NCCN Guidelines Insights: Hematopoietic Growth Factors, Version 1.2020

Management of febrile neutropenia (FN) is an integral part of supportive care for patients undergoing cancer treatment. The NCCN Guidelines for Hematopoietic Growth Factors provide suggestions for appropriate evaluation, risk determination, prophylaxis, and management of FN. These NCCN Guidelines are intended to guide clinicians in the appropriate use of growth factors for select patients undergoing treatment of nonmyeloid malignancies. These NCCN Guidelines Insights highlight important updates to the NCCN Guidelines regarding the incorporation of newly FDA-approved granulocyte-colony stimulating factor biosimilars for the prevention and treatment of FN.

Relation between measurable residual disease and morphologic relapse in AML

7535

Background: Measurable residual disease (MRD) in AML portends a poor prognosis. The outcomes and treatments of MRD after an initial MRD negative complete remission (MRD- CR) are unclear. Methods: We retrospectively identified 432 patients ≥ 18 years of age treated for AML or high grade myeloid neoplasm (10-19% blasts in blood and/or marrow) at University of Washington/Seattle Cancer Care Alliance from 2008-2017 who achieved MRD- CR after initial treatment. Next disease recurrence was recorded, with patients either developing MRD ( < 5% blasts via multiparameter flow cytometry; n = 44) or developing morphologic relapse (≥5% blasts; n = 100). The remaining patients remained in MRD- CR (n = 288, median follow up time 3.7 years). A landmark analysis at one year was performed to compare overall survival (OS). Results: Patients who developed MRD tended to be older (p = 0.009), but baseline characteristics were otherwise similar. Therapies for MRD included allogeneic transplant, low intensity chemotherapy, and high intensity chemotherapy; no significant associations were found between type MRD directed therapy and survival. Landmark OS at 1 year after MRD- CR was significantly different for patients without relapse at 1 year compared to those with MRD or morphologic relapse (median OS was 8.5 years for no relapse, 2.2 years for MRD, and 1.0 years for morphologic relapse). A multivariable Cox regression model among patients alive at 1 year showed patients without relapse had significantly improved OS compared to those with morphologic relapse [HR 0.18 (95% CI 0.1-0.31)]. Although there was a trend towards improved OS, we did not identify a significant difference between patients with MRD relapse compared to morphologic relapse [HR 0.54 (95% CI 0.27-1.11)]. There were no significant differences in patient characteristics for patients with MRD vs morphologic relapse matched by time of relapse (days 30-90, 90-150, 150-210). Conclusions: Following MRD- CR, development of either MRD or morphologic relapse were both associated with decreased OS. Notably, no significant differences in terms of survival were seen between patients who presented with MRD as opposed to morphologic relapse. No clear predictors were identified for MRD vs morphologic relapse. In this cohort, development of MRD carried a poor OS prognosis, similar to the prognosis of developing morphologic relapse. Future clinical trials should focus on MRD directed therapies, as no consensus exists about optimal treatment of MRD.

Bortezomib and Vorinostat Therapy as Maintenance Therapy after Autologous Transplant for Multiple Myeloma

BACKGROUND

In multiple myeloma (MM), relapse is a frequent complication after autologous hematopoietic stem cell transplant (ASCT). To reduce the risk of relapse, additional therapy has been added post-ASCT. In a nontransplant relapse setting, the combination of intravenous bortezomib and oral vorinostat (BV) was studied and showed efficacy. Therefore, it was reasonable to study this combination therapy post-ASCT.

PATIENTS AND METHODS

We report on BV given post-ASCT. All 30 patients underwent conditioning for ASCT with high-dose melphalan. After recovery from the acute transplant-related toxicity, BV therapy was started and given for a total of 12 (28-day) cycles.

RESULTS

The most common toxicities were hematological, gastrointestinal (diarrhea and nausea), fatigue, and peripheral neuropathy. The median follow-up for BV patients is 7.8 (range: 6.12-9.03) years. After BV therapy, 18 patients (60%) are alive, and 9 (30%) are alive without disease progression.

CONCLUSIONS

BV can be given post-ASCT with an acceptable toxicity profile and produces reasonable disease-free and overall survival rates. A randomized study comparing the BV regimen to single-agent lenalidomide or bortezomib is needed.

A phase III trial to evaluate the efficacy of uproleselan (GMI-1271) with chemotherapy in patients with relapsed/refractory acute myeloid leukemia

TPS7066

Background: Binding of E-selectin (E-sel) to sialyl Lex, the E-sel ligand (E-sel-L), on the leukemic cell surface activates cell survival pathways and promotes chemotherapy resistance in AML. Expression of E-sel-L is associated with increased relapse and poor survival. Uproleselan (GMI-1271), a novel E-sel antagonist, disrupts cell survival pathway activation, enhances chemotherapy response and protects from toxicity such as mucositis with improved survival in vivo. Preclinical data support combination with multiple agents to achieve improved chemosensitivity and toxicities. A phase I/II study of uproleselan added to chemotherapy in R/R AML showed promising remission rates (CR/CRi) and survival outcomes, and reduced rates of mucositis. High E-sel-L expression on leukemic blasts in the bone marrow, rather than connoting treatment resistance and poor survival, instead correlated with longer survival than expected with addition of uproleselan. Breakthrough Therapy Designation was granted by FDA for treatment of patients with R/R AML. A pivotal phase 3 study (NCT03616470) is underway to assess the efficacy and safety of uproleselan with standard salvage chemotherapy in R/R AML. Methods: This study is a global, randomized, double-blind, phase 3 trial in adults aged 18-75 years with R/R AML and fit for chemotherapy. Patients may have primary refractory AML (received 1 prior induction containing an anthracycline and cytarabine), or be in untreated first or second relapse; prior HSCT is allowed. Treatment is MEC (mitoxantrone, etoposide, cytarabine) or FAI (fludarabine, cytarabine, idarubicin) induction regimen with blinded study drug (Uproleselan:placebo at 1:1 ratio) administered 1 day prior (sentinel dose) and then BID through 2 days post chemotherapy. Consolidation (HIDAC/IDAC) with uproleselan/placebo (same assignment) up to 3 cycles is allowed. The primary endpoint is overall survival; key secondary endpoints include the incidence of severe oral mucositis during induction and CR/CRh rate. Measurable residual disease, E-sel-L expression on leukemic cells, event free survival, safety, and pharmacokinetics will also be evaluated. Clinical trial information: NCT03616470.

