Biomedical subjects

J E Kolitz

Publications and source records attributed to J E Kolitz.

At least 19 recordsLinked to original sources

PubMed2004

Modern diagnostics in chronic myeloproliferative diseases (CMPDs).

According to the new WHO classification a group of chronic myeloproliferative diseases (CMPDs) were defined: chronic myeloid leukemia (CML), chronic neutrophilic leukemia (CNL), chronic eosinophilic leukemia and hypereosinophilic syndrome (CEL/HES), polycythemia vera (PV), chronic idiopathic myelofibrosis (with extramedullary hematopoiesis, CIMF), essential thrombocythemia (ET), and so called CMPD/unclassifiable. As clinical features and laboratory findings differ widely between these diseases several diagnostic approaches are mandatory at diagnosis for classification and are needed also for follow up studies, especially for the measurement of minimal residual disease (MRD). We here outline the laboratory set up at diagnosis and during follow up in CMPDs with specific focus on the respective therapeutical consequences. Only by using a comprehensive diagnostic panel including cytomorphology, cytogenetics, and molecular genetic methods establishing the correct diagnosis, optimizing treatment as well as evaluating treatment response is possible in CMPDs today.

Blood Cell Count↗

PubMed2001

BAALC, the human member of a novel mammalian neuroectoderm gene lineage, is implicated in hematopoiesis and acute leukemia.

The molecular basis of human leukemia is heterogeneous. Cytogenetic findings are increasingly associated with molecular abnormalities, some of which are being understood at the functional level. Specific therapies can be developed based on such knowledge. To search for new genes in the acute leukemias, we performed a representational difference analysis. We describe a human gene in chromosome 8q22.3, BAALC (brain and acute leukemia, cytoplasmic), that is highly conserved among mammals but evidently absent from lower organisms. We characterized BAALC on the genomic level and investigated its expression pattern in human and mouse, as well as its complex splicing behavior. In vitro studies of the protein showing its subcellular localization suggest a function in the cytoskeleton network. Two isoforms are specifically expressed in neuroectoderm-derived tissues, but not in tumors or cancer cell lines of nonneural tissue origin. We show that blasts from a subset of patients with acute leukemia greatly overexpress eight different BAALC transcripts, resulting in five protein isoforms. Among patients with acute myeloid leukemia, those overexpressing BAALC show distinctly poor prognosis, pointing to a key role of the BAALC products in leukemia. Our data suggest that BAALC is a gene implicated in both neuroectodermal and hematopoietic cell functions.

3T3 Cells↗

PubMed2001

Absence of the wild-type allele predicts poor prognosis in adult de novo acute myeloid leukemia with normal cytogenetics and the internal tandem duplication of FLT3: a cancer and leukemia group B study.

The FLT3 gene is mutated by an internal tandem duplication (ITD) in 20-25% of adults with acute myeloid leukemia (AML). We studied 82 adults <60 years of age with primary AML and normal cytogenetics, who received uniform high-dose therapy and found FLT3 ITD in 23 (28%) patients. When the 23 FLT3 ITD+ cases were compared with the 59 cases with wild-type (WT) FLT3, disease-free survival (DFS) was inferior (P = 0.03), yet overall survival (OS) was not different (P = 0.14). However, 8 (35%) of 23 FLT3 ITD/+ cases also lacked a FLT3 WT allele (FLT3(ITD-R)) as determined by PCR and loss of heterozygosity. Thus, three genotypic groups were identified: normal FLT3(WT/WT), heterozygous FLT3(ITD/WT), and hemizygous FLT3(ITD/-). DFS and OS were significantly inferior for patients with FLT3(ITD/-) (P = 0.0017 and P = 0.0014, respectively). Although DFS and OS for FLT3(WT/WT) and FLT3(ITD/WT) groups did not differ (P = 0.32 and P = 0.98, respectively), OS of the FLT3(ITD/-) group was worse than the FLT3(WT/WT) (P = 0.0005) and FLT3(ITD/WT) (P = 0.008) groups. We propose a model in which FLT3(ITD/-) represents a dominant positive, gain-of-function mutation providing AML cells with a greater growth advantage compared with cells having the FLT3(WT/WT) or FLT3(ITD/WT) genotypes. In conclusion, we have identified the FLT3(ITD/-) genotype as an adverse prognostic factor in de novo AML with normal cytogenetics. A poor prognosis of the relatively young FLT3(ITD/-) adults (median age, 37 years), despite treatment with current dose-intensive regimens, suggests that new treatment modalities, such as therapy with a FLT3 tyrosine kinase inhibitor, are clearly needed for this group of patients.

