Disease-stabilizing treatment with all-trans retinoic acid and valproic acid in acute myeloid leukemia: serum hsp70 and hsp90 levels and serum cytokine profiles are determined by the disease, patient age, and anti-leukemic treatment

Heat shock protein (HSP) 70 and HSP90 are released by primary human acute myeloid leukemia (AML) cells during stress-induced spontaneous in vitro apoptosis. The AML cells also show constitutive release of several cytokines and the systemic serum levels of several soluble mediators are altered in patients with untreated AML. In the present study, we have investigated serum levels of HSP70/HSP90 and the serum cytokine profiles of patients with untreated AML and patients receiving AML-stabilizing palliative treatment based on all-trans retinoic acid (ATRA) plus valproic acid. Patients with untreated AML showed increased HSP90 levels and a distinct serum cytokine profile when compared with healthy controls, and low pre-therapy HSP90 levels were associated with a prolonged survival during treatment with ATRA + valproic acid + theophyllin. Hierarchical cluster analysis showed a close association between HSP70, HSP90, IL-1 receptor antagonist (IL-1ra), and hepatocyte growth factor (HGF) levels. Furthermore, disease-stabilizing therapy altered the serum-cytokine profile, but the correlations between HSP70/HSP90/IL-1ra/HGF were maintained only when ATRA + valproic acid were combined with theophyllin but not when combined with cytarabine. We conclude that both HSP levels and serum cytokine profiles are altered and may represent possible therapeutic targets or prognostic markers in human AML.

[Presence of B cell clones in acute myelomonocytic leukemia]

The coexistence of acute myeloid leukemia and chronic lymphocytic leukemia in the same patient is rare. The majority of the cases correspond to patients that developed acute leukemia during the evolutionary course of a chronic lymphatic leukemia following treatment with chemotherapy drugs. We report a case of acute myelomonocytic leukemia concurrent with untreated B-cell chronic lymphocytic leukemia in which the use of flow cytometry analysis with a large panel of monoclonal antibodies, allowed the demonstration of different pathological populations and determine immunophenotyping patterns. Published cases of simultaneous chronic lymphocytic leukemia and acute leukemia are reviewed. The use of multiparametric flow cytometry to differentiate the populations demonstrates the utility of this technology in the diagnosis of these hematological malignancies.

Comparative analysis of genes regulated in acute myelomonocytic leukemia with and without inv(16)(p13q22) using microarray techniques, real-time PCR, immunohistochemistry, and flow cytometry immunophenotyping

Acute myeloid leukemia with inv(16)(p13q22), also known as M4Eo, is a distinct type of leukemia with characteristic clinicopathologic and cytogenetic features. Patients with M4Eo have monocytosis, high blast counts, and abnormal bone marrow eosinophils that contain large basophilic granules. The inv(16)(p13q22) or, less commonly, the t(16;16)(p13;q22) causes fusion of the CBFbeta gene at 16q22 and the MYH11 gene at 16p13, creating the novel chimeric protein CBFbeta-MYH11. To understand the underlying molecular mechanisms unique to M4Eo biology, we determined the gene expression profile of M4Eo cases by using cDNA and long oligonucleotide microarrays. Cases of acute myelomonocytic leukemia without CBFbeta-MYH11 (M4) acted as our control. We found that in the gene expression profile of M4Eo, NF-kappaB activators and inhibitors were upregulated and downregulated, respectively, suggesting that the NF-kappaB signaling pathway is activated at a higher level in M4Eo than in acute myelomonocytic leukemia M4. In addition, the gene expression profile of M4Eo indicates high cell proliferation and low apoptosis. We used real-time PCR, immunohistochemistry, and flow cytometry immunophenotyping to confirm some of our microarray data. These findings most likely represent the functional consequences of the abnormal chimeric protein CBFbeta-MYH11, which is unique to this disease, and suggest that NF-kappaB is a potential therapeutic target for treating M4Eo patients.

[Depressing the immune escape of acute myelomonocytic leukemia via an anti-Fas ribozyme]

In order to investigate the inhibition role of anti-Fas hammerhead ribozyme on Fas expression and Fas-mediated apoptosis in CTLL-2 cells (mouse CTL cell line), and to explore a new way for enhancing the ability of T cells against Leukemia in donor lymphocytes infusion, CTLL-2 cells were transfected with pEGFP-RZ596 and pEGFPC1 (mock-transfected) via electroporation. Fas expression on CTLL-2 cells was detected by RT-PCR and Western blot. The killing effect of CTL against WEHI-3 (mouse acute myelomonocytic leukemia cell line) highly expressing FasL in vitro was detected by MTT assay. The caspase-3 proteolytic activity and the apoptosis rate of CTLL-2 cells were detected by means of BD AproAlert Caspase-3 Colorimetric kit and FITC labeled Annexin-V apoptosis detecting kit respectively. The results showed that the anti-Fas ribozyme could be successfully introduced into mouse CTLL-2 cells; Fas expression on the surface of cells transfected with the ribozyme was obviously decreased, in comparison with control and mock-transfected cells; after cocultured with WEHI-3 cells, the viability of CTLL-2 cells transfeced with the ribozyme was significantly increased, as compared with other two groups; caspase-3 activity and apoptosis rate of the ribozyme-transfeced cells were significantly decreased, the killing effect of CTLL-2 transfected with the ribozyme was stronger than that of other groups. It is concluded that anti-Fas ribozyme can remarkably decrease Fas expression on CTLL-2 cells, so as to avoid Fas-mediated apoptosis by Fas ligand on WEHI-3 cells, and to enhance their killing activity against WEHI-3 cells, as a result, the immune escape of acute myelomonocytic leukemia was depressed.

[Immunophenotypic and cytogenetic features of acute myelomonocytic leukemia]

BACKGROUND & OBJECTIVE

The expression of some antigens has been involved in cytogenetic abnormalities in leukemia. This study was to explore the immunophenotypes of acute myelomonocytic leukemia (M4), analyze the correlation of M4 to cytogenetic abnormalities, and provide evidences for the diagnosis and therapy.

METHODS

Immunophenotypic analysis was performed using a panel of monoclonal antibodies and three-color immunofluorescent staining methods of flow cytometry in 81 patients with M4 leukemia. Cytogenetic records of 73 patients were available, among which 35 were further investigated by dual-color interphase fluorescent in situ hybridization (FISH) and the immunophenotype of inv(16)-positive patients were analyzed.

RESULTS

Among the 81 M4 leukemia patients, CD33 (84.0%) was the most commonly expressed antigen, followed by CD13 (81.5%) and CD14 (24.7%). CD34 was detected in 48 (59.3%) patients. T lymphoid-and B lymphoid-associated antigens were expressed in 23 (28.4%) and 10 (12.3%) patients, respectively. All the 11 patients with M4Eo had CD13 expression. CD33, CD34, and CD2 were expressed in 10, 7, and 5 patients, respectively. Of the 14 patients with inv(16), 13 expressed CD13, 11 expressed CD33, 8 expressed CD34, 5 expressed CD14, 3 expressed CD7, and 3 expressed CD2. Of the 73 patients with cytogenetic records, 30 (41.1%) had clonal chromosomal abnormalities. The expression of CD2 and CD34 was associated with karyotypic abnormalities. The expression of CD2 was higher in M4Eo patients, with no correlation to inv(16).

CONCLUSIONS

Acute myelomonocytic leukemia mainly expresses myeloid lineage antigens. The expression of CD2 and CD34 is correlated to karyotypic abnormalities. The expression of CD2 is higher in M4Eo. Inv(16) exists in 40% of M4 patients and the expression of all the antigens has no correlation to inv(16).

