Decreases in Ikaros activity correlate with blast crisis in patients with chronic myelogenous leukemia

Gene targeting studies in mice have shown that the lack of Ikaros activity leads to T-cell hyperproliferation and T-cell neoplasia, establishing the Ikaros gene as a tumor suppressor gene in mice. This prompted us to investigate whether mutations in Ikaros play a role in human hematological malignancies. Reverse transcription-PCR was used to determine the relative expression levels of Ikaros isoforms in a panel of human leukemia/lymphoma cell lines and human bone marrow samples from patients with hematological malignancies. Among the cell lines examined, only BV-173, which was derived from a chronic myelogenous leukemia (CML) patient in lymphoid blast crisis, overexpressed the dominant-negative isoform, Ik-6. In 9 of 17 samples of patients in blast crisis of CML, Ikaros activity had been reduced either by drastically reducing mRNA expression (4 of 17) or by overexpressing the dominant-negative isoform Ik-6 (5 of 17). Significantly, expression of Ikaros isoforms seemed normal in chronic phase CML patients and patients with other hematological malignancies. In some cases, overexpression of the dominant-negative Ik-6 protein was confirmed by Western blot analysis, and Southern blot analysis indicated that decreases in Ikaros activity correlated with a mutation in the Ikaros locus. In summary, these findings suggest that a reduction of Ikaros activity may be an important step in the development of blast crisis in CML and provide further evidence that mutations that alter Ikaros expression may contribute to human hematological malignancies.

[A case of rheumatoid arthritis with bucillamine-induced myasthenia gravis treated by immunoadsorption therapy]

We report a case of 48-year old female with rheumatoid arthritis (RA) complicated with myasthenia gravis. In 1988, she was diagnosed of having RA, and several therapeutic drugs were administered, but her disease activity was in poor control. In July 1993, bucillamine (BU) was started at a dose of 100 mg/day, and her arthritis subsided. However, in October 1996, she was admitted with a rapidly progressive ptosis and double vision in the left eye, which became prominent in the evening. Because serum concentration of the antibody to acetylcholine receptors (AchR Ab) was elevated at 12.6 nmol/l, and the ptosis was reversed immediately after a tensilon test, ocular type myasthenia gravis (MG) was diagnosed and it was thought to have been induced by BU. Immunoadsorption therapy was started after discontinuation of this drug, and was continued for 6 months, resulting in improvement of neurological symptoms and decrease in AchR Ab level. MG has not recurred since. Although several cases of D-penicillamine (DP) induced MG are reported, only two cases are reported which were induced by BU, sulfhydryl compound which has a structure similar to DP. Since BU has been widely used as one of the disease modifying anti-rheumatic drugs in Japan, MG induced by this drug should be paid attention as one of the adverse effects.

Molecular characterization of total kininogen deficiency in Japanese patients

Kininogens are multifunctional plasma glycoproteins. There are two forms of human kininogen: low molecular weight kininogen (LK) and high molecular weight kininogen (HK). Both are derived from the same gene by alternative splicing. Some patients with kininogen deficiency have been reported to be deficient only in HK while others are deficient in both HK and LK (total kininogen deficiency). We analyzed three Japanese patients with total kininogen deficiency by the Csp45I digestion study of exon 5 as previously reported in Williams trait and found that two had the same point mutation of C to T at base 22 of exon 5, resulting in a transition of CGA (Arg) codon to TGA (Stop) codon. This is the first report of molecular characterization of total kininogen deficiency in the Japanese population.