Acute Disease↗

PubMed2001

Impact of therapy With chlorambucil, fludarabine, or fludarabine plus chlorambucil on infections in patients with chronic lymphocytic leukemia: Intergroup Study Cancer and Leukemia Group B 9011.

PURPOSE: We sought to determine whether therapy with single-agent fludarabine compared with chlorambucil alone or the combination of both agents had an impact on the incidence and spectrum of infections among a series of previously untreated patients with B-cell chronic lymphocytic leukemia (CLL). PATIENTS AND METHODS: Five hundred fifty-four previously untreated CLL patients with intermediate/high-risk Rai-stage disease were enrolled onto an intergroup protocol. Patients were randomized to therapy with chlorambucil, fludarabine, or fludarabine plus chlorambucil. Data pertaining to infection were available on 518 patients. Differences in infections among treatment arms were tested with the Kruskal-Wallis, Wilcoxon, and chi(2) tests. RESULTS: A total of 1,107 infections (241 major infections) occurred in 518 patients over the infection follow-up period (interval from study entry until either reinstitution of initial therapy, therapy with a second agent, or death). Patients treated with fludarabine plus chlorambucil had more infections than those receiving either single agent (P <.0001). Comparing the two single-agent arms, there were more infections on the fludarabine arm (P =.055) per month of follow-up. Fludarabine therapy was associated with more major infections and more herpesvirus infections compared with chlorambucil (P =.008 and P =.004, respectively). Rai stage and best response to therapy were not associated with infection. A low serum immunoglobulin G was associated with number of infections (P =.02). Age was associated with incidence of major infection in the combination arm (P =.004). CONCLUSION: Combination therapy with fludarabine plus chlorambucil resulted in significantly more infections than treatment with either single agent. Patients receiving single-agent fludarabine had more major infections and herpesvirus infections compared with chlorambucil-treated patients.

Administration, Oral↗

PubMed2001

High frequency of immunophenotype changes in acute myeloid leukemia at relapse: implications for residual disease detection (Cancer and Leukemia Group B Study 8361).

Multiparameter flow cytometry (MFC) has the potential to allow for sensitive and specific monitoring of residual disease (RD) in acute myeloid leukemia (AML). The use of MFC for RD monitoring assumes that AML cells identified by their immunophenotype at diagnosis can be detected during remission and at relapse. AML cells from 136 patients were immunophenotyped by MFC at diagnosis and at first relapse using 9 panels of 3 monoclonal antibodies. Immunophenotype changes occurred in 124 patients (91%); they consisted of gains or losses of discrete leukemia cell populations resolved by MFC (42 patients) and gains or losses of antigens on leukemia cell populations present at both time points (108 patients). Antigen expression defining unusual phenotypes changed frequently: CD13, CD33, and CD34, absent at diagnosis in 3, 33, and 47 cases, respectively, were gained at relapse in 2 (67%), 15 (45%), and 17 (36%); CD56, CD19, and CD14, present at diagnosis in 5, 16, and 20 cases, were lost at relapse in 2 (40%), 6 (38%), and 8 (40%). Leukemia cell gates created in pretreatment samples using each 3-antibody panel allowed identification of relapse AML cells in only 68% to 91% of cases, but use of 8 3-antibody panels, which included antibodies to a total of 16 antigens, allowed identification of relapse AML cells in all cases. Thus, the immunophenotype of AML cells is markedly unstable; nevertheless, despite this instability, MFC has the potential to identify RD in AML if multiple antibody panels are used at all time points. (Blood. 2001;97:3574-3580)

Adolescent↗

PubMed2001

Novel methylation targets in de novo acute myeloid leukemia with prevalence of chromosome 11 loci.