Identification of an immunogenic CD8+ T-cell epitope derived from gamma-globin, a putative tumor-associated antigen for juvenile myelomonocytic leukemia

Juvenile myelomonocytic leukemia (JMML) is a rare clonal myeloproliferative disorder. Although allogeneic stem cell transplantation can induce long-term remissions, relapse rates remain high and innovative approaches are needed. Since donor lymphocyte infusions have clinical activity in JMML, T-cell-mediated immunotherapy could provide a nonredundant treatment approach to compliment current therapies. Gamma-globin, an oncofetal protein overexpressed by clonogenic JMML cells, may serve as a target of an antitumor immune response. We predicted 5 gamma-globin-derived peptides as potential human leukocyte antigen (HLA)-A2 restricted cytotoxic T lymphocyte (CTL) epitopes and showed that 4 (g031, g071, g105, and g106) bind A2 molecules in vitro. Using an artificial antigen-presenting cell (aAPC) that can process both the N- and C-termini of endogenously expressed proteins, we biochemically confirmed that g105 is naturally processed and presented by cell surface A2. Furthermore, g105-specific CD8(+) CTLs generated from A2-positive healthy donors were able to specifically cytolyze gamma-globin(+), but not gamma-globin(-) JMML cells in an A2-restricted manner. These results suggest that this aAPC-based approach enables the biochemical identification of CD8(+) T-cell epitopes that are processed and presented by intact cells, and that CTL immunotherapy of JMML could be directed against the gamma-globin-derived epitope g105.

Human CD34+ cells expressing the inv(16) fusion protein exhibit a myelomonocytic phenotype with greatly enhanced proliferative ability

The t(16:16) and inv(16) are associated with FAB M4Eo myeloid leukemias and result in fusion of the CBFB gene to the MYH11 gene (encoding smooth muscle myosin heavy chain [SMMHC]). Knockout of CBFbeta causes embryonic lethality due to lack of definitive hematopoiesis. Although knock-in of CBFB-MYH11 is not sufficient to cause disease, expression increases the incidence of leukemia when combined with cooperating events. Although mouse models are valuable tools in the study of leukemogenesis, little is known about the contribution of CBFbeta-SMMHC to human hematopoietic stem and progenitor cell self-renewal. We introduced the CBFbeta-MYH11 cDNA into human CD34+ cells via retroviral transduction. Transduced cells displayed an initial repression of progenitor activity but eventually dominated the culture, resulting in the proliferation of clonal populations for up to 7 months. Long-term cultures displayed a myelomonocytic morphology while retaining multilineage progenitor activity and engraftment in NOD/SCID-B2M-/- mice. Progenitor cells from long-term cultures showed altered expression of genes defining inv(16) identified in microarray studies of human patient samples. This system will be useful in examining the effects of CBFbeta-SMMHC on gene expression in the human preleukemic cell, in characterizing the effect of this oncogene on human stem cell biology, and in defining its contribution to the development of leukemia.

Treatment of Refractory CMV-Infection Following Hematopoietic Stem Cell Transplantation with the Combination of Foscarnet and Leflunomide

BACKGROUND

Treatment of cytomegalovirus (CMV) disease after allogeneic hematopoietic stem cell transplantation (HSCT) is limited by toxicities of current antiviral drugs and the occurrence of drug resistant strains. Leflunomide, an immunosuppressive agent used for treatment of rheumatoid arthritis, also has activity against CMV by impairing viral assembly. Here we report the control of refractory CMV disease by the combined use of foscarnet and leflunomide.

PATIENTS AND RESULTS

A 1S-year-old boy with juvenile myelo-monocytic leukemia (JMML) received an allogeneic HSCT with bone marrow stem cells from a mismatched, unrelated donor (MMUD, recipient and donor CMV-positive). CMV-reactivation two months post transplantation (Tx) could only be controlled by the use of cidofovir. Because of secondary graft failure, the boy received a second HSCT with peripheral blood stem cells (PBSC) of the same donor after overall 6 months. CMV-infection was noticed three weeks later, associated with a considerable rise of both CMV-copy number and pp65-antigen. Since reinduction with cidofovir was ineffective and ganciclovir not warranted due to the history of graft failure, the child then received a combination of foscarnet/leflunomide, leading to a rapid decline of his CMV-copy number and to an afebrile state. Hematological, hepatic or renal toxicities were not observed.

CONCLUSION

This case report suggests that leflunomide may be of use in the management of transplant recipients with CMV-infection refractory or intolerant to conventional antiviral therapy.

Standard induction chemotherapy followed by attenuated consolidation in elderly patients with acute myeloid leukemia

The benefits of intensive post-remission chemotherapy have not been verified in elderly patients with acute myeloid leukemia (AML). To reduce fatal complications caused by intensive post-remission therapy, we performed a prospective phase II multicenter trial of standard induction chemotherapy ('7+3' of cytarabine plus daunorubicin), followed by two cycles of attenuated consolidation therapy ('5+1' of cytarabine plus daunorubicin) for elderly patients with AML, excluding those with M3. Of the 41 patients enrolled in the study, 24 (58.5%) attained CR. Of these 24, 17 (70.8%) completed both planned cycles of consolidation therapy. After a median follow-up of 566 days (range, 63-1190 days) among surviving patients, 15 relapsed, with an actuarial 3-year disease-free survival rate of 22.5%. There were no fatal complications during consolidation therapy. Actuarial 3-year overall survival was 17.0%. These findings suggest that, when compared with previous findings using more intensive consolidation therapy, attenuated consolidation therapy does not compromise outcomes in elderly AML patients.

Vaccination with leukemia cells expressing cell-surface-associated GM-CSF blocks leukemia induction in immunocompetent mice

The fundamental basis for immunotherapy of leukemia is that leukemic cells express specific antigens that are not expressed by normal hematopoietic cells. However, the host immune system appears to be tolerant to leukemia cells. To overcome this tolerance, we vaccinated immunocompetent mice with murine leukemia cells (WEHI-3B and BCR-ABL+ 32D cells) transduced with a specifically constructed transmembrane form of granulocyte-macrophage colony-stimulating factor (tmGM-CSF). The transduced cells expressed tmGM-CSF on the cell-surface. To determine whether tmGM-CSF-expressing WEHI-3B leukemia cells would prevent leukemia formation as a vaccine, immunocompetent mice (BALB/c and C3H/HEJ) were immunized with lethally irradiated murine leukemia cells expressing cell-surface tmGM-CSF before challenging mice with murine leukemia cells. Two immunocompetent mouse models were investigated, either WEHI-3B cells in BALB/c mice or BCR-ABL+ 32D cells in C3H/HEJ mouse. The results showed that 100% of WEHI-3B/tmGM-CSF-vaccinated BALB/c mice and about 65% of 32D+ BCR-ABL/tmGM-CSF-vaccinated C3H/HEJ mice were protected from leukemia after leukemia cell challenge, whereas all non-vaccinated mice succumbed to leukemia. Spleen and marrow cell suspensions from vaccinated mice challenged with WEHI-3B cells lacked detectable GFP+ WEHI-3B cells at 82 days post-challenge. A significant delay of death was observed in C3H/HEJ mice challenged with the very aggressive DA-1 cell line expressing BCR-ABL. Vaccination of mice with WEHI-3B/CD40L cells protected 80% of the mice from the WEHI-3B challenge. Notably, 60% of the WEHI-3B/BALB/c mice were also protected from leukemia when WEHI-3B/tmGM-CSF vaccination was carried out after the leukemia challenge. In order to determine whether cellular immunity is involved in this vaccine-mediated protection, either CD4+ or CD8+ T cells were depleted from mice after the WEHI-3B/tmGM-CSF vaccination. The results indicate that CD8+ T-cells mediated the protective immune response provided by the irradiated tmGM-CSF-expressing WEHI-3B cells. In addition, vaccination of nude mice did not provide protection from WEHI-3B leukemia induction. Importantly, 80% of non-vaccinated mice were also protected from a WEHI-3B cell challenge after receiving spleen cells from vaccinated mice 1 day before challenge with leukemia cells. These results indicate that overexpression of tmGM-CSF on the leukemia cell-surface can enhance the recognition of leukemic cells by CD8+ T cells, and can either prevent or significantly delay leukemia induction. These findings suggest that injection of irradiated leukemia cells expressing cell-surface-bound GM-CSF has the potential as an immunological approach to treat leukemia.