Myeloid Growth Factors, Version 2.2017, NCCN Clinical Practice Guidelines in Oncology

Myeloid growth factors (MGFs) are given as supportive care to patients receiving myelosuppressive chemotherapy to reduce the incidence of neutropenia. This selection from the NCCN Guidelines for MGFs focuses on the evaluation of regimen- and patient-specific risk factors for the development of febrile neutropenia (FN), the prophylactic use of MGFs for the prevention of chemotherapy-induced FN, and assessing the risks and benefits of MGF use in clinical practice.

Mitoxantrone, etoposide and cytarabine following epigenetic priming with decitabine in adults with relapsed/refractory acute myeloid leukemia or other high-grade myeloid neoplasms: a phase 1/2 study

DNA methyltransferase inhibitors sensitize leukemia cells to chemotherapeutics. We therefore conducted a phase 1/2 study of mitoxantrone, etoposide, and cytarabine following “priming” with 5-10 days of decitabine (dec/MEC) in 52 adults (median age 55 [range: 19-72] years) with relapsed/refractory acute myeloid leukemia (AML) or other high-grade myeloid neoplasms. During dose escalation in cohorts of 6-12 patients, all dose levels were well-tolerated. As response rates appeared similar with 7 and 10-days of decitabine, a 7-day course was defined as the recommended phase 2 dose (RP2D). Among 46 patients treated at/above the RP2D, 10 (22%) achieved a complete remission (CR), 8 without measurable residual disease; five additional patients achieved CR with incomplete platelet recovery, for an overall response rate of 33%. Seven patients (15%) died within 28 days of treatment initiation. Infection/neutropenic fever, nausea, and mucositis were the most common adverse events. While the CR rate compared favorably to a matched historic control population (observed/expected CR ratio=1.77), CR rate and survival were similar to two contemporary salvage regimens used at our institution (G-CLAC and G-CLAM). Thus, while meeting the pre-specified efficacy goal, we found no evidence that dec/MEC is substantially better than other cytarabine-based regimens currently used for relapsed/refractory AML.

A randomized study of melphalan 200 mg/m(2) vs 280 mg/m(2) as a preparative regimen for patients with multiple myeloma undergoing auto-SCT

We aimed to examine whether doses of melphalan higher than 200 mg/m(2) improve response rates when used as conditioning before autologous transplant (ASCT) in multiple myeloma (MM) patients. Patients with MM, n=131, were randomized to 200 mg/m(2) (mel200) vs 280 mg/m(2) (mel280) using amifostine pretreatment. The primary end point was the proportion of patients achieving near complete response (⩾nCR). No treatment-related deaths occurred in this study. Responses following ASCT were for mel200 vs mel280, respectively, ⩾nCR 22 vs 39%, P=0.03, ⩾PR 57 vs 74%, P=0.04. The hazard of mortality was not statistically significantly different between groups (mel200 vs mel280; hazard ratio (HR)=1.15 (95% confidence interval (CI), 0.62-2.13, P=0.66)) nor was the rate of progression/mortality (HR=0.81 (0.52-1.27, P=0.36)). The estimated PFS at 1 and 3 years were 83 and 46%, respectively, for mel200 and 78 and 54%, respectively, for mel280. Amifostine and mel280 were well tolerated, with no grade 4 regimen-related toxicities and only one grade 3 mucositis (none with mel200) and three grade 3 gastrointestinal (GI) toxicities (two in mel200). Hospitalization rates were more frequent in the mel280 group (59 vs 43%, P=0.08). Mel280 resulted in a higher major response rate (CR+nCR) and should be evaluated in larger studies.

Mesenchymal stromal cells derived from acute myeloid leukemia bone marrow exhibit aberrant cytogenetics and cytokine elaboration

Bone marrow-derived mesenchymal stromal cells (BM-MSCs) play a fundamental role in the BM microenvironment (BME) and abnormalities of these cells may contribute to acute myeloid leukemia (AML) pathogenesis. The aim of the study was to characterize the cytokine and gene expression profile, immunophenotype and cytogenetics of BM-MSCs from AML patients compared to normal BM-MSCs from healthy donors. AML BM-MSCs showed decreased monocyte chemoattractant protein-1 levels compared to normal BM-MSCs. AML BM-MSCs expressed similar β1 integrin, CD44, CD73, CD90 and E-cadherin compared to normal BM-MSCs. Cytogenetic analysis revealed chromosomal aberrations in AML BM-MSCs, some overlapping with and others distinct from their corresponding AML blasts. No significant difference in gene expression was detected between AML BM-MSCs compared to normal BM-MSCs; however, comparing the differences between AML and MSCs from AML patients with the differences between normal hematopoietic cells and normal MSCs by Ingenuity pathway analysis showed key distinctions of the AML setting: (1) upstream gene regulation by transforming growth factor beta 1, tumor necrosis factor, tissue transglutaminase 2, CCAAT/enhancer binding protein alpha and SWItch/Sucrose NonFermentable related, matrix associated, actin dependent regulator of chromatin, subfamily a, member 4; (2) integrin and interleukin 8 signaling as overrepresented canonical pathways; and (3) upregulation of transcription factors FBJ murine osteosarcoma viral oncogene homolog and v-myb avian myeloblastosis viral oncogene homolog. Thus, phenotypic abnormalities of AML BM-MSCs highlight a dysfunctional BME that may impact AML survival and proliferation.

