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A Guarini

Publications and source records attributed to A Guarini.

At least 19 recordsLinked to original sources
PubMed1994

Interleukin-2 may induce prolonged remissions in advanced acute myelogenous leukemia.

The administration of interleukin-2 (IL-2) may induce complete remissions in acute myelogenous leukemia (AML) patients with a low proportion of residual bone marrow (BM) blasts. To confirm this preliminary observation, we treated 14 AML patients with advanced disease and with a residual BM blastosis that ranged between 7% and 24% with repeated 5-day cycles of high-dose recombinant IL-2 administered by daily continuous intravenous infusion. Patients who responded have been subsequently submitted to a monthly maintenance scheme with subcutaneous IL-2 at lower doses. While using this schedule and closely monitoring clinical and laboratory conditions, side effects were acceptable and no toxic deaths recorded. Eight of the 14 patients treated with high-dose IL-2 obtained a complete remission (CR). Five remain in persistent CR (four in third CR and one in fourth CR) after a median follow-up time of 32 months (14, 30, 32, 33, and 68 months, respectively). In all five patients, the IL-2-induced remission is the longest in the natural history of the disease. These findings show that IL-2 displays an antileukemic effect in AML with limited residual disease, and suggest that IL-2 should be considered a therapeutic option for resistant or relapsed AML patients.

Adolescent↗
PubMed1994

Transduction of the IL2 gene into human acute leukemia cells: induction of tumor rejection without modifying cell proliferation and IL2 receptor expression.

BACKGROUND: Previous studies have suggested that some of the limitations associated with the administration of high-dose exogenous interleukin 2 (IL2) may be overcome, at least partly, by cytokine gene transfer modalities. These findings have prompted investigations into whether human tumor cells may be transduced with the IL2 gene and whether tumor cell lines could be engineered to release IL2. PURPOSE: The purpose of this study was to evaluate the possibility of inducing a productive transfer of the IL2 gene into human acute leukemia cells and to assess the phenotypic and proliferative changes generated in the engineered cells, as well as their tumorigenic potential in nude mice. METHODS: Three retroviral vectors (DC/TK/IL2, DC/AD/R/IL2, and N2/CMV/IL2) carrying the IL2 gene were used to transduce three human leukemic cell lines: K562 and U937 (myeloid) and ST4 (lymphoid). Messenger RNA expression of the IL2 gene was analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR) and productive IL2 release using a human IL2 assay and an enzyme-linked immunosorbent assay kit. The expression of the p55 (alpha) and p75 (beta) chains of the IL2 receptor were determined by RT-PCR and indirect immunofluorescence. The kinetics of in vitro growth and proliferation of parental and engineered cells were also measured. Parental and IL2 gene-transduced ST4 lymphoblasts were injected into immunosuppressed nude mice that had their tumors measured twice weekly. RESULTS: The productive insertion of the IL2 gene was achieved in all three cell lines studied. The amounts of IL2 constitutively released by the engineered neoplastic cells ranged between 1 and 11 U/mL of IL2 produced from 10(6) cells in 72 hours. A fivefold increase in IL2 production was obtained in ST4 cells by further limiting dilution cloning of the bulk-infected cells. The stable integration of the IL2 gene did not modify the phenotype of the leukemic cells, the expression of the IL2 receptor alpha and beta chains and of several cytokine genes, or the kinetics of in vitro growth and proliferation. In nude mice injected with various IL2-producing ST4 clones, tumor growth associated inversely with the amounts of IL2 secreted by the leukemic cells. CONCLUSIONS: The results of this study demonstrate that the IL2 gene can be productively transduced into human myeloid and lymphoid leukemic cells without modifying their phenotypic and proliferative properties and that this transduction leads to a reduced or abrogated in vivo tumorigenic potential.

Acute Disease↗
PubMed1994

Serum levels of tumour necrosis factor-alpha in patients with B-cell chronic lymphocytic leukaemia.