[Blocking the escape of leukemic cells from killing of T cell by combining anti-Fas ribozyme and CD80-IgG fusion protein]

OBJECTIVE

To study Fas expression regulation of cytotoxic T lymphocyte(CTL)via anti-Fas ribozyme, increasing of CD80 epitope on the surface of acute myelomonocytic leukemia cells by CD80-IgG fusion protein and their effects on the apoptosis and killing ability against acute myelomonocytic leukemia cells of CTL.

METHODS

A hammerhead ribozyme gene targeting the Fas mRNA was synthesized and its expression vector pEGFP-RZ596 was constructed and transfected into the mouse spleen T cells via electroporation. The Fas expression on T cells was detected by RT-PCR and Western bloting. In the meantime the eukaryotic expression vector pcDNA/CD80-IgG was constructed by gene recombinant technique and transfected into ovarian cells of hamster of the line CHO. The CD80-IgG fusion protein was purified from the supernatant of G418-selected CHO cells by Protein G affinity chromatography method. Then allogeneic mixed lymphocytes culture between the mouse spleen T cells transfected with pEGFP-RZ596 and WEHI-3 cells (mouse acute myelomonocyte leukemia cell line) incubated with CD80-IgG fusion protein was performed. The apoptosis rate of the T cells was detected with annexin V-FITC. The proliferation and killing ability in vitro against WEHI-3 cells of the T cells were detected by MTT colorimetry.

RESULTS

The luminance of Fas Western bloting results from the mouse spleen T cells negative control, transfected with pEGFPC1 and transfected with pEGFP-RZ596 were separately 1, 0.98 and 0.45 (P < 0.01). After being cocultured with WEHI-3 cells, which has higher expression of Fas ligand (64% +/- 3%), the apoptosis rate and the killing ability against WEHI-3 cells of the mouse spleen T cells transfected with pEGFP-RZ596 were separately 37% and 67%. Whereas that of the mouse spleen T cells negative control and transfected with pEGFPC1 were separately 88%, 84% (P < 0.01) and 32%, 31% (P <0.01). The CD80 positive expression rate of WEHI-3 cells was upregulated from 5.1% +/- 0.4% to 27.4% +/- 2.2% after these cells were preincubated with CD80-IgG fusion protein (P < 0.01). The killing ability of the mouse spleen T cells against WEHI-3 cells preincubated and not preincubated with CD80-IgG fusion protein were separately 64% and 49% (P <0.01), but that of the mouse spleen T cells, which were transfected with pEGFP-RZ596, was further promoted to 82% (P < 0.01)

CONCLUSION

The apoptosis of mouse CTL inducing by FasL-Fas pathway could be avoided and the killing ability of mouse CTL against WEHI-3 cells can be significantly promoted at the same time by combining anti-Fas ribozyme and CD80-IgG fusion protein.

[Correlation of immunophenotype to cytogenetics and clinical features of adult acute myeloid leukemia]

BACKGROUND & OBJECTIVE

New WHO classification has been rapidly used in diagnosis of leukemia. Based on coexpression and correlation of lineage-associated antigens, multiparameter high-resolution flow cytometry has been developed to precisely identify lineage characteristics of leukemia. Some immunophenotypes correlate with cytogenetic abnormality and prognosis. This study was to analyze immunophenotype of naive acute myeloid leukemia (AML), and explore its correlations to cytogenetics, clinical features, and FAB subtype of AML.

METHODS

Multiparameter high-resolution flow cytometry with a panel of 25 different monoclonal antibodies was used to analyze the surface and cytoplasmic antigens expressions of 96 adults with AML; G-binding technique was used to analyze karyotype of 73 of the 96 patients.

RESULTS

In these AML patients, some antigens were correlated with FAB subtypes:expression of CD2 was enhanced in AML-M3; HLA-DR, CD34, and CD56 were absent in AML-M3; expression of CD19 was increased in AML-M2; expressions of CD14 and CD56 were enhanced in AML-M5; MPO was absent in AML-M0. Karyotype abnormality was detected in 40(54.8%) patients. CD22, CD56, and TdT expressions were correlated with karyotype abnormality. t(8; 21) was only detected in 10 AML-M2 patients with high expressions of CD15, CD19, CD34, and CD56; no lymphoid lineage antigens were detected in 7 AML-M3 patients with t (15; 17). Expressions of CD4 and TdT were positively correlated with patient's age; expressions of CD7 and CD14 were positively correlated with high white blood cell count; expressions of CD4, CD14, and CD56 were positively correlated with high platelet count.

CONCLUSIONS

The abnormal antigen expression of AML is tightly linked with karyotype abnormality. Detection of immunophenotype may help to diagnose and classify AML.

Impact of trisomy 8 on cytobiological and clinical features of acute myelomonocytic and monocytic leukemia

To evaluate the impact of trisomy 8 on cytobiological and clinical features of acute myelomonocytic and monocytic leukemia (M(4), M(5)), a total of 56 cases of acute myelomonocytic and monocytic leukemia were investigated. Karyotypes were analyzed by G-banding or R-banding. The immunotypes in all cases were detected by flow cytometry. And the clinical characteristics at the first visit were analyzed retrospectively. The results showed that thirty-four of 56 (60.7%) patients had normal cytogenetics; 10 (17.9%) patients had trisomy 8 in their karyotypes, including 3 (5.4%) patients with trisomy 8 as the sole aberration; and 12 (21.4%) patents had other cytogenetic abnormalities (except trisomy 8). All trisomy 8 cases demonstrated a increased expression frequency of surface markers of myeloid progenitor cells CD34 (P < 0.01) and CD117 (P < 0.05) and a decreased expression frequency of surface markers of mature monocytes CD11c (P < 0.01) and CD14 (P < 0.05), compared with normal cytogenetics cases. Patients with trisomy 8 were slightly older (P < 0.05), which had lower percentages of peripheral blasts (P < 0.05) and lower WBC (P < 0.05) than the patients without trisomy 8. Patients with trisomy 8 had a shorter disease-free survival time than that of patients with normal cytogenetics (P < 0.05). It is concluded that trisomy 8 may play an important role in the pathogenesis and progression of acute myelomonocytic/monocytic leukemia (M(4)/M(5)), whic seems to be related with a block in differentiation of monocytes. Therefore, trisomy 8 may be an adverse prognostic factor for patients with M(4) or M(5).

[Clinical study on anti-leukemia effect mediated by dentritic cells]

Immunotherapy of tumor is extensively attentioned as an important part of combined therapy of tumor in recent years. Dendritic cell (DC) is the most powerful antigen presenting cell (APC) by now which not only activates auto-immunity to attack tumor cells, but also does help to enhance antitumor effect for allogenic bodies. To explore the feasibility and safety of clinical therapy application of peripheral blood derived DC cultured ex vivo, and analyze the influence of DC-inducing-immunotherapy upon long-term survival of ANLL patients accepted autologous bone marrow transplantation, peripheral blood mononuclear cells (PBMNC) of 13 ANLL patients after autologous bone marrow transplantation were collected by using CS3000Plus. DC immunotherapy was administered after cultivation of PBMNC ex vivo for 2 weeks, desease-free survival time was observed after therapy for long time follow-up. The results showed that no any severe adverse event associated with DC therapy was observed, the survival analysis of Kaplan-Meier suggested that five year survival rate was 75.52% in DC group while 45.71% in non-DC group. DC group surpassed non-DC group in accumulative survival rate. It is concluded that the ex vivo cultivation and clinical therapy application of DC derived from peripheral blood are feasible and safe, DC immunotherapy in patients with acute non-lymphocytic leukemia after autologous bone marrow transplantation prolongs desease-free survival time and enhances long-term survival rate.

