Yukihiro Tokumine

B Cell Lymphoma Showing Clinicopathological Features of Malignant Histiocytosis

This report describes a case of B cell lymphoma, the clinicopathological features of which are quite similar to those of malignant histiocytosis. The clinical features included fever, anemia, and marked hepatosplenomegaly without lymphadenopathy. Histological findings revealed diffuse and noncohesive proliferation of cytologically atypical cells and benign-appearing histiocytes in the splenic red pulp, where the erythrophagocytosis was frequently found. Immunological studies, however, revealed a B cell nature of proliferating atypical cells. Accordingly, the histology of this patient was interpreted as a neoplastic proliferation of B cells accompanied by marked proliferation and activation of the histiocytes.

OKM1-positive T-cell leukemias. Relationships among morphologic features, phenotype, and functional activities

The morphologic features, phenotype, and functions of OKM1+ leukemic T‐cells were studied. The leukemic T‐cells in two patients with chronic lymphocytic leukemia (CLL) had specific features of large granular lymphocytes (LGL), and those in two patients with acute lymphocytic leukemia (ALL) had L2 morphologic characteristics. The phenotype of the leukemic cells from one patient with CLL was OKM1+, ER+, OKT3+, OKT4+, OKT8−, OKIa1−, IgGFc receptor (EAγ)+, Leu‐7+, Leu‐11b+, and anti‐Tac−. The cells had antibody‐dependent cell‐mediated cytotoxicity (ADCC), but no natural killer (NK) activity. They had a definitive helper effect on pokeweed mitogen‐induced normal B‐cell differentiation. The leukemic cells from the other patient with CLL were Leu‐7−, and Leu‐11b−, and lacked both ADCC and NK activity. The leukemic cells in the two patients with ALL were ER+, OKM1+, Leu‐7−, and Leu‐11−, and did not have any cytotoxicity. One was EAγ+, and the other was EAγ−. These findings suggest that OKM1+ leukemic T‐cells consist of at least two subgroups: (1) T‐cells with the morphologic features of LGL; and (2) those with a lymphoblastic morphologic type. In either case, the phenotype is novel and suggests the emergence of a small, distinct lymphocyte subset.

Establishment of a new cell line from a patient with hairy cell leukemia-Japanese variant.

A cell line, JHC-2, was established from the peripheral blood of a patient with hairy cell leukemia (HCL)-Japanese variant. The JHC-2 cells have cytologic features similar to those of the original tumor cells. They displayed hairy cytoplasmic projections by phase contrast and scanning electron microscopy. The tartrate-resistant acid phosphatase reaction was weakly positive. The immunophenotype of the JHC-2 cells was CD5-, CD10-, CD11c+/-, CD19+, CD21+, CD23+, CD24-, CD25+/-, CD38- and FMC-7+. The expression of surface immunoglobulin (IgG, kappa) and the configuration of Ig gene rearrangements in the JHC-2 cells were identical to those in the original leukemic cells, and the JHC-2 cells displayed trisomy 9 on cytogenetic examination. Southern blot analysis for the Epstein-Barr virus (EBV) genome showed that the JHC-2 cells contained the EBV genome, although the freshly isolated leukemic cells did not. These results indicate that the JHC-2 cell line is an EBV spontaneously transformed B cell line originating from HCL cells.

Quantitative polymerase chain reaction analysis with allele-specific oligonucleotide primers for individual IgH VDJ regions to evaluate tumor burden in myeloma patients

Quantitative polymerase chain reaction (PCR) with patient-specific, allele-specific oligonucleotide (ASO) primers for individual immunoglobulin H VDJ region (ASO-PCR) amplification was performed using several sources of clinical material, including mRNA from peripheral blood cells (PBMNCs), whole bone marrow cells (BMMNCs), and the CD20+ CD38- B-cell population in bone marrow, as well as cell-free DNA from the sera of patients with multiple myeloma (MM). We designed the ASO primers and produced sufficient PCR fragments to evaluate tumor burden in 20 of 30 bone marrow samples at diagnosis. Polymerase chain reaction amplification efficiency depended on primer sequences because the production of ASO-PCR fragments did not correlate with serum M-protein levels. However, the ASO-PCR levels in BMMNCs showed statistically significant correlations with those in PBMNCs and CD20+ CD38- B-cells. The good association between the BMMNC and PBMNC data indicated that PBMNCs could be a suitable source for monitoring minimal residual disease (MRD). In the case of cell-free DNA, ASO-PCR levels showed a unique pattern and remained high even after treatment. Because the sequence information for each ASO-PCR product was identical to the original, the cell-free DNA might also be useful for evaluating MRD. Moreover, the ASO-PCR products were clearly detected in 17 of 22 mRNA samples from CD20+ CD38- populations, suggesting that MM clones might exist in relatively earlier stages of B cells than in plasma cells. Thus, ASO-PCR analysis using various clinical materials is useful for detecting MRD in MM patients as well as for clarifying MM pathogenesis.