Serum levels of tumour necrosis factor-alpha (TNF-alpha) have been evaluated in the peripheral blood of 91 patients with B-cell chronic lymphocytic leukaemia (B-CLL), and have been correlated with the clinical stage (according to Rai's staging system) and relevant haematological and immunological data. Increased values were detected, compared to 36 normal age-matched controls (36 pg/ml +/- 5 versus 0.11 pg/ml +/- 0.08; P < 0.05). An increase of TNF-alpha serum levels was observed in all stages including stage 0, with a progressive increase in relation to the stage of the disease. A significant relationship between serum TNF-alpha levels and the number of circulating monocytes (P < 0.002) and an inverse correlation with the level of the haemoglobin (P < 0.001) was established, as defined by the Pearson's correlation test. In contrast, no correlation was observed between TNF-alpha serum levels and the other parameters taken into account, including the white blood cell and platelet counts, the absolute number of peripheral blood (PB) lymphocytes, CD5+ B lymphocytes, CD57+ lymphocytes, serum levels of lactic dehydrogenase, total serum immunoglobulins and the serum levels of IgG, IgA and IgM. These data suggest that, in addition to the B-CLL neoplastic cells, the PB monocytes may be involved in the release of TNF-alpha.

Aged↗
PubMed1994

Cytokine gene therapy in oncology.

Over the last few years the possibility of introducing foreign material into the genome of host cells has become technically feasible. This has opened a new era in the treatment of congenital disorders, but has also offered potential innovative avenues in the management of cancer patients. Here, we shall discuss how cytokine genes may be successfully transduced into the DNA of different experimental tumours and how through this approach the tumorigenicity of the neoplastic cells may be abrogated. Emphasis will be given on the demonstration that following cytokine gene transfer, namely with the interleukin 2 (IL-2) gene, two of the primary goals of an optimal immunotherapeutic approach, i.e. anti-tumour specificity and memory, may be achieved. Attention will be focused, in particular, on the results so far obtained, as well as on ongoing studies, with human tumour cells engineered to release different cytokine genes. The design and activation of the first clinical protocols aimed at treating advanced cancer patients with cytokine gene-transduced neoplastic cells will also be discussed, together with other strategies of genetic engineering currently under investigation.

Animals↗
PubMed1992

Retroviral vector-mediated lymphokine gene transfer into human renal cancer cells.

Effective vaccination against cancer, either for prophylaxis or therapy, has been an elusive goal for years. Cytokine gene therapy offers a novel approach to generate immunogenic tumor cell vaccines. To examine the feasibility of cytokine gene transfer into human renal cancer (RC) cells, we introduced the cDNAs for human interleukin-2 (IL-2) or interferon-gamma (IFN-gamma) into various RC cell lines with retroviral vectors. Using the NIH3T3 amplification assay, no replication competent retroviral particles were detectable in cell culture supernatants taken from gene-modified RC cell lines. Efficient expression of both lymphokines was achieved. Depending on the cell line and the vector construct used, lymphokine gene-modified human RC cell lines released 4 to 29 units/10(6) cells of IL-2, or up to 10 units/10(6) cells of IFN-gamma within 48 h. Fluorescence-activated cell sorter analysis of SK-RC-29 cells releasing IFN-gamma showed increased expression of major histocompatibility complex class I antigen, beta 2-microglobulin, and ICAM-1, as well as induction of major histocompatibility complex class II antigen expression [human leukocyte antigen(HLA)-DR, -DP], but no changes in these cell surface markers were observed with SK-RC-29 cells releasing IL-2. Following in vitro gamma-irradiation with 5,000 or 10,000 rad, growth of lymphokine gene-modified RC cells was abrogated, but their capability to release lymphokine and express lymphokine-induced antigenic determinants, such as HLA-DR, was retained. Tumor formation by the human RC cell line SK-RC-29 in BALB/c nude mice was not affected by IFN-gamma secretion, but was inhibited by in vivo release of IL-2 from s.c. injected tumor cells. These studies demonstrate the feasibility of retroviral mediated lymphokine-gene transfer into human RC cells and suggest a means for generating autologous or HLA-matched allogeneic tumor cell vaccines for the treatment of patients with renal cell carcinoma.

Animals↗
PubMed1992

IL2 treatment for cancer: from biology to gene therapy.