A prospective study of lenalidomide monotherapy for relapse after Allo-SCT for multiple myeloma

Allo-SCT can result in long-term remission in patients with multiple myeloma (MM), although its overall role in disease management remains controversial. We evaluated lenalidomide monotherapy response and tolerability among 18 patients with MM who progressed or relapsed after Allo-SCT, who were enrolled a median of 12 months (range 3-104) following transplant. Treatment duration of lenalidomide was 8 months (range 1-57). Ten patients required dose reductions from 25 to 5-20 mg at a median of three cycles (range 1-12): eight for neutropenia, one for thrombocytopenia and one for myalgias and weakness. Serious adverse events (N=5) included H1N1 influenza (2), bacterial pneumonia (2) and fever, myalgia and hypoxia. Two patients died at 3 and 5 months of gastrointestinal or hepatic GVHD occurring within 1 month of dosing. Responses included complete response (CR) (5), very good partial response (2), partial response (PR) (3), minimal response (1) and stable disease (2) for an overall response rate (≥ PR) of 56%. Ten patients discontinued therapy for progressive disease (PD) at a median of 8.5 (1-43) months. Six patients died from PD. Five patients remained on therapy at 39 months (range 14-57), with four in CR. Lenalidomide for relapse of MM after Allo-SCT can result in extended disease control (>12 months) in 50% of patients.

One amino acid change located in the conserved region of the alpha 1 domain specifies the novel HLA-C*07:147 allele

The novel HLA-C allele HLA-C*07:147 contains one nucleotide substitution in exon 2 leading to an amino acid change in the alpha 1 domain from phenylalanine to leucine.

Two amino acid changes located in the alpha 1 domain specify the novel HLA-B*27:67 allele affecting the peptide-binding-site characteristics

The novel HLA-B*27:67 contains three nucleotide substitutions in exon 2 leading to two amino acid changes.

Cancer- and chemotherapy-induced anemia

Anemia is a common condition in patients with cancer, and its correction through either transfusion with packed red blood cells or the administration of erythropoiesis-stimulating agents (ESAs) is a supportive care measure. The purpose of the guidelines is to operationalize the evaluation and treatment of anemia in cancer patients and to enable patients and clinicians to evaluate treatment options in the context of risks and benefits. The updated guidelines include a number of important changes that respond to new FDA recommendations limiting the use of ESAs in cancer patients. Updates also include new tables on the risks and benefits of ESAs versus red blood cell transfusion and recommendations for administering parenteral iron products.

For the most recent version of the guidelines, please visit NCCN.org

High-dose cyclophosphamide, BCNU, and VP-16 (CBV) conditioning before allogeneic stem cell transplantation for patients with non-Hodgkin's lymphoma

Allogeneic stem cell transplantation (SCT) has been shown to be a curative therapy for some patients with non-Hodgkin's lymphoma (NHL). Total-body irradiation and high-dose cyclophosphamide combinations are the most established conditioning regimens used in this setting. We examined the efficacy and toxicity of cyclophosphamide, BCNU, and VP-16 (CBV) as a suitable chemotherapy-only regimen for NHL patients. In total, 18 patients, median age 42 years, with NHL were treated with CBV followed by allotransplant. Patients had received a median of two prior chemotherapy regimens. Median times to neutrophil and platelet recovery were 19 and 15 days, respectively. Interstitial pneumonitis occurred in one patient. There have been four relapses after a median follow-up of 39 months. Overall, there were four deaths, one because of relapse. The 2-year estimates of relapse-free and overall survival are 56 and 76%, respectively. CBV is a safe and an effective alternative to TBI-containing regimens before allogeneic SCT for NHL.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) priming with successive concomitant low-dose Ara-C for elderly patients with secondary/refractory acute myeloid leukemia or advanced myelodysplastic syndrome

Patients with advanced MDS and secondary AML respond poorly to chemotherapy. Granulocyte-macrophage colony-stimulating factor (GM-CSF) can stimulate proliferation of leukemic blasts and sensitize these cells to the cytotoxic effects of S-phase-specific drugs. This is the first report of safety and efficacy of GM-CSF prior to and during cytarabine in a low-dose, intermittent regimen for elderly patients with poor risk acute myelogenous leukemia or myelodysplastic syndrome. Twenty patients, age 68 to 86 years, each received 250 microg/m2 of GM-CSF (Sargramostatin; Immunex, Seattle, WA, USA) subcutaneously (s.c.) or intravenously (i.v.) for 3 days followed by GM-CSF at the same dose and cytarabine 100 mg/m2 i.v. for 3 days. GM-CSF and cytarabine were both administered for 3 days during weeks 2 and 3 followed by a 3-week rest period. Rates of CR and PR were 20% and 40%, respectively. These included clinically significant resolution of cytopenias and transfusion requirements. Many of the responding patients had been heavily pretreated prior to enrollment. One- and 2-year survival estimates are 44% and 19%, respectively. Myelosuppression was the most significant toxicity. Our findings suggest that this novel combination of GM-CSF with sequential and concomitant low-dose cytarabine can benefit patients with poor risk myeloid malignancies.

Prospective evaluation of antiemetic outcome following high-dose chemotherapy with hematopoietic stem cell support

Considerable progress has been made in improving the control of chemotherapy-induced emesis. The impact of available antiemetic options for patients receiving stem cell transplants is unclear, as few prospective data have been collected. We prospectively evaluated antiemetic outcome in patients receiving stem cell transplantation over a 7-day period following the initiation of chemotherapy. The primary endpoints were the number of emetic episodes and the extent of nausea measured on a four-point scale. Eighty-two patients were evaluated. Ninety-five percent of patients had nausea during the first week of treatment; 80% had at least one emetic episode. The percentage of patients with emesis was as follows: day 1: 13%, day 2: 21%, day 3: 30%, day 4: 38%, day 5: 44%, day 6: 39%, day 7: 18%. In multivariate analysis, gender, emesis with prior chemotherapy, history of morning or motion sickness, type of transplant (auto vs allo), use of total body irradiation, or use of dexamethasone did not effect emesis control. Most patients receiving high-dose chemotherapy experience incompletely controlled emesis. Control of nausea and emesis progressively worsened with each subsequent day following initiation of chemotherapy, reaching a nadir on day 5. New treatment approaches are needed to improve emesis control in this patient population.

