Hereditary chronic neutrophilic leukemia in a four-generation family without transformation to acute leukemia.

Chronic neutrophilic leukemia (CNL) is a rare myeloproliferative neoplasm (MPN) characterized by peripheral blood neutrophilia, marrow granulocyte hyperplasia, hepatosplenomegaly, and driver mutations in the colony-stimulating factor 3 receptor (CSF3R). Designation of activating CSF3R mutations as a defining genomic abnormality for CNL has led to increased recognition of the disease. However, the natural history of CNL remains poorly understood with most patients reported being of older age, lacking germline data, and having poor survival, in part due to transformation to acute leukemia. CSF3R driver mutations in most patients with CNL have been reported to be acquired, although rare cases of germline mutations have been described. Here, we report the largest pedigree to date with familial CNL, spanning four generations with affected family members ranging in age from 4 to 53 years, none of whom have transformed to acute leukemia. A heterozygous T618I CSF3R mutation was identified in peripheral blood and mesenchymal stromal cells from the proband and in all affected living family members, while the unaffected family members tested were homozygous wild type. We show that the T618I mutation also confers a survival advantage to neutrophils in an MCL1-dependent manner. Collectively, these data provide additional insights into the natural history of familial CNL arising from T618I CSF3R mutations and suggest that enhanced neutrophil survival also contributes to the high neutrophil count observed in patients with CNL.

Pharmacogenetic and clinical predictors of voriconazole concentration in hematopoietic stem cell transplant recipients receiving CYP2C19-guided dosing.

CYP2C19-guided voriconazole dosing reduces pharmacokinetic variability, but many patients remain subtherapeutic. The aim of this study was to evaluate the effect of candidate genes and a novel CYP2C haplotype on voriconazole trough concentrations in patients receiving CYP2C19-guided dosing. This is a retrospective candidate gene study in allogeneic hematopoietic cell transplant (HCT) patients receiving CYP2C19-guided voriconazole dosing. Patients were genotyped for ABCB1, ABCG2, CYP2C9, CYP3A4, CYP3A5, and the CYP2C haplotype. Of 185 patients, 36% were subtherapeutic (of which 79% were normal or intermediate metabolizers). In all patients, CYP2C19 (p < 0.001), age (p = 0.018), and letermovir use (p = 0.001) were associated with voriconazole concentrations. In the subset receiving 200 mg daily (non-RM/UMs), CYP2C19 (p = 0.004) and ABCG2 (p = 0.015) were associated with voriconazole concentrations; CYP2C19 (p = 0.028) and letermovir use (p = 0.001) were associated with subtherapeutic status. CYP2C19 phenotype and letermovir use were significantly associated with subtherapeutic voriconazole concentrations and may be used to improve voriconazole precision dosing, while further research is needed to clarify the role of ABCG2 in voriconazole dosing.

Equal access to care and nurse navigation leads to equitable outcomes for minorities with aggressive large B-cell lymphoma.

BACKGROUND: Aggressive large B-cell lymphomas (LBCLs) are curable, but previous studies have shown inferior outcomes in minorities. Nurse navigation programs can improve patient outcomes by providing patient support. This study presents the outcomes of White and minority patients with aggressive LBCL at an institution with an active nurse navigation program. METHODS: The authors prospectively collected baseline characteristics, treatment regimens, and outcome data for patients with aggressive LBCL. Navigation encounters were characterized as low or high intensity. Overall survival (OS) and progression-free survival (PFS) were calculated with Kaplan-Meier methods. Baseline characteristics were compared with Fisher exact tests. RESULTS: Two hundred four consecutive patients (47 minority patients and 157 White patients) were included. Results were presented as minorities versus Whites. There were no differences in prognostic scores (Revised International Prognostic Index score of 3-5, 43% vs 47%; P = .50), frontline chemotherapy (98% vs 96%; P = .68), or the incidence of relapsed/refractory disease (40% vs 38%; P = .74). For relapsed/refractory LBCL, similar proportions of patients underwent hematopoietic stem cell transplantation (32% vs 29%; P > .99) or chimeric antigen receptor T-cell therapy (16% vs 19%; P > .99). Enrollment in clinical trials was comparable (17% vs 14%; P = .64). More than 85% received nurse navigation, but minorities had higher intensity navigation encounters (42% vs 21%; P = .01). The 2-year OS rates were 81% and 76% for minorities and Whites, respectively (P = .27); the 2-year PFS rates were 62% and 65%, respectively (P = .78). CONCLUSIONS: This study shows similar survival between Whites and minorities with aggressive LBCL, which was likely due to equal access to guideline-concordant therapy. Minorities received higher intensity navigation encounters, which may have helped them to overcome socioeconomic disadvantages.

