Identification of megakaryocyte precursors in peripheral blood stem cell collections from normal donors

Platelet engraftment, the time course and magnitude of platelet recovery (PR) post-transplant, is imprecisely defined but is most often reported as the time to transfusion (tx) independence and/or a platelet count > or = 20,000/microl. While correlations between engraftment time for granulocytes (PMN) and the dose of CD34-positive cells per kilogram are established, such associations have not been established for platelet engraftment. The objective of this study was to quantify subpopulations of CD34-positive cells in peripheral blood stem cell (PBSC) collections of normal, colony-stimulating factor-granulocyte) (G-CSF) primed donors that might represent megakaryocyte (MK) precursors, and to determine whether there is a statistical association between the dose transfused and the time course of the recovery. Based on previously published data of the sequential expression of CD34, HLA-DR, and CD61, among others, during MK maturation, a combination of corresponding antibodies for the detection of various antigen coexpressions by flow cytometry fluorescence-activated cell sorting [FACS] was chosen. CD34-positive cells were further subdivided into CD34++ (bright) and + (dim). Ploidy of density-gradient separated cells was examined in subsequent donor samples by FACS. For the entire group of patients, there was no strong correlation between any of the studied subpopulations and time to PR. Only in a selected groups of patients whose platelet counts showed a sustained increase during the first 6 days after engraftment, there was a weak correlation between the time to PR and the quantity of CD34+/+CD61+ (r = -0.57) and CD34++HLA-DR-CD61+ (r = -0.62) cells infused. The magnitude of platelet production in these pt., a product of the peripheral blood platelet count and the patient's blood volume, was correlated with the time to PR (r = -0.73). We conclude from this study that subpopulations within CD34+ cells are making some contribution to PR in allogeneic peripheral blood stem cell transplantation, but the correlations are not sufficiently strong because there are probably too many unpredictable and unknown variables in the allogeneic setting that influence the pattern of engraftment.

Invasive Aspergillus sinusitis during bone marrow transplantation

Aspergillus sinusitis is usually a lethal condition in bone marrow transplanted patients. We report the case of a patient known to have a sinus infection with Aspergillus flavus before treatment with allogenic bone marrow transplantation for a refractory acute myelogenous leukemia. Exacerbation of the sinusitis during the neutropenic period required a multidisciplinary approach. Cure was achieved after treatment with a combination of surgery (Caldwell-Luc procedure), long term ABCD (amphotericin B colloidal dispersion) therapy (7 months) and granulocyte transfusions during the period preceding engraftment. The use of granulocyte transfusion in this salvage setting is discussed. Aggressive multimodality management of aspergillus sinusitis in immunosuppressed patients may lead to a cure and might not preclude allogenic transplantation.

Treatment of neutropenia-related fungal infections with granulocyte colony-stimulating factor-elicited white blood cell transfusions: a pilot study

Neutropenia-related fungal infections can be life-threatening despite antifungal therapy. We evaluated the role of recombinant granulocyte colony-stimulating factor (rG-CSF)-elicited white blood cell (WBC) transfusions in patients with neutropenia-related fungal infections. Adult patients with hematologic malignancies, absolute neutrophil counts (ANC) <500/microl and fungal infections refractory to amphotericin B, received daily transfusions of rG-CSF-elicited and irradiated WBC transfusions from related donors. Donors received 5 microg/kg/day of rG-CSF subcutaneously. Donors achieved a mean ANC of 29.4 x 10(3) per microliter. The mean yield of neutrophils per transfusion was 41 x 10(9) (range, 10-116). Fifteen patients received a median of eight transfusions (range, 3-16). Fourteen patients had received rG-CSF for a median of 12 days. The median ANC baseline was 20/microl. Eleven patients had favorable responses and eight of them remained free of infection 3 weeks after therapy. Favorable responses occurred among patients with better Zubrod performance status (median, 3 vs 4) and shorter duration of both profound neutropenia (median, 15 vs 25 days) and active infection (median, 8 vs 17 days). The mean 1- and 24-h post-transfusion ANCs were 594/microl (range, 98-1472/microl) and 396/microl (range, 50-1475/microl), respectively. Adverse reactions were observed in nine of 35 donors and in the recipients of six of 130 transfusions. rG-CSF-elicited WBC transfusions may be a safe and promising approach for treating neutropenia-related fungal infections.

Splenectomy in the accelerated or blastic phase of chronic myelogenous leukemia: a single-institution, 25-year experience

BACKGROUND

Patients in the accelerated or blastic phases of chronic myelogenous leukemia (CML) often have painful splenomegaly and secondary thrombocytopenia. We tested the hypothesis that splenectomy can be performed with minimal complications in advanced CML, thereby alleviating pain, reversing thrombocytopenia, and minimizing transfusion requirements.

METHODS

We reviewed the records of 53 patients in the accelerated or blastic phases of CML who underwent splenectomy between 1970 and 1995 at the U. T. M. D. Anderson Cancer Center.

RESULTS

Twenty-eight patients were in accelerated phase and 25 in blastic phase at the time of splenectomy. The most common indications for splenectomy were symptomatic splenomegaly (median splenic weight, 1000 gm; range, 120 to 6700 gm) or thrombocytopenia (platelet count less than 100,000/microliter) or both. There was 1 death within 30 days of splenectomy. The preoperative platelet count increased 3.72-fold +/- 0.53-fold (mean +/- SEM) by postoperative day 7 (p < 0.001; paired t test). Patients with transfusion-dependent thrombocytopenia had significantly fewer platelet and red blood cell transfusions in the 6 months after splenectomy than in the 6 months before splenectomy (p = 0.016; sign test).