In this review we shall discuss the biological rationale and the clinical findings obtained using Interleukin 2 (IL2)-based immunotherapy in the management of cancer patients. Objective and long-lived clinical responses have been documented in a proportion of cases, particularly renal cell carcinoma, melanoma and acute myeloid leukaemia. Though encouraging, the clinical use of IL2 has so far been limited by toxicity, as well as by the heterogeneous and unpredictable responses and by the lack of specific anti-tumour effect. These considerations have led to the belief that more sophisticated technologies aimed at introducing the IL2 gene into the neoplastic cells may potentially overcome some of the limitations coupled to the in vivo infusion of high doses of IL2. The data accumulated in animal models and, more recently, also with human tumour cells indicate that the IL2 gene may be successfully inserted into neoplastic cells. The constitutive secretion of IL2 by the tumour cells leads to a reduced or abrogated tumorigenicity in several different tumour models. The evidence that in some experimental tumours the transduction of the IL2 gene into the neoplastic cells may elicit a specific cytotoxic response and confer anti-tumour memory, suggests that vaccination protocols based on this innovative strategy may represent a potential new tool in the management of cancer patients.

Animals↗
PubMed1992

Constitutive production of tumor necrosis factor-alpha in hairy cell leukemia: possible role in the pathogenesis of the cytopenia(s) and effect of treatment with interferon-alpha.

PURPOSE: In view of the pleomorphic role cytokines play in human lymphoproliferative disorders, we investigated the possible involvement of tumor necrosis factor-alpha (TNF) in hairy cell leukemia (HCL). PATIENTS AND METHODS: The levels of TNF were measured in the serum of untreated patients, and in the culture supernatants of unstimulated and stimulated enriched hairy cells (HC). Furthermore, the presence of TNF mRNA transcripts in HC was analyzed. The possibility that HC could inhibit the in vitro growth of normal erythroid progenitors via the release of TNF was also investigated. Finally, in an attempt to correlate the circulating levels of TNF with the course of the disease, these were retested during and after treatment with interferon-alpha (IFN). RESULTS: Significantly increased levels of TNF were found in the sera of untreated HCL patients compared with normal control sera were seen from patients with other diseases (P less than .001), with values greater than 10 pg/mL in 21 of 42 samples tested. A significant decrease (P less than .01) of TNF levels was recorded following IFN-2a administration in 16 cases with detectable pretreatment serum levels of TNF. In two cases, an increase in TNF values was associated with persistence or progression of disease. The likelihood that the circulating levels of TNF were caused by the pathologic cells is supported by the evidence that purified HC may release TNF spontaneously. The values can be markedly increased following in vitro activation with the phorbol ester 12-0-tetradecanoylphorbol-13 acetate (PMA), with B-cell growth factor (BCGF), and, to a further extent, with the combination of PMA and BCGF. Furthermore, the constitutive mRNA for TNF was found in seven of eight HC samples analyzed. Although supernatants of enriched HC, were capable of reducing the growth of normal bone marrow erythroid progenitors by 50%, duplicate experiments using an anti-TNF antibody produced an almost complete disappearance of the inhibitory effect. CONCLUSION: The results of this study suggest that TNF plays an important role in the pathogenesis of the cytopenia(s) characteristically associated with HCL.

Adult↗
PubMed1992

Has IL2 a role in the management of minimal residual disease for acute leukemia?

Based on pre-clinical findings and on more recent preliminary in vivo data it has been suggested that immunotherapy with Interleukin 2 (IL2) may be employed in the treatment of acute leukemia patients. Here we shall discuss the biological and clinical observations which indicate that this innovative therapeutic approach may play a role in the management of minimal residual disease.

Acute Disease↗
PubMed1992

Interleukin 2 (IL2) in the management of acute myeloid leukemia: clinical and biological findings.

In this paper we review some of the preclinical findings which have led us to believe that immunotherapy with interleukin 2 (IL2)/lymphokine activated killer (LAK) cells may be a feasible approach in the management of acute myeloid leukemia. The main clinical and biological results so far obtained with IL2 treatment, and the currently ongoing protocols and strategies are discussed.

Acute Disease↗
PubMed1992

Autologous bone marrow transplantation followed by interleukin-2 in children with advanced leukemia: a pilot study.