Chimaerism analyses and subsequent immunological intervention after stem cell transplantation in patients with juvenile myelomonocytic leukaemia

Chimaerism analysis was performed by polymerase chain reaction amplification of short-tandem repeat markers in 30 children following haematopoietic stem cell transplantation for juvenile myelomonocytic leukaemia (JMML). Fourteen patients always had complete chimaerism (CC); one of them relapsed after the discontinuation of the study and 13 continued in complete remission (CR). Mixed chimaerism (MC) was noted in 16 patients. Of those 12 patients demonstrated increasing MC (i-MC); 10 relapsed and two achieved CC following discontinuation of immunosuppressive therapy (IST). Four other patients demonstrating only transient MC are alive in CR. MC with up to 20% of autologous cells could be successfully eradicated without induction of severe graft-versus-host disease when IST was reduced or discontinued directly after the first demonstration of MC. At the same time, MC with up to 10% of autologous cells could disappear without intervention. The interval between MC and relapse ranged from 0-320 d (median 38 d). Donor leucocyte infusion was given to six patients with i-MC, but only one patient responded. Peripheral blood seems as valuable as bone marrow for chimaerism studies. In conclusion, serial quantitative chimaerism studies can identify patients with i-MC who are at high risk for relapse of JMML. Immediate withdrawal of IST is advised in these patients.

Monitoring of acute myeloid leukemia by flow cytometry

Monitoring of minimal residual disease (MRD) becomes increasingly important in the risk-adapted management of patients with acute myeloid leukemia (AML). In selected patients with AML, multiparameter flow cytometry has shown accuracy and sensitivity in the quantification of MRD levels with independent prognostic impact. The applicability of this approach is superior to that of other methods such as quantitative polymerase chain reaction: Up to 80% of all patients can be monitored by flow cytometry. Nonetheless, significant technical advances are anticipated to extend the applicability of flow cytometry to 100% and to improve its sensitivity. Large clinical trials will determine the role of immunologic monitoring in the prognostic stratification of patients with AML.

Soluble CD163: a marker molecule for monocyte/macrophage activity in disease

By immunoprecipitation we have identified a soluble plasma form of CD163 (sCD163), the IL-6 inducible macrophage-receptor for clearing haptoglobin-haemoglobin complexes. A sandwich ELISA for measuring sCD163 was established and used to determine the sCD163 levels in normal subjects and patients with inflammatory and myeloproliferative diseases. In normal subjects, the concentration of sCD163 was high (median 1.9 mg/l) with low intra-individual variation. Highly increased levels were seen in patients with sepsis, myeloid leukaemia and in patients with Gaucher disease characterized by accumulation of tissue macrophages. Although the physiological role of sCD163 remains unknown, our present data suggest that sCD163 might prove to be a valuable marker molecule in infectious and myeloproliferative diseases.

[Experimental study on activating antileukemic T cells by vaccination with dendritic cells pulsed with survivin]

The objective of this study is to investigate the effect of vaccination with dendritic cells pulsed with survivin antigen on activation of antileukemic T cells, and inhibiting proliferation of leukemic cells. The expression of survivin on acute leukemic cells were detected by cofocal microscopy and immunoprecipitation-Western blot. DCs collected from peripheral blood mononuclear cells were pulsed with survivin purified proteins. Stimulation index (SI) and antileukemia CTL induction were analyzed with (3)H-TdR incorporation and (51)Cr releasing assay, respectively. The phenotype of T cells and DCs were identified by flow cytometry. By immunofluorescence of bone marrow and peripheral blood mononuclear cells, survivin expression was detected in 16 out of 19 AML cases (84.2%). The results showed that survivin fluorescence distribution was in cytoplasm. DCs from peripheral blood mononuclear cells were successfully induced, with typical DC morphologic characteristic. The vaccination with dendritic cells pulsed with survivin antigen dramatically stimulated the proliferation of T cells. The DCs loading survivin activated T cells with higher CD4(+) T(H) ratio as compared with DCs group, T cells activated with DCs expressed CD8 and CD56. Survivin DCs significantly inhibited the growth of leukemic cells in vitro. In conclusion, survivin antigen expressed in the cytoplasm of leukemic cells, leukemic vaccination with DCs pulsed with survivin antigen in vitro inhibited the proliferation of leukemic cells, that may be a pathway for therapy of leukemia.

Use of polymerase chain reaction for diagnosis of disseminated adenovirus infection

We report a fatal case of disseminated adenovirus infection with fulminant hepatic failure in an 8-month-old child after peripheral blood stem cell transplantation. The virus was identified in blood, urine, respiratory aspirate and stool samples and was typed as adenovirus type 2 through PCR and sequencing of part of the hexon gene, with the use of degenerated consensus primers.

TRAIL expression by activated human CD4(+)V alpha 24NKT cells induces in vitro and in vivo apoptosis of human acute myeloid leukemia cells

Human Valpha24NKT cells are activated by alpha-galactosylceramide (alpha-GalCer)-pulsed dendritic cells in a CD1d-dependent and a T-cell receptor-mediated manner. Here, we demonstrate that CD4(+)V alpha 24NKT cells derived from a patient with acute myeloid leukemia (AML) M4 are phenotypically similar to those of healthy donors and, in common with those derived from healthy donors, express tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) when the cells are activated by alpha-GalCer-pulsed dendritic cells but not prior to activation. We also show that myeloid leukemia cells from patients with AML M4, but not from patients with AML M0 or M1, undergo apoptosis following culture with TRAIL-expressing autologous or allogeneic healthy donor V alpha 24NKT cells. Apoptosis of AML M4 leukemia cells from patient peripheral blood was almost completely blocked by a neutralizing monoclonal antibody against TRAIL, indicating that TRAIL on V alpha 24NKT cells is essential for the induction of apoptosis in AML M4 leukemia cells. A nonobese diabetic-severe combined immunodeficient human leukemia (AML M4) model showed that human activated CD4(+)V alpha 24NKT cells induced apoptosis of human leukemia cells in vivo. This is the first evidence that activated V alpha 24NKT cells express TRAIL and that TRAIL causes apoptosis of monocytic leukemia cells from patients with AML M4 in vitro and in vivo. Adoptive immune therapy with activated V alpha 24NKT cells, or other strategies to increase activated V alpha 24NKT cells in vivo, may be of benefit to patients with AML M4. (Blood. 2001;97:2067-2074)

The efficient generation of CD83 positive immunocompetent dendritic cells from CD14 positive acute myelomonocytic or monocytic leukemia cells in vitro

The ability of leukemic cells to differentiate to mature dendritic cells (DCs) was investigated in six acute myelomonocytic or monocytic leukemia cases. It was found that CD14 positive cells were more efficiently changed to CD83 positive mature typed DCs with granulocyte-macrophage colony-stimulating factor (GM-CSF)/interleukin-4 (IL-4) and tumor necrosis factor alpha (TNF-alpha) compared with CD14 negative cells. Such leukemia derived DCs expressed a sufficient level of costimulatory molecules (CD80 and CD86), and were shown to be monoclonal based on an the X-inactivation analysis. They also stimulated not only allo- but auto-T lymphocytes, which thereafter became cytotoxic T lymphocytes (CTLs).

Myeloid leukemic cells express and secrete bioactive pituitary-sized 23 kDa prolactin

Prolactin (PRL) is a 23 kDa polypeptide hormone of pituitary origin which is of major importance for reproduction. In addition, PRL has immunomodulatory effects and can be produced in small quantities in nonpituitary tissues. To address possible autocrine or paracrine functions of PRL in leukemia, we characterized immunoreactive PRL from the culture medium of leukemic cells. The myeloid cell line Eol-1 expresses the long extrapituitary type mRNA for PRL and synthesizes immunoreactive PRL with a molecular weight of 23 kDa. The biological activity in Eol-1 culture medium was determined using the Nb2 bioassay. This activity co-eluted with recombinant human (rh) PRL on an S-200 Sephacryl gel filtration column and could be blocked by anti-PRL antiserum. Western blot analysis and Nb2 bioassays also suggest that acute myelogenous leukemic blasts secrete bioactive 23 kDa PRL in one out of three tested patients.