CONCLUSIONS

Splenectomy can be performed with minimal morbidity and mortality in advanced CML, thereby relieving symptomatic splenomegaly, reversing thrombocytopenia, and minimizing transfusion requirements.

Effects of in vitro and in vivo cytokine treatment, leucapheresis and irradiation on the function of human neutrophils: implications for white blood cell transfusion therapy

Treatment of human polymorphonuclear leucocytes (PMNL) separated by density sedimentation (DS) from normal donors (PMNL-NL-DS) with interferon-gamma (IFN-gamma) + granulocyte colony-stimulating factor (G-CSF) lessens the damage caused by isolation and irradiation. We have studied granulocyte-macrophage colony-stimulating factor (GM-CSF) in this system, as well as the behaviour of PMNL collected by continuous flow leucapheresis (CFL) from donors treated with G-CSF (PMNL-GCSF-CFL). After isolation, PMNLs were treated with IFN-gamma + G-CSF, GM-CSF or IFN-gamma + G-CSF + GM-CSF, irradiated with 0 or 30 Gy and studied after 0 and 20 h in cell culture. All regimens reduced apoptosis of PMNL-NL-DS. Killing of Candida albicans by 20-h-old PMNL-NL-DS was best preserved by IFN-gamma + G-CSF treatment. A similar pattern of results was obtained for assays of PMNL-NL-DS chemotaxis and superoxide production. There was a consistent trend toward reduced function after irradiation in all assays. PMNL-GCSF-CFL less often demonstrated the morphological features of apoptosis, and this was further reduced by cytokine regimens containing IFN-gamma + G-CSF. In assays of C. albicans killing and chemotaxis, 20-h-old untreated PMNL-GCSF-CFL performed as well as freshly isolated PMNL-GCSF-CFL. PMNL-GCSF-CFL showed decay in CD11b (CR3), CD16 (Fc gamma III) and CD64 (Fc gamma R1) expression after 20 h in cell culture, but treatment with IFN-gamma + G-CSF preserved expression. There was a trend toward reduced function after radiation. Comparison of PMNL-GCSF separated by CFL and DS demonstrated that CFL itself is a strong inducer of the morphological features of apoptosis. This study shows that while separation by CFL, and irradiation are damaging to PMNLs, damage may be reduced by use of cytokines.

Photopheresis therapy for cutaneous T-cell lymphoma

BACKGROUND

Cutaneous T-cell lymphoma is a chronic peripheral lymphoma in which aggressive combined therapy elicits high response rates but does not improve survival. Photopheresis therapy has reportedly induced remissions and prolonged survival in patients with advanced disease.

OBJECTIVE

We studied all patients who began photopheresis treatment between February 1988 and July 1994 to determine whether we could confirm the remission rates of previous studies, to evaluate variables that might predict a response, and to discover whether an accelerated delivery system would improve the remission rate or response time.

METHODS

After an oral dose of methoxsalen was administered, a leukocyte-enhanced quantity of blood was exposed to UVA radiation for 1.5 hours and returned to the patient. With our accelerated system, 6 x 10(9) cells were irradiated in nine cycles. Treatments were given on 2 consecutive days once a month.

RESULTS

Among 34 patients whose results could be evaluated, the overall response rate (complete and partial remissions) was 50%; most patients had mild side effects. All responders except one had erythroderma. Responders had a decrease of 75% in mean skin scores, whereas nonresponders had an increase of 21%.

CONCLUSION

Photopheresis appears to be effective for selected patients with erythrodermic cutaneous T-cell lymphoma, although we did not achieve as high a remission rate as previously reported by others.

Results with high-dose chemotherapy and unpurged autologous stem cell transplantation in 73 patients with chronic myelogenous leukemia: the MD Anderson experience

The purpose of this study was to evaluate the effectiveness of unpurged autologous stem cell transplantation (ASCT) for chronic myelogenous leukemia (CML) and its impact on the survival of patients in first and late chronic phase (CML-CP) including those resistant to or unable to tolerate interferon alfa (IFN-alpha) therapy. Between 1982 and 1993, 73 patients with CML who underwent ASCT were evaluated. Twenty-eight patients had signs of transformation, 20 were in second or subsequent CP, 22 had CML-CP and had shown resistance to or were unable to tolerate IFN-alpha therapy, and there had Philadelphia (Ph) chromosome-negative CML. Survival of patients in CML-CP who underwent ASCT was compared to controls who were in first CP receiving INF-a therapy. Patients and controls were matched for age, decade of therapy, response to IFN-alpha therapy (resistance vs toxicity) and the time to ASCT (study group) vs time to resistance (control group). Nine 12% patients failed to achieve hematologic recovery, and five (7%) had early death secondary to toxicity. Twenty-seven (58%) patients who received transplants in advanced-stage CML and 18 (82%) transplanted in CML-CP achieved complete hematologic remission (CHR). The incidence of complete cytogenetic response was 10 and 14%, respectively. The median survival of these two groups of patients was 5 and 34 months, respectively (P < 0.001). However, the survival of patients in CML-CP was not significantly different from controls (34 vs 49 months; P = 0.17). We conclude that unpurged ASCT does not prolong the survival of patients in CML-CP who are resistant to IFN-alpha therapy. Progress in autotransplantation in CML might require innovative approaches to eradicate the leukemic cells from the autologous stem cells prior to transplants.