The molecular basis for the cytokine-induced defect in homing and engraftment of hematopoietic stem cells

OBJECTIVE

Hematopoietic stem cell homing and engraftment is dramatically altered by cytokine exposure. These studies address the molecular mechanisms responsible for the observed changes in transplantation biology.

METHODS

Primitive murine hematopoietic stem cells were isolated by fluorescence-activated cell sorting of lineage depleted (Lin(-)) cells exhibiting low staining of Hoechst 33342 and rhodamine 123 dyes or Lin(-) cells bearing Sca. Adhesion receptor expression was examined by immunofluorescence and reverse transcriptase polymerase chain reaction. In vitro adhesion assays were employed to define binding interactions between stem cells and stroma or extracellular matrix proteins.

RESULTS

Adhesion of Lin(-)Sca+ cells to Dexter stroma could be blocked by about 90% with antibodies to PECAM-1, alphaa(4), or beta(1), and partially blocked by antibodies to alpha(5), CD44, or L-selectin. By immunofluorescence, about 30% of purified Lin(-)Ho(lo)Rho(lo) cells expressed alpha(4), alpha(5), beta(1), and L-selectin, about 15% expressed alpha(L) and alpha(6), half expressed PECAM-1, and none expressed alpha(1) or alpha(2). After 48 hours in expansion cytokines, only 9% of the cells expressed alpha(4) and none expressed beta(1), whereas alpha(L) expression was fully restored, PECAM-1 and L-selectin partially restored, CD44 expression was newly induced, and adhesion to both fibronectin and laminin was reduced. Adhesion to purified collagen, fibronectin, or laminin enhanced expression of beta(1) integrins.

CONCLUSION

Expansion cytokines that move quiescent primitive hematopoietic stem cells into S phase markedly altered adhesion receptor expression and reduced their functional binding to extracellular matrix, which could reduce engraftment after transplant.

Variables to predict engraftment of umbilical cord blood into immunodeficient mice: usefulness of the non-obese diabetic--severe combined immunodeficient assay

Umbilical cord blood is an alternative stem cell source for patients without matched family donors. In this study, we examined several parameters that have not been studied in detail -- radiation dose, cell dose, age of mice, and maternal and neonatal characteristics of the cord blood donor -- that affect engraftment of cord blood in non-obese diabetic-severe combined immunodeficient (NOD--scid) mice. Engraftment, measured using flow cytometry analyses of human CD45(+) cells, was highest in 400 cGy-treated mice. Successful engraftment was demonstrated up to 6 months, with a mean engraftment of 31% (range 0--67%) of human cells in recipient bone marrow. Engraftment was skewed to B lymphocytes. The radiation dose of 350 cGy resulted in superior survival of the murine recipients compared with 400 cGy (P = 0.03). The sex of the NOD--scid recipients had a significant effect on survival (female superior to male, P = 0.01), but not on engraftment. There were high levels of variability among different cord units and among animals injected with the same cord unit. This variability may limit the clinical usefulness of the NOD--scid mice as hosts for the quantification of human stem cells.

Manipulation of the stem cell as a target for hematologic malignancies

Hematologic malignancies affect more than 80,000 patients in the United States each year. Some patients with lymphoma and leukemia are cured with conventional chemotherapy treatments. For others, autologous or allogeneic bone marrow transplantation may be the best therapeutic option. This chapter will explore novel therapies for the hematologic malignancies, using the stem cell as a target. We review work in the murine model looking at (1) the phenotype of the engrafting cells, (2) stem cell competition and host stem cells, (3) allochimerism with low-dose total body irradiation, and (4) the tolerance approach with costimulator blockade. Human data, including stem cell migration, adhesion receptor expression, and manipulations for gene therapy, are reviewed. The NOD/scid mouse model serves as a bridge between the basic bench work and human clinical trials, and we discuss applications related to umbilical cord blood and gene therapy, as well as discuss the inherent variability of this system. Finally, we address unique clinical applications in gene therapy, high-dose cell transplants, minimal myeloablation, and cellular immune therapy as approaches to treatment of for patients with hematologic malignancies.

Gene transfer to ankyrin-deficient bone marrow corrects spherocytosis in vitro

OBJECTIVE

The goal of this study was to transfer by retroviral vector the cDNA for ankyrin to progenitors from normal bone marrow and from the nb/nb spherocytosis mutant deficient in expression of full-length ankyrin to achieve erythroid expression of functional ankyrin protein.

MATERIALS AND METHODS

A minigene composed of the human ankyrin promoter, murine ankyrin cDNA, and the 3' human domain corresponding to the ankyrin 2.2 isoform was assembled in the retroviral vector, pG1. Murine erythroleukemia (MEL) cells, normal murine bone marrow cells, 3T3 fibroblasts, and nb/nb mutant bone marrow and spleen cells were transduced with the retroviral supernatant. Transduced mutant cells were induced to differentiate in liquid culture. Gene transfer was assessed by colony polymerase chain reaction (PCR) and reverse transcriptase (RT)-PCR, immunofluorescence, and Southern, Northern, and Western blot analysis.

RESULTS

MEL cells, normal bone marrow progenitors, and nb/nb cells were all successfully transduced and expressed ankyrin by RT-PCR and Western blot. Transduced murine 3T3 fibroblasts and MEL cells exhibited cell membrane staining by immunofluorescence. Colony RT-PCR demonstrated dependence of expression on erythropoietin. In vitro, the transduced nb/nb cells matured to polychromatophils, whereas nontransduced nb/nb cells matured to microspherocytes.

CONCLUSION

Retroviral transfer of ankyrin corrected the defect leading to formation of microspherocytes in erythroid differentiation cultures from the nb/nb mutant. The human ankyrin promoter conferred erythropoietin-dependent expression in normal and mutant erythroid progenitors, which could have implications for the gene therapy of human hemolytic anemias.