Detection of myeloperoxidase by flow cytometry in acute leukemia

The value of flow cytometric detection of myeloperoxidase (MPO) in the differential diagnosis of acute leukemia was evaluated in 57 cases of acute leukemia and in 9 leukemia cell lines. Cells were fixed and permeabilized with Fix & Perm cell permeabilization kit at room temperature for 15 min each, and stained with anti-MPO monoclonal antibody (MPO-7) by direct immunofluorescence. One myeloid cell line, HL-60, was MPO-positive, while the other myeloid cell lines (KG-1, K-562, and MEG-01) as well as lymphoid cell lines (KM-3, NALM-6, Raji, REH, and T-ALL-1) were MPO-negative as previously described. Among acute leukemias, MPO was detected in 23 of 26 cases of acute myeloid leukemia (AML), 7 of 23 cases of B-lineage acute lymphoblastic leukemia (ALL), 1 of 6 cases of T-lineage ALL (T-ALL), and 1 of 2 cases of acute unclassified leukemia (AUL). The intensity of MPO expression in 6 of 7 B-lineage ALL cases was weak compared with AML labeling. There was no detectable cytochemical MPO in the cells of ALL, AUL, or AML that stained negative for anti-MPO. No relationship between the expression of MPO and myeloid lineage surface antigens was observed in ALL. Three cases of MPO-positive ALL and AUL could be reclassified as biphenotypic leukemia according to the revised Catovsky scoring system. These results indicate that anti-MPO is an excellent marker for the diagnosis and classification of acute leukemia and can be reliably detected by flow cytometry. This rapid technique should be a valuable addition to routine immunophenotyping of acute leukemia.

Biphasic expression of CD4 in acute myelocytic leukemia (AML) cells: AML of monocyte origin and hematopoietic precursor cell origin

In 227 of 495 (45.9%) Japanese adult patients with acute myelocytic leukemia (AML), leukemic cells expressed CD4. Incidence of CD4 expression in each FAB subtype was as follows: M1 37.4%, M2 33.7%, M3 35.4%, M4 65.0%, and M5 78.3%. The typical expression pattern of myelomonocytic differentiation antigens and cytokine receptors in CD4+ AML was CD34lowCD33high CD11bhighGM-CSFRhigh. AML cases with 11q23 abnormalities and with inv(16) were frequently CD4-positive. These data collectively indicate that CD4 expression in AML cells is associated with monocytic characteristics. However, CD4+CD34high AML cases appear to have unique immature characteristics including low expression of myelomonocytic differentiation antigens (ie CD33 and CD11b), and accumulation of chromosome abnormalities (ie t(8;21) in CD4lowCD34high AML and chromosome 7 abnormalities in CD4highCD34high AML). We speculate that these leukemia subsets originate from CD4+ hematopoietic precursor cells, therefore then should be considered separately from most of the CD4+ AML as represented by CD34lowCD33high CD11bhighGM-CSFRhigh. Overall survival of patients with CD4+ AML in our series was worse than that of those with CD4 AML (P = 0.0202).

Clinical importance of interleukin-2 receptor alpha-chain expression in acute leukemia. The Japan Cooperative Group of Leukemia/Lymphoma

To clarify the clinical importance of interleukin-2 (IL-2) receptor (IL-2R) expression in acute leukemia, we examined 517 adult patients with acute leukemia and CML blast crisis (CML-BC). IL-2R alpha was expressed in 42/311 AML, 5/11 acute unclassified leukemia, 24/116 pre-B ALL, 2/32 T-ALL, and 27/47 CML-BC, while IL-2R beta was expressed only in 2 T-ALL. Expression of IL-2R alpha was closely associated with that of different lineage markers, CD11b, CD34, and Ph1+ abnormality. IL-2R alpha(+) non-T leukemic cells did not respond to IL-2. Clinical outcome of IL-2R alpha (+) leukemia showed lower response to conventional chemotherapy and poorer prognosis than IL-2R alpha (-) cases. Serum IL-2R alpha level in IL-2R alpha (+) cases increased at the onset. Our findings indicate the diagnostic importance of IL-2R alpha expression in acute leukemia as a prognostic risk factor with a close relation to the particular cellular characteristics.

Myeloid antigen, CD13, CD14, and/or CD33 expression is restricted to certain lymphoid neoplasms