In an attempt to prolong disease-free survival in children with acute leukemia, we tested the feasibility of interleukin-2 (IL-2) administration after an autologous bone marrow transplantation (ABMT). We report the clinical and biological data obtained in three children with acute myelocytic leukemia (AML) in second complete remission (CR) and in seven children with acute lymphocytic leukemia (ALL) in second or subsequent CR, who received IL-2 at a median interval of 78 days (range 38-125) from ABMT. Patients were treated with 1-2 cycles of IL-2 given by continuous infusion over a 5-day period using a daily escalating protocol, from 100 micrograms/m2 per day to the maximum tolerated dose, followed after 3 weeks by low-dose IL-2 for 5 days monthly over a 6-h infusion on an out-patient basis. Side effects greater than grade 2 (WHO system), consisting of thrombocytopenia, fever, cutaneous rash, nausea and vomiting, diarrhoea were common during the high-dose IL-2 cycles, but resolved 24-48 h after stopping IL-2. Only one patient developed liver toxicity (grade 3, WHO) on day +3 of the first cycle which prompted us to stop the administration of IL-2. An increase in lymphocytes and eosinophils was also observed. IL-2 treatment was followed by a normalization of NK function and by the generation of a high proportion of endogenous LAK cells. All seven ALL patients relapsed at a median of 5 months (range 1-23). Two AML patients relapsed at 1 and 11 months, while the other is still in continuous CR at 23 months after IL-2 treatment. Our IL-2 schedule for treatment of leukemia in children after ABMT is thus feasible but its efficacy requires further investigation.

Adolescent↗
PubMed1991

Defective lymphokine-activated killer cell generation and activity in acute leukemia patients with active disease.

In 26 myeloid and lymphoid acute leukemia patients at presentation the capacity to generate interleukin-2 (IL-2)-induced lymphokine-activated killer (LAK) cells effective against the natural killer (NK)-resistant Raji cell line, as well as the susceptibility of the blasts to normal peripheral blood (PB) LAK cells and to autologous LAK effectors was analyzed. The overall PB LAK activity against Raji cells was significantly lower in acute leukemia patients compared with normal controls (mean, 1,473 +/- 971 SD LU/10(8) LAK effectors v 3,340 +/- 1,862; P less than .001). The sensitivity of the blasts to autologous LAK cells was also significantly lower than to normal LAK effectors (517 +/- 593 LU/10(8) LAK effectors v 1,304 +/- 1,066; P less than .01). When the data were analyzed independently, four patterns of behavior could be recognized. The relatively largest group (9 of 26) included patients in whom effective LAK cells could be generated against the Raji line, but in whom the blasts were resistant to autologous PB-LAK effectors while being susceptible to normal LAK cells (defective specific LAK activity). In 5 of 26 cases, an incapacity to generate LAK activity against both allogeneic and autologous target cells was observed (defective LAK generation). In six further cases, the blasts were resistant to both allogeneic and autologous LAK populations, though the latter were effective against the Raji line (resistant blasts). The same defects could also be shown with bone marrow-derived LAK cells. Only in six cases did the leukemic blasts appear susceptible to autologous and allogeneic LAK cells. In four patients the analysis could be repeated at remission, and in three a restoration of the LAK function against the primary blasts was recorded. In the 10 cases studied at relapse, the blasts were resistant to autologous LAK effectors in nine and to normal LAK in seven. These data demonstrate that in most acute leukemia patients with active disease, a defect of the LAK machinery, either a deficient generation of LAK cells or the resistance of the blasts to LAK effectors, may be documented, pointing therefore to a possible contributory role of the LAK system in the control of leukemic cell growth. In view of the frequent normalization of the autologous LAK activity at the time of remission, immunotherapy with IL-2/LAK cells should be primarily aimed to patients with minimal residual disease.

Cell Line↗
PubMed1991

Peripheral blood and bone marrow immunophenotypic and functional modifications induced in acute leukemia patients treated with interleukin 2: evidence of in vivo lymphokine activated killer cell generation.