Principles of bone marrow processing and progenitor cell/mononuclear cell concentrate collection in a continuous flow blood cell separation system

The application of continuous flow apheresis technology to processing bone marrow for collection of the mononuclear progenitor cell population appears to follow the same principles as collection of mononuclear cells from peripheral blood. Unlike peripheral blood, however, where mobilization of cells from extravascular sites during the procedures contributes significantly to the final cell yield, the entire quantity of progenitor cells available for recovery from marrow is present in the original marrow when it is pooled. The process then becomes one of attempting optimal recovery of the cells of interest while excluding contaminating erythrocytes and cells of the myeloid series. This study reports the development of a protocol for recovery of MNC, CD33+, CD34+, and CD34+/DR- cells from harvested marrow for autologous and allogeneic transplants using a continuous flow blood cell separator, the variables influencing the recovery of the cells of interest and the clinical response to infusion of the processed cells.

Protection of human polymorphonuclear leukocyte function from the deleterious effects of isolation, irradiation, and storage by interferon-gamma and granulocyte-colony-stimulating factor

BACKGROUND

Fungal infections represent a difficult challenge to clinicians caring for neutropenic patients with hematologic malignancies, as antifungal therapy often has limited success in that setting. One promising yet problematic alternative approach is leukocyte transfusion. The isolation of polymorphonuclear leukocytes (PMNs) induces apoptosis and functional deterioration, and irradiation to prevent transfusion-associated graft-versus-host disease causes further functional deterioration.

STUDY DESIGN AND METHODS

The ability of interferon-gamma and granulocyte-colony-stimulating factor (G-CSF), used both alone and in combination, to protect PMNs after 0 or 20 hours' storage in cell culture (as a model for function after transfusion) and irradiation with 0, 5, or 30 Gy was studied.

RESULTS

Without cytokine treatment, 20-hour-old PMNs showed marked apoptosis, no appreciable chemotaxis, and no ability to kill Candida albicans. In contrast, cytokine treatment significantly reduced apoptosis and protected chemotaxis, C. albicans killing, and surface-receptor expression from both storage and irradiation. Although the majority of the benefit appeared to be due to G-CSF, consistent trends suggested better function of PMNs after combined treatment with interferon-gamma and G-CSF.

CONCLUSION

Judicious use of cytokines may preserve PMN function. These findings have important implications for the transfusion of PMNs to cytopenic patients.

Collection and transfusion of granulocyte concentrates from donors primed with granulocyte stimulating factor and response of myelosuppressed patients with established infection

Fifteen patients with prolonged neutropenia (a median of 23 days with granulocyte [PMN] < or = 500/microliters) and established fungal infections that had not responded to adequate antifungal therapy were transfused with PMN concentrates collected from 35 cytokine-primed granulocyte colony-stimulating factor (GCSF) donors. Patients received a median of six transfusions. Leukocytosis and granulocytosis were observed within 24 hours of the first GCSF injection, which yielded concentrates averaging 55 x 10(9) white blood cells and 41 x 10(9) PMN. Data analysis suggested that response might be related to the duration of neutropenia and known infection, as patients given PMN tx earlier in the infectious course tended to have a better response. No significant toxicity was observed in donors.

Abnormalities of von Willebrand factor multimers in drug-associated thrombotic microangiopathies

Six patients with thrombotic microangiopathy associated with drug therapy had serial analyses of von Willebrand factor (vWF) multimeric patterns in their EDTA-plasma samples by sodium dodecyl sulfate-1% agarose gel electrophoresis and autoradiography. In the plasma of five patients (one with chronic myelogenous leukemia, two with prostatic cancer, and two with lymphoma), vWF abnormalities were observed during evolution of the thrombotic microangiopathy. These abnormalities were either the presence of unusually large (UL)vWF multimers of the type similar to those found within, and released or secreted by, endothelial cells (three patients) or a relative decrease in the largest plasma vWF multimers of the type that can be induced to attach to platelets (one patient) or both vWF abnormalities in different serial samples (one patient). In the one cardiac transplant patient who did not develop vWF multimeric abnormalities associated with thrombotic microangiopathy, vWF antigen levels were elevated more than threefold. This later individual received therapy with cyclosporin A alone. The other five thrombotic microangiopathy patients received cyclosporin A in combination with other chemotherapeutic agents (two patients); mitomycin-C, along with other chemotherapy (two patients); or multiple chemotherapeutic drugs, but not cyclosporin A or mitomycin C (one patient). The finding of vWF multimeric abnormalities during serial analysis of plasma samples from five of six patients with drug-associated thrombotic microangiopathy suggests the possibility that ULvWF forms derived from damaged or stimulated endothelial cells, along with the largest plasma vWF multimers, may be involved in the intravascular platelet clumping that is an essential part of the pathophysiology of this disorder.

Depletion of patients' plasma tryptophan using tryptophan side-chain oxidase columns

The use of the enzyme tryptophan side-chain oxidase, isolated from Pseudomonas XA, was explored in 3 patients with refractory acute lymphocytic leukemia. Patients were given either a low-tryptophan diet or tryptophan-free hyperalimentation, prior to and during therapy. Their plasma, separated by pheresis, was continuously passed through a tryptophan depletion column containing the immobilized tryptophan side-chain oxidase. Up to 4 plasma volumes were passed through the column daily, 5 days per week for 2-3 weeks, and plasma tryptophan levels, both free and total, were measured by high-performance liquid chromatography. Pre- and postcolumn plasma samples were collected throughout the pheresis procedure. All postcolumn plasma samples had unmeasurable tryptophan levels throughout the treatment period, whereas precolumn samples were always measurable. Generally, tryptophan levels of plasma isolated from peripheral blood decreased after therapy, but rebounded by the next day. The enzyme depletion column reduces circulating plasma tryptophan levels, and its use is well tolerated by patients. However, further development of this method will require study of the effects of diet and of the duration, interval, and frequency of use of this column on therapeutic efficacy. Problems include difficulties with extended diet compliance and apparently intensive mobilization of tryptophan from body stores, which may preclude the clinical application of this enzyme depletion column.