Aberrant DNA methylation is believed to be important in tumorigenesis by causing either transcriptional inactivation of genes or chromosomal instability. Several laboratories have identified promoter hypermethylation of tumor suppressor genes in acute myeloid leukemia (AML). However, these studies do not provide a global assessment of overall methylation changes and do not allow the identification of novel methylated sequences. Previously, nonrandom CpG island methylation was reported in 17 adult de novo AML diagnostic samples when compared with the corresponding remission samples by means of restriction landmark genomic scanning (RLGS). That study has been expanded on by an analysis of a larger set of CpG islands (1740 vs 1184), which now provides details of 33 cloned methylated loci, including 21 known genes or expressed sequence tags. Five of these cloned loci appear to be methylated only in AML and not in the 6 solid tumors studied in this study (more than 98 samples analyzed). Chromosomal location was available for 30 of the 33 loci, and 5 of these 30 (17%) are localized to chromosome 11, suggesting a trend toward overrepresentation of methylation events on this chromosome. These results provide evidence for widespread aberrant methylation in AML, with identification of novel methylation targets, epigenetic changes that appear unique to AML, and apparent preferential methylation on chromosome 11.

Adult↗

PubMed2001

Comparison of cytogenetic and molecular genetic detection of t(8;21) and inv(16) in a prospective series of adults with de novo acute myeloid leukemia: a Cancer and Leukemia Group B Study.

PURPOSE: To prospectively compare cytogenetics and reverse transcriptase-polymerase chain reaction (RT-PCR) for detection of t(8;21)(q22;q22) and inv(16)(p13q22)/t(16;16)(p13;q22), aberrations characteristic of core-binding factor (CBF) acute myeloid leukemia (AML), in 284 adults newly diagnosed with primary AML. PATIENTS AND METHODS: Cytogenetic analyses were performed at local laboratories, with results reviewed centrally. RT-PCR for AML1/ETO and CBFbeta/MYH11 was performed centrally. RESULTS: CBF AML was ultimately identified in 48 patients: 21 had t(8;21) or its variant and AML1/ETO, and 27 had inv(16)/t(16;16), CBFbeta/MYH11, or both. Initial cytogenetic and RT-PCR analyses correctly classified 95.7% and 96.1% of patients, respectively (P =.83). Initial cytogenetic results were considered to be false-negative in three AML1/ETO-positive patients with unique variants of t(8;21), and in three CBFbeta/MYH11-positive patients with, respectively, an isolated +22; del(16)(q22),+22; and a normal karyotype. The latter three patients were later confirmed to have inv(16)/t(16;16) cytogenetically. Only one of 124 patients reported initially as cytogenetically normal was ultimately RT-PCR-positive. There was no false-positive cytogenetic result. Initial RT-PCR was falsely negative in two patients with inv(16) and falsely positive for AML1/ETO in two and for CBFbeta/MYH11 in another two patients. Two patients with del(16)(q22) were found to be CBFbeta/MYH11-negative. M4Eo marrow morphology was a good predictor of the presence of inv(16)/t(16;16). CONCLUSION: Patients with t(8;21) or inv(16) can be successfully identified in prospective multi-institutional clinical trials. Both cytogenetics and RT-PCR detect most such patients, although each method has limitations. RT-PCR is required when the cytogenetic study fails; it is also required to determine whether patients with suspected variants of t(8;21), del(16)(q22), or +22 represent CBF AML. RT-PCR should not replace cytogenetics and should not be used as the only diagnostic test for detection of CBF AML because of the possibility of obtaining false-positive or false-negative results.

Adult↗

PubMed1999

Extended Rituximab (anti-CD20 monoclonal antibody) therapy for relapsed or refractory low-grade or follicular non-Hodgkin's lymphoma.

BACKGROUND: Rituximab is a chimeric monoclonal antibody directed against the B-cell CD20 antigen which has been utilized for therapy of B-cell non-Hodgkin's lymphoma (NHL). A previous clinical trial demonstrated that treatment with four weekly doses of 375 mg/m2 of Rituximab in patients with relapsed or refractory low-grade or follicular B-cell non-Hodgkin's lymphoma was well tolerated and had significant clinical activity. PATIENTS AND METHODS: To assess the safety and efficacy of Rituximab treatment, an open-label, single-arm, multi-center, phase II study of eight consecutive weekly infusions of 375 mg/m2 Rituximab in patients with low-grade or follicular B-cell NHL who had relapsed or had failed primary therapy was conducted. Thirty-seven patients with a median age of 55 years were treated. RESULTS: Grade 1 or 2 adverse events were the majority of reported toxicities and occurred most frequently with the first infusion, decreasing with subsequent infusions. No patients developed a host antibody response (HACA) to Rituximab. The mean serum immunoglobulin levels for IgG, IgA, and IgM stayed within the normal range throughout the study. The majority of patients who were bcl-2 positive at baseline in peripheral blood became bcl-2 negative during treatment and remained negative at the time of B-cell recovery. In the 37 intent-to-treat patients, 5 (14%) had a complete response and 16 (43%) had a partial response for an overall response rate of 57%. Of 35 evaluable patients, 21 (60%) responded to treatment (14% CR and 46% PR). In responders, the median time to progression (TTP) and the median response duration have not been reached after 19.4+ months and 13.4+ months, respectively. CONCLUSIONS: The safety profile and efficacy achieved in this pilot study of extended treatment with Rituximab compares favorably with those seen with four weekly doses. Further studies are warranted to investigate whether this or other extended Rituximab schedules will result in increased efficacy in all or in certain subgroups of patients with low-grade or follicular NHL.

