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Pulmonary function tests (standard vital capacity, SVC; total lung capacity, TLC; forced expiratory volume in 1 second-forced vital capacity ratio, FEV1/FVC; carbon monoxide transfer factor, DLCO) were prospectively evaluated in patients (median age 25 years, 13-52 years; median follow-up 20 months, 6-51 months) with Hodgkin's disease (15 patients), non-Hodgkin's lymphoma (9 patients), and inflammatory breast cancer (3 patients) treated with sequential high-dose therapy comprising the following phases over approximately 2 months: a) cyclophosphamide (7 g/m2); b) vincristine (1.4 mg/m2), methotrexate (8 g/m2), and cisplatinum (120 mg/m2) or etoposide (2 g/m2); c) total body irradiation (TBI; 12.5 gy, 5 fractions over 48 hours), intravenous melphalan (120-180 mg/m2), and transplantation of autologous peripheral blood and/or bone marrow hematopoietic stem cells. Within 2 months after transplantation, 12 patients also received 25 Gy radiotherapy boost to mediastinum and clavicular regions. In vivo dosimetry evaluations of fractionated TBI treatments showed that mean radiation dose absorbed by lungs was 12.18 Gy (97.4% of TBI dose). Despite such a high radiation dose, we observed only transient and subclinical decrease of SVC, TLC, and DLCO. The decrease of SVC, TLC, and DLCO was more evident and prolonged in patients receiving radiotherapy boost. All parameters progressively recovered to normal values within 2 years after transplantation. In contrast, FEV1/FVC remained within normal limits in all patients, thus demonstrating the absence of obstructive ventilatory changes. In addition, no interstitial pneumonia was observed.

Antigen CD34+ cells represent 1-4% of adult bone marrow cells comprising virtually all hematopoietic colony-forming progenitors in-vitro and probably also stem cells capable of restoring hematopoiesis of lethally irradiated hosts. We report that sizable numbers of CD34+ cells transiently circulate in the peripheral blood (PB) of patients treated with high-dose (7 g/sqm) cyclophosphamide (HD-CTX) with or without recombinant human glycosylated granulocyte macrophage colony stimulating factor (rhGM-CSF). Evidence is presented demonstrating that CD34+ cells from PB possess qualitatively normal hematopoietic colony growth and high cloning efficiency similarly to marrow CD34+ cells. In addition, CD34+ cells from PB are shown to display heterogeneous flow cytometry characteristics and differentiation antigens analogous to those from bone marrow, i.e., CD34+/CD33-, CD34+/CD13-, CD34+/CD38-, CD34+/CD11b, CD34+/DRlow+ cells have light scatter properties of small lymphocytes while CD34+/CD33+, CD34+/CD13+, CD34+/CD38+, CD34+/CD11b+, CD34+/DRhigh+ cells have light scatter properties of blast-like cells. In HD-CTX treated patients, CD34+ cell circulation is 5-fold enhanced by rhGM-CSF 5.5 micrograms/kg/day by continuous iv infusion for 14 days. During the second-third week after HD-CTX, large-scale collection of PB leukocytes by 3-4 continuous-flow leukaphereses allows the yield of 2.19-2.73 x 10(9) or 0.45-0.56 x 10(9) CD34+ cells, depending on whether or not patients receive rhGM-CSF. The number of CD34+ cells retrieved from PB by leukaphereses exceeds the number that can be harvested by multiple bone marrow aspirations under general anesthesia.(ABSTRACT TRUNCATED AT 250 WORDS)

Twenty-seven cancer patients underwent peripheral blood stem cell apheresis during hematopoietic regeneration following induction high-dose cyclophosphamide (7 g/sqm; HD-CTX). Among these patients, eleven were also treated with granulocyte-macrophage colony stimulating factor (rhGM-CSF) for 14 days after HD-CTX. We describe technique, peripheral blood cell yields and side effects of 76 leukaphereses performed using a continuous-flow blood cell separator COBE 2997. Leukaphereses, carried out through 2-5 consecutive days per patient, were started significantly earlier in rhGM-CSF treated patients. In comparison to patients receiving HD-CTX only, administration of rhGM-CSF resulted in a significantly higher yield per leukapheresis of mononuclear cells and granulocyte-macrophage colony forming units (CFU-GM) (two-fold and eight-fold, respectively). Procedures were completed and well tolerated in all cases. Minor side effects were unfrequent. Our results suggest that rhGM-CSF accelerates hematopoietic recovery after HD-CTX and facilitates large-scale collection of peripheral blood stem cells utilizable for autologous transplantation.

