimal in localized disease. In advanced stages, a more aggressive treatment regimen with newer agents should be sought.

Prognostic factors for mature natural killer (NK) cell neoplasms: aggressive NK cell leukemia and extranodal NK cell lymphoma, nasal type.

BACKGROUND: Patients with natural killer (NK) cell neoplasms, aggressive NK cell leukemia (ANKL) and extranodal NK cell lymphoma, nasal type (ENKL), have poor outcome. Both diseases show a spectrum and the boundary of them remains unclear. The purpose of this study is to draw a prognostic model of total NK cell neoplasms. PATIENTS AND METHODS: We retrospectively analyzed 172 patients (22 with ANKL and 150 with ENKL). The ENKLs consisted of 123 nasal and 27 extranasal (16 cutaneous, 9 hepatosplenic, 1 intestinal and 1 nodal) lymphomas. RESULTS: Complete remission rate for ENKL was 73% in stage I, but 15% in stage IV, which was consistent with that for ANKL (18%). The prognosis of ENKL was better than that of ANKL (median survival 10 versus 1.9 months, P < 0.0001) but was comparable when restricted to stage IV cases (4.0 months, P = 0.16). Multivariate analysis showed that four factors (non-nasal type, stage, performance status and numbers of extranodal involvement) were significant prognostic factors. Using these four variables, an NK prognostic index was successfully constructed. Four-year overall survival of patients with zero, one, two and three or four adverse factors were 55%, 33%, 15% and 6%, respectively. CONCLUSION: The current prognostic model successfully stratified patients with NK cell neoplasms with different outcomes.

The International Prognostic Index predicts outcome in aggressive adult T-cell leukemia/lymphoma: analysis of 126 patients from the International Peripheral T-Cell Lymphoma Project.

BACKGROUND: The International Peripheral T-cell Lymphoma Project was organized to better understand the T-cell and natural killer (NK) cell lymphomas, and our task is to present the clinicopathologic correlations and therapeutic results for adult T-cell leukemia/lymphoma (ATL). PATIENTS AND METHODS: Among 1153 patients with T-cell or NK cell lymphomas, 126 patients (9.6%) with ATL were represented in this project. All were categorized as aggressive ATL, i.e. acute or lymphoma type, and 87% fell into the lymphoma type. RESULTS: The median age was 62 years and the male to female ratio was 1.2 : 1. Significant prognostic factors for overall survival (OS) by univariate analysis were the presence of B symptoms (P = 0.018), platelet count <150 x 10(9)/l (P = 0.065), and the International Prognostic Index (IPI; P = 0.019). However, multivariate analysis indicated that only the IPI was an independent predictor of OS. Combination chemotherapy including anthracyclines was given as the initial therapy in 109 of the 116 patients (94%) who received treatment, and the overall and complete response rates were 70% and 34%, respectively. However, there was no survival benefit for those receiving an anthracycline-containing regimen. CONCLUSION: Patients with aggressive ATL have a poor clinical outcome and the IPI is a useful model for predicting outcome in ATL of the lymphoma type.

Expression of chemokines and chemokine receptors in cutaneous CD30+ lymphoproliferative disorders.

BACKGROUND: Little is known about the mechanisms involved in skin-specific homing in CD30+ cutaneous lymphoproliferative disorders (CLPD). Chemokine/chemokine receptor interactions have been implicated in the homing of lymphoma cells to various tissue sites. OBJECTIVES: To investigate tissue samples from patients with CD30+ CLPD for the expression of the chemokine receptors CXCR3, CCR4 and CCR3 and their ligands MIG, TARC and RANTES. METHODS: Tissue samples from patients with primary cutaneous anaplastic large cell lymphoma (PCALCL, n=12) and lymphomatoid papulosis (LyP, n=13) were studied by immunohistochemistry on paraffin-embedded sections. Immunohistochemical analysis was also performed for CD20 (for B cells), CD45RO and CD3 (for T cells), CD30 and ALK-1. A portion of each skin specimen was stored at -80 degrees C and later examined using monoclonal antibodies against CD2, CD3, CD4, CD5, CD8, CD15, CD19, CD20 and CD30. RESULTS: CD30+ atypical lymphoid cells were frequently seen in PCALCL, and to a variable degree in LyP. In both disorders there were scattered CD3+ and CD45RO+ atypical lymphoid cells, but CD2, CD5, CD15, CD19, CD20 and ALK-1 showed negative reactivity. In addition, CD4+, but not CD8+, atypical lymphoid cells were occasionally seen in both disorders. CCR3 was expressed by atypical lymphoid cells in 10 of 12 (83%) cases of PCALCL, but in only five of 13 (38%) cases of LyP. CXCR3 was expressed in 11 of 13 (85%) cases of LyP, but in only one of 12 (8%) cases of PCALCL. CCR4 was expressed in 11 of 12 (92%) cases of PCALCL, but in only two of 13 (15%) cases of LyP. RANTES was strongly expressed by lymphoma cells in PCALCL (11 of 12: 92%), but was weak or sporadic in LyP (seven of 13: 54%). TARC showed weak or sporadic reactivity in both LyP and PCALCL, and MIG did not show a distinctive expression pattern in either disorder. CONCLUSIONS: We speculate that CCR3 is associated with the autocrine function in PCALCL, as evidenced by CCR3 coexpression with its ligand RANTES. We also found that LyP cells expressed CXCR3, which might support their migration towards the CXCR3 ligand MIG, which is expressed in stromal cells of the skin.