Association of specific tyrosine phosphorylation with stages of B-cell differentiation in human lymphoid leukemias

In vitro protein phosphorylation in various types of human fresh lymphoid leukemic cells (C-ALL, B-CLL, HCL and PCL: B-cell lineage and T-ALL, ATL and T-CLL: T-cell lineage) were studied. In cases of B-CLL and HCL, tyrosine protein kinase (TPK) activity was at least 5-fold higher than that in other cases of B- and T-cell lineages. B-cell leukemic cells at various differentiation stages had different endogenous substrates in tyrosine phosphorylation as well as distinct TPK activity. The P-tyr-containing proteins of 68K, 59K and 56K were detected commonly in all the cases of B-cell lineage. The phosphorylated protein of 32K was present only in cases of PCL. On the other hand, in T-ALL and ATL, the major substrate in tyrosine phosphorylation was 58K. These results suggest that the characterization of in vitro tyrosine phosphorylation provides a new means not only to distinguish T- and B-lymphoid leukemia, but also to differentiate stages of lymphoid development.

Tentative diagnostic criteria and disease severity classification for Castleman disease: A report of the research group on Castleman disease in Japan

Abstract Objectives: To determine the tentative diagnostic criteria and disease severity classification for Castleman disease (CD) and describe the clinical and pathologic features among human herpesvirus 8 (HHV-8) negative idiopathic multicentric CD (iMCD) in the Japanese population. Methods: We established the working groups for the research of CD in Japan and had meetings to discuss and define the tentative diagnostic criteria and disease severity classification for CD. We subsequently analyzed 142 patients classified into iMCD by using the nationwide Japanese patient registry. Results: We proposed the preliminary diagnostic criteria and disease severity classification for CD based on our discussion. In addition, we made a proposal for the disease activity score. We identified clinical and pathological features of patients with iMCD diagnosed by these diagnostic criteria. In the disease severity classification, 37, 33 and 30% patients were categorized into mild, moderate and severe diseases, respectively. Conclusion: This is the first proposal for diagnosis and classification of CD by the Japanese group. Further studies are required to validate whether they can distinguish CD from other inflammatory diseases and to determine their sensitivity and specificity.

Chronic lymphocytic leukemia and related lymphoproliferative disorders in Japan.

The clinical and cytological features of 73 patients with chronic (mature) B-cell leukemias were studied. Large lymphocytes or cleft cells were often seen in patients referred to us as chronic lymphocytic leukemia (CLL). Immunophenotypical and histopathological studies were performed and the diagnosis of leukemic phase of non-Hodgkins lymphoma (follicular lymphoma; FL and intermediate lymphocytic lymphoma; ILL) was made in a significant portion of the patients and only ten cases were diagnosed as CLL including mixed cell type.Although hairy cell leukemia (HCL) is quite rare in Japan, a disproportionally large number of patients were referred to our laboratory. Typical HCL seen in Western countries, was found in nine cases. On the other hand, most (29 cases) showed cytologic features distinct from typical HCL and were classified into HCL-Japanese Variant (HCL-J). Morphology of HCL-J cells in May-Giemsa stained films resembled large CLL lymphocytes, but several features shared by typical HCL and HCL-J including typical hairy morphology under phase contrast microscopy, CD11c+, L30- phenotype and the histology distinguished the disease from CLL and other B-cell leukemias. In two cases, the cells displayed prominent nucleoli and surface villi, the features consistent with those described for HCL Variant (prolymphocytic variant). Some patients were differentiated from HCL and were diagnosed as leukemic phase of ILL with large spleens or splenic lymphoma with villous lymphocytes (SLVL). Under phase contrast, fine cytoplasmic processes were obseved in ILL cells. Surface morphology of SLVL cells considerably varied from cell to cell; some displayed prominent cytoplasmic projections similar to those of hairy cells, while others had a few, short villi or lacked villi even by phase contrast microscopy. The spleen histology showed prominent involvement in the white pulp with the features of lymphoplasmacytic lymphoma.