Generation of the NUP98-HOXD13 fusion transcript by a rare translocation, t(2;11)(q31;p15), in a case of infant leukaemia

We report a case of de novo acute myelomonocytic leukaemia with the t(2;11)(q31;p15) translocation in a Japanese female infant. The NUP98-HOXD13 fusion transcript generated by the translocation was detected in the patient's bone marrow cells by reverse transcription-polymerase chain reaction (RT-PCR). Additionally, ectopic expression of the normal allele of the HOXD13 gene was observed in this patient, suggesting that it might be associated with leukaemogenic development. This case is the third report of t(2;11) leukaemia with NUP98-HOXD13 and the first report showing that NUP98 rearrangements are associated with infant leukaemia, as well as therapy-related acute myelogenous leukaemia or myelodysplastic syndrome.

A novel translocation (17;19)(p13;p13) in a patient with acute myelomonocytic leukemia

We report on a patient with acute myeloid leukemia (AML M4) and a so far unrecorded translocation (17;19). The leukemia transformed from a myeloproliferative disorder (MPD) and showed a progressive fatal course. Following transformation, all leukemic cells showed an apparently balanced translocation (17;19)(p13;p13). The breakpoint regions harbor genes such as TP53 (17p13) and E2A, ENL, or LYL1 (19p13), which could be relevant in leukemogenesis. We suspect that the translocation (17;19)(p13;p13) may be a prognostic factor for transformation from chronic MPD to acute leukemia.

Fas receptor-Fas ligand system is independent of both CD34 status and chemosensitivity in acute myeloid leukemia

OBJECTIVE

To determine whether the Fas receptor-Fas ligand (FasR-FasL) system, which triggers apoptosis in sensitive cells, is an important mechanism of cytotoxicity in acute myeloblastic leukemia (AML).

MATERIALS AND METHODS

We investigated FasR expression in primary AML cells and its upregulation by tumor necrosis factor (TNF), as well as the apoptosis induced by anti-Fas antibody and the potential interaction between the FasR-FasL system and the cytotoxic drug daunorubicin (DNR).

RESULTS

FasR was expressed on all 25 AML samples and three normal bone marrow harvests. The intensity of expression was variable (range 1. 6-2.1 in normal bone marrow CD34(+) cells and 1.5-5.1 in AML cells, median 2.4) and was related to the morphologic FAB classification, with the highest expression in FAB types M4 and M5 (range 1.6-5.1, median 3.2). No relationship was found between FasR expression and expression of the CD34 antigen. FasR was heterogeneously upregulated in all AML cells on treatment with TNF-alpha. The degree of FasR upregulation induced was found to be related to the FAB subtype, with the greatest response observed in immature FAB types M1, M2, and M6 (range 11.0-207.1%, median 48.7%). Apoptosis could be induced in all AML samples, but not in normal bone marrow CD34(+)ve cells, by the CH11 anti-FasR antibody, although the response was variable (range 4.1-37.6%, median 16.5%). The monocytic differentiated M4 and M5 AML cells exhibited the greatest sensitivity to Fas-mediated apoptosis (range 4.4-37.6, median 20.65%); however, no relationship was found between sensitivity to Fas-mediated apoptosis and FasR expression or CD34 positivity. Apoptosis in response to DNR was observed in all AML cases; however, sensitivity was heterogeneous and found to be unrelated to FasR expression or sensitivity to Fas-mediated apoptosis. The blocking anti-FasR antibody ZB4 blocked anti-FasR-mediated apoptosis but had no inhibitory effect on DNR-induced apoptosis in AML blasts. No cytotoxic synergistic effect was demonstrated when anti-FasR antibody was used in combination with DNR.

CONCLUSION

In AML, DNR induces apoptosis through an Fas-independent pathway. However, the induction of apoptosis through the Fas pathway might be a novel and effective approach for leukemia immunotherapy, particularly because Fas-mediated apoptosis was noted in CD34(+) and CD34(-) cases.

Jumping translocation in acute leukemia of myelomonocytic lineage: a case report and review of the literature

Jumping translocation (JT) is a very rare cytogenetic event, occurring especially in cancer. We describe a case of secondary acute monocytic leukemia (AML5b) with a JT involving the 3q13-3qter segment and leading to a partial trisomy 3. Each clone with JT was associated with trisomy 8 or tetrasomy 8. The literature of JT in AML cases is reviewed: only 13 cases of AML associated with JT have been previously described, seven of which are AML4/5 FAB subtype. Jumping translocation involvement in leukemogenesis is discussed. Leukemia (2000) 14, 119-122.

Azacytidine plus verapamil induces the differentiation of a newly characterized biphenotypic human myeloid-B lymphoid leukemic cell line BW-90

The biphenotypic cell line BW-90 was established from the peripheral blood of a a patient with a refractory acute myelomonocytic leukemia. All cells were HLADr+, CD34-. Dual color flow cytometry showed simultaneous expression of myeloid (CD33) and B-lymphoid surface markers (CD19) on 60% of cells, CD54 on 91% of cells. Lymphoid lineage markers included CD20/CD22 coexpressed on 89% of cells, CD71 (70%), CD11a (48%), CD18 (54%), and surface lambda light chain (33%). Exposure to various cytokines individually and in combination for up to 14 days had no effect on cell proliferation or differentiation. Only long-term (10-14 days) exposure to 5637 cell-conditioned medium (CCM) induced growth inhibition and differentiation along the monocytic pathway. Differentiation-inducing agents retinoic acid (RA), dimethyl sulfoxide (DMSO) and phorbol 12-myristate 13-acetate (PMA) did not induce differentiation. Differentiation into the monocytic pathway was induced by 5-azacytidine (5AzaC) alone or in combination with verapamil (VP). The BW-90 cell line may serve as a model to study early steps of leukemogenesis and early hematopoiesis. It may provide insight leading to development of an effective therapy for treatment-resistant biphenotypic leukemias.

Acute myeloid leukemia with 11q23 translocations: myelomonocytic immunophenotype by multiparameter flow cytometry

11q23 translocations (t(11q23)) are recurring cytogenetic abnormalities in both acute myeloid leukemia (AML) and acute lymphoblastic leukemia, involving the same gene, ALL1 (or MLL). Mixed lineage antigen expression has been reported in these leukemias, but its frequency and clinical significance are unknown. We immunophenotyped leukemia cells from 19 adult de novo AML patients with t(11q23) by multiparameter flow cytometry. Translocations included t(6;11)(q27;q23), t(9;11)(p22;q23), t(9;11;19)(p22;q23;q13.3), t(2;11)(11;17)(q37;q11q23;q11), t(11;17)(q23;q25), t(11;19)(q23;p13.1), t(11;19)(q23;p13.3) and t(11;22)(q23;q11). FAB types were M4 and M5. The committed stem cell and myeloid antigens HLADr, CD4dim, CD11b, CD13, CD15, CD32, CD33, CD38 and CD64 were each expressed in 80-100% of cases, and the early stem cell and lymphoid antigens CD34, CD56, CD3, CD2 and CD7 in 42, 39, 16, 5 and 5%, respectively. Antigen expression frequencies did not differ from those in 443 adequately karyotyped M4 and M5 cases without t(11q23). Fifteen patients (79%) attained complete remission (CR); median CR duration and survival were 10.0 and 15.1 months. CR duration and survival did not correlate with antigen expression. In particular, patients with t(9;11) survived longer than those with other t(11q23) (median not reached vs 7.6 months; P = 0.048), but antigen expression did not differ in the two groups. Thus frequencies of lymphoid antigen expression are similar in AML with t(11q23) and in other FAB M4 and M5 cases, treatment outcome does not differ in t(11q23) cases with and without lymphoid antigen expression, and better outcome of patients with t(9;11) compared to other t(11q23) does not correlate with differences in antigen expression. Mixed lineage antigen expression is not a distinctive feature of AML with t(11q23).