Successful autologous bone marrow transplant without the use of blood product support

We describe a successful autologous bone marrow transplant without the use of any blood products. The patient had relapsed large cell lymphoma. He was a Jehovah's Witness and would not accept transfusions of red blood cells or platelets. He enrolled in our Bloodless Medicine and Surgery Program and was maintained on a regimen of erythropoietin, iron, Amicar, and G-CSF throughout the transplant. He tolerated the transplant well and is alive with no evidence of disease 10 months after autografting.

Effect of ex vivo cytokine treatment on human cord blood engraftment in NOD-scid mice

Umbilical cord blood transplantation is considered an alternative to traditional bone marrow transplantation for patients who do not have matched sibling donors. In this study, we examined the effects of ex vivo treatment of human cord blood cells with cytokine mixtures and assessed the ability of treated cells to engraft in NOD-scid mice. We incubated the cord blood with a four-factor cytokine mixture of interleukin (IL)-3, IL-6, IL-11 and stem cell factor, or with a two-factor cytokine mixture of thrombopoietin and flt-3. Incubation of cord blood for 48 h with either cytokine mixture did not affect progenitor cell number or proliferative potential as measured by the high proliferative potential (HPP) assay. Cytokine-treated cord blood injected into irradiated NOD-scid mice resulted in multilineage human engraftment. Overall, incubation with cytokines resulted in variable levels of engraftment with different cord blood samples. Incubation of cord blood with the four-factor cytokine mixture resulted in increased survival of irradiated NOD-scid recipients. These results demonstrate that short-term ex vivo treatment of human progenitor cells gives variable results on in vivo multipotential capabilities.

Adhesion receptor expression by hematopoietic cell lines and murine progenitors: modulation by cytokines and cell cycle status

Hematopoietic progenitor cells are incubated with cytokine combinations for in vitro expansion of stem cells and to enhance retrovirus-mediated gene transfer. Optimization of the engraftment of these treated cells would be critical to the success of stem cell transplantation or gene therapy. Previous studies demonstrated that a 48-hour incubation of donor BALB/c bone marrow with a mixture of four cytokines (IL-3, IL-6, IL-11, and SCF), resulted in expansion of primitive progenitor/stem cells but a loss of long-term engraftment in nonmyeloablated or myeloablated recipients. We have established the expression pattern for a number of adhesion receptors by normal hematopoietic progenitors and cell lines and the modulation in expression induced by cytokines or cell cycle progression to ascertain the molecular basis for such defective engraftment. Northern blot analysis demonstrated that the cytokine combination of IL-3, IL-6, IL-11, and SCF dramatically down-regulated alpha 4 integrin receptor expression in HL-60 cells. Synchronized FDC-P1 cells exhibited modulation of alpha 4 expression through cell cycle progression, both by quantitative RT-PCR and flow cytometry. Normal murine bone marrow lineage-depleted, Sca+ cells expressed a number of adhesion receptors, including alpha L, alpha 1, alpha 3, alpha 4, alpha 5, alpha 6, beta 1, L-selectin, CD44, and PECAM as assessed by flow cytometry, immunofluorescence, and RT-PCR. There was modulation of the expression of several of these receptors after incubation in the four cytokines for 24 and/or 48 hours: the proportion of cells expressing alpha L, alpha 5, alpha 6, and PECAM increased, whereas the proportion of cells expressing alpha 4 and beta 1 decreased, after cytokine incubation. There was a demonstrable concomitant decline in adhesion of these cells to fibronectin after the cytokine incubation, a finding that correlates with the decrease in expression of alpha 4. These changes in adhesion receptor expression and function with cytokines and during cell cycle transit may be critical to stem cell homing and engraftment after transplantation, as multiple receptors could be involved in the process of rolling, attachment to endothelium, endothelial transmigration, and migration within the marrow space.

Immunofluorescence characterization of key extracellular matrix proteins in murine bone marrow in situ

The mechanism of hemopoietic stem cell homing to the bone marrow involves molecular interactions that mediate the recognition and interaction of these cells with the marrow microenvironment, including the extracellular matrix. On selective binding, this environment, in combination with soluble cytokines, regulates stem cell proliferation and differentiation. Using immunofluorescence labeling, we analyzed the location of the prominent extracellular matrix proteins fibronectin, collagen Types I, III, and IV, and laminin in sections of murine femoral bone marrow. Collagen Types I, IV, and fibronectin were localized to the endosteum, the region of the femoral microenvironment for which homing stem cells have a high affinity. The results further demonstrated a strong spatial association of collagen Type IV and laminin with the bone marrow vessels, including arterioles, veins, and sinuses. Fibronectin was distributed throughout the central marrow region, and all the proteins analyzed except collagen Type III were present in the bone, although at different levels. Fibronectin, collagen Types III and IV, and laminin were also present in the periosteum. The distinct locations of particular extracellular matrix proteins support the notion that they may play an important mechanistic role in the homing of engrafting cells.

Giant platelets with abnormal surface glycoproteins: a new familial disorder associated with mitral valve insufficiency

PURPOSE

To study the platelets from a family with a new form of inherited giant platelet disorder.

PATIENTS AND METHODS

Two siblings exhibited a hemorrhagic disorder characterized by moderate thrombocytopenia, giant platelets, and markedly prolonged bleeding time. The parents had no discernible platelet defect. Both children also developed mitral regurgitation requiring medication, and one underwent surgical replacement at the age of 3 years.

RESULTS

The mean platelet size was greater than 20 microm3. Direct measurements of the two major axes of each of 12 platelets on electron micrographs revealed a range of 2x4 to 4x6 microm. Electron microscopy did not demonstrate any abnormality of granule content. The platelets agglutinated normally with ristocetin and aggregated normally with collagen. However, the aggregation was slightly slower than normal with ADP, epinephrine, and Na arachidonate. Two-dimensional unreduced versus reduced SDS-polyacrylamide gel electrophoresis of surface radioiodinated platelet glycoproteins revealed absence of proteins Ia, Ic, and IIa in both affected children, whereas GP Ib, IIb, and IIIa appeared normal. The 2D gels of platelet glycoproteins from both parents were identical to controls. Western blots demonstrated that GP Ic, Ic', Ib, and Ia/IIa were present.