Peripheral blood stem cell transplantation for breast cancer patients with bone marrow metastases using GM-CSF priming

Twenty-seven patients with metastastic breast cancer to the bone marrow underwent successful collection of peripheral blood progenitor cells (PBPC) following GM-CSF cytokine priming and were engrafted following courses of high-dose chemotherapy. Myeloid engraftment was observed in a median of 12 days, with a range of 8-29 days. The cell dose infused correlated, although weakly, with days to engraftment, although assays of CFU-GM and CD34+ cells did not, suggesting refinement in such assays is needed. The failure to observe complete remission of the tumor suggests alternative chemotherapy regimens should be investigated.

Effect of retinoids on the release and gene expression of tumor necrosis factor-alpha in human peripheral blood monocytes

The effect of retinoic acid (RA) and retinol (ROH) on the release of tumor necrosis factor (TNF) by human peripheral blood monocytes (HPBM) was determined. HPBM were cultured for various periods of time in either 5% complete (cAB) or delipidized (DLS) AB serum. TNF release (L929 cytolytic assay) in the presence of cAB occurred during the first 3 days of in vitro culture. Delipidization of AB serum completely inhibited the lipopolysaccharide (LPS)-induced release of TNF by HPBM. Addition of RA (0.5 microM) to DLS restored LPS-induced TNF release by HPBM, and supplementation with ROH (1.0 microM) resulted in release of TNF-like activity, but only after 3 days of in vitro culture. The maintenance of TNF release by the addition of exogenous RA after 3 days of in vitro culture suggested that depletion of endogenous RA was partially responsible for loss of TNF-like activity. The levels of endogenous TNF protein and mRNA were not influenced by delipidization of serum and were found to be similar to those of HPBM cultured in the presence of AB serum. TNF protein and mRNA were undetectable in HPBM ROH-treated cell lysates, although cytolytic activity was observed in culture supernatants. These results suggest that retinoids are required for the release of cytolytic factors from HPBM and that non-TNF cytolytic factors may be released by these cells at different stages of maturation.

Hematopoiesis in limiting dilution cultures: influence of cytokines on human hematopoietic progenitor cells

We have modified a limiting dilution liquid culture assay, used to quantify hematopoietic progenitor frequency, to simultaneously assess cellular proliferation and differentiation. The frequency of colonies from cord blood obtained with recombinant human interleukin 3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF) in combination was comparable to cultures with IL-3 alone. However, IL-3 and GM-CSF in combination were synergistic for higher granulocyte proliferation than IL-3 alone, indicating that enhanced granulocyte production occurred via action of GM-CSF on progenitor cell populations already stimulated into proliferation by IL-3. Peak proliferation was evident at 4 weeks in culture, with metamyelocytes predominating; at 6 weeks, mostly neutrophils and eosinophils were present, and eosinophils were more numerous in cultures with IL-3. Increasing concentrations of erythropoietin (epo) in liquid culture with IL-3 or GM-CSF decreased absolute granulocyte yield while stimulating erythroid proliferation. The influence of epo on lineage morphology for cells plated in methylcellulose was markedly less evident by comparison, arguing against an inductive effect of epo to shift progenitor cell lineage. This liquid culture methodology may be a useful tool for preclinical screening of cytokines on human hematopoietic progenitor cells.

High dose cyclophosphamide, BCNU and VP-16 with autologous blood stem cell support for refractory multiple myeloma

Eleven patients with advanced multiple myeloma refractory to standard doses of alkylating agents and salvage therapy with vincristine, adriamycin and dexamethasone (VAD) were treated with high dose cyclophosphamide, BCNU and VP-16 (CBV) with autologous blood stem cell support. Seven patients had marked marrow plasmacytosis (greater than 30%) and four had extensive pelvic bone disease precluding autologous marrow harvest. Four patients responded with a median remission duration of 7 months. Recovery of granulocytes and platelets occurred promptly in 10 evaluable patients with complete hematologic recovery. Autologous blood stem cells can provide safe and effective support for high dose CBV treatment of myeloma patients with extensive marrow plasmacytosis. The short remissions call for better cytoreductive regimens with consideration for earlier use when the myeloma may be more responsive to therapy.

Inhibition of lymphokine-activated killer cell generation by blocking factors in sera of patients with head and neck cancer

Cytolytic activation of peripheral blood lymphocytes by recombinant interleukin-2 (rIL-2) in patients with squamous cell carcinoma (SCC) of the head and neck may be inhibited by serum blocking factors, and this could influence therapeutic efficacy. Peripheral blood lymphocytes from 21 patients with this disease and 17 controls were incubated with 10-1000 U rIL-2 for 6 days in supplemented complete medium (containing 10% fetal calf serum) or the same medium plus 10% autologous serum. After washing the effector cells, we determined their cytotoxicity against K562 and MDA1386, a lymphokine-activated-killer(LAK)-sensitive SCC cell line, using a 51Cr-release assay. Patient sera inhibited LAK-generated lysis of both MDA1386 and K562, while control sera from healthy persons inhibited LAK-generated lysis of MDA1386. The blocking activity of patient sera tended to be greater than that of control sera. The sera of patients with untreated or recurrent disease and those who were free of disease had equivalent inhibitory capacity. The serum blocking factor acted in a dose-dependent manner, and inhibition was overcome by increasing the dose of rIL-2. Levels of circulating immune complexes (measured by the C1q binding method) did not correlate significantly with inhibition. A clinical protocol of repeated plasma exchange in patients with advanced and recurrent squamous cell carcinoma of the head and neck allowed sequential study of one patients's serum before, during, and after treatments. Plasmapheresis removed serum inhibitory factors, albeit temporarily. The activity of serum blocking factors in patients with this disease can be modulated by increasing doses of rIL-2 and by plasma exchange. This modulation may be important to improving clinical response rates for patients undergoing immunotherapy.