Adult↗

PubMed1995

Morphological, ultrastructural, and genetic characterization of an unusual T-cell lymphoma in a patient with sinus histiocytosis with massive lymphadenopathy.

Sinus histiocytosis with massive lymphadenopathy (SHML) is a rare benign disease of unknown etiology. It is rarely associated with malignant lymphoma. This report documents the first case of a T-cell lymphoma, which developed in a patient with a 10-year history of SHML. The disease was complicated by hypereosinophilia and massive retroperitoneal lymphadenopathy. Histological examination of a cervical lymph node biopsy during the terminal phase identified a lymphoma composed of cells with morphological plasmacytoid features. Ultrastructurally, the tumor cells showed poorly developed cytoplasm, nuclei with peripheral chromatin clumping, and inconspicuous nucleoli. Cytogenetic studies showed two related clones. On immunohistochemical staining tumor cells were positive with monoclonal antibodies (mAb) CD3 and CD45RO. Southern blotting analysis identified clonal rearrangements in the T-cell receptor (TCR) alpha, beta and gamma genes. Thus, T-cell lineage of the tumor cells was established. In situ hybridization of interleukin-2 (IL-2) and interleukin-5 (IL-5) cDNA probes on tissue sections identified the synthesis of IL-5 by the eosinophils, suggesting an autocrine pathway of eosinophilopoiesis leading to hypereosinophilia in this patient.

Clone Cells↗

PubMed1992

A phase II pilot trial of high-dose hydroxyurea in chronic myelogenous leukemia.

Suppression or eradication of the Philadelphia (Ph1) chromosome has been a major goal in the therapy of chronic myelogenous leukemia (CML). Variable levels of Ph1 chromosome negativity have been achieved using interferon-alfa, busulfan, combination chemotherapy, and allogeneic bone marrow transplantation. This study evaluated the effect of achieving a predetermined level of myelosuppression using hydroxyurea on bone marrow cytogenetics in CML. Fourteen patients with chronic phase CML received 25 cycles of therapy. Fourteen of the 25 cycles were associated with cytogenetic responses consisting of 25% or more Ph1 negative metaphases (range, 25% to 100%). Nine of the responses consisted of 50% or greater Ph1 negative metaphases. Toxicity was exclusively due to consequences of myelosuppression, including febrile neutropenia and thrombocytopenia. In chronic phase CML, hydroxyurea induces cytogenetic responses with tolerable toxicity and is an attractive agent for further study as a component of treatment strategies aimed at eradicating the Ph1 + population in CML.

Administration, Oral↗

PubMed1991

The immunotherapy of human cancer with interleukin 2: present status and future directions.

Interleukin-2 (IL-2) is the principal soluble factor responsible for the proliferation of activated T cells. In animal models and humans, administration of IL-2 can induce regressions of established cancers. These antitumor effects may be partially mediated by cytotoxic effector cells activated by IL-2, including lymphokine-activated killer (LAK) cells and cytotoxic T lymphocytes. IL-2 has additional effects on other components of the cellular immune system, including B cells and macrophages, and induces secretion of other soluble mediators, including tumor necrosis factors (TNF) alpha and beta, and interferon-gamma. These effects may contribute to the antitumor activity of IL-2 as well as its dose-related toxicity. Multiple Phase I and II trials have been completed or are ongoing evaluating the clinical and biological effects of IL-2 given by diverse routes and schedules, both alone and in combination with infusions of ex vivo IL-2-activated autologous LAK cells. Other studies have begun to explore the potential for antitumor synergy when IL-2 is combined with the different interferons, TNF, monoclonal antibodies, and cytotoxic drugs. The biology, toxicity, and clinical activity documented in IL-2 clinical trials to date are reviewed, and prospects for future directions outlined.