Cost saving, patient centered algorithm for progenitor cell mobilization for autologous hematopoietic cell transplantation.

Administration of plerixafor with granulocyte-colony stimulating factor (G-CSF) mobilizes CD34+ cells much more effectively than G-CSF alone, but cost generally limits plerixafor use to patients at high risk of insufficient CD34+ cell collection based on low peripheral blood (PB) CD34+ counts following 4 days of G-CSF. We analyzed costs associated with administering plerixafor to patients with higher day 4 CD34+ cell counts to decrease apheresis days and explored the use of a fixed split dose of plerixafor instead of weight-based dosing. We analyzed 235 patients with plasma cell disorders or non-Hodgkin's lymphoma who underwent progenitor cell mobilization and autologous hematopoietic cell transplantation (AHCT) between March 2014 and December 2017. Two hundred ten (89%) received G-CSF plus Plerixafor and 25 (11%) received G-CSF alone. Overall, 180 patients (77%) collected in 1 day, 53 (22%) in 2 days and 2 (1%) in 3 days. Based on our data, we present a probabilistic algorithm to identify patients likely to require more than one day of collection using G-CSF alone. CD34+ cell yield, ANC and platelet recovery were not significantly different between fixed and standard dose plerixafor. Plerixafor enabled collection in 1 day and with estimated savings of $5000, compared to patients who did not receive plerixafor and required collection for three days. While collection and processing costs and patient populations vary among institutions, our results suggest re-evaluation of current algorithms.

T618I CSF3R mutations in chronic neutrophilic leukemia induce oncogenic signals through aberrant trafficking and constitutive phosphorylation of the O-glycosylated receptor form.

Activating mutations in the membrane-proximal region of the colony-stimulating factor 3 receptor (CSF3R) are a hallmark of chronic neutrophilic leukemia (CNL) with the T618I mutation being most common. The mechanisms underlying constitutive activation of the T618I CSF3R and its signal propagation are poorly understood. Ligand-independent activation of the T618I CSF3R has previously been attributed to loss of receptor O-glycosylation and increased receptor dimerization. Here, we show that the T618I CSF3R is indeed glycosylated but undergoes enhanced spontaneous internalization and degradation that results in a marked decrease in its surface expression. Inhibition of the proteasome dramatically increases expression of the O-glycosylated T618I CSF3R. We also demonstrate that the O-glycosylated wild-type CSF3R is tyrosine phosphorylated in response to ligand but constitutively phosphorylated in cells expressing T618I CSF3R. Constitutive tyrosine phosphorylation of the O-glycosylated T618I receptor form correlated with activation of JAK2 and both the mutant receptor and JAK2 were found to be constitutively ubiquitinated. These observations provide novel insights into the mechanisms of oncogenic signaling by T618I CSF3R mutations in CNL.

A Review of Growth Factor Support in Bloodless Autologous Hematopoietic Stem Cell Transplant.