The authors examined the expression of myeloid antigens (MyAg): CD11b, CD13, CD14, CD15, and CD33 in 249 adults with lymphoid neoplasms using flow cytometric analysis. In this study, acute leukemia that was myeloperoxidase negative by light microscopy and had at least one lymphoid antigen was defined as acute lymphoblastic leukemia (ALL). The patients were classified as follows: 6 with unclassified ALL, 35 early B precursor ALL, 32 T-ALL, 25 B-cell chronic lymphocytic leukemia (B-CLL) and its variants, 24 B-cell non-Hodgkin's lymphoma (B-NHL), 7 plasma cell disorders, 8 T-CLL, 2 adult T-cell leukemia, and 10 T-NHL. CD11b and CD15 were present in a wide range of lymphoid disorders irrespective of B/T lineage and maturity. Unclassified ALL and phenotypically immature ALL frequently expressed CD13 and CD33, and occasionally expressed CD14. Among early B precursor ALL, CD13, and/or CD33 were significantly associated with the presence of stem cell marker CD34 and the chromosomal abnormality t(9;22). In addition, ALL with deletion of chromosome 7 commonly expressed CD13 and CD33. Taken together, CD13 and/or CD33 positive ALL may originate from a multipotential stem cell. Among mature neoplasms, CD14 was frequently, and CD13 and CD33 were occasionally expressed in B-cell, but not T-cell tumors. These results suggest that CD13, CD14, and CD33 are preferentially expressed in two types of lymphoid neoplasms, namely undifferentiated ALL and mature B-cell lymphoproliferative disorders.

Biological characteristics of CD7(+) acute leukemia

Eighty six of 430 acute myeloblastic leukemia (AML) patients (20.0%) and forty of 173 acute lymphoblastic leukemia (ALL) patients (23.1%) had CD7 on their leukemia cells. CD7(+) AML occurred at a younger age than CD7(-) AML, and is more frequent in males. Hepatomegaly and central nervous system involvement were also more frequent in CD7(+) AML than in CD7(-) AML. The age of onset of CD7(+) ALL is also younger than that of CD7(-) ALL. Phenotypically, CD(+) AML expressed CD34, HLA-DR, and TdT more frequently than CD7(-) AML while CD7(+) ALL expressed CD13/33 more often than CD7(-) ALL cells responded most significantly to interleukin 3 (IL-3), whereas most CD7(-) AML cells responded more significantly to granulocyte macrophage-colony stimulating factor (GM-CSF) and/or granulocyte (G)-CSF than to IL-3. CD7(+)sCD3(-)CD4(-)CD8(-) ALL expressed G-CSF receptor and c-kit mRNA more frequently, which is not usual in other types of ALL. P-glycoprotein (P-gp)/multi-drug resistance gene (MDR1), thought to be expressed in hematopoietic stem cells, is expressed in CD7(+) AML and CD7(+)sCD3(-) CD4(-)CD8(-) ALL significantly more often than in CD7(-) acute leukemias and the CR rate and overall survival of CD7(+)AML was worse than CD7(-) AML. These data, collectively, suggest the close association of CD7(+) AML and CD7(+)sCD3(-)CD4(-)CD8(-) ALL, not only the common expression of CD7 itself but also because their phenotypical immaturity, cytokine receptor expression, P-gp/MDR1 expression and clinical manifestations including the frequent occurrence in males and the poor prognosis. We propose that CD7(+) acute leukemia is an hematopoietic stem cell leukemia which may be separate entity.

Establishment of an undifferentiated leukemia cell line (Kasumi-3) with t(3;7)(q27;q22) and activation of the EVI1 gene

A novel human leukemia cell line (Kasumi-3) was established from the blast cells of a 57-year-old man suffering from myeloperoxidase-negative acute leukemia. The cell line had five distinctive features, as follows. 1) Flow cytometric analyses showed cell surface expression of CD7, CD4, CD13, CD33, CD34, HLA-DR and c-Kit. This phenotype is compatible with that of acute myelocytic leukemia cells with the M0 subtype in the French-American-British classification. 2) Kasumi-3 cells carried chromosomal abnormalities of t(3;7)(q27:q22), del(5)(q15), del(9)(q32), and add(12)(p11). The breakpoint of 3q27 was located near the EVI1 gene, and a high level of expression of the EVI1 gene was observed. 4) Kasumi-3 cells treated with TPA showed maturation to monocytic lineage. 5) Treatment with either interleukin (IL)-2, IL-3, IL-4, granulocyte-macrophage colony-stimulating or stem cell factor induced the proliferation of Kasumi-3 cells. Thus, the Kasumi-3 cell line shows the characteristic features of undifferentiated leukemia. It should, therefore, be useful both for studying the biological characteristics of acute myelogenous leukemia M0 subtype and for investigating the role of the EVI1 gene in leukemogenesis.