Clinical Trials as Topic↗

PubMed1990

Pharmacokinetics of recombinant interleukin 2 in humans.

This report summarizes the pharmacokinetics in humans of recombinant interleukin 2 (IL-2) given as an i.v. bolus, i.v. or i.p. infusion, and i.m. or s.c. injection. Immediately after an i.v. bolus the serum IL-2 level equals the dose divided by the plasma volume, in a typical human 650 units/ml for a dose of 10(6) units/m2. The level initially decreases with a half-life of 12.9 min, followed by a slower phase with a half-life of 85 min out to 4 h after the bolus. The median steady state level during an i.v. infusion of 10(6) units/m2 over 6 h is 41 units/ml. A clearance rate of approximately 120 ml/min is obtained from either the i.v. bolus or infusion data and is consistent with the renal filtration being the major route of clearance. Serum levels remain fairly constant for about 8 h after s.c. or i.m. injection but are approximately 2% of the level seen immediately after an i.v. bolus. The area under the time-concentration curve suggests that about 30% of the IL-2 activity is transported from the site of an i.m. injection to the blood. After i.p. infusion IL-2 is only slowly transported to the blood. The median serum IL-2 levels are 430-fold lower than levels in the i.p. fluid and decrease with a median half-life of 6.3 h.

Biological Assay↗

PubMed1989

A phase-II study of low-dose cyclophosphamide and recombinant human interleukin-2 in metastatic renal cell carcinoma and malignant melanoma.

Recent preclinical and clinical studies that have demonstrated antitumor activity of high-dose recombinant interleukin-2 (rIL-2), and animal models that demonstrated a synergistic effect of low-dose cyclophosphamide, led us to study rIL-2 (Cetus Corp., Emeryville, Calif) in a phase II clinical trial in combination with low-dose cyclophosphamide in 32 patients, 18 with malignant melanoma and 14 with renal cell carcinoma. rIL-2 was given once daily at 3 x 10(6) U/m2, as a 30-min infusion for 14 days in cycle I and for 2 x 5 days in cycles II and III respectively; if tolerated, the dose was increased to a maximum of 6 x 10(6) U m-2 day-1; the cycles, separated by 1 week treatment-free intervals, were preceded each by a single i.v. bolus of cyclophosphamide at 350 mg/m2. The most prominent side-effects encountered in this trial consisted of a capillary leak syndrome, myalgia and fever that required dose reduction during the first cycle in one-half of the patients. Given the limit of tolerable toxicities in a standard care unit, the regimen employed achieved minor antitumor activity. No remission was achieved in patients with renal cell carcinoma, and 15% of melanoma patients showed objective responses (partial response + minor response).

Adult↗

PubMed1988

A phase I trial of intraperitoneal recombinant interleukin 2 in patients with ovarian carcinoma.

Seven patients with refractory stage III ovarian carcinoma were treated with escalating doses of human recombinant interleukin 2 (rIL-2) administered via the intraperitoneal (IP) route in an attempt to establish a dose and schedule of rIL-2 suitable for prolonged outpatient IP administration. Three patients went on to receive outpatient maintenance treatment twice weekly for 2-3 months. Doses ranged from 10(5) to 5 x 10(7) U/m2. The dose found most suitable for twice weekly outpatient IP administration was 10(6) U/m2. Dose-limiting toxicities consisted of diarrhea resulting in hypovolemia (5 patients) fever and chills (4 patients), nausea and vomiting (1 patient), mental status changes (2 patients), and azotemia (1 patient). These side effects were not prevented by indomethacin. Significant hypotension was not observed. Pharmacokinetic studies revealed extremely high IP concentrations of IL-2 which persisted for more than 24 hours. After a dose of 10(6) U/m2, the IP concentrations ranged from 670 to 760 U/ml. In one patient in whom concurrent serum concentrations were determined, the IP concentrations were over 100-fold higher than serum levels. After a dose of 10(7) U/m2, the IP concentrations of IL-2 ranged from 8700 to 14000. Concurrent serum levels in one patient revealed IP concentrations over 500-fold higher than serum levels. There were no consistent changes in T cell surface and activation markers on mononuclear cells from peripheral blood in 3 patients tested. Natural killer cell (NK) activity in peripheral blood increased in the three patients in whom it was measured. Four of the 7 patients progressed on treatment; 3 patients remained stable. We conclude that 10(6) U/m2 of rIL-2 is well-tolerated when administered by the IP route and that concentrations of IL-2 well in excess of that required to enhance cell-mediated cytotoxicity in vitro persist in the IP fluid for at least 24 hours.