Hematopoietic stem cell transplantation for natural killer-cell lineage neoplasms.

Neoplasms of natural killer (NK)-lineage are rare. Their prognosis is generally poor except for cases of solitary nasal NK-cell lymphoma. The NK-cell Tumor Study Group performed a survey in Japan on patients diagnosed between 1994 and 1998. Of 228 patients selected for analysis, 40 underwent HSCT (15 allografts and 25 autografts). The underlying diseases were myeloid/NK cell precursor acute leukemia (n = 4), blastic NK-cell lymphoma (n = 11), aggressive NK-cell leukemia (n = 3), and nasal-type extranodal NK-cell lymphoma (n = 22). At the time of HSCT, 22 patients were in complete remission (CR), 11 were in relapse, and seven were primary refractory. All patients received myeloablative conditioning regimens including total-body irradiation. Sixteen died of disease progression, and six of treatment-related causes. Overall, 4-year survival was 39% with a median follow-up of 50 months; this was significantly better than that of patients who did not undergo HSCT (21%, P = 0.0003). For patients transplanted in CR, the 4-year overall survival was 68%, which was significantly better than that of patients who went into CR but did not undergo HSCT (P = 0.03). These findings suggest that the HSCT is a promising treatment strategy for NK-cell lineage.

Gene expression profile of cytokines and chemokines in microdissected primary Hodgkin and Reed-Sternberg (HRS) cells: high expression of interleukin-11 receptor alpha.

We microdissected Hodgkin and Reed-Sternberg (HRS) cells from 14 Hodgkin's lymphoma tissue samples (nodular sclerosis = 5; mixed cellularity = 9), and after isolation and amplification of mRNA, analyzed the expression profile of 140 genes of chemokines, cytokines and their receptors by cDNA microarray methods. We also compared the profile with those of germinal center (GC) cells in reactive lymphadenitis. Unsupervised clustering revealed a relatively homogeneous expression profile in HRS cells. HRS cells tended to express mainly Th2 T cell-associated molecules rather than those of Th1, compared with GC cells. Interleukin-11 receptor alpha (IL-11Ralpha), a previously unknown HRS cell-specific gene, was detected in addition to known genes. Immunohistochemical staining confirmed the expression of IL-11Ralpha at the protein level. In contrast, only few cases were positive for IL-11Ralpha in B cell lymphoma, diffuse large cell lymphoma and follicular lymphoma. This is the first analysis report of tissue HRS cells with cDNA microarray technique.

Low-grade follicular lymphoma with t(14;18) presents a homogeneous disease entity otherwise the rest comprises minor groups of heterogeneous disease entities with Bcl2 amplification, Bcl6 translocation or other gene aberrances.

Follicular lymphomas (FL) are morphologically classified into grades 1, 2, 3a and 3b by the World Health Organization. Bcl2, Bcl6 and CD10 are phenotypic markers of FL while the Bcl2 t(14;18) and Bcl6 t(3q27) gene translocations are common genetic changes. However, to date, there has been no integrated analysis based on phenotype, grade and genotype from large numbers of FL cases. We graded 261 cases of FL and determined their phenotypes and gene alterations. According to the antigen markers and gene alterations of 147 cases, we classified FL into typical and the others types. The typical group, which includes 69% cases of FL, is characterized by low histological grade (grade 1, 2), coexpression of BCL2 and CD10 and Bcl2 gene translocation. The rest comprises a small part of low-grade FL without Bcl2 gene translocation and high-grade (grade 3a, 3b) FL. These FLs include some heterogeneous disease entities. They are characterized by high histological grade (87%), no definite expression of BCL2 or CD10 and several kinds of gene aberrances including Bcl2 translocation, Bcl6 translocation, Bcl2 amplification or other unknown gene abnormality. Our findings indicate that typical FL presents a homogeneous disease entity whereas the rest comprises heterogeneous diseases entities.