Changes in laminin content in livers of patients with alcoholic liver disease

An increase in serum laminin levels has been reported in patients with liver disease; however, the mechanisms for this increase have not yet been clarified. In the present study, the laminin content of liver biopsy specimens obtained from patients with alcoholic liver disease and non-alcoholic liver disease was determined with a one-step sandwich enzyme-immunoassay system, using monoclonal antibodies for human placental laminin. Hepatic laminin content was significantly higher in patients with liver disease than in normal controls. In alcoholic liver disease, the content in patients with mild fibrosis was lower than in patients with advanced types of alcoholic liver disease. In non-alcoholic liver disease, the hepatic laminin content tended to increase in parallel with the progression of fibrosis. The laminin content in alcoholic liver disease was significantly higher than in the corresponding type of non-alcoholic liver disease. The ratio of laminin to total collagen content was highest in alcoholic liver disease showing mild fibrosis and decreased in parallel with the progression of fibrosis. In contrast, the ratio was low in all types of nonalcoholic liver disease. The ratio in patients with alcoholic liver disease was significantly higher than these with the corresponding non-alcoholic liver disease. Hepatic laminin content increased in parallel with the increase in hepatic type IV collagen in alcoholic liver disease, and the correlation was statistically significant. However, similar correlation was not found in non-alcoholic liver disease. These results indicate that the response to laminin synthesis to alcoholic liver disease is strong in mild fibrosis and reached a plateau at a relatively early stage of fibrosis. The stimulation for laminin synthesis in non-alcoholic liver disease is different from that in alcoholic liver disease.

[Myelofibrosis complicated by T-cell lymphoma followed by leukemic transformation]

A 37-year-old man was admitted because of pancytopenia with leukoerythroblastosis and anisocytosis in January 1986. Bone marrow aspiration resulted in a dry tap and biopsy showed marked myelofibrosis. Three months after admission, generalized lymph node swelling and multiple skin tumors were recognized. A biopsied lymph node revealed lymphoblastic lymphoma. The surface markers of lymphoma cells showed an immature T-cell phenotype, whereas T-cell receptor beta and gamma chain genes showed germ line configuration. The patient was treated with combination chemotherapy in June 1986. A month later, he developed leukemic transformation with features of acute myelocytic leukemia and he died of pneumonia. Autopsy disclosed extramedullary hematopoiesis in the liver and spleen. Primary myelofibrosis complicated by T-cell lymphoma is extremely rare.

[Acute promyelocytic leukemia following ulcerative colitis]

We report a case of acute promyelocytic leukemia (APL) following ulcerative colitis (UC). A 23-year-old man was diagnosed as UC in January 1991 and had been treated with salazosulfapyridine and prednisolone with good effect. In September 1993, he developed bleeding tendency and a diagnosis of APL with disseminated intravascular coagulation was made based on the results of bone marrow aspiration and coagulation profile. Complete remission was achieved with All-trans retinoic acid together with combined chemotherapy. He died of sepsis during consolidation chemotherapy in December 1993. Autopsy revealed no recurrence of UC.

Acute myelomonocytic leukemia in a patient with multiple myeloma: evidence for different clonal origin

A case of 77-year-old female with multiple myeloma (IgG-k) developed acute myelomonocytic leukemia (AMMoL) following a myelodysplastic stage after chemotherapy with melphalancyclophosphamide combinations for 6 years. The leukemic blast cells expressed both myeloid antigens (CD11b, CD13, CD14, CD15, CD33 and CD34) and T/B lymphoid antigens (CD2, CD4, CD22 and PCA1). Cytogenetic analysis revealed a chromosome deletion -7. Analysis of immunoglobulin genes showed the heavy chain genes in germ line configuration. These findings indicate that the AMMoL was a therapy-related stem cell leukemia and was a clonal origin genetically different from multiple myeloma irrespective of plasma cell phenotype.