Circulating myeloid progenitor cell kinetics during hematologic recovery from chemotherapy and subsequent recombinant human granulocyte-macrophage colony-stimulating factor administration

Hematopoietic recovery from chemotherapy may be associated with an increase in circulating myeloid progenitor cell concentration (CFU-GM); these cells may be harvested by apheresis and used for autologous transplantation after high-dose cytoreductive therapy. Not all patients will demonstrate this increase, possibly due to damage to the stem cell compartment from prior chemoradiotherapy. Elevated circulating CFU-GM has also been reported in patients after short-term administration of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF); whether elevation would persist during longer duration is unknown. We measured circulating CFU-GM (by both limiting dilution in liquid culture and colony formation in semisolid media) in patients with sarcoma who began infusion of rhGM-CSF during recovery from chemotherapy. Patients with elevated circulating CFU-GM did not sustain these levels during subsequent rhGM-CSF infusion. By contrast, patients without rebound elevation of circulating CFU-GM following chemotherapy recovery did increase CFU-GM levels with rhGM-CSF administration. The proportion of marrow CFU-GM in cell cycle during chemotherapy recovery was elevated in both patient groups and remained elevated with rhGM-CSF administration. Both marrow and peripheral blood limiting dilution assays demonstrated linear growth kinetics, indicating a direct effect of the in vitro growth factor (also rhGM-CSF) on progenitor cells without excessive influence or dependence on accessory cells in culture. The use of rhGM-CSF to restore circulating CFU-GM for apheresis during recovery in patients lacking such elevation merits further study.

Arachidonic acid metabolites produced by platelet-depleted human blood monocytes: a possible role in thrombogenesis

The arachidonic acid metabolites produced by human peripheral blood monocytes were studied to determine which metabolites could have a role in thrombogenesis. Monocytes were found to be free of platelets by scanning electron microscopy and by measurement of 12-HETE. Human peripheral blood monocytes produce thromboxane as their major metabolite. Thromboxane levels reached a plateau at 12-16 hours of culture. Monocytes produced relatively little prostaglandin E2 or F2. In contrast to our control platelet preparation, neither A23187 (1-10 microM) nor exogenous arachidonic acid (0-40 microM) caused an increase in monocyte thromboxane B2. On the other hand, lipopolysaccharide (20 micrograms per ml), collagen (2.5 mg per 10(7) cells), and thrombin (5-10 units per ml) caused a two- to fivefold increase in monocyte thromboxane B2 in most donors but had no effect on prostaglandin F1 alpha levels. Blockage of thromboxane synthase by 1-benzylimidazole abolished thromboxane B2 production but did not increase prostaglandin F1 alpha. Finally, aspirin-treated platelets from a volunteer donor, which were refractory to 30 microM arachidonate, could be aggregated by isolated blood monocytes. Our data indicate that monocytes are capable of producing thromboxane in large amounts. The regulation of this increase, however, appears to be quite different from platelets. We postulate that monocytes may have a role in hemostasis by virtue of their ability to adhere at sites of vascular injury and release thromboxane, which may enhance platelet aggregation and thrombus formation.

Analysis of peripheral blood granulocyte-macrophage colony growth by limiting dilution assay

Analysis of myeloid progenitor cells in the peripheral blood (peripheral blood colony-forming unit granulocyte-macrophage; PBCFU-GM) is limited by their low frequency and by the presence of inhibitory cell populations. These factors limit the study of cytokines and cellular influences on PBCFU-GM in semisolid media assays and complicate the interpretation of data. We have developed a limiting dilution assay (LDA) in liquid culture for PBCFU-GM that allows evaluation of inhibitory or accessory effects of other cell populations and estimation of progenitor cell frequency. Using this system we have examined the inhibitory effect of autologous monocytes on in vitro colony growth. After monocyte depletion by counterflow centrifugal elutriation and adherence, colony growth with recombinant human granulocyte-macrophage colony-stimulating factor was linear over a wide range of cell densities, indicating a direct proliferative effect on circulating myeloid progenitor cells. Simultaneous PBCFU-GM assays in agar demonstrated monocyte inhibition but did not afford reliable interpretation of either progenitor frequency or linear growth kinetics in a statistically verifiable fashion. LDA in liquid culture may be a useful tool to study the effects of various cytokines and cell populations on PBCFU-GM in vitro and in vivo.

TGF-beta inhibits the in vitro induction of lymphokine-activated killing activity

Employing serum-free media, human peripheral blood mononuclear cells, and purified recombinant interleukin-2 (IL-2), conditions were observed in which the development of IL-2-driven cytotoxic activity was suppressed. The cytotoxic activity of such IL-2-generated lymphokine activated killing (LAK) was tested against natural killer-resistant cultured tumor cells (Daudi, Raji, and a glioma). LAK generation was inhibited by addition of some normal sera, normal platelets, or some tumor cells. Because recent reports have indicated that transforming growth factor-beta (TGF-beta)-like factors are often secreted by tumors and the acidic alpha granules of platelets and can be present in sera, we tested the effect of purified human TGF-beta on the activation of LAK. Our results indicated that TGF-beta is very suppressive for LAK induction, and can completely prevent both the IL-2-driven proliferation and cytotoxicity at concentrations as low as 5 ng/ml. Titrations of IL-2 and of TGF-beta indicated that the suppression is dose-dependent and can be avoided by employing higher levels of IL-2. It was also found that the suppressive effect of TGF-beta can be overcome by washing suppressed cell populations and further culture in low levels of IL-2. Collectively, these data indicate that TGF-beta can be a potent inhibitor of LAK generation under standard activation conditions, but that this effect is regulated by the relative level of IL-2 and may be overcome and/or reversed in vitro.