Clinicopathological features of cutaneous lesions of adult T-cell leukaemia/ lymphoma.

BACKGROUND: Adult T-cell leukaemia/lymphoma (ATLL) is a human malignancy associated with human T-cell leukaemia virus type I (HTLV-I). ATLL frequently involves the skin. OBJECTIVES: To correlate the clinicopathological features and prognosis in patients with ATLL and cutaneous lesions. METHODS: We examined the HTLV-I proviral state and the clinicopathological features of the cutaneous lesions in 80 patients with serum anti-ATL antibody, to clarify the correlation between macroscopic/histopathological findings and prognosis. Southern blot analysis was performed in all cases to detect monoclonal HTLV-I proviral DNA integration. RESULTS: The cutaneous lesions of 46 patients were positive for proviral DNA integration. The median survival time of patients with monoclonal proviral DNA integration in cutaneous lesions was 14 months, which was markedly shorter than that of patients negative for proviral DNA integration (72 months). Of the 46 patients with proviral DNA, 21 had solitary or multiple red nodules (including three with subcutaneous induration), eight had multiple red papules and 17 had erythema. Patients with papules and nodules had poorer prognosis than those with erythema. Histopathologically, the prognosis was poorer in patients with nodular or diffuse infiltration of medium-sized to large lymphoma cells, compared with those with perivascular infiltration of small to medium-sized lymphoma cells. CONCLUSIONS: Our results show a close correlation between clinicopathological features of HTLV-I-associated cutaneous lesions and prognosis.

Prognostic significance of hepatocyte growth factor and c-MET expression in patients with diffuse large B-cell lymphoma.

The expression and prognostic significance of hepatocyte growth factor (HGF) and its receptor c-MET (MET proto-oncogene) was analysed in 96 cases of diffuse large B-cell lymphoma (DLBCL). Tissue sections were immunohistochemically stained for HGF and c-Met. The prognosis of HGF-positive and c-Met-positive cases was significantly worse than negative cases (HGF: P = 0.0036; c-Met: P = 0.0002). In addition, in the low-risk international prognostic index group, HGF-negative and c-Met-negative cases had a significantly better prognosis than positive cases (HGF: P = 0.0009; c-Met: P < 0.0001). Our results suggest that HGF/c-MET is a useful clinical marker of prognosis for patients with DLBCL.

Aggressive natural killer-cell leukemia revisited: large granular lymphocyte leukemia of cytotoxic NK cells.

Aggressive natural killer-cell leukemia (ANKL) is a rare form of large granular lymphocyte leukemia, which is characterized by a systemic proliferation of NK cells. The clinical features of 22 ANKL cases were analyzed. Hepatomegaly (64%), splenomegaly (55%) and lymphadenopathy (41%) were also frequently observed. Leukemic cells were identified as CD1-, CD2+, surface CD3-, CD4-, CD5-, CD7+, CD8+/-, CD10-, CD11b+/-, CD13-, CD16+, CD19-, CD20-, CD25-, CD33(-), CD34-, CD38+, CD56+, CD122+, HLA-DR+ and TCR-. Two of the 16 cases examined for CD57 were positive and three of the seven cases examined for cytoplasmic CD3. Epstein-Barr virus was detected in the tumor cells of 11 of the 13 cases examined. No common cytogenetic abnormalities were identified and 6q anomaly was detected in only one. Three of 13 patients treated with chemotherapy containing anthracycline/anthraquinone attained complete remission, in contrast to none of the eight who were treated with regimens without anthracycline. Although the overall prognosis was poor with a median survival of 58 days, those who attained remission showed better prognosis (P=0.005). These findings suggest that ANKL is an entity of mature cytotoxic NK-cell neoplasms with distinct phenotype and disease presentations. Intensive treatment for ANKL may result in a better prognosis.