Induction of cell surface interleukin 2 receptor alpha chain expression on non-T lymphoid leukemia cells

We examined nine cases of adult non-T lymphoid leukemia to investigate the cell surface inducibility of interleukin 2 receptor alpha chain (IL-2R alpha) and beta chain (IL-2R beta) after in vitro culture with and without recombinant human interleukin-1 beta (rhIL-1 beta). Induction of IL-2R alpha was observed in four of six cases with precursor B-cell acute lymphoblastic leukemia (pre-B ALL) and in all of three cases with B-cell mature lymphoid neoplasm (two chronic lymphocytic leukemia and one leukemic phase of non-Hodgkin's lymphoma). All of the IL-2R alpha-inducible cases could express this spontaneously even without rhIL-1 beta, while IL-2R beta did not appear on leukemic cells from any of the cases tested. IL-2R alpha-inducible pre-B ALL cases displayed stem cell antigen CD34 and induced myeloid-associated antigen CD13 simultaneously. These results suggest that IL-2R alpha but not IL-2R beta is easily inducible in certain cases of mature B-cell lymphoid neoplasm and pre-B ALL with immature characteristics.

Differential expression of interleukin-2 receptors (alpha and beta chain) in mature lymphoid neoplasms

We investigated the expression of interleukin-2 receptors (IL-2R) in 60 adult patients with mature lymphoid neoplasms by flow cytometric analysis, using two monoclonal antibodies, anti-Tac for IL-2R alpha-chain (IL-2R alpha) and Mik-beta 1 for IL-2R beta-chain (IL-2R beta). Among B-cell malignancies, IL-2R alpha was found in 13/25 (52%) cases of chronic lymphocytic leukemia (CLL) and its variants, 3/14 (21%) of a heterogeneous group of non-Hodgkin's lymphoma (NHL) and none of the plasma cell diseases. IL-2R beta was not observed in any of B-cell neoplasms. IL-2R alpha was more frequently expressed in CD11b(+) B-cell neoplasms than in CD11b(-) (P < 0.05). In T-cell disorders, all three cases of adult T-cell leukemia/lymphoma expressed IL-2R alpha but not IL-2R beta. IL-2R beta was detected in 3/8 cases of CLL and 2/3 of NHL and none of these cases expressed IL-2R alpha. CD8(+) malignant T-cells commonly displayed IL-2R beta. These data indicate that the IL-2R alpha and IL-2R beta in mature lymphoid neoplasms was expressed independently each other and was associated with the particular phenotypical characteristics of neoplastic cells, respectively.

Induction of interleukin-2 receptor alpha chain expression of immature acute myelocytic leukemia cells

Leukemic cells from 27 adult patients with acute myelocytic leukemia (AML) were investigated to determine the cell surface inducibility of interleukin-2 receptor (IL-2R) in in vitro culture with and without interleukin-1 beta (IL-1 beta). IL-2R alpha chain (IL-2R alpha) was induced on leukemic cells in 11 of 27 cases. Most of the cases could induce IL-2R alpha spontaneously without IL-1 beta, while the IL-2R beta chain (IL-2R beta) did not appear on leukemic cells from any of the cases tested. AML cases expressing CD7 or HLA-DR antigen could induce IL-2R alpha more frequently than any other type of AML. Among interleukin-3 (IL-3), granulocyte-macrophage colony stimulating factor (GM-CSF) and G-CSF, IL-3 showed a more prominent effect on DNA synthesis in IL-2R alpha inducible cases than in its uninducible cases. These results suggest that IL-2R alpha but not IL-2R beta was easily inducible on AML cells with immature characteristics.

Quadruple cancers in a human T-cell leukemia virus type 1 carrier

Human T-cell leukemia virus type 1 (HTLV-1) infection is considered to contribute to the risk of malignancies other than adult T-cell leukemia. We report a 64-year-old male HTLV-1 carrier who developed quadruple malignancies such as cancer of the urinary bladder, skin, larynx and liver.

CD7, CD4 and myeloid antigen-positive acute lymphoblastic leukemia

We report a case of acute lymphoblastic leukemia (ALL, FAB-L2) with unique cellular characteristics. Leukemic cells were negative for various cytochemical stainings except acid phosphatase. Immunophenotypic studies revealed CD7+, CD4+, CD8-, CD2+, CD3-, CD13+, CD25+, CD33+ and CD34+. The immunoglobulin heavy chain and T-cell receptor beta, gamma and delta chain genes were germline configurations. This patient had a karyotype of complex abnormalities involving Nos. 5 and 7. Leukemic cells showed a prominent response to interleukin-3, granulocyte macrophage colony stimulating factor (GM-CSF) and G-CSF with partial granulocytic differentiation in a colony assay. A binding assay confirmed the presence of both high and low affinity receptors for GM-CSF. These findings suggest that CD7+CD4+CD8-CD3- putative T-cell precursors may retain the capacity to differentiate to myeloid lineage.