Seventeen patients with breast cancer (nine patients with 10 ipsilateral metastatic axillary nodes, eight patients with inflammatory breast carcinoma) previously untreated with cytotoxic chemotherapy received high-dose cyclophosphamide, 7 g/sqm (HD-CTX) as initial step of a high-dose sequential chemotherapy program. Eleven patients received also intravenous recombinant human granulocyte macrophage-colony stimulating factor (GM-CSF), 5.5 micrograms/kg per day for 7-14 days after HD-CTX. This growth factor significantly ameliorated leukopenia and thrombocytopenia induced by HD-CTX therapy thus allowing earlier delivery of subsequent courses of chemotherapy.

Two patients (aged 52 and 44) received high-dose sequential chemotherapy followed by myeloablative therapy and autotransplantation as first line treatment of a stage III multiple myeloma with high plasmacell labelling index. Autograft was performed with peripheral blood cells collected after high-dose etoposide followed by rhGM-CSF continuous infusion. During this period very high numbers of circulating hemopoietic progenitors were detected in both patients. Prompt, complete and durable hematological recovery was observed after autograft with peripheral blood stem cells. Thus, we conclude that massively released progenitors after high-dose chemotherapy and rhGM-CSF include stem cells capable of marrow reconstitution.

Circulating haematopoietic progenitors from 36 cancer patients were collected by continuous-flow leukapheresis during the phase of rapid haematopoietic recovery after pancytopenia induced by high-dose cyclophosphamide and then cryopreserved for autologous transplantation. 20 of the patients also received intravenous infusion of recombinant human granulocyte macrophage-colony stimulating factor (rhGM-CSF) for 7, 10 or 14 days after cyclophosphamide. 106 leukapheresis procedures were done for 2-5 consecutive days. Leukapheresis was started significantly earlier in patients receiving rhGM-CSF. In these patients, yields of peripheral blood elements (leucocytes, mononuclear cells, haematopoietic progenitors and platelets) were significantly higher than in controls treated with cyclophosphamide only. In particular, the mean number of granulocyte-monocyte colony-forming cells was 43.88 X 10(4) vs. 6.16 X 10(4) per kg patient body weight per leukapheresis. Side-effects of leukapheresis were limited to central venous catheter occlusion and fever in 4% and 2% of all procedures, respectively.

An assay of high sensitivity and specificity for detection of residual malignant cells in remission bone marrow from patients with acute lymphoblastic leukemia (ALL) and non-Hodgkin's lymphoma (NHL) has been developed. The assay combines an immunoselection step with immunoglobulin gene rearrangement analysis by high specific-activity DNA probes. In experimental conditions, less than one contaminating tumor cell out of 1000 bone marrow cells was detected. A bone marrow contamination was detected in morphologically negative bone marrow specimens from two intermediate-grade non-Hodgkin's lymphoma patients. This method can be of value in determining a true remission status in high-risk ALL and NHL patients.

We studied optimal conditions for ex vivo elimination of mature T cells from human bone marrow by T101 immunotoxin (T101-IT) with criteria applicable to graft-versus-host disease (GVHD) prophylaxis prior to allogeneic marrow transplantation. T101-IT consisted of T101 anti-CD5 monoclonal antibody conjugated to purified ricin A-chain toxin. Marrow mononuclear cells isolated by Ficoll-Hypaque or by fractionation with soybean lectin (SBA- cells) were incubated with T101-IT at 37 degrees C with or without ammonium chloride and/or verapamil as potential enhancers of immunotoxin potency. As controls, competitive inhibition studies with unconjugated T101 or irrelevant IgG2a antibody were carried out. Residual T cells were quantified by limiting dilution in phytohemagglutinin (PHA)-interleukin 2 (IL-2) feeder-cell-containing microcultures and hematopoietic progenitors by CFU-GM assay. We demonstrated that T101-IT in the range of 1-100 nM does not affect early total cell viability; that its delayed cytotoxicity is T-cell-specific, greatly enhanced by ammonium chloride, and moderately by verapamil--which also is not synergistic with ammonium chloride; and that 10 nM X 3 fractionated doses (i.e., added at 0, 1.5, and 3 hr of incubation) in the presence of 10 mM ammonium chloride for 4 hr at pH 7.8 consistently induces 2 log T cell depletion. In addition, if the same T101-IT treatment is preceded by fractionation with soybean lectin (i.e., T101-IT treatment of SBA- marrow cells), 3 log T cell depletion is accomplished. We conclude that T101-IT is highly effective in eliminating T cells from donor grafts. However, data presented here indicate that T101-IT should be associated with additional methods, such as soybean lectin fractionation, to ensure more effective ex vivo T cell depletion and acute GVHD prevention.