CONCLUSIONS

This disorder represents a new syndrome of thrombocytopenia with giant platelets distinct from Bernard-Soulier, Montreal giant platelets, Swiss cheese platelets, May-Hegglin anomaly, and other previously described syndromes.

Spontaneous splenic rupture following administration of granulocyte colony-stimulating factor (G-CSF): occurrence in an allogeneic donor of peripheral blood stem cells

Granulocyte colony-stimulating factor (G-CSF) has been used to improve granulocyte count in chronic neutropenia and myelodysplasia, to minimize the incidence and duration of neutropenia during conventional chemotherapy, and to mobilize peripheral blood stem cells prior to leukapheresis for use in autologous and allogeneic marrow transplantation. The most common toxicity is bone pain, and other reactions such as inflammation at the site of injection have also occurred. In patients with chronic neutropenia, splenomegaly has been described with long-term use, and extramedullary hematopoiesis has also been reported. However, thus far, no life-threatening sequelae of these effects are found in the literature. We now describe a case of spontaneous splenic rupture four days following a six-day course of G-CSF therapy in an allogeneic donor of peripheral blood stem cells.

Laminin promotes differentiation of NB4 promyelocytic leukemia cells with all-trans retinoic acid

The promyelocytic leukemia cell line, NB4, carries the t(15; 17) translocation and undergoes limited maturation in response to differentiation agents. Growth on laminin enhanced the ability of all-trans retinoic acid (ATRA) to promote morphologic maturation of these cells. Although exposure to ATRA in suspension yielded minimal maturation beyond the myelocyte stage, after 72 hours of exposure to ATRA on laminin the cells acquired the histologic appearance of metamyelocytes, band forms, and segmented neutrophils. After 96 hours, some cells acquired a spindle shape and became tightly adherent. Growth on collagen types I, III, IV, or fibronectin did not have this effect, although some cells did adhere to fibronectin. NB4 cells treated with ATRA in suspension or on laminin acquired the equivalent ability to reduce nitroblue tetrazolium or cytochrome C. Despite the improved morphologic maturation on laminin, the cells did not express secondary granule proteins such as lactoferrin or neutrophil collagenase. In addition, growth on laminin abolished cell proliferation in the presence of ionomycin. Growth on laminin and/or with ATRA induced new expression of alpha 6 integrin, a laminin receptor, as assessed by reverse transcription-polymerase chain reaction. Different conditions of growth (laminin or differentiation agent) resulted in specific patterns of expression of the alpha 6A and alpha 6B isoforms. Treatment with ATRA also resulted in the acquisition of high-level surface expression of alpha 6 integrin, as assessed by flow cytometry. Thus, treatment of NB4 promyelocytic leukemia cells with ATRA induced expression of alpha 6 integrin (a laminin receptor alpha-chain) and enabled more advanced maturation when the cells were grown on the extracellular matrix component, laminin, compared with tissue culture plastic.

Similarity between the 38-kilodalton lipoprotein of Treponema pallidum and the glucose/galactose-binding (MglB) protein of Escherichia coli

The recent discovery that abundant and immunogenic lipoproteins constitute the integral membrane proteins of Treponema pallidum has prompted efforts to investigate their importance in the physiology and ultrastructure of the organism and in immune responses during infection. Earlier studies identified a 38-kDa lipoprotein of T. pallidum believed to be specific to the pathogen. In the present study, monoclonal antibodies generated against the 38-kDa lipoprotein of T. pallidum reacted with cognate 37-kDa molecules in the nonpathogens Treponema phagedenis, Treponema denticola, and Treponema refringens. Cloning and expression of the 38-kDa-lipoprotein gene of T. pallidum in Escherichia coli revealed that the recombinant product displayed a slightly larger (39-kDa) apparent molecular mass but remained reactive with anti-38-kDa-protein monoclonal antibodies. The recombinant product was processed and acylated in E. coli. DNA and amino acid sequence analyses indicated an open reading frame encoding 403 amino acids, with the first 25 amino acids corresponding to a leader peptide terminated by a signal peptidase II processing site of Val-Val-Gly-Cys. The predicted mature protein is 378 amino acids in length with a deduced molecular weight of 40,422 (excluding acylation). Southern blotting failed to demonstrate in nonpathogenic treponemes genomic sequences homologous with the 38-kDa-lipoprotein gene of T. pallidum. Computer analysis revealed that the 38-kDa lipoprotein of T. pallidum had 34.2% identity and 58.9% similarity with the glucose/galactose-binding protein (MglB) of E. coli and Salmonella typhimurium. Furthermore, of the 19 amino acids of MglB involved in carbohydrate binding, the 38-kDa lipoprotein had identity with 11. These studies have allowed the first putative functional assignment (carbohydrate binding) to a T. pallidum integral membrane protein. Recognition of this potential physiological role for the 38-kDa lipoprotein underscores the possibility that the membrane biology of T. pallidum may more closely resemble that of gram-positive organisms, which also utilize lipoproteins as anchored transporters, than that of gram-negative bacteria to which T. pallidum often is analogized.