Acute myeloblastic leukemia with hyperleukocytosis: risk factors for early mortality in induction

Eighty-five patients with acute myeloblastic leukemia (AML) presenting with hyperleukocytosis (HL) were analyzed to assess morbidity and mortality in early induction. Patients who failed to achieve remission were older and more often had pulmonary leukostasis (62% vs 23%, p = .01) and hepatomegaly (54% vs 31%, p = .06) at presentation. Thirty-seven patients (44%) did not achieve complete remission (CR); 17 (54%) died early in induction therapy, 11 directly as a result of pulmonary hemorrhage with respiratory failure, while 5 had both pulmonary hemorrhage with respiratory failure and CNS hemorrhage. Early death patients were older and more often had pulmonary leukostasis (88% vs 29%, p less than .0001), hepatomegaly (71% vs 34%, p = .01), hyperbilirubinemia (60% vs 16%, p = .01) and hypofibrinogenemia (47% vs 12%, p less than .01) at presentation. Primarily for technical reasons, preinduction leukapheresis was not employed as often in this very-high-risk group as in other patients (56% vs 82%, respectively). Thus, sufficient heterogeneity exists in patients presenting with HL to define a subset of patients at particularly high risk for early mortality. Preinduction leukapheresis applied in a prospective controlled fashion should be evaluated to assess if such treatment may decrease early mortality in this group.

Mononuclear cell (MNC) collection by continuous-flow centrifugation (CFC)

Mononuclear cell separation and collection by continuous-flow centrifugation relates to centrifugal acceleration, total blood processed, peripheral blood concentration, and probable mobilization from extravascular sites during the procedure. At low-G forces, 70-80% of mononuclear cells are cleared. As G forces are increased, 95-100% of mononuclear cells can be cleared, but excessive platelet depletion occurs. An average of three billion cells were harvested from 2-3 liters of blood, rising to nine billion when 6 liters were processed. The total blood processed is defined by citrate infusion rates and ionized calcium changes. Large quantities of mononuclear cells were collected from normal donors without any significant depletion. If the objective of harvesting mononuclear cells is depletion, intensive schedules may be needed.

Identification of a human monocyte cytotoxicity-inducing factor from T cell hybridomas produced from Sezary's cells

Sezary's syndrome is a leukemic proliferation of OKT4+ lymphocytes. Sezary cells were isolated by differential centrifugation and fused to CEM.8azar.C, and HGPRTase-lacking clone of CEM. The hybrid cells were studied for their ability to produce soluble mediators of human monocyte cytotoxicity. The product of a single clone, FtF3, which bore the surface phenotype of Sezary cells, was characterized. Monocyte cytotoxicity-inducing factor (MCF) was found to be stable at pH 2 for 1 hr, unlike IFN-gamma, and was found to be more heat stable as well. Moreover, treatment of MCF with antisera to IFN-gamma, IFN-alpha or a combination of IFN-gamma and IFN-alpha failed to neutralize its biologic activity. MCF binds to matrix gel Red A. MCF eluted from this dye-ligand was found to have an apparent m.w. of 11,500 by gel filtration and 14,700 by SDS-polyacrylamide gel electrophoresis. MCF produced by hybridized Sezary cells appear to be neither IFN-gamma nor an altered molecular form of IFN-gamma, yet is a potent inducer of human monocyte cytotoxicity.

Identification of a human monocyte cytotoxicity-inducing factor from T cell hybridomas produced from Sezary's cells

Sezary's syndrome is a leukemic proliferation of OKT4+ lymphocytes. Sezary cells were isolated by differential centrifugation and fused to CEM.8azar.C, and HGPRTase-lacking clone of CEM. The hybrid cells were studied for their ability to produce soluble mediators of human monocyte cytotoxicity. The product of a single clone, FtF3, which bore the surface phenotype of Sezary cells, was characterized. Monocyte cytotoxicity-inducing factor (MCF) was found to be stable at pH 2 for 1 hr, unlike IFN-gamma, and was found to be more heat stable as well. Moreover, treatment of MCF with antisera to IFN-gamma, IFN-alpha or a combination of IFN-gamma and IFN-alpha failed to neutralize its biologic activity. MCF binds to matrix gel Red A. MCF eluted from this dye-ligand was found to have an apparent m.w. of 11,500 by gel filtration and 14,700 by SDS-polyacrylamide gel electrophoresis. MCF produced by hybridized Sezary cells appear to be neither IFN-gamma nor an altered molecular form of IFN-gamma, yet is a potent inducer of human monocyte cytotoxicity.

Piperazinedione, total body irradiation, and autologous bone marrow transplantation in chronic myelogenous leukemia

Eleven patients with Philadelphia chromosome (Ph1)-positive chronic myelogenous leukemia (CML) in blast crisis (ten patients) or accelerated disease (one patient) were treated with piperazinedione (PIP) and fractionated total body irradiation (TBI) followed by autologous bone marrow transplantation (ABMT). Three patients were transplanted with marrow from which the Ph1 clone had been eradicated by prior intensive chemotherapy. All patients responded with disappearance of blasts in bone marrow and peripheral blood. Six patients achieved a second chronic phase lasting 3 to 14 months (median, 6 months). Two patients had incomplete recovery, and three patients failed to engraft and died from infection. Transplantation with Ph1-negative bone marrow did not improve response duration or survival. Recurrence of blast crisis and incomplete engraftment continue to be the two major problems in this patient group, and more active regimens need to be investigated.