Selective removal of malignant cells from human bone marrow is one requirement for autologous bone marrow transplantation. In earlier studies treatment with multiple monoclonal antibodies and C' was more effective than treatment with individual reagents in eliminating clonogenic Burkitt's lymphoma cells from a twenty-fold excess of human bone marrow. To explore possible mechanisms underlying the additive or synergistic effects observed with multiple reagents, clones of malignant cells that have survived treatment with antibody and C' have now been isolated at limiting dilution. Marked heterogeneity has been observed in binding of different monoclonal antibodies and in resistance to C'-dependent lysis among these different clones. Phenotypic traits were stable for at least two weeks in culture. Clones that survived treatment with the J5 anti-CALLA antibody and C' exhibited a relative decrease in CALLA expression but did not exhibit an increased susceptibility to lysis by anti-CALLA and C'. No selective decrease in gp-26 or B1 was observed in clones treated with J2 or anti-B1. A correlation between CALLA and gp-26 expression was observed in clones treated with J2 and anti-B1, but no clear correlation was observed between antigen expression and susceptibility to C'-dependent lysis. In this model system, escape from C' dependent cytotoxicity does not appear related to the existence of phenotypically stable C' resistant variants within the tumor cell population.

A monoclonal antibody reactive with the immunoglobulin heavy chain (TEC IgM) has been conjugated to saporin-6 (SAP), which is the major ribosome-inactivating protein from the seeds of the plant Saponaria officinalis. Studies with Burkitt's lymphoma cell line Bjab 113 demonstrate that this immunotoxin is capable of killing 3 logs (99.9%) of clonogenic lymphoma cells after a 2-hour incubation. The presence of human bone marrow inhibits the activity of the conjugate. However, full potency of TEC IgM-SAP immunotoxin is restored by adding 1 mM amantadine to the incubation medium. The reaction is highly specific and is inhibited by the presence of excess anti-mu-antibody or human serum. Clonal growth of other Burkitt's lymphoma cell lines is inhibited to a lesser extent by the immunotoxin. The presence of surface IgM on the different cell lines is directly correlated to target cell killing by TEC IgM-SAP. Isolation of Bjab 113 clones surviving treatment demonstrates that only a minority are truly resistant and that the others randomly escape the treatment. The highly potent and specific activity of this conjugate in the presence of bone marrow buffy coat and its exceptionally rapid onset of action make this conjugate a good candidate for the ex vivo elimination of neoplastic cells from the bone marrow of non-Hodgkin's lymphoma patients.

Long-term bone marrow cultures were established from single-cell suspensions of human bone marrow that had been treated with monoclonal antibodies and complement. Each treated cell suspension was evaluated for production of hematopoietic stem cells over 20 weeks. Treatment with antibody to HLA-DR (Ia), B1, J2, or J5 did not remove adherent cells including those differentiating to adipocytes in 17-hydroxycorticosteroid. In contrast, treatment with monoclonal antibody directed against human beta 2-microglobulin reduced adipocyte numbers by 100-fold and reduced the total adherent cell density over 70%. Cumulative total nonadherent cell and granulocyte-macrophage colony-forming units (GM-CFUc) production over 20 weeks was not significantly altered by one cycle of anti-Ia plus complement or up to three cycles of treatment with complement and anti-J2, -J5, or -B1. However, one cycle of treatment with anti-beta 2-micro-globulin depressed production of both GM-CFUc and nonadherent cells by over 100-fold compared to other treatment groups. While one cycle of treatment of anti-Ia and complement killed all detectable cells forming CFU-erythroid-granulocyte-megakaryocyte-macrophage, blast-forming units (erythroid), and GM-CFUc, GM cluster-forming cells survived. Treatment of marrow with three cycles of anti-Ia and complement removed all detectable GM colony- and GM cluster-forming cells; however, this marrow produced fewer cumulative Ia-positive GM-CFUc. Long-term bone marrow cultures may prove to be an interesting system for in vitro analysis of the effects of new immunotherapeutic agents including other monoclonal antibodies prior to clinical use.