Tissue-specific alternative splicing of protein 4.1 inserts an exon necessary for formation of the ternary complex with erythrocyte spectrin and F-actin

Erythrocyte protein 4.1 is an 78- to 80-Kd peripheral membrane protein that promotes the interaction of spectrin with actin protofilaments and links the resulting interlocking network to the integral membrane proteins. There are several isoforms of protein 4.1 that appear to be expressed in a restricted group of tissues. These arise from alternative mRNA splicing events that lead to the combinational insertion or deletion of at least 10 blocks of nucleotides (motifs) within the mature mRNA. One of these, motif I, consists of 63 nucleotides encoding 21 amino acids in the N-terminal region of the putative spectrin/actin-binding domain. The expression of the motif U-containing isoform occurs late in erythroid maturation. We generated recombinant isoforms of protein 4.1 and of the putative 10-Kd spectrin/actin-binding fragment that contain or lack this 21 amino acid sequence and examined their ability to form a ternary complex with erythrocyte spectrin and F-actin. The isoforms of the complete protein and of the 10-Kd fragment that contain the sequence encoded by motif I efficiently form the ternary complex. Isoforms that lack this sequence, but are otherwise identical, do not participate in the formation of the ternary complex. These results, in conjunction with the expression of motif I during late erythroid maturation, suggest that interaction with actin and the erythroid form of spectrin is a specialized property of the erythrocyte form of protein 4.1. Alternative mRNA splicing in developing red blood cells thus plays a key adaptive role in the formation of the highly specialized erythrocyte membrane.

Multifocal necrotizing leukoencephalopathy with pontine predilection in immunosuppressed patients: a clinicopathologic review of 16 cases

Multifocal necrotizing leukoencephalopathy (MNL) is characterized by multiple, usually microscopic, foci of necrosis confined primarily to the white matter of the basis pontis, but sometimes found elsewhere in the central nervous system. All 16 patients in whom we identified MNL had underlying immunosuppression, either naturally occurring or iatrogenic, including the acquired immunodeficiency syndrome (seven patients), acute leukemias (four patients), and lymphoma (one patient). One patient each had severe combined immunodeficiency, orthotopic liver transplantation, Shwachman-Diamond syndrome, and idiopathic thrombocytopenic purpura treated with high-dose steroids. Histologically, lesions of MNL show demyelination, spongiosis, axonal swelling, minimal histiocytic infiltrates, and frequent axonal calcification. Multifocal necrotizing leukoencephalopathy lesions were found in the pons of all patients, most commonly in the crossing pontocerebellar fibers, but often in the descending white matter tracts and rarely in the tegmentum. Three cases also showed nonpontine foci of MNL involving the white matter of the medulla, cerebellum, and cerebral hemispheres. Multifocal necrotizing leukoencephalopathy is a distinct entity usually localized to the basis pontis and is most consistently associated with immunosuppression, but as yet lacks other clearly defined clinical correlates.

Beta spectrin kissimmee: a spectrin variant associated with autosomal dominant hereditary spherocytosis and defective binding to protein 4.1

We analyzed the DNA sequence of the cDNA encoding the NH2 terminal region of beta spectrin from members of a kindred with autosomal dominant hereditary spherocytosis associated with defective protein 4.1 binding. We found a point mutation at codon 202 within the 272 amino acid NH2-terminal region of beta spectrin. TGG was changed to CGG, resulting in the replacement of tryptophan by arginine. The base change eliminates a normally occurring PvuII restriction site and creates a new MspI site. This finding enabled rapid detection or exclusion of the mutation at the DNA level among the family members, including one member for whom this analysis was performed prenatally. The mutation was found only in the affected family members and occurred as a de novo mutation in the proband. It has not been found in 20 other kindreds. The recombinant peptide derived from the normal cDNA retains the capacity to sediment with protein 4.1 and F-actin. The mutant peptide spontaneously degrades. This variant represents both the first point mutation and the first beta spectrin mutation demonstrated in autosomal dominant hereditary spherocytosis. Furthermore, the mutation is located within a conserved sequence among spectrinlike proteins and may define an amino acid critical for protein 4.1 binding activity.

Cytokine expression of macrophages in HIV-1-associated vacuolar myelopathy

Macrophages are frequently present within the periaxonal and intramyelinic vacuoles that are located primarily in the posterior and lateral funiculi of the thoracic spinal cord in HIV-associated vacuolar myelopathy. But the role of these macrophages in the formation of the vacuoles is unclear. One hypothesis is that cytokines, such as interleukin-1 (IL-1) and tumor necrosis factor (TNF)-alpha, are produced locally by macrophages and have toxic effects on myelin or oligodendrocytes. The resulting myelin damage eventually culminates in the removal of myelin by macrophages and vacuole formation. We studied thoracic spinal cord specimens taken at autopsy from HIV-positive (+) and HIV-negative individuals. The predominant mononuclear cells present in HIV+ spinal cords are macrophages. They are located primarily in the posterior and lateral funiculi regardless of the presence or absence of vacuolar myelopathy. Macrophages and microglia are more frequent in HIV+ than HIV-negative individuals and these cells frequently stain for class I and class II antigens, IL-1, and TNF-alpha. Activated macrophages positive for IL-1 and TNF-alpha are great increased in the posterior and lateral funiculi of HIV+ individuals with and without vacuolar myelopathy, suggesting they are present prior to the development of vacuoles. Cytokines, such as TNF-alpha, may be toxic for myelin or oligodendrocytes, leading to myelin damage and removal by macrophages and vacuole formation.