A multicenter trial to document the efficacy and safety of a rapidly excreted analog of hydroxyethyl starch for leukapheresis with a note on steroid stimulation of granulocyte donors

Currently, the frequency of granulocyte donation is limited by the prolonged circulation of hydroxyethyl starch (HES). We conducted a Phase I, uncontrolled, multicenter trial to evaluate both the efficacy and safety of a rapidly excreted low-molecular-weight analog of HES (LMW-HES). Seventy-five donors underwent 179 centrifugation leukapheresis procedures using LMW-HES as the red-cell-sedimenting agent. The efficacy of LMW-HES was established by harvesting adequate numbers of leukocytes. Most granulocyte concentrates contained at least 20 X 10(9) neutrophils when 8 l of blood was processed from donors optimally stimulated with steroids. The safety of LMW-HES was documented by the detection of almost no clinically significant adverse effects. In only 1.7 percent of procedures did donors require special attention, and only 1 of 179 procedures (0.6%) was permanently discontinued. Results of laboratory studies were usually normal or their values decreased transiently (approximately 15-25%) as a consequence of plasma volume expansion (dilution). Based on previous experience with HES, LMW-HES and HES perform comparably during leukapheresis. When commercially available, use of this new, rapidly excreted analog should permit more frequent leukapheresis donation.

Centrifugal elutriation as a method for isolation of large numbers of functionally intact human peripheral blood monocytes

Centrifugal elutriation was used further to isolate human peripheral blood monocytes (HPBM) from mononuclear-enriched cells harvested as a secondary component following platelet concentration collection samples. HPBM were recovered in either one or two populations consisting of either total HPBM or small (SM) and large monocytes (LM). The elutriation was carried out at 3,500 +/- 5 rpm for the separation of lymphocytes and HPBM in Ca++- and Mg++-free PBS without EDTA. An average of 5.05 +/- 1.50 X 10(8) HPBM were recovered in the total HPBM with a purity of 95% +/- 3%. The SM and LM were obtained by splitting the total HPBM into two equal populations with an HPBM purity of 92% +/- 3% and 93% +/- 3, respectively, by nonspecific esterase staining. The elutriation media were shown to have no effect on viability by trypan blue exclusion. All three HPBM populations were shown to be histochemically (lack of reactivity to leu-1 and leu-7) and functionally (depletion of NK cell activity) purified from the lymphocyte population. The HPBM populations were enriched in HLA-Dr, OKM-1, OKM-5, MY-8, and leu M-3 monoclonal antibody marker staining. There were no differences in percent positive cells between SM and LM populations for any of the monocyte-specific monoclonal antibodies. All three monocyte populations mediated antibody-dependent cell-mediated cytotoxicity to human red blood cells, with LM mediating more lysis (27.0% +/- 5%) than SM (7% +/- 3%).(ABSTRACT TRUNCATED AT 250 WORDS)

Chronic myelogenous leukemia: a multivariate analysis of the associations of patient characteristics and therapy with survival

The prognostic importance of patient pretreatment clinical and laboratory features was investigated in a group of 303 patients with Philadelphia chromosome-positive benign-phase chronic myelogenous leukemia. Intensive chemotherapy was given to 97 patients, and 78 underwent an early elective splenectomy. The overall median survival time, dated from hospital admission, was 39 months. Patient characteristics associated with shortened survival were age 60 years or older, black race, the presence of hepatomegaly, splenomegaly, symptoms, weight loss, and poor performance status. Adverse blood and bone marrow parameters were anemia, thrombocytosis or thrombocytopenia, a high proportion of peripheral blasts plus promyelocytes or of basophils, a high proportion of marrow blasts or basophils, decreased marrow megakaryocytes, and cytogenetic abnormalities in addition to the Philadelphia chromosome. Several of these factors were interrelated. A multivariate regression analysis demonstrated that the combination blood basophilia, race, additional cytogenetic abnormalities, age and marrow basophilia had the strongest predictive relationship to survival time. This resulted in a model segregating patients into low-, intermediate-, and high-risk groups, with median survivals of 53, 39, and 25 months, respectively. Another model was derived that did not include the marrow features and identified splenomegaly and platelet counts as adding to the prognosis prediction by blood basophilia, race, and age. Evaluation of the effect of therapy, after adjusting for differences in prognostic characteristics, showed that intensive chemotherapy was associated with survival prolongation among patients at intermediate and high risk of death. We conclude that a combination of pretreatment factors identifies different risk subcategories in patients with chronic myelogenous leukemia and is helpful in assessing overall prognosis and treatment effect.

Continuous-flow techniques for platelet concentrate collection: a step toward standardization and yield predictability

This study chronicles leukocyte- and erythrocyte-depleted platelet concentrate collection by a dual stage channel in which three variables: 1) donor peripheral blood platelet concentration, 2) total blood processed, and 3) collection volume were statistically correlated with platelet yield as determined by a multiple regression analysis of single variables. Platelet concentration in the final yield was related to donor precount and collection rate, and could be varied as indicated for individual applications. Total blood processed was established by procedure time, which in turn was defined by citrate-induced calcium changes in the donor. Reduction in peripheral blood platelet concentration averaged 24% for a mean platelet yield of 3.8 X 10(11). An average of 40% of transfused platelet concentrates were recovered in recipient peripheral blood 1 hr posttransfusion and were hemostatically effective, as determined by correction of bleeding time. Platelet yields and patient response were sustained during current collection procedures, verifying the principles described during the investigative period.

Response of chronic myelogenous leukemia patients to COAP-splenectomy. A Southwest Oncology Group study

Eighty-seven patients from 18 institutions with a confirmed diagnosis of chronic myelogenous leukemia were registered on a Southwest Oncology Group protocol for multiagent induction and single-agent maintenance chemotherapy, with randomization to an immunotherapy arm. Elective surgical splenectomy was performed for 42 patients at the completion of 3 months of induction therapy. Final analysis of the study revealed statistically significant survival advantages were correlated with age, splenectomy, the absence of hepatic leukemic infiltrate at the time of splenectomy, and race.