Imbalance between apoptosis and telomerase activity in myelodysplastic syndromes: possible role in ineffective hemopoiesis.

The myelodysplastic syndromes (MDS) are a group of disorders characterized by peripheral pancytopenia despite normo- or hyper-cellular bone marrow. This is thought to be due to apoptosis of hematopoietic bone marrow cells, resulting in ineffective hematopoiesis. The heterogeneous nuclear ribonucleoprotein (hnRNP) B1 is involved in pre-mRNA processing and binds to telomeric cDNA repeats. The hnRNP B1 is a marker for early cancer. The aim of our study was to clarify the relationships between prognosis and apoptosis, telomerase activity (TA) and hnRNP expression in the bone marrow. The subjects were 51 patients with MDS, including patients with refractory anemia (RA) (n = 32), refractory anemia with ringed sideroblasts (RARS) (n = 1), refractory anemia with excess blasts (RAEB) (n = 7), refractory anemia with excess blasts in transformation (RAEB-t) (n = 8) and chronic myelomonocytic leukemia (CMMoL) (n = 3). We also studied 6 cases with acute myelogenous leukemia (AML) arising from MDS (AML-MDS) and 10 control subjects. Bone marrow biopsies were stained immunohistochemically for caspase-3 (marker of apoptotic activity) and human telomerase reverse transcriptase (hTERT), and hnRNP B1. Fatal pancytopenia was the cause of death in 19 of the 51 patients. The caspase-3 positive cell rate was higher in MDS (16.3%) than in controls (4.4%) and AML-MDS (0.5%). The percentage of hnRNP B1-positive cells was higher in MDS (15.3%) and AML-MDS (56.3%) than in controls (5.6%). In MDS, hnRNP B1 levels were higher in RAEB and RAEB-t subtypes than in RA and RARS. The percentage of hTERT-positive cells was higher in AML-MDS (50.0%) than in controls (20.2%) and MDS (23.6%). Our findings suggest that activation of apoptosis occurs in MDS in the absence of hTERT expression, implicating high apoptosis in the absence of high TA with ineffective hematopoiesis. Poor prognosis correlated with higher caspase-3 and lower hTERT rates. In MDS, hnRNP B1 activity may be associated with leukemic transformation.

Non-HTLV-1-associated primary gastric T-cell lymphomas show cytotoxic activity: clinicopathological, immunohistochemical characteristics and TIA-1 expression in 31 cases.

AIMS: Most primary gastrointestinal lymphomas are of B-cell origin and T-cell origin is very rare. Recent studies have suggested that human T-cell lymphotrophic virus type 1 (HTLV-1) may be involved in the development of primary gastric T-cell lymphoma. We analysed 31 patients with primary gastric T-cell lymphoma in south-west Japan, an area endemic for HTLV-1, and determined their phenotypes, genotypes, and HTLV-1 status. METHODS AND RESULTS: Here we present 31 cases of primary gastric T-cell lymphoma in a HTLV-1-endemic area in Japan and analyse the clinical status, histology, phenotype and virus status. The median age at onset of primary gastric T-cell lymphoma was 57 years with a gender ratio of M:F = 1.58:1. Six of the 31 primary gastric T-cell lymphoma cases had HTLV-1 proviral DNA (five males, one female), nine of the 31 cases were positive for anti-adult T cell leukaemia antibody, without examination of HTLV-1 proviral DNA (five males, four females), eight were non-HTLV-1-associated primary gastric T-cell lymphoma (four males, four females) and the other eight cases were unknown. Primary gastric T-cell lymphoma usually presented as a large ulcerated tumour at the corpus to the antrum and histologically consisted of anaplastic large cell type (n = 2), pleomorphic large cell type (n = 3), pleomorphic medium and large cell type (n = 14), pleomorphic medium cell type (n = 11), and angioimmunoblastic T-cell lymphoma type (n = 1). There were no clear macroscopic and microscopic differences between HTLV-1-associated and non-HTLV-1-associated primary gastric T-cell lymphoma. Most patients died within 2 years of diagnosis, and both types of primary gastric T-cell lymphoma (with and without HTLV-1) were associated with poor prognosis. Cytotoxic marker analysis showed that HTLV-1-associated lymphomas were negative for TIA-1, while non-HTLV-1-associated lymphomas were positive for TIA-1. CONCLUSIONS: Our results suggest that in HTLV-1-endemic areas, patients with HTLV-1-associated primary gastric T-cell lymphoma should be managed carefully and that TIA-1 seems to be useful for identifying the aetiology of this lesion.