The effect of treatment with interleukin 2 (IL2) on the phenotypic and functional immune system of acute leukemia patients was investigated. Fifteen acute myeloid leukemia and acute lymphoid leukemia patients with evidence of persistent disease were further subdivided into two groups according to the percentage of bone marrow (BM) blasts: group a had 6-15% blasts and group b had 30-65%. Following two cycles of IL2 (Glaxo Imb, Geneva, Switzerland) given i.v. by continuous infusion at escalating doses, no major changes in the proportion of CD3-, CD4-, and CD8-positive cells were encountered in the blood or in the marrow of either group of patients. When these could be retested after four cycles of IL2, a significant increase of CD3+ and CD4+ cells was documented in the peripheral blood (PB), as well as a significant increase of CD3+ cells in the BM. Irrespective of the number of cycles administered, the proportion of CD16+ cells increased significantly in the blood in both groups of patients and in the marrow of group a patients only. The expression of CD25 was significantly enhanced in all samples tested. Following IL2 administration, an enhancement of the natural killer compartment was documented. This was consistently more evident in patients with more limited disease. A significant amplification of the in vitro-induced lymphokine-activated killer function was noted in the BM of the treated patients. Furthermore, we documented the presence both in the PB and in the BM of "spontaneous" lymphokine-activated killer cells generated in vivo following IL2 administration. These results demonstrate that in acute leukemia of both myeloid and lymphoid origin, treatment with IL2 is capable of inducing profound immunophenotypic and functional modifications in PB and in BM lymphocytes, particularly in patients with more limited disease. The evidence of the in vivo activation of cytotoxic cells, particularly in the BM, may help to explain the clinical responses preliminarily observed in individual acute leukemia patients.

Acute Disease↗
PubMed1991

Thrombocytopenia in acute leukaemia patients treated with IL2: cytolytic effect of LAK cells on megakaryocytic progenitors.

In vivo administration of recombinant interleukin 2 (IL2) has been associated, in acute leukaemia as well as in other tumours, with a variable degree of thrombocytopenia. In two patients with acute myeloid leukaemia who showed a progressive and severe fall in platelet count during daily continuous i.v. infusion of IL2, we assessed whether peripheral blood IL2-generated lymphokine activated killer (LAK) lymphocytes could affect growth of the autologous bone marrow megakaryocytic progenitor cell compartment (CFU-MK) in vitro. Following overnight pre-incubation in liquid culture of the marrow cells with autologous LAK effectors, there was an almost complete abrogation of the CFU-MK colony growth (97% and 89% inhibition). Pre-incubation in the presence of a monoclonal antibody to tumour necrosis factor alpha (TNF) completely reversed the inhibitory effect. The role played by TNF was confirmed by the finding that recombinant TNF caused a dose-dependent inhibition of the growth of CFU-MK. IL2 alone was ineffective. These results suggest that the often severe thrombocytopenia observed in patients with acute leukaemia treated with IL2 is at least partly due to autologous LAK cells activated in vivo following the administration of IL2.

Adult↗
PubMed1990

Lymphokine-activated killer (LAK) cell activity in B and T chronic lymphoid leukemia: defective LAK generation and reduced susceptibility of the leukemic cells to allogeneic and autologous LAK effectors.

The capacity to generate lymphokine-activated killer (LAK) cells and the susceptibility of the neoplastic cells to both allogeneic and autologous LAK effectors were studied in B and T chronic lymphoproliferative disorders. While in B-cell chronic lymphocytic leukemia (B-CLL) the depressed natural killer function could be restored after a 7-day incubation with recombinant interleukin (IL-2), B-CLL mononuclear cells showed a reduced LAK activity compared with normal LAK cells. Furthermore, in all but 1 of the 20 B-CLL samples tested the leukemic cells were totally resistant to autologous LAK effectors. In most cases the leukemic cells were also resistant to normal allogeneic LAK cells. Competition experiments demonstrated that the patients' LAK cells, as well as normal LAK effectors, were capable of recognizing B-CLL cells, pointing, therefore, to a postbinding cytolytic defect. In hairy cell leukemia (HCL) an overall reduced LAK activity against allogeneic targets was documented, but, at variance from B-CLL, hairy cells were often susceptible to the lytic effect of normal LAK cells, and in half of the cases tested the neoplastic population was also sensitive in an autologous system. Similarly to B-CLL, in the great majority of T chronic lymphoproliferative disorders studied, the pathologic cells were resistant to normal and autologous LAK effectors and a defective LAK generation was found. These results demonstrate that in most B and T chronic leukemias the LAK function is defective and, when inducible, does not appear directed against the leukemic population. The possibility of exploiting an immunotherapeutic approach with IL-2/LAK cells in the management of chronic lymphoproliferative disorders does not gain support by these findings.

Cells, Cultured↗