Circulating DNA has been extracted from plasma of 6 patients with pulmonary embolism; it appears of low molecular weight (about 400 base pairs) and of uniform size; its staining sensitivity to ethidium bromide suggests it is mainly double stranded. DNA circulates linked with proteins.

We evaluated the cytotoxicity of the immunotoxin OKT1-SAP on fresh B-chronic lymphocytic leukemia (B-CLL) cells from 31 consecutive patients. OKT1-SAP comprised the OKT1 (CD5) monoclonal antibody disulfide linked to saporin-6 (SAP) ribosome-inactivating protein from the plant Saponaria officinalis. The effect of OKT1-SAP on target CD5-positive B-CLL cells was estimated using an in vitro proliferation inhibition assay in which control or OKT1-SAP-treated B-CLL cells were induced to proliferate by sequential stimulation with insolubilized anti-C3b receptor CB04 (CD35) antibody and low molecular weight B-cell growth factor. In 90% of patients, OKT1-SAP specifically suppressed B-CLL cell proliferation in a dose-related manner (50% inhibitory concentration, 4.0-6.8 nM). Taken together the findings reported in this article provide information relevant to the clinical development of immunotoxins because: (a) the in vitro conditions under which B-CLL cell proliferation is inhibited by OKT1-SAP are achievable in vivo without nonspecific toxicity according to our previous toxicology and pharmacokinetics studies in primates; and (b) the B-CLL cell proliferation inhibition assay described here provides a basis for future comparative studies.

We isolated and treated in vitro with a novel CD5-specific saporin immunotoxin, referred to as OKT1-SAP, the cells infiltrating an irreversibly rejected renal allograft from a patient who rejected while on cyclosporine plus steroids and then failed to respond to multiple courses of high-dose steroids, intravenous OKT3 antibody, and local irradiation to the graft. We report here that under experimental conditions achievable in vivo the immunotoxin OKT1-SAP was capable of eliminating in vitro more than 95% of clonable T-lymphocytes infiltrating the rejected allograft of this patient despite their resistance to previous aggressive immunosuppression. To our knowledge, this is the first report of an immunotoxin-mediated suppression of the clonogenic growth of rejected renal allograft infiltrating T-lymphocytes.

The authors report on the first part of an ongoing controlled trial (52 cases) on the evaluation of the effectiveness of Li2CO3 treatment of drug-induced leukopenia in patients with solid tumors. The results indicate that treatment with 750 mg/day per os of Li2CO3 for 7 days is capable of raising the leukocyte count to a highly significant extent, without serious side effects. The leukocytosis is due to an increase in neutrophil granulocytes.

Effective autologous bone marrow transplantation for leukemia and lymphoma is likely to depend upon the selective removal in vitro of malignant cells from normal human bone marrow precursors. Highly specific cytotoxic conjugates formed by coupling ricin A chain to monoclonal antibodies might prove useful for the selective elimination of malignant cells. Consequently, ricin A chain conjugates have been prepared with several different murine monoclonal antibodies and tested for their ability to eliminate clonogenic Burkitt's lymphoma cells from an excess of human bone marrow. The most active reagents included an antibody:A chain conjugate which bound to the nonpolymorphic chain of the la molecule and another which reacted with the mu heavy chain of cell surface immunoglobulin. Conjugates formed with anti-common acute lymphoblastic leukemia antigen, anti-Mr 26,000 glycoprotein, and anti-B1 were much less active on these Burkitt's cells, contrasting with results of complement-dependent tumor cell lysis. Tumor cell kill was partially inhibited by the addition of greater than 2 X 10(6) human bone marrow cells/ml but could be potentiated by increasing the concentration of conjugate or by the addition of 10 mM ammonium chloride. In the presence of ammonium chloride, at least 4 logs of clonogenic tumor cells could be eliminated within 24 h from a 20-fold excess of bone marrow using 10(-7) M ricin A chain linked to one or two different antibodies. Similar treatment of normal human bone marrow temporarily inhibited granulocyte-macrophage colony-forming units (cell) formation but did not compromise establishment of continuous bone marrow cultures. The degree of selective elimination of tumor cells with A chain antibody conjugates was comparable to that achieved with 4-hydroperoxycyclophosphamide or with multiple monoclonal antibodies and complement.