Adult↗

PubMed1988

Anti-tumor efficacy of interleukin-2-activated killer cells in human neuroblastoma ex vivo.

We studied the ex vivo sensitivity of continuously cultured neuroblastoma cells from 3 different patients towards interleukin-2-induced cell-mediated cytotoxicity. A mean (+/- SD) target cell lysis (4 h 51Cr release) of 49 +/- 11, 46 +/- 8, and 32 +/- 11% in SMS-SAN, LA-N-1, and SK-N-BE2 cell lines, respectively, was achieved when neuroblastoma cells were co-cultured at an effector-to-target (E:T) ratio of 50:1 with peripheral blood mononuclear cells (PBMC) that had been preincubated for 4 days in the presence of recombinant interleukin-2 (rIL-2; 100 U/ml). Under identical conditions, 93 +/- 9% of Daudi cells (a standard target for rIL-2-activated killer cells) were lysed. Preincubation of rIL-2-induced PBMC cultures in the presence of irradiated neuroblastoma targets (LA-N-1, SK-N-BE2) resulted in a significant cytolytic augmentation. At E:T ratios of 50:1 and 10:1, day-4 rIL-2/LA-N-1-stimulated PBMC produced 69 +/- 7 and 41 +/- 11% lysis of LA-N-1 cells, as compared to 46 +/- 8 and 22 +/- (mean +/- SD) 7% lysis by untargeted PBMC that were preincubated with rIL-2 (100 U/ml) in the absence of LA-N-1 target cells (p less than 0.05). Co-incubation of rIL-2-induced PBMC preparations with irradiated LA-N-1 and SK-N-BE2 cells, respectively, did not significantly enhance the cytolytic activity against other neuroblastoma targets and the standard Daudi cell line (p greater than or equal to 0.3).(ABSTRACT TRUNCATED AT 250 WORDS)

Cytotoxicity, Immunologic↗

PubMed1988

Cell-mediated toxicity of interleukin-2-activated lymphocytes against autologous and allogeneic human myeloma cells.

We studied the sensitivity of human myeloma (plasma cell leukemia) toward autologous and allogeneic lymphokine-activated killer (LAK) cells. Fresh plasma cell leukemia (PCL)-derived peripheral blood mononuclear cells (PBMC) and PBMC from 3 normal donors were cultured in the presence of recombinant interleukin-2 (rIL2; 1,000 U/ml) for subsequent use as cytotoxic effectors against fresh and continuously cultured myeloma cells. Target cell lysis was measured in a 4-hour 51Cr radioisotope release assay. At an effector to target (E:T) ratio of 50:1, rIL2-induced PCL-PBMC lysed 48 +/- 19% (mean +/- 1 SD) of autologous myeloma targets, as compared to 89 +/- 5, 95 +/- 15, and 100 +/- 9% lysis of standard LAK-sensitive Daudi cells and allogeneic myeloma cell lines SKO-007, and RPMI-8226, respectively. Normal PBMC-derived rIL2-induced (LAK) cells exhibited a slightly lower cytotoxic reactivity against allogeneic targets (61 +/- 9, 60 +/- 6, and 81 +/- 8% cytolysis of SKO-007, RPMI-8226, and Daudi cells, respectively, at a 50:1 E:T ratio). Cytotoxicity against myeloma (PCL) of autologous PCL-derived killer cells could be significantly (at least 2-fold) enhanced when rIL-2-induced effector cells were preincubated for 18 h in the presence of recombinant Interferon-alpha rIFN-alpha; 1,000 U/ml). In summary, our results indicate the potential antitumor efficacy of rIL2- and rIL2 + rIFN-alpha-activated killer cells in human myeloma (PCL).

Cells, Cultured↗

PubMed1988

Ewing's sarcoma: ex vivo sensitivity towards natural and lymphokine-activated killing.