Cytokine expression in the brain during the acquired immunodeficiency syndrome

The pathogenesis of central nervous system (CNS) disease in acquired immunodeficiency syndrome (AIDS) is poorly understood but may be related to specific effects of the immune system. Cytokines such as tumor necrosis factor and interleukin-1 may have toxic effects on CNS cells and have been postulated to contribute to the pathogenesis of the neurological complications of human immunodeficiency virus (HIV) infection. To characterize viral and immunological activity in the CNS, frozen specimens taken at autopsy from the cerebral cortex and white matter of HIV-seropositive and -seronegative individuals were stained immunocytochemically for mononuclear cells, major histocompatibility complex (MHC) antigens, HIV, astrocytes, and the cytokines interleukin-1 and -6, tumor necrosis factor-alpha and -beta, and interferon gamma. Levels of soluble CD4, CD8, and interleukin-2 receptor, as well as interferon gamma, tumor necrosis factor-alpha, beta 2-microglobulin, neopterin, and interleukin-6 and -1 beta were assayed in the cerebrospinal fluid and plasma of many of these individuals during life. The HIV-seropositive group included individuals without neurological disease, those with CNS opportunistic infections, and those with HIV encephalopathy. Perivascular cells, consisting primarily of macrophages with some CD4+ and CD8+ T cells and rare B cells, were consistently MHC class II positive. MHC class II antigen was also present on microglial cells, which were frequently positive for tumor necrosis factor-alpha. HIV p24 antigen, when present, was found on macrophages and microglia. Endothelial cells were frequently positive for interleukin-1 and interferon gamma and less frequently for tumor necrosis factor and interleukin-6. There were gliosis and significant increases in MHC class II antigen, interleukin-1, and tumor necrosis factor-alpha in HIV-positive patients compared to HIV-negative brains. Cerebrospinal fluid from most of the patients tested had increased levels of tumor necrosis factor, beta 2-microglobulin, and neopterin. There was no correlation in HIV-positive individuals between levels of cytokines and the presence or absence of CNS disease. These data indicate that there is a relative state of "immune activation" in the brains of HIV-positive compared to HIV-negative individuals, and suggest a potential role for the immune system in the pathogenesis of HIV encephalopathy.

Epstein-Barr virus in AIDS-related primary central nervous system lymphoma

Primary central nervous system lymphoma occurs more often in patients with AIDS. Epstein-Barr virus (EBV) has been detected in these tumours, but the degree of association has not been defined because of both the highly restricted expression of EBV in malignant tissue and the lack of a technique that is reliable in formalin-fixed paraffin-embedded specimens. EBV-transformed lymphocytes contain short non-protein coding EBV transcripts (EBERs), which are expressed in much higher quantity than other EBV-latency transcripts. We describe a new strategy for detection of latent EBV with these transcripts as targets for in-situ hybridisation. 18 cases of AIDS-related primary CNS lymphoma from a consecutive necropsy series together with specimens from 3 further cases were studied. In each case, a strong positive signal over tumour cells indicated abundant expression of the EBV-EBER1 transcript. This 100% association suggests that the pathogenesis of these AIDS-associated lymphomas may differ from the systemic disease in which only 30-50% of tumours are associated with EBV. A pathogenetic role for EBV was further supported by showing expression of a viral protein (the latent membrane protein) that is implicated as an effector for EBV-associated lymphomagenesis. EBV might have a role as a tumour marker in the diagnosis and management of AIDS-related primary CNS lymphoma.

Neuropathologic changes with experimental spinal instrumentation: transpedicular versus sublaminar fixation

Fifty-six mature beagles underwent lumbar spine destabilization, followed by fusion using four techniques. Spinal cord neuropathologic analysis was carried out to determine the number of abnormalities within each group. Group I (n = 14) had posterolateral bone grafting without instrumentation. Group IIa (n = 14) had Cotrel-Dubousset (CD) pedicle screws and rods. Group IIb (n = 14) had Steffee pedicle screws and plates. Group III (n = 14) had sublaminar wires and rods. All of the animals remained clinically neurologically normal throughout the 6 months of the study. The incidence of moderate to severe neuropathologic changes was 21% in Group I, 18% in Group II, and 64% in Group III. Thus, a significantly higher percentage of neuropathologic abnormalities occurred with sublaminar instrumentation than with no instrumentation (p = 0.027), or with transpedicular instrumentation (p = 0.027). In this controlled animal study, the theoretical advantage of pedicle screws, which should not violate the spinal canal, over sublaminar devices, which must enter the canal, was confirmed.

Radiolabel-transfer cross-linking demonstrates that protein 4.1 binds to the N-terminal region of beta spectrin and to actin in binary interactions

Erythrocyte protein 4.1 plays a major role in stabilizing the spectrin-actin junction of the erythrocyte membrane skeleton. The particular sites on spectrin responsible for the binding of actin and protein 4.1 have not been specifically defined, although the general region of the 'tail' end, opposite the self-association site, has been deduced by electron microscopy. Using a photoactivatable, radiolabel-transfer cross-linker, 1-[N-(2-hydroxy-5-azidobenzoyl)-2-aminoethyl]-4-(N-hydroxysuccinimidyl)- succinate, we have determined that the binding site for protein 4.1 on spectrin resides in the N-terminal region of beta spectrin within a sequence homologous to the actin-binding region of alpha actinin. Moreover, this technique provided clear evidence for a direct binding interaction between actin filaments and protein 4.1 that was confirmed by rapid-sedimentation assays. In summary, use of radiolabel-transfer cross-linking has enabled assignment of the protein-4.1-binding site on erythrocyte spectrin and has identified a previously ill-defined binary interaction between protein 4.1 and F-actin.

Acquired immunodeficiency syndrome: correlation of radiologic and pathologic findings in the brain

The appearance on magnetic resonance (MR) and computed tomographic (CT) images of specific central nervous system disorders associated with acquired immunodeficiency syndrome in 12 cases was correlated with autopsy findings. There were three cases of human immunodeficiency virus (HIV) encephalopathy; three, primary lymphoma; three, toxoplasmosis; one, cryptococcosis; one, cytomegalovirus infection; and one, progressive multifocal leukoencephalopathy. MR imaging demonstrated the various cranial lesions more clearly than did CT. On the basis of MR imaging characteristics, HIV encephalopathy could be distinguished from other lesions, particularly progressive multifocal leukoencephalopathy. Basal ganglia were the most common sites of involvement in opportunistic infections and primary lymphoma. Reliable distinguishing features among lesions of the basal ganglia were not found, except for cryptococcal lesions, which had a unique appearance.

Neuropathological changes in early HIV-1 dementia

Early pathological abnormalities in human immunodeficiency virus (HIV-1)-related dementia have not been well documented. We report a homosexual man with fatigue and intermittent diarrhea in whom early HIV-1-related dementia was demonstrated during neurological screening in the Multicenter AIDS Cohort Study. Within 4 months he died of massive epistaxis, and the brain revealed astrocytosis of white matter and mild pallor of myelin staining in the absence of inflammation, multinucleated giant cells, and brain atrophy.