Rescue by peripheral blood mononuclear cells in dogs from bone marrow failure after total-body irradiation

In order to determine the minimum dose of buffy coat cells necessary to achieve hematopoietic rescue following supralethal irradiation, mongrel dogs under general anesthesia were subjected to leukacytapheresis using three different techniques of cell separation. The buffy coats were frozen with dimethylsulfoxide and stored at -196 degrees C until transfused. Sixteen dogs were irradiated with 800 rads and were supported with antibiotics and transfusions of irradiated homologous blood. They were transfused with the frozen and thawed buffy coat cells, and, if they survived, they were followed for 100 days, sacrificed, and their tissues studied. The mean yield of mononuclear cells during leukocytapheresis ranged from 4.1 +/- 2.0 X 10(9) (mean +/- SD) to 6.0 +/- 4.0 X 10(9) for the three leukacytapheresis methods; one technique was not as satisfactory as the other two. Six of the 16 dogs fully recovered with evidence of marrow rescue; however, only one had a dose of mononuclear cells less than 11.1 X 10(9). These data indicate that seven to 17 leukacytapheresis procedures would be required to reconstitute a 70 kilogram patient. These preliminary findings suggest that, because the yields of transplantable cells with current technology are not adequate, the transplantation potential of buffy coat cells exposed to mobilizing agents should be evaluated.

The function and structure of granulocytes collected using the IBM 2997 separator

The effect of oral methylprednisolone and the sedimenting agent, hydroxyethyl starch, on granulocyte recovery, morphology, and function was studied in a volunteer donor programme. Using the IBM 2997, 10 litres of whole blood were processed, with an average procedure time of 2.4 hours and a collection volume of 300 ml. Donors not receiving methylprednisolone (n = 80) had a mean total granulocyte count of 3.5 X 10(9)/litre (range 1.6-5.3 X 10(9)/litre) and mean granulocyte yields were 1 X 10(10) (range 0.2-3.0 X 10(10)). Those receiving 48 mg oral methylprednisolone 6-8 hours before the procedure (n = 320) had a mean granulocyte count of 6.3 X 10(9)/litre (range 3.2-11.4 X 10(9)/litre) and significantly superior mean granulocyte yields of 2.0 X 10(10) (0.3-6.5 X 10(10)) (P less than 0.05). For both groups the mean packed cell volume of 0.08 litre/litre (range 0.02-0.17) and platelet contamination 1.9 X 10(11) (range 0.3-5.0 X 10(11)). In all these procedures, hydroxyethyl starch was added to the blood entering the centrifuge channel. In none of the procedures were any untoward symptoms experienced by the donors. Light microscopy and ultrastructural studies showed no difference between control granulocytes and those collected following the addition of hydroxyethyl starch or after oral methylprednisolone. Similarly, granulocyte function measured with a random migration, chemotaxis, phagocytosis, and intracellular killing was not significantly different between control cells and those exposed to the sedimenting agent or the adrenocorticosteroids (P greater than 0.10). It is concluded that donor premedication with methylprednisolone significantly enhances granulocyte yields in the presence of hydroxyethyl starch and neither agent has any demonstrable effect on granulocyte morphology or function.

Altered heterogeneity of monocytes in acute myelomonocytic leukemia

Human peripheral blood monocytes isolated from normal donors and patients with acute myelomonocytic leukemia (AMML) were separated on a discontinuous density gradient of bovine serum albumin (BSA) into five fractions. Cells from each fraction were assayed for cell surface markers, prostaglandin E2 (PGE2) production, ability to affect proliferation in response to antigen by autologous peripheral blood lymphocytes previously depleted of monocytes, and ability to regulate immunoglobulin (Ig) synthesis by allogeneic B-lymphocytes. Fractions 1-5 from normal donors contained 11, 10, 23, 34, and 22%, respectively, of the total number of monocytes. In contrast, in 6 patients with AMML fraction 3 was considerably larger (52%) than any other fraction, in 1 patient comprising 87% of her monocytes. Cells from each fraction differed markedly in accessory function. In general, cells from fraction 3 were poorer as helper cells than cells from other fractions. They also produced after stimulation larger amounts of PGE2 than did cells from other fractions of the gradient. These data show that PBL contain a subpopulation of monocytes, which either helps poorly or suppresses in vitro immunologic function of T-cells (proliferation) and B-cells (lg synthesis), and that this subpopulation is increased in the blood of patients with AMML.

Comparative functional analysis of lymphocytes and monocytes from plateletapheresis

Large numbers (2.9 +/- 1.2 X 10(9)) of mononuclear cells can be obtained from incidental samples collected during routine plateletapheresis. We conducted studies comparing characteristics and functions of mononuclear cells derived from venous blood samples and from routine plateletapheresis in the same normal donors. Cell viability was similar in both samples (96 +/- 1% plateletapheresis vs 97 +/- 2% venous blood). Higher concentration of monocytes were observed in the plateletapheresis samples (32.3 +/- 6%) than in the venous blood (14.3 +/- 4%). The procedure of plateletapheresis does not seem to alter lymphocyte or monocyte function. Thus, the functional integrity of these cell populations was demonstrated in terms of natural killer cell activity, blastogenic response to mitogens, local graft-versus-host reactions, monocyte-mediated antibody-dependent cellular cytotoxicity against human red cells, monocyte-mediated tumor cell cytotoxicity, latex phagocytosis, and monocyte-dependent lymphocyte blastogenesis. We conclude that monocytes and lymphocytes obtained during routine plateletapheresis are functionally intact.