Apoptosis and prognostic factors in myelodysplastic syndromes.

The myelodysplastic syndromes (MDS) are a group of disorders characterized by peripheral pancytopenia despite normo- or hyper-cellular bone marrow. This is thought to be due to apoptosis of hematopoietic bone marrow cells, resulting in ineffective hematopoiesis. Several studies have confirmed the presence of a high apoptotic rate and proliferative state in the bone marrow of MDS. However, MDS is a heterogeneous disease from the point of view of prognosis. Some patients develop only anemia and show long survival with or without maintenance therapy, while others develop fatal pancytopenia or leukemic changes and therefore show a poor prognosis. This review focuses on the relationship between prognosis and apoptotic or proliferative processes affecting hematopoietic cells in the bone marrow of patients with MDS.

Accessory cell tumour: a clinicopathological study of 16 aggressive tumours containing EBV-positive Hodgkin and Reed-Sternberg-like giant cells.

AIMS: Lymph nodes contain non-lymphoid accessory cells including follicular dendritic cells and interdigitating dendritic cells. Functionally, these cells belong to the category of immune accessory cells involved in antigen presentation to B or T-lymphocytes. Neoplastic proliferation of these cells is very uncommon. We present here the clinicopathological features of 16 cases of accessory cell tumour. METHODS AND RESULTS: We performed electron microscopic and immunohistochemical examinations, and used in-situ hybridization for EBV-encoded RNA (ISH-EBV) to detect the EBV genome in 11 cases, and Southern blot analysis to assess EBV clonality in two cases. Tumour cells were composed of oval-to-spindle cells arranged in diffuse, vague storiform, fascicular and sometimes whorled patterns in a background of small lymphocytes. In all cases, binucleated or multinucleated Hodgkin and Reed-Sternberg-like giant cells were encountered. Staining for CD68 was positive in all cases. CD21, CD35, Ki-M4p, Ki-FDC1p, and S100 exhibited variable reactivity. ISH-EBV yielded positive labelling in seven of 11 cases, of which five exhibited EBV only in Hodgkin and Reed-Sternberg-like giant cells. Southern blot analysis showed clonality of EBV terminal repeats (EBV-TR) in the two cases examined. Electron microscopic examination showed that many of the tumour cells had numerous interwoven long villous cell processes connected by occasional desmosomes. Many tumours were very refractory to chemotherapy and radiation, with a few exceptions, and half of the cases classified initially as stage IV. A short survival time, of 10 months or less, was observed in seven of 16 patients. CONCLUSIONS: Our study identified more aggressive behaviour of accessory cell tumours. Our results suggest that EBV may potentially induce activation of accessory cells to form Hodgkin and Reed-Sternberg-like giant cells, which correspond with poor prognosis.

Chronic lymphocytic leukemia (CLL) is rare, but the proportion of T-CLL is high in Japan.

Chronic lymphocytic leukemia (CLL) is a rare disease in Japan. Recent advances in molecular biology, diagnostic criteria and classification of CLL have reinforced the concept of each category of CLL as a distinct entity. Since there have been no recent studies on the incidence and prevalence of CLL in Japan, the Kyushu Hematology Organization for Treatment (K-HOT) Study Group conducted two studies of CLL. One study is a prospective registration of newly diagnosed hematological disorders, which gave us some idea of the incidence of CLL in our region (Kyushu island) where adult T-cell leukemia is endemic. A total of 677 patients with hematological disorders were registered over a 6-month period and 11 patients were diagnosed as having CLL among 182 leukemia patients. This amounts to 6% of all leukemias, which is twice as frequent as previously reported in Japan. The other study is a retrospective analysis of CLL. Eleven institutions of the K-HOT Group analysed their diagnostic records of chronic lymphoid leukemia, and 145 patients with CLL were found over a period of 3-12 yr. After the data were reviewed 11 patients were excluded through having a different type of leukemia. The proportion of chronic B-cell lymphoid leukemia was 73% (98/134), while that of T-cell leukemia was 18% (24/134). The proportion of T-cell chronic leukemia was 5-6 times higher than that in Western countries. Two institutions had a complete database on hematological disorders. From this database, the annual incidence of CLL was estimated to be 0.48 per 100 000. Thus, the incidence of CLL in Japan is at least 4-5 times lower than that in Western countries, suggesting that chronic B-cell leukemia is really rare, but chronic leukemia of T-cell lineage develops in Japan as frequently as in Western societies. Further investigation is required to delineate why the incidence of B-CLL is so low in Japan.