Bloodless autologous hematopoietic cell transplantation is associated with risks of severe bleeding and profound anemia. RBC or platelet transfusions are often used to prevent these hematologic complications. However, in patients such as Jehovah's Witnesses who refuse major blood components, the lack of transfusion support is not an absolute contraindication to an autologous hematopoietic cell transplant. Pennsylvania Hospital performed the world's first bloodless hematopoietic cell transplant more than 15 years ago and has gradually improved its technique with a sizable patient population. Erythropoiesis-stimulating agents were successfully employed as part of their pretransplant regimen to prevent severe anemia. Thrombopoietin agonists' potential role in bloodless transplant is also currently being explored. Although there is limited literature, available reports in combination with physiologic reasoning may support the use of these growth factors to promote transplant success. These agents offer potential benefit and may be of utility in minimizing complications of a bloodless transplant. In this review, we summarize the available literature and offer insight into how we may incorporate growth factors to allow bloodless autologous hematopoietic cell transplantation to be an available option to patients who may otherwise be denied.

Peripheral Immunotype Correlates with Minimal Residual Disease Status and Is Modulated by Immunomodulatory Drugs in Multiple Myeloma.

Data indicate reversal of immune dysfunction with active treatment; however, the precise contribution of specific immune effector and immune suppressor components to achieve a minimal residual disease (MRD) state and immunomodulatory drug-mediated immunomodulatory effects in multiple myeloma (MM) patients remains poorly understood. In this prospective proof-of-principle study we sought to determine the dynamic alterations in natural killer (NK), NK-T, and T cells, including maturation and activating/inhibitory repertoire associated with MRDpos versus MRDneg status after autologous stem cell transplantation (ASCT) and during lenalidomide-based maintenance therapy. Of the 46MM patients enrolled, 36 had bone marrow MRD assessment 60+ days post-ASCT, 30 had longitudinal blood immunotyping during maintenance (pretherapy and after cycles 1, 3, and 6), and 20 had both MRD assessment and longitudinal immunotyping. Multicolor flow cytometry was used for MRD and immunotyping. Although the absolute number of NK cells was significantly lower in patients with MRDpos response, phenotypically NK cells in these patients displayed higher expression of activating receptors KIRDS4 and decreased expression of inhibitory molecules NKG2A compared with the MRDneg group. Furthermore, we observed significantly lower frequencies of T cells displaying KIR3DL1 in MRDpos versus MRDneg patients. Longitudinal immunotyping during lenalidomide maintenance showed loss of mature NK effector function, augmentation of NK-T effector function, and acquisition of PD1 independent anergic state. Our findings also suggest skewing of T cells toward an exhausted state during the maintenance phase in MRDpos patients. Put together, these observations provide a distinctive signature for MRDneg and MRDpos groups. These data support exploration of immune profiling in prospective clinical trials according to MRD-defined responses to identify patients that may benefit from maintenance intensification/modification or maintenance withdrawal.

Effect of CYP3A4, CYP3A5, and ABCB1 Polymorphisms on Intravenous Tacrolimus Exposure and Adverse Events in Adult Allogeneic Stem Cell Transplant Patients.

Pharmacogenetics influences oral tacrolimus exposure; however, little data exist regarding i.v. tacrolimus. We investigated the impact of genetic polymorphisms in CYP3A4, CYP3A5, and ABCB1 on i.v. tacrolimus exposure and toxicity in adult patients receiving an allogeneic hematopoietic stem cell transplant for hematologic malignancies. Germline DNA was extracted from buccal swabs and genotyped for CYP3A4, CYP3A5, and ABCB1 polymorphisms. Continuous i.v. infusion of tacrolimus .03 mg/kg/day was initiated on day +5 post-transplant, and steady-state blood concentrations were measured 4days later. We evaluated the association between phenotypes and prevalence of nontherapeutic target concentrations (below or above 5 to 15 ng/mL) as well as tacrolimus-related toxicities. Of 63 patients, 28.6% achieved the target concentration; 71.4% were >15ng/mL, which was more common in CYP3A4 intermediate/normal metabolizers (compared with rapid) and those with at least 1 ABCB1 C2677T loss-of-function allele (P < .05). ABCB1 C2677T was significantly associated with concentrations >15ng/mL (odds ratio, 6.2; 95% confidence interval, 1.8 to 23.6; P = .004) and tacrolimus-related toxicities (odds ratio, 7.5; 95% confidence interval, 1.6 to 55.2; P = .02). ABCB1 C2677T and CYP3A4 are important determinants of i.v. tacrolimus exposure, whereas ABCB1 C2677T also impacts tacrolimus-related toxicities in stem cell transplants.