We have synthesized 3 immunotoxins (ITs) by covalently coupling the saporin-6 hemitoxin (SAP) to OKT11, SOT3, and SOT1a murine monoclonal antibodies that recognize human T lymphocyte CD2, CD3, and CD5 surface antigens, respectively. The resulting ITs, referred to as OKT11-SAP, SOT3-SAP, and SOT1a-SAP, are equally effective in inhibiting eukaryotic protein synthesis in a cell-free system, and all 3 ITs bind to human T lymphocytes in an almost comparable manner. However, these reagents differ markedly in their ability to kill target T lymphocytes as assessed by measuring the inhibition of DNA synthesis and growth of clonable T lymphocytes in response to mitogenic and allogeneic stimuli. Whereas the anti-CD2 IT, OKT11-SAP, shows moderate cytotoxicity against T lymphocytes, the anti-CD3 IT, SOT3-SAP, and the anti-CD5 IT, SOT1a-SAP, are highly effective in eliminating the same target cells. The concentrations inhibiting 50% (IC50) of T lymphocyte DNA synthesis are 60 nM, 4.5 nM, and 1.4 nM for OKT11-SAP, SOT3-SAP, and SOT1a-SAP, respectively. Among 3 tested lysosomotropic amines, i.e., ammonium chloride, chloroquine, and amantadine, the latter only moderately potentiates the cytotoxicity of SOT1a-SAP (IC50 0.36 nM). We show that the conditions under which T lymphocyte killing is accomplished require less than 10 min exposure of T lymphocytes to the ITs, in the absence of adjuvant molecules artificially added to the incubation medium and at physiologic culture pH. These experimental characteristics of unprecedented closeness to a physiologic in-vivo model are likely to reflect the biophysical properties of the SAP moiety of the ITs. We conclude that clinical studies are warranted to define the advantage of using SAP ITs over previously described immunoconjugates.

A patient with T-cell acute lymphoblastic leukemia (T-ALL) in second remission was treated with high doses of chemotherapy and radiotherapy, followed by transplantation of autologous bone marrow purged ex-vivo with an anti-CD5-saporin immunotoxin (OKT1-SAP). Prior to transplantation the bone marrow graft had been considered in complete remission, as assessed by morphology and immunophenotyping. Twenty-two days after transplantation, the disease relapsed in the bone marrow with the same phenotype as at the onset. Retrospective analysis of the transplanted marrow cells by a recently developed high sensitivity and specificity assay (HSS assay), involving immunologic fractionation and T-cell receptor rearrangement analysis, revealed a graft contamination of approximately 0.5% malignant T-cells. This finding, together with the early post-transplant leukemic relapse, strongly suggests that the bone marrow was the source of the leukemic cells. The data are discussed for their implications on residual leukemia detection by gene rearrangement studies.

Bone marrow aspirates from 13 patients with non-Hodgkin's lymphoma of B- and T-lineage were drawn during staging procedures and examined by a combined technique involving immune selection and gene rearrangement analysis with DNA probes specific for the heavy-chain immunoglobulin gene (JH) or T cell receptor gene (T beta and T gamma). Morphologic examination of bone marrow biopsies revealed involvement by lymphoma in one case and suspicious accumulation of blasts in another. Southern blot analysis of the samples showed the presence of a rearranged clonal band in two samples, including the morphologically involved marrow. Clonal rearrangements were not detected in the suspected marrow. Bone marrow relapses were not observed in any of these patients after a median follow-up of 20 months. Antigen receptor rearrangements are tumor-specific markers which may increase the sensitivity and the specificity of morphologic examination, and may be useful in the proper staging and follow-up of lymphoma patients.