Clinical importance of CD7 expression in acute myelocytic leukemia. The Japan Cooperative Group of Leukemia/Lymphoma

Forty patients (9 females and 31 males; mean age 41.9 years) with CD7+ acute myelocytic leukemia (AML) were investigated; they were classified into the following subgroups according to French-American-British classification: 15 M1, 18 M2, 3 M4, and 4 M5. Leukemic cells from all the patients were negative for T-cell-specific antigens, surface CD3, and T-cell-receptor molecules. The sex and age distributions were different from those of CD7- AML patients (P < .01). Hepatomegaly and central nervous system involvement were also frequent in the CD7+ AML patients. The phenotype of and responsiveness to hematopoietic growth factors by the leukemic cells showed their immaturity, as evidenced by frequent expression of CD34, HLA-DR, and TdT, and the greatest growth response to interleukin-3. No particular karyotypic abnormality was shown. One hundred eighty AML patients were treated with a therapeutic regimen routinely used for AML. The CD7+ AML patients showed a significantly lower response than CD7- AML patients (P < .01), and had a poorer prognosis (P < .01). CD7+ AML patients with M1 or M5b had unfavorable responses to the therapeutic regimen in comparison with patients with M2, M4, or M5a. In addition, 3 of 4 CD7+ CD2+ AML patients, who did not respond to the therapy, were induced into complete remission with an acute lymphoblastic leukemia therapy. The results presented here indicate the diagnostic importance of CD7 positivity in AML, suggesting that the cellular and clinical characteristics of CD7+ AML are sufficient for it to be recognized as a distinct category of AML.

Studies on capillarization of the hepatic sinusoids in alcoholic liver disease

It has been reported that basement membranes were found around the sinusoidal walls in cirrhotic livers, indicating the development of capillarization of the sinusoids. It has been also emphasized that capillarization of the sinusoids is more prominent in alcoholic liver disease (ALD). In the present study, factor VIII related antigen (VIII-Ag) and UEA-1 were identified immunohistochemically in order to analyze capillarization of the sinusoids in chronic liver diseases. Electron microscopic studies on the endothelial cells and sinusoids were also performed. Electron microscopic studies revealed that the number of fenestra in the endothelial cells decreased and basement membranes were clearly observed in the space of Disse from an early stage of ALD. However, these changes were not observed in the early stage of non-ALD. VIII-Ag or UEA-1 was not stainable in the sinusoidal cells of normal livers or at an early stage of non-ALD. However, in ALD, both VIII-Ag and UEA-1 were clearly demonstrated in the sinusoidal cells from the early stage of fibrosis. These results suggest that the sinusoidal endothelial cells may transform to vascular endothelial cells from an early stage of ALD. The alterations in the sinusoidal endothelium and the basement membrane formation in the Disse space indicate that capillarization of the sinusoid may occur. Capillarization of the sinusoid may cause a disturbance in exchanges of many bioactive substances between the sinusoidal blood and hepatocytes across the Disse space and may thereby contribute to the pathogenesis of ALD.

Type IV collagen and laminin contents of livers from patients with alcoholic liver disease

Characteristic histological features of alcoholic liver disease (ALD) are pericellular and perivenular fibrosis. It has been emphasized from immunohistochemical studies that pericellular and perivenular fibrosis may be caused by the increase of type IV collagen (IV-C) and/or laminin (LM). However, quantitative changes of hepatic IV-C and LM contents in ALD are not well known. Recently, we have developed assay systems for IV-C and LM contents in liver biopsy specimens. In the present study, hepatic IV-C and LM contents in ALD and non-ALD patients were measured. Liver biopsy specimens were obtained from 36 patients with ALD, 24 patients with non-ALD and five patients without liver disease. IV-C and LM contents in liver biopsy specimens were measured using the one-step sandwich enzyme immunoassay system for human serum IV-C and LM levels. Total collagen (T-C) content was also measured by the method of Leon and Rojkind. Hepatic IV-C, LM and T-C contents were significantly higher in all types of liver disease than in controls, and tended to increase with the progression of fibrosis. Especially in ALD, both IV-C and LM contents increased from the early stage, and the values in each type of ALD were significantly higher than those in the corresponding type of non-ALD. The ratio of IV-C or LM to T-C was also significantly higher in ALD than in the corresponding non-ALD. The prominent increases of IV-C and LM at the early stage of fibrosis may be one of the characteristics of collagen metabolism in ALD.(ABSTRACT TRUNCATED AT 250 WORDS)