Comparison of outcomes of allogeneic transplantation for chronic myeloid leukemia with cyclophosphamide in combination with intravenous busulfan, oral busulfan, or total body irradiation.

Cyclophosphamide (Cy) in combination with busulfan (Bu) or total body irradiation (TBI) is the most commonly used myeloablative conditioning regimen in patients with chronic myeloid leukemia (CML). We used data from the Center for International Bone Marrow Transplantation Research to compare outcomes in adults who underwent hematopoietic cell transplantation for CML in first chronic phase after myeloablative conditioning with Cy in combination with TBI, oral Bu, or intravenous (i.v.) Bu. Four hundred thirty-eight adults received human leukocyte antigen (HLA)-matched sibling grafts and 235 received well-matched grafts from unrelated donors (URD) from 2000 through 2006. Important differences existed between the groups in distribution of donor relation, exposure to tyrosine kinase inhibitors, and year of transplantation. In multivariate analysis, relapse occurred less frequently among patients receiving i.v. Bu compared with TBI (relative risk [RR], .36; P = .022) or oral Bu (RR, .39; P = .028), but nonrelapse mortality and survival were similar. A significant interaction was detected between donor relation and the main effect in leukemia-free survival (LFS). Among recipients of HLA-identical sibling grafts, but not URD grafts, LFS was better in patients receiving i.v. Bu (RR, .53; P = .025) or oral Bu (RR, .64; P = .017) compared with TBI. In CML in first chronic phase, Cy in combination with i.v. Bu was associated with less relapse than TBI or oral Bu. LFS was better after i.v. or oral Bu compared with TBI.

Better leukemia-free and overall survival in AML in first remission following cyclophosphamide in combination with busulfan compared with TBI.

Cyclophosphamide combined with total body irradiation (Cy/TBI) or busulfan (BuCy) are the most widely used myeloablative conditioning regimens for allotransplants. Recent data regarding their comparative effectiveness are lacking. We analyzed data from the Center for International Blood and Marrow Transplant Research for 1230 subjects receiving a first hematopoietic cell transplant from a human leukocyte antigen-matched sibling or from an unrelated donor during the years 2000 to 2006 for acute myeloid leukemia (AML) in first complete remission (CR) after conditioning with Cy/TBI or oral or intravenous (IV) BuCy. Multivariate analysis showed significantly less nonrelapse mortality (relative risk [RR] = 0.58; 95% confidence interval [CI]: 0.39-0.86; P = .007), and relapse after, but not before, 1 year posttransplant (RR = 0.23; 95% CI: 0.08-0.65; P = .006), and better leukemia-free survival (RR = 0.70; 95% CI: 0.55-0.88; P = .003) and survival (RR = 0.68; 95% CI: 0.52-0.88; P = .003) in persons receiving IV, but not oral, Bu compared with TBI. In combination with Cy, IV Bu is associated with superior outcomes compared with TBI in patients with AML in first CR.

Prognostic significance of myeloid-derived suppressor cells and systemic inflammation in newly diagnosed diffuse large B cell lymphoma treated with chemoimmunotherapy.