We studied the ex vivo cell-mediated cytotoxicity of natural killer (NK) and lymphokine-activated killer (LAK) cells against continuously cultured Ewing's sarcoma cells from 3 different patients. Target cell lysis was measured in a 4-hour 51Cr radioisotope release assay. At an effector to target (E:T) ratio of 50:1, the mean (+/- 1 SD) cytolysis by fresh purified large granular lymphocytes (NK cells) was 20 +/- 8, 25 +/- 2, and 21 +/- 3% in Ewing's sarcoma cell lines 6647, 5838, and A4573, respectively. Under identical conditions, NK cells lysed 56 +/- 7% of K562 (a standard NK target), and 3 +/- 3% of Daudi (a standard NK-resistant LAK target). When compared to fresh unseparated peripheral blood mononuclear cells (PBMC), purified NK cells did not exhibit an enhanced cytotoxic reactivity against either Ewing's sarcoma target. In contrast, LAK cells (i.e., PBMC that were preincubated for 4 days in the presence of rIL-2) were highly cytotoxic against all three Ewing's sarcoma targets. LAK activity was dependent on the concentration of rIL-2 used in PBMC cultures. Optimum cell-mediated toxicity against the standard LAK target Daudi (99 +/- 10% cytolysis at 50:1 E:T ratio) was achieved at rIL-2 concentrations of 1,000 u/ml. LAK cells grown under these conditions were also effective against Ewing's sarcoma cells. At an E:T ratio of 50:1, 86 +/- 16, 85 +/- 16, and 67 +/- 13% inhibition was observed in 6647, 5838, and A4573 cells, respectively, as compared to 17 +/- 10, 19 +/- 15, and 29 +/- 11% cytolysis by fresh uninduced PBMC. In summary, our results suggest that rIL-2-induced LAK-type immune effector cells may be of some therapeutic value in the treatment of poor prognosis Ewing's sarcoma.

Cell Line↗

PubMed1988

Phase I trial of recombinant interleukin-2 and cyclophosphamide: augmentation of cellular immunity and T-cell mitogenic response with long-term administration of rIL-2.

Long-term subcutaneous (s.c.) administration of recombinant Interleukin-2 (rIL-2) was evaluated in 18 patients with advanced malignancy who received escalating doses of rIL-2 (1.0-9.8 X 10(6) U/m2) s.c. five times per week for a median of 38 days (range 5-228 days). Prior to the s.c. phase of the study, 24 patients received low doses (50 or 350 mg/m2) of cyclophosphamide (CPM) i.v. on day 1 followed by 10 doses (days 5-9 and 12-16) of rIL-2 (1 X 10(6) U/m2) given by 6 h i.v. infusion. There were no major antitumor effects. Toxicity was not clearly dose-related, with pain and induration at s.c. injection sites, fatigue, malaise, and palpitations most often observed. Pretreatment baseline ranges (PBR), which are 95% prediction intervals that reflect both intra- and interpatient variability, were calculated for nine hematologic and immunologic variables derived from 21 of the 24 patients. While pretreatment with CPM had no significant effect on these variables during the i.v. phase of the study as compared to a prior study using an identical rIL-2 i.v. infusion schedule, prolonged administration of s.c. rIL-2 was associated with (a) enhancement of natural killer (NK) cytotoxicity against K562 in 13 of 21 patients (p less than 0.00001), (b) increases in cytotoxicity against K562 (15 patients) and against Daudi (9 patients) in the presence of 10 U/ml of rIL-2 (p = 0.007), (c) increases in the proliferative response in vitro to OKT3 and rIL-2 in 12 patients (p less than 0.00001), (d) lymphocytosis with increase in percentage of Tac (13 patients, p less than 0.00001), T8 (11 patients, p = 0.0005), and T9 (8 patients, p = 0.021) expression, and (e) eosinophilia. While initial rises in some of these variables occurred during the i.v. phase of the study, maximum increases for all variables except T9 positivity occurred during prolonged s.c. therapy. Nine of 10 patients studied while on therapy greater than 50 days had anti-rIL-2 antibodies in an enzyme-linked immunosorbent assay; in only one case was the antibody neutralizing. This study demonstrates that significant enhancement of cytotoxicity against both NK-sensitive and -resistant targets and improvements in T-cell mitogenic response occur with long-term administration of rIL-2. Further evaluation of long-term administration of tolerable doses of rIL-2 is warranted.

Antibodies, Monoclonal↗