K. Shimazaki

Perforin and Fas pathways of cytotoxic T-cells in histiocytic necrotizing lymphadenitis.

Cell death can be divided into necrosis and apoptosis. In histiocytic necrotizing lymphadenitis (HNL), apoptosis is the main form of cell death. Two molecular mechanisms of T‐cell‐mediated cytotoxicity, one perforin‐based and the other Fas‐based, have been demonstrated, and both systems induce apoptosis of the target cells. This study was designed to investigate the Fas and perforin pathways in HNL.

Prognostic clinicopathologic factors, including immunologic expression in diffuse large B-cell lymphomas.

The aim of this study was to assess the clinical significance and potential prognostic value of the expression of a panel of surface markers, proliferating, suppressor and oncogenic proteins in diffuse large B‐cell lymphomas (DLBCL). Biopsies were collected from 158 patients with DLBCL and analyzed immunohistochemically for p53, p21/WAF1, bcl‐2, cyclin‐D1, bcl‐6, mdr, CD5, CD30, epithelial membrane antigen (EMA), Ki‐67 and c‐myc positive tumor cells. Among these, 76 young and middle‐aged patients (20–65 years) were selected to investigate the relationship between protein expression, clinical features, and survival. Survival analysis showed that advanced stage, high lactic dehydrogenase level, and high International Prognostic Index (IPI) were poor prognostic factors associated with a shorter overall survival (OS) and disease‐free survival (DFS) times. A high p53 expression and low bcl‐6 expression were associated with a shorter DFS time. The histological variant type, cyclin‐D1+ CD5+ DLBCL, positive epithelial membrane antigen (EMA+) CD30– DLBCL, high bcl‐2 expression, and low Ki‐67 proliferation activity tended to be associated with worse survival, but the correlations were not statistically significant. In the multivariate analysis, the most significant factors were age, followed by IPI and last p53. The expression of p21/WAF1, mdr, and c‐myc proteins did not influence OS and DFS. The expression of p53 and bcl‐6 proteins may be useful prognostic indicators in DLBCL. Cyclin‐D1+ CD5+ or EMA+ CD30– DLBCL tended to predict a worse survival and may probably bear a significant prognostic value worthy of consideration. Overall, clinical factors appeared to be more important than biologic parameters in determining the prognosis of diffuse large B‐cell lymphomas.

Nasal T/NK cell lymphomas commonly express perforin and Fas ligand: important mediators of tissue damage.

Two molecular mechanisms of T/natural killer (NK) cell‐mediated cytotoxicity, one perforin based and the other Fas based, have been demonstrated, and both systems induce cytotoxicity in the target cells. The Fas‐based mechanism involves the transducing molecule Fas and its ligand (FasL). In addition, perforin and/or FasL are also expressed in the cytotoxic T/NK cells. This study was thus designed to investigate the Fas and perforin pathways of the cytotoxic T/NK lymphoma cells in the nasal cavity.

Evaluation of apoptosis as a prognostic factor in myelodysplastic syndromes

The myelodysplastic syndromes (MDS) are a group of disorders characterized by peripheral pancytopenia despite normo‐ or hypercellular bone marrow. This is thought to be as a result of the apoptosis of haematopoietic bone marrow cells resulting in ineffective haematopoiesis. To clarify the relationship between prognosis and apoptosis and/or cell proliferation in the bone marrow, we studied 51 cases with MDS. Bone marrow biopsies were stained immunohistochemically for MIB‐1 (marker for proliferating cells) and CD34 (marker for stem cells). Apoptosis was visualized by detection of DNA fragmentation using TdT incorporation of nucleotides on 3′ ends of DNA (TUNEL technique) and expressed as the apoptotic rate. MDS patients included 32 with refractory anaemia (RA), one RA with ringed sideroblasts (RARS) patient, seven RA with excess of blasts (RAEB) patients, eight patients with RAEB in transformation (RAEB‐t) and three patients with chronic myelomonocytic leukaemia (CMMoL). In addition, we also studied six cases with acute myeloid leukaemia (AML) arising from MDS (AML‐MDS) and ten control subjects. Fatal pancytopenia was the cause of death in 19 out of 51 patients. The apoptotic rate was higher in MDS patients (5·5%) than in control subjects (0·6%) and AML‐MDS patients (0·4%). The percentage of MIB‐1 positive cells was higher in MDS and AML‐MDS than in control. The percentage of CD34‐positive cells was higher in AML‐MDS, RAEB, RAEB‐t and CMMoL patients than control subjects and RA patients. Our findings indicate the activation of both the proliferative and apoptotic rates in MDS. Poor prognosis correlated significantly with higher apoptotic rates, but not with percentages of MIB‐1 and CD34‐positive cells. Our results suggest that apoptosis might be a useful prognostic factor and inhibition of apoptotic mechanisms may induce leukaemic transformation in MDS.