Interleukin-2 receptor alpha chain on acute myelocytic leukemia cells is involved in cell-to-cell interactions

Leukemic cells from 21 to 197 adult patients with de novo acute myelocytic leukemia (AML) were positive for IL-2R alpha chain (IL-2R alpha), whereas IL-2R beta chain (IL-2R beta), which is responsible for IL-2 signal transduction, was not found on leukemic cells from any of these cases tested. The expression of IL-2R alpha was closely associated with that of adhesion molecules CD4, CD11b and CD22, and endopeptidase CD10. None of the IL-2R alpha (+) AML cells responded to recombinant human IL-2. These data suggest that IL-2R alpha on AML cells may not be involved in cellular proliferation as one of growth factor receptors but may have a role in the control of cell-to-cell interactions.

Phenotypical characteristics of acute myelocytic leukemia associated with the t(8;21)(q22;q22) chromosomal abnormality: frequent expression of immature B-cell antigen CD19 together with stem cell antigen CD34

Twenty-three acute myelocytic leukemia (AML) patients with t(8;21) chromosomal abnormality, all classified as M2 (French-American-British [FAB] classification), were investigated. Blastic cells from all patients were positive for the stem cell-associated antigens, CD34 and HLA-DR, and the immature myeloid antigens, CD13 and CD33. The nonblastic leukemic cells expressed the more mature myeloid antigens, CD11b and CD15, with loss of the immature phenotype. The incidence of positivities for the stem cell-associated antigens, CD34 and HLA-DR, in t(8;21) AML cells was significantly higher in comparison with those in other AML showing granulocytic differentiation (M2 or M3). AML cells with t(8;21) also showed some phenotypic abnormalities. Frequent expression of CD19 was found in the blastic population of t(8;21) AML (18 of 23 cases) without other B-cell antigens and Ig gene rearrangements. CD19 expression was confirmed by immunocytochemistry and Northern blotting. The CD19+ blastic cells coexpressed both CD34 and HLA-DR. In addition, CD33+ cells among the blastic fraction in t(8;21) AML cells were fewer in number than in those of M2 or M3 AML without t(8;21). Our findings indicate that leukemic blasts of t(8;21) AML commonly express CD19 while preserving the stem cell-associated antigens, and differentiate into the granulocytic pathway with discordant maturation such as low CD33 expression.

c-kit gene expression in CD7-positive acute lymphoblastic leukemia: close correlation with expression of myeloid-associated antigen CD13

Expression of human c-kit proto-oncogene and interleukin-7 receptor (IL-7R) in acute lymphoblastic leukemia (ALL) cells expressing CD7 was examined by Northern-blot analysis and reversed transcription polymerase chain reaction (RT-PCR) assay in relation to the phenotypes. Leukemic cells from four out of 12 CD7+ ALL patients, all of which fulfilled the criteria of ALL in the FAB classification, expressed c-kit genes. Surface CD3 (sCD3) was absent in all of these cases, while cytoplasmic CD3 (cCD3) was found in the two sCD3- cases. CD3 epsilon transcripts were detected in one of the sCD3- cCD3- cases. IL-7R genes were transcribed in the three cases with c-kit gene expression. In addition, there was a good correlation between c-kit gene expression and myeloid associated antigen CD13 positivity of the leukemic cells. None of the patients with c-kit gene expression had mediastinal tumor. Our results show that leukemic cells in a proportion of CD7+ ALL express receptors for cytokines that are secreted by bone marrow stromal cells. Ligands for c-kit genes and IL-7 could play an important role for the regulation of proliferation and differentiation of T-cell progenitors in bone marrow.