Autologous peripheral blood progenitor cell transplantation mobilized with high-dose cytarabine in acute myeloid leukemia in first complete remission

BACKGROUND

The aim of this study was to increase disease-free survival (DFS) in AML in CR1 using a high-dose cytarabine consolidation plus G-CSF as in vivo purging and mobilization of CD34+ cells before ablative therapy and peripheral blood autograft.

PATIENTS AND METHODS

Fifty-six consecutive AML patients (pts) (including 11 children < 15 years), with a median age of 32 years, were analyzed. After achievement of CR with cytarabine-mitoxantrone (7 + 3) in adults and a BFM-like protocol in children, pts were intensified with cytarabine 2 g/m2 x six doses plus mitoxantrone for adults, or, 3 g/m2 x six doses plus etoposide for children, followed by G-CSF 5 micrograms/kg SC daily. The ablative regimens used were busulfan and cyclophosphamide (Bu/Cy) in standard-risk pts plus etoposide (2400 mg/m2) for high-risk pts.

RESULTS

For the 54 pts who underwent autologous transplant, the median time to reach > 1.0 x 10(9)/l neutrophils was 13 days (8-48), and to reach platelets > 25 x 10(9)/l 32 days (8-364), and the median numbers of red blood cell and platelet units transfused were 3 and 5, respectively. Six pts had treatment-related deaths (11%). The disease-free survival and overall survival at 30 months (mos) for the 56 eligible pts were 61% and 62%, respectively. Only two relapses were observed after 21 mos, while there were 12 relapses within 12 mos.

CONCLUSIONS

The above treatment results in a similar DFS rate as does rescue with bone marrow cells, with faster neutrophil and platelet recovery.

Human leukemia-derived dendritic cells: ex-vivo development of specific antileukemic cytotoxicity

The human myeloid leukemias are a diverse group of disorders characterized by massive clonal expansion of myeloid cells showing variable degrees of differentiation block. Leukemic dendritic cells were generated in culture from chronic myelogenous leukemia (CML). These were used to stimulate autologous T cells to develop leukemia-specific cytotoxicity. Available data suggest that the cells responsible for the cytolytic activity are at least in part CD8+ and HLA restricted in their function. Additional data suggest that some anti-CML cellular activity may be Fas mediated. T-cell receptor studies provide evidence for an oligoclonal response implying a recognition of a limited number of antigens. We have used culture techniques similar to those used for CML to study the ability of AML cells to differentiate toward dendritic cells. Four of five patients have shown acute leukemia-derived dendritic cells. This work offers an avenue for the development of novel strategies for the control of human myeloid leukemias.

Detection of a dup(17q) and inv(16) by fluorescence in situ hybridization in acute myelomonocytic leukemia

Two cases of acute myelomonocytic leukemia (AMMoL) of FAB type M4Eo are described in which a primary subclone containing a dup(17)(q21q25) and a subclone containing dup(17)(q21q25), inv(16)(p13q22) were seen in one patient, and -7, dup(17)(q21q25) in another. Fluorescence in situ hybridization (FISH) was carried out for the confirmation of the duplicated segment and breakpoint of inv(16). Inv(16) is a well known anomaly in AMMoL, whereas dup(17q) is rare though as not yet confirmed, this anomaly could be a nonrandom or novel change in AMMoL.

Incidence and prognostic relevance of CD34 expression in acute myeloblastic leukemia: analysis of 141 cases

In 141 adult patients with diagnosis of acute myeloid leukemia the overall expression and intensity of expression of CD34 antigen on leukemic cells was investigated. Myeloid blasts were tested by applying direct immunofluorescence staining using anti-CD34 fluorescein monoclonal antibody in flow cytometry. CD34 antigen was found in 73 out of 141 (51%) cases and in particular in M0, M1 and M4 French-American-British (FAB) cytotypes, while M3 and M5 cases were rarely positive. In patients whose blasts expressed CD34 antigen a significantly lower rate of complete remission (CR) was observed as opposed to CD34 negative cases (61% vs 88%) (P = 0.001). Furthermore, a negative correlation between high intensity of CD34 expression, measured as a mean fluorescence index (MFI), and CR rate was observed. In particular, patients with a higher CD34 fluorescence intensity (MFI > 23), showed a further reduction in CR rate (48%). Also, these patients had a significantly lower overall survival (P = 0.03) as compared to patients with no expression of CD34 and patients with CD34 MFI < 23. In conclusion, these findings confirm that CD34 expression is frequently associated with "immature" FAB cytotypes (M0, M1 and M4) and with a reduced probability to achieve CR. Furthermore, a high CD34 intensity of expression should be considered as a reliable poor prognostic factor.

Chromosomal abnormality inv(3)(q21q26) associated with multilineage hematopoietic progenitor cells in hematopoietic malignancies

We have identified ten patients with acute myeloid leukemia (AML) and one patient with chronic myeloid leukemia with megakaryocytic crisis who displayed an inv(3)(q21q26). Seven of them had an additional monosomy 7. Most of them had a myelodysplastic syndrome (MDS) preceding AML, normal or increased platelet counts, increased number of megakaryocyte, megakaryocytic dysplasia, and erythroid dysplasia. There was a high incidence of resistance to induction chemotherapy, short remission time, and early relapse. Seven patients were immunologically analyzed. The main immunophenotypes were as follow: CD7+, CD34+, HLA-DR+, CD38+, CD13+, CD33+, CDw65+, CD2-, CD3-, CD4-, CD8-, CD19+, CD20-, CD11b-. Our results suggest that the leukemia with inv(3)(q21q26) represents a new cytogenetic-clinicopathologic subtype, characterized by 1) abnormal megakaryopoiesis and multiple hematopoietic lineage involvement; 2) an antecedent MDS; 3) poor response to conventional chemotherapy; and 4) expression of CD7, CD34, CD38, HLA-DR, CD13, and CD33 antigens. We propose that the malignant transformation in patients with inv(3)(q21q26) occurs in an early stem cell prior to lineage commitment.

Differential activation of the nuclear factor-kappa B by TNF muteins specific for the p60 and p80 TNF receptors

Human TNF is a highly pleiotropic cytokine that mediates its effects by binding to two distinct receptors, viz p60 and p80, which transmit their signals independently of each other. Activation of the transcription factor NF-kappa B is one of the earliest events induced by TNF, but whether it is mediated through one or both forms of the TNF receptor is controversial. in the present studies, we examined the role of each receptor in the activation of NF-kappa B by using TNFs that has been designed by site-specific mutagenesis to bind either the p60 (R32W; S86T) or the p80 (D143N; A145R) form of the receptor. Human myelogenous leukemic ML-1 a cells known to express almost equal amounts of the two receptors were used. The binding of TNF to these cell could be inhibited equally by either TNF(p60) or TNF(p80) mutein. Treatment of these cells with TNF(p60) mutein activate NF-kappa B within 30 min, whereas TNF(p80) mutein, even at a 1000-fold excess, had no effect, suggesting that the activation of NF-kappa B is differentially regulated through the p60 receptor. Consistent with these results, treatment with either anti-p80 monoclonal or polygonal Abs blocked the binding of TNF to the p80 receptor without affecting TNF-mediated activation of NF-kappa B TNF(p60) mutein was also effective in cell killing, but the TNF(p80) mutein was totally ineffective. The effect was not cell type-specific, since other p80-expressing cell lines were also unresponsive. Overall, our results clearly demonstrate that the activation of NF-kappa B and cytotoxicity by TNF is differentially regulated through the p60 receptor.