Gastrointestinal T Cell Lymphoma: Predominant Cytotoxic Phenotypes, Including Alpha/Beta, Gamma/Delta T Cell and Natural Killer Cells

Gastrointestinal T cell lymphoma (TCL) is a rare subset of peripheral TCL, presenting with or without cytotoxic phenotype, a history of coeliac disease (CD) and enteropathy. However, CD is rare in Japan. Here, we describe the clinicopathological features of 18 Japanese cases. Lesions were found in the small intestine (n=13), stomach (n=3) and colon (n=2). Seven patients presented with enteropathy but none had a history of CD. Lymphomas appeared as ulceration (n=ll), tumour formation (n=6), or polypoid growth (n=1). Histologically (REAL classification), neoplastic lesions were composed of intestinal type T cell lymphoma (ITCL, n=13, including one case with NK type), anaplastic large cell (ALCL, n=2), adult T cell leukaemia/lymphoma (ATLL, n=2), and lymphoblastic type (n=1). Epstein Barr virus infection was detected by EBER-1 in situ hybridization in 6 of 11 cases with ITCL but not in the other types. ALCL expressed CD30. CD56 was expressed in 3 of 11 cases of ITCL but not in other types. Among the 10 examined cases, 8 were αβ T cell type [CD2+, CD3+, T cell receptor (TCR)δ-1-, βF1+], one was γδ T cell type [CD2+, CD3+, TCR8-1+, (βF1-], and the remaining case expressed natural killer (NK) cell type [CD2+, CD3-, CD56+, TCRδ-1-, βF1-]. Among the 8 examined cases, 3 expressed CD103 molecule, which was associated with extrathymic T cells of intraepithelial lymphocytes. All cases except ATLL expressed the cytotoxic-ity-associated molecule of TIA-1, and 11 of 14 TIA-1 positive cases expressed activated cytotoxic molecules of perforin, granzyme B, and/or Fas ligand. Despite the morphological, genetic and phenotypic heterogeneity, prognosis was poor, and 11 of 13 patients with small intestinal lesions died albeit appropriate treatment, but 3 of 4 patients with gastric or colonic lesions were still alive. The main cause of death was intestinal perforation. The latter might be due to the site specificity of small intestine and tumour cytotoxicity.

Apoptosis of cytotoxic T-cells in histiocytic necrotizing lymphadenitis.

Abstract Cell death is necrotic or apoptotic. In histiocytic necrotizing lymphadenitis (HNL), apoptosis is the main form of cell death, resulting in the creation of nuclear debris that is one of the characteristic features of HNL. To investigate the cell type of apoptotic cells, 12 cases of HNL were analyzed using the immunohistochemical staining for TIA-1, a cytotoxic granule of either cytotoxic T or NK cells. One quarter to over half of all apoptotic cells were positive for TIA-1, and some of the nuclear debris was also positive. The necrotic lesions of HNL were found to consist of nuclear debris, apoptotic cells, histiocytes and lymphocytes. The lymphocytes were mainly CD8-positive T-cells or CD4-positive cells, while B- and NK cells were only rarely observed. The number of TIA-1-positive lymphocytes was more closely related to the number of CD8-positive cells than to the number of CD4 cells. In double staining, the TIA-1 positive lymphocytes were mainly CD8 positive, but rarely CD4 positive. In HNL, then, CD8-positive cytotoxic T-cells are likely to undergo apoptosis.

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) <formula>(<italic>n</italic>=32),</formula> refractory anemia with ringed sideroblasts (RARS) <formula>(<italic>n</italic>=1),</formula> refractory anemia with excess blasts (RAEB) <formula>(<italic>n</italic>=7),</formula> refractory anemia with excess blasts in transformation (RAEB-t) <formula>(<italic>n</italic>=8)</formula> and chronic myelomonocytic leukemia (CMMoL) <formula>(<italic>n</italic>=3).</formula> 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.