Changes in pattern of immunoglobulin heavy chain gene rearrangement and MIB-1 staining before and after eradication of Helicobacter pylori in gastric mucosa-associated lymphoid tissue (MALT) lymphoma.

Gastric low-grade mucosa-associated lymphoid tissue (MALT) lymphomas are strongly associated with infection by Helicobacter pylori (H. pylori). Antibiotic treatment for H. pylori induces a sustained remission in a significant number of patients. We report here the outcome in 13 patients with gastric low-grade MALT lymphomas or suspected gastric lesions, treated for eradication of H. pylori. Patients were followed closely with sequential histological studies, polymerase chain reaction (PCR) amplification of the immunoglobulin heavy chain (IgH) gene and immunohistochemistry for MIB-1. Antibiotic therapy resulted in eradication of H. pylori in all but one case, as assessed histologically. In 12 cases with successful eradication, complete regression was observed histologically in 9 cases (75%) and no regression in 3 (25%). In 7 of 9 (78%) patients who had a complete remission, clonal bands of IgH gene detected on PCR before therapy disappeared after therapy. All 9 patients with complete regression showed a reduced number of MIB-1 positive cells, while 4 cases with no change or disease progression showed no change or increased number of MIB-1 positive cells. There was a strong relationship between density of MIB-1-positive cells and histological score. These results indicate that combination analysis of PCR of IgH and MIB-1 seems to represent a very good current approach for the diagnosis of gastric low-grade MALT lymphoma and to assess the effects of chemotherapy, especially in problematic cases.

Rearrangements of bcl-1, bcl-2, bcl-6, and c-myc in diffuse large B-cell lymphomas.

Diffuse large B-cell lymphoma (DLBL) is characterized by a marked degree of morphologic and clinical heterogeneity. We studied 137 patients with de novo DLBL for rearrangements of the bcl-1, bcl-2, bcl-6 and c-myc oncogenes by Southern blot analysis. Structural alterations of bcl-1, bcl-2, bcl-6, and c-myc were detected in 21 of 137 (15.3%), 8 of 137 (5.8%), 22 of 137 (16.1%), 14 of 137 (10.2%) patients, respectively. Two cases showed a combination of bcl-1 and bcl-6 rearrangements. Chromosomal analysis was performed in 31 cases of the 137 DLBL. 27 of these showed karyotypic abnormalities, and two had translocations 3q27 involving bcl-6. However, one of two cases had no rearrangement of bcl-6. Patients with rearranged bcl-6 and c-myc tended to have poorer survival than patients with germ-line. Furthermore, bcl-1 and bcl-2 rearrangements tended to have a better outcome, although the above differences were not statistically significant. Rearrangements of the bcl-1, 2, 6, and c-myc gene correlated with the clinical outcome in DLBL and may thus serve as prognostic markers in patients with this form of malignant lymphoma. However, other genetic factors are probably involved in determining prognosis.

Analysis of the immunoglobulin heavy chain gene variable region of intravascular large B-cell lymphoma.

Intravascular large B-cell lymphoma (IVLBL) is a rare neoplasm characterized by proliferation of lymphoma cells within the blood vessels. The cell origin of IVLBL has not yet been determined. We examined cell lineage, with immunohistochemical staining and molecular analysis, using polymerase chain reaction (PCR) of the variable region of the immunoglobulin heavy chain (Ig-VH) gene. We also investigated the cell origin using direct sequence analysis of the complementary-determining region 2 (CDR2) and framework region 3 (FR3) in six cases, consisting of two male and four female patients. The sequences in five cases showed frequent mutations. The percent homology to their closest germline genes ranged from 74.7 to 91.8%. However, one case showed a percent homology of 99.4% in CDR2 and FR3 of Ig-VH. All cases showed rearrangements of VH3 family genes. Interestingly, three of the IVLBL cases with hypermutated IgH genes showed the expression of CD5. Therefore, expression of CD5 in lymphoma cells does not indicate that the origin of IVLBL is the same as mantle cell lymphoma having the character of CD5 expression, which develops in pre-germinal center cells. Our results indicate that most IVLBLs may originate in the post-germinal center cells, based on the presence of somatic mutation in VH genes, although some heterogeneous cases are intermingled within IVLBL.