Strength of binding between leukemic blasts and cytotoxic lymphocytes

Strength of binding (Sb), a new parameter defined by the ratio of binding capacity and dissociation rate constants, was estimated and used for the characterization of conjugate formation between leukemic blasts and cytotoxic lymphocytes. Lymphokine activated killer (LAK) cells, i.e., interleukin-2 activated peripheral blood lymphocytes (PBL) displayed significantly (P < 0.001) higher Sb with leukemic blasts when compared to fresh, nonactivated PBL. Interaction of both fresh PBL and LAK effector cells with acute myeloid leukemia (AML) blasts was characterized by a significantly (P < 0.05) lower Sb when compared to the K562 cell line. Interaction of LAK effector cells with leukemic cell-lines of lymphoid origin (Daudi, Raji, and HuT78) was characterized by a significantly (P < 0.005) lower Sb than with K562 myeloid cell line. Sb for the interaction of natural killer (NK)-derived CD16+/CD56+ LAK with leukemic blasts was significantly (P < 0.001) higher than that of T-cell-derived CD3+LAK. We conclude that calculation of Sb provides a relatively simple and independent way to evaluate systems of interacting cells at a single time and may be used to compare results between different cell systems and laboratories.

Autologous platelet transfusion in alloimmunized patients with acute leukemia

Seventy-eight transfusions of autologous platelets were given to eight alloimmunized patients receiving curative chemotherapy for acute leukemia. Platelets were collected at regeneration of hematopoiesis after a chemotherapy cycle, cryopreserved with 5% dimethylsulfoxide in liquid nitrogen, and retransfused during bone marrow aplasia following the next treatment cycle. The in vitro platelet recovery after freezing, thawing, and washing was 85 +/- 4%. The in vivo corrected count increment 1 h after autologous platelet transfusions was 11 +/- 5 x 10(9)/l. With the exception of moderate urticaria and slight nausea each after one transfusion, no immediate or chronic side effects occurred. The bleeding time was shortened and hemorrhage during bone marrow aplasia was prevented in all alloimmunized patients by autologous platelet transfusions.

Expression of the MAGE gene family in human lymphocytic leukemia

The MAGE gene family, encoding tumor-rejection antigens recognized by cytotoxic T lymphocytes, is frequently expressed in human solid cancers. However, its expression in leukemia has not been well studied. We have investigated MAGE gene expression at the mRNA level in human leukemia. The MAGE gene family was expressed in 17 of 34 (50%) examples of T cell leukemia (12/21 patients' peripheral blood mononuclear cells and 5/13 cell lines), in 7 of 16 (44%) cases of B cell leukemia (1/8 and 6/8 respectively), but in none of 23 myelomonocytic leukemia cases (0/16 and 0/7), as evaluated by the primers common to the MAGE-1, -3, -4 (-4a and/or -4b), and -6 genes and the semi-quantificative reverse transcription/polymerase chain reaction method. None of a panel of normal lymphoid cells expressed the MAGE gene family. As revealed by the primers specific for each of the MAGE genes, the MAGE-1, -2, -3, -4 or -6 gene was expressed in 8, 8, 6, 2, or 6 respectively out of 23 types of leukemia cell lines. Expression of the MAGE-1 protein in both the cell lines and patients' cells was confirmed by immunoblot analysis with the polyclonal antibody to recombinant MAGE-1 protein. Cellular MAGE-4 protein in the cell lines was measured by an enzyme-linked immunosorbent assay with the polyclonal and monoclonal antibodies to recombinant MAGE-4b protein. In summary, the MAGE gene family was found to be expressed in the substantial proportion of T cell leukemias, but in no case of myelomonocytic leukemia. Antigens coded by the MAGE gene family could be important molecules for understanding specific immunity against lymphocytic leukemia.

Congenital leukemia: report of two cases

Congenital leukemia is a rare disease in which a leukemic process is present at birth or immediately thereafter. The majority of cases presented in the literature were reported prior to the availability of contemporary immunophenotyping methods, and lineage assignment was often made on the basis of morphology alone. Congenital leukemias may be of various lineages, although, historically, monocytic and myelomonocytic congenital leukemias appear to be the most prevalent. We present two cases of congenital leukemia with detailed immunophenotypic and cytochemical characterization. One case is of the lymphoid lineage, and the second is of myelomonocytic lineage. Neither patient displayed trisomy 21.

Dependency on intercellular adhesion molecule recognition and local interleukin-2 provision in generation of an in vivo CD8+ T-cell immune response to murine myeloid leukemia

The immune response to a murine myeloid leukemia (cell line C1498) was studied in vitro and in vivo. Natural killer (NK) cells and CD8+ cytotoxic T lymphocytes (CTL) were shown to lyse C1498 in vitro through the binding of leukocyte function antigen-1 (LFA-1) on effectors and intercellular adhesion molecule-1 (ICAM-1) and ICAM-2 on C1498 target cells. However, the ability of nonimmunized mice to resist an in vivo challenge of a low dose (10(4)) of C1498 was NK-cell, but not T-cell dependent. The failure of T cells to participate in the immune surveillance of a low leukemia burden appeared, in part, because of a lack of expansion of leukemia reactive CTL precursors (CTLp). Leukemia reactive CTLp frequency estimations in naive and leukemia bearing mice were not significantly different (range, 1:20,600 to 1:74,000) in contrast to immunized mice (range, 1:1,400 to 1:4,400). Leukemia reactive CTLp could be expanded to a level that could apparently mediate in vivo immune surveillance of 10(5) leukemia cells by injection of irradiated leukemia cells intraperitoneally (IP) or subcutaneously (SC), but not intravenously (IV). However, IV injection of 10(5) live leukemia cells engineered to secrete interleukin-2 (IL-2) resulted in systemic immunity mediated primarily by CD8+ T cells. We conclude that NK cells can mediate immune surveillance of a low leukemia burden. CD8+ CTL-mediated immune surveillance can eliminate a higher leukemia burden than NK cells, but requires T-cell help, which can be delivered by local IL-2. Both NK and CTL-mediated immune surveillance of C1498 murine myeloid leukemia is dependent on recognition through the LFA-1:ICAM adhesion pathway.

ALL-1 gene rearrangements in acute myeloid leukemia: association with M4-M5 French-American-British classification subtypes and young age

We have analyzed by Southern blotting the ALL-1 (MLL, HRX, Hrtx 1) gene configuration in a series of 126 patients with acute myeloid leukemia (AML) representative of all ages and French-American-British Classification groups and correlated this genetic feature with clinical and biological features at diagnosis. ALL-1 gene rearrangements were detected in 17 of the 74 cases with M4-M5 (myelomonocytic and monocytic) AML and in 2 of the 52 cases with other leukemic subtypes (P < 0.01). Within the series of 74 M4-M5 patients, ALL-1 rearrangements were significantly associated with French-American-British Classification M5 (P = 0.009), high WBC (P = 0.002), and young age. In particular, all 5 infant (< 1.5 years) AML cases, 6 of the 19 (31%) patients between 1.5 and 18 years of age, and 6 of the 50 (12%) patients > 18 years old showed an altered ALL-1 genomic configuration (P < 0.001). Immunophenotypic characterization revealed coexpression of lymphoid and myeloid markers in 6 of 17 ALL-1 rearranged M4-M5 cases. The IgH gene configuration was studied in 77 of 126 AMLs. Five patients (6%) showed IgH clonal rearrangements and all were in the ALL-1 rearranged group (P < 0.0001). Our findings indicate that ALL-1 rearrangement is the commonest genetic alteration presently detectable in M4-M5 AML, particularly in childhood where it is found in up to one-third of all cases. The association of IgH rearrangements with ALL-1 alterations in AML, coupled to the frequent detection in this subset of lymphoid associated markers, further supports the origin of these tumors from a common multipotent precursor with bipotential lymphoid and monocytic differentiation capability.