Clinical, immunohistochemical and phenotypic features of aggressive nodal cytotoxic lymphomas, including α/β, γ/δ T-cell and natural killer cell types

Abstract Cytotoxic cells include natural killer (NK) cells and cytotoxic αβ and γδ T lymphocytes (CTLs). These cells express cytotoxic molecules of T-cell restricted intracellular antigen(TIA-1), and activated cytotoxic molecules of perforin, granzyme B, and FasL. Recent studies suggest that most extranodal T-cell lymphomas are derived from CTLs, and that NK cell lymphomas are extranodal. However, only a few nodal NK and cytotoxic lymphomas have been described so far. We present here the clinicopathological features of seven cases of nodal cytotoxic T and NK cell lymphomas. The study excluded anaplastic large-cell lymphomas expressing cytotoxic molecules. The neoplastic cells of all cases contained activated cytotoxic molecules of TIA-1, granzyme B, Fas ligand, and/or perforin. Phenotypically and genotypically, four cases showed αβ T cell type [CD2+, CD3+, T-cell receptor (TCR) δ-1–, βF1+, and TCR gene rearrangement], two cases showed γδ T-cell type [CD2+, CD3+, T-cell receptor (TCR)δ–1+, βF1–, and TCR gene rearrangement], and one case showed NK cell type [CD2+, CD3-, CD56+, T-cell receptor (TCR)δ-1–, βF1–, and TCR gene germline]. Using Southern blot analysis, Epstein-Barr virus (EBV) sequences were detected in six cases, and monoclonal terminal repeat proliferation was confirmed. In addition, in situ hybridization (ISH) studies for EBV showed EBV infection in almost all neoplastic cells. Clinically, all patients presented with peripheral lymphadenopathy in high clinical stages and showed an aggressive course. Hepatosplenomegaly was detected in six cases. During the course of the disease, bone marrow and extranodal invasion were noted in five cases. The nodal type showed an aggressive clinical course in all cases but one, as did the extranodal type. The nodal type varied in phenotype, but was closely associated with EBV infection.

Basic Fibroblast Growth Factor and Fibrosis in Hodgkin's Disease

Hodgkins disease (HD) is characterized by the presence of Hodgkin and Reed-Sternberg (H-RS) cells against a hyperplastic background of reactive cells such as lymphocytes, histiocytes, plasma cells, eosinophils, neutrophils and stromal cells. In addition, the HD nodular sclerosis (NS) subtype shows characteristic fibrous bundles, while the other subtypes do not. The fibrosis is considered to correlate with multiple cytokines and cytokine networks. Basic fibroblast growth factor (bFGF), one of the potent stimulators of fibroblasts, has also been linked to the fibroproliferative process. To investigate the relationship of fibrosis and bFGF, we thus performed both immunostaining, in situ hybridization (ISH) and reverse transcriptase-polymerase chain reaction (RT-PCR) on 25 cases of HD, which included 12 cases with NS subtype, 10 cases with mixed cellularity (MC), and 3 cases with lymphocyte predominance (LP). In NS, the expression of bFGF was stronger than that in LP and MC. In addition, the H-RS cells in NS frequently expressed bFGF. The stromal cells and histiocytes in the background expressed bFGF in NS. However, in MC and LP the number of bFGF-expressed H-RS cells was small, and the bFGF expression of background cells was rarely detected. However, the amount of bFGF varied in each case with HD NS. The above results support the possibilities that H-RS cells and background cells are a cellular source of bFGF and that the bFGF expression of those cells is also one of the influencing factors in the development of fibrosis in the HD NS subtype.

Clinicopathological findings of virus‐associated hemophagocytic syndrome in bone marrow: Association with Epstein‐Barr virus and apoptosis

Non‐neoplastic hemophagocytic syndrome (HPS), also called virus‐associated hemophagocytic syndrome (VAHS), has been thought to be a distinct clinical entity. A spontaneous recovery is common, but the prognosis of Epstein‐Barr virus (EBV)‐associated VAHS is poor. However, the role of EBV has yet to be clearly elucidated. A retrospective study of the bone marrow of 30 cases, in which the diagnosis of non‐neoplastic VAHS was clinicopathologically confirmed, was performed. We were unable to histologically confirm the presence of neoplastic lesions, especially lymphoma cell infiltration. Ten of the patients were children (aged less than 15 years) and young adults (aged under 20 years; median age, 10 years). Twenty patients were adults (aged over 21 years; median age, 48 years). Twelve of these patients died, while 18 showed a spontaneous recovery. We performed immunological staining and in situ hybridization (ISH) for EBV. To clarify the presence of apoptosis, an in situ apoptosis detection (tunnel) method was used. In situ hydridization showed an EBV‐presence in 16 of the 30 patients. In addition, the EBV‐presence was confined in the lymphocytes, especially T lymphocytes in double stainings. The number of EBV‐infected cells varied; however, the EBV presence was associated with ages. Nine of the 10 children and young adults showed an EBV‐presence, while EBV was detected in seven of the 20 adults. Especially in 10 patients aged over 49 years, no EBV was detected. According to the in situ apoptosis detection, apoptotic cells were increased in number and considered to be lymphoid cells, but not myeloid or histiocytic cells. Some apoptotic cells were phagocyted with histiocytes. Histologically, apoptosis may be one of the factors that induced phagocytosis.