Induction of graft-versus-leukemia (GVL) activity in murine leukemia models after IL-2 pretreatment of syngeneic and allogeneic bone marrow grafts

To investigate GVL effects, Balb/c mice (H-2d) received 5 x 10(5) A20 (B cell leukemia) or 1 x 10(6) WEHI-3 (myelomonocytic leukemia) cells. These cell lines lead to death after a median of 19 (WEHI-3) or 30 days (A20). A lethal dose of total body irradiation followed by syngeneic BMT resulted in significantly prolonged survival of leukemia-bearing animals. Transplantation of (C57 x Balb/c)F1 (H-2bxd) allogeneic, but GVH-non-reactive marrow grafts differentially influenced the relapse rates in the two leukemia models. Whereas allogeneic BMT reduced the relapse rates in A20-bearing mice, the leukemia-free survival was not improved in mice bearing the leukemia WEHI-3 compared with syngeneic BMT. Pre-treatment of allogeneic (C57 x Balb/c)F1 or syngeneic Balb/c marrow cells with 200 U/ml IL-2 for 24 h did not reduce relapse rates in animals inoculated with A20 leukemia cells compared with unmanipulated bone marrow. In contrast, IL-2 treatment of syngeneic or allogeneic GVH non-reactive donor marrow significantly decreased the relapse rate in mice inoculated with WEHI-3 leukemia cells. The NK cell-mediated lysis of cultured leukemia cells was determined in vitro using a conventional 56Cr-release assay. Our data revealed a strong correlation between the level of natural killer activity determined in vitro and GVL activity in vivo.

[Immunological deficiency in patients with the myeloid forms of acute leukemia and the methods for its correction]

Immunologic and cytochemical studies were done in 162 patients with myeloid forms of acute leukosis, among whom 130 had acute myeloblastic leukemia (AML), and thirty two--and acute myelomonoblastic leukemia (AMML), before and after the therapy instituted. Immunocorrection was attempted with immunomodulating agents prodigiosane and tactivin. Striking inhibition of T-cellular immunity (T-total, T-active, TPhres, TPhsen, as well as blast transformation of lymphocytes with PHA) was revealed. All patients experienced significant rise in circulating immune complexes before treatment. Investigation designed to study intracellular metabolism of neutrophils demonstrated significant decline in the activities of G-6-P-ase, NAD- and NADP-oxidases, cationic proteins and NBT-test. Immunocorrective agents improve the state of immunologic reactivity, make for arresting infections and inflammatory processes and prolongation of remission in patients with acute myeloid forms of leukoses.

Difference in response to colony-stimulating factors and involvement of protein kinase C signal transduction system in three subclones from the ME-1 cell line and two sublines

We previously established a cell line from a patient with acute myelomonocytic leukemia with eosinophilia (M4E0), ME-1. ME-1 cells are responsive to colony-stimulating factors (CSFs) such as interleukin-3 (IL-3), IL-4, and granulocyte-macrophage CSF (GM-CSF), and exhibit monocyte-macrophage differentiation. We isolated three subclones, ME-F1 from ME-1, and ME-F2 and ME-F3 from two sublines of ME-1. These subclones had different morphologic, cytochemical, phenotypic, and cytogenetic features. They represented different monocytic-lineage differentiation stages and exhibited different responses to IL-3, GM-CSF, and especially IL-4. IL-3, GM-CSF, and IL-4 enhanced proliferation and differentiation to macrophage-like cells in the ME-F1 subclone. However, they enhanced only proliferation of ME-F2 cells and only differentiation to macrophage-like cells in the ME-F3 subclone. To elucidate possible differences in signal transduction mechanisms in ME-F1, ME-F2, and ME-F3 cells following stimulation by CSFs, we studied the effects of IL-3 and IL-4 on protein kinase C (PKC) activity. Both IL-3 and IL-4 induced a rapid, transient decrease of cytosolic PKC in ME-F1 cells, but did not affect PKC activity in ME-F2 and ME-F3 cells. The PKC inhibitors, 1-(5-isoquinolinyl-sulfonyl)-2-methylpiperazine (H-7) and calphostin C inhibited IL-3-induced enhancement of proliferation and differentiation of ME-F1 cells, but did not inhibit enhancement of proliferation of ME-F2 cells and differentiation of ME-F3 cells. Our data suggest that PKC-dependent signal transduction is considerably related to IL-3-induced proliferation and differentiation of ME-F1 cells. In addition, it was demonstrated that the two subclones, ME-F2 and ME-F3, lost one of the two responses of ME-F1 cells to CSFs, either proliferation or differentiation, and simultaneously lost PKC-dependent response to CSFs.

The immunophenotype of acute promyelocytic leukemia (APL): an ECOG study

In 452 adult patients with de novo acute myeloid leukemia (AML), a series of 22 monoclonal antibodies was used to identify immunophenotypic characteristics of acute promyelocytic leukemia (APL) as compared to other AMLs (groups FAB M1/M2 and M4/M5). Only those patients with FAB M3 cytology were included in the analysis for which APL was confirmed by the presence of the t(15;17) cytogenetic aberration and the detection of the PML/RAR alpha gene fusion transcript by PCR amplification (35 cases). Significantly fewer APL blast cells were positive for the stem cell antigen, CD34 (p = 0.0001) as well as for HLA-DR (p < 0.0001). With respect to myeloid antigens, APLs less frequently expressed the myelomonocytic antigens, CD11b (p = 0.0001) and CD14 (p = 0.0013), whereas expression of CD33, a pan-myeloid marker, was more frequent in APL (p = 0.0001). CD15, the X-hapten carbohydrate structure (lacto-N-fucopentaose-III), typically expressed at the maturation stage of normal promyelocytes, was found to be sialylated on APL blasts as recognized by differential binding of the anti-CD15 antibodies, VIM-D5 (non-sialylated CD15) and VEP-9 (sialylated CD15). Expression of the T-cell associated CD7 antigen was rarer on APL than non-APL cells (p = 0.0001), as was that of the multidrug resistance P-glycoprotein (p = 0.0038). Marginal correlations existed between antigen profile (particularly CD2) and the type of PML/RAR alpha transcripts. In addition to its unique genotypic features, these data establish APL as a distinct immunophenotypic entity.

Immuno- and cytochemical characterization of congenital leukemia: a case report

Congenital leukemia (CL) is a rare disorder, which usually presents as a myelocytic leukemia based on morphological features. Very few reports include data on cyto- or immunochemical parameters. A case of CL with detailed description of immunochemical, cytochemical features, and colony formation properties of the progenitor cells is reported. This leukemia was classified as an M4 in FAB classification based on the morphological features and special stains. Two different cell populations were identified by flow cytometry. One consisted of small cells expressing early T- and early B-cell associating antigens as well as early myeloid-associated antigens, but not CD10 (CALLA antigen), which is normally present in cord blood lymphocytes. The other was a population of large cells expressing myeloid-associated antigens and a pan-T-antigen. The growth pattern of hematopoietic progenitors in the patient was compatible with both acute myeloid and acute lymphatic leukemia as well as erythroleukemia.

Relapse of aggressive myeloma after complete remission in secondary acute leukemia: coincidence or consequence?

We describe a patient with multiple myeloma who developed secondary acute myelomonocytic leukemia after long-term melphalan treatment. Following two courses of low-dose cytarabine, complete remission of the A.M.L. was achieved. Shortly thereafter an aggressive relapse of the quiescent myeloma occurred with acute renal failure and massive infiltration of bone marrow with multinucleated giant plasma cells. Although it is well known that administration of melphalan to patients with multiple myeloma increases the likelihood of A.M.L., this case demonstrates that treatment of A.M.L. in a patient with multiple myeloma may perhaps influence the course of multiple myeloma.