The revised International Prognostic Index (R-IPI) is an important prognostic tool in diffuse large B cell lymphoma (DLBCL); however, outcomes can vary markedly within R-IPI groups, and additional prognostic markers are needed. We conducted a prospective observational study to evaluate the circulating immature myeloid (IM) cell subsets and cytokine profiles of 31 patients with newly diagnosed DLBCL before and after chemoimmunotherapy. Among circulating IM cells, myeloid-derived suppressor cells (MDSCs) were the predominant cell type (73.8% ± 26%). At baseline, circulating monocytic MDSCs (M-MDSCs) and polymorphonuclear MDSCs (PMN-MDSCs) were predominantly mutually exclusive. Patients with DLBCL clustered into three distinct immunotypes according to MDSC levels and subtype predominance: M-MDSChigh, PMN-MDSChigh, and MDSClow. The M-MDSChigh immunotype was associated with the germinal center B cell-like (GCB) subtype and elevated serum IL-8 and MIP-1α levels. PMN-MDSChigh was associated with the non-GCB subtype and elevated IL-8, MCP-1, IP-10, TNFα, and IL-1Ra levels. Standard chemoimmunotherapy partially reduced M-MDSC distribution across the MDSClow and M-MDSChigh groups. By contrast, among the MDSClow and PMN-MDSChigh groups, PMN-MDSCs persisted after treatment. Two high-risk patients with non-GCB DLBCL and MDSClow immunotype experienced early disease recurrence within 12 months of treatment completion. This study demonstrates that distinct types of MDSCs are associated with subtypes of DLBCL. MDSC levels are dynamic and may be associated with disease status. Persistence of PMN-MDSCs among high-risk patients with DLBCL may be associated with early relapse.

Genetic Predictors of Ibrutinib-related Cardiovascular Side Effects in Patients with Chronic Lymphocytic Leukemia.

PURPOSE: Patients with chronic lymphocytic leukemia (CLL) treated with ibrutinib are at risk of developing cardiovascular side effects (CVSE). The molecular determinants of CVSEs have not been fully elucidated. We interrogated genetic polymorphisms in the Bruton tyrosine kinase (BTK) signaling pathway for their association with ibrutinib-related CVSEs. EXPERIMENTAL DESIGN: We conducted a retrospective/prospective observational pharmacogenetic study of 50 patients with newly diagnosed or relapsed CLL who received ibrutinib at a starting daily dose of 420 mg for at least 6 months. CVSEs, primarily atrial fibrillation and hypertension, occurred in 10 patients (20%), of whom 4 discontinued therapy. DNA was isolated from buccal swabs of all 50 patients and genotyped for 40 SNPs in GATA4, SGK1, KCNQ1, KCNA4, NPPA, and SCN5A using a customized next-generation sequencing panel. Univariate and multivariate logistic regression analysis were performed to determine genetic and clinical factors associated with the incidence of ibrutinib-related CVSEs. RESULTS: GATA4 rs804280 AA (P = 0.043), KCNQ1 rs163182 GG (P = 0.036), and KCNQ1 rs2237895 AA (P = 0.023) genotypes were univariately associated with ibrutinib-related CVSEs. On the basis of multivariate analysis, a high genetic risk score, defined as the presence of at least two of these genotypes, was associated with 11.5-fold increased odds of CVSEs (P = 0.019; 95% confidence interval, 1.79-119.73). CONCLUSIONS: Our findings suggest possible genetic determinants of ibrutinib-related CVSEs in CLL. If replicated in a larger study, pretreatment pharmacogenetic testing for GATA4 and KCNQ1 polymorphisms may be a useful clinical tool for personalizing treatment selection for CLL and/or instituting early risk mitigation strategies.

An update on stem cell transplantation in autoimmune rheumatologic disorders.

Stem cell transplant (SCT) has long been the standard of care for several hematologic, immunodeficient, and oncologic disorders. Recently, SCT has become an increasingly utilized therapy for refractory autoimmune rheumatologic disorders (ARDs). The efficacy of SCT in ARDs has been attributed to resetting an aberrant immune system either through direct immune replacement with hematopoietic stem cells or through immunomodulation with mesenchymal stem cells. Among ARDs, refractory systemic sclerosis (SSc) and systemic lupus erythematosus (SLE) are the most common indications for SCT. SCT has also been used in refractory rheumatoid arthritis, inflammatory myopathies, antiphospholipid syndrome, granulomatosis with polyangiitis, and pediatric ARDs. Complete responses have been reported in approximately 30 % of patients in all disease categories. Transplant-related mortality, however, remains a concern. Future large multi-center prospective randomized clinical trials will help to better define the specific role of SCT in the treatment of patients with ARDs.

Can G-CSF cause leukemia in hematopoietic stem cell donors?

A large majority of allogeneic hematopoietic stem cell donations are achieved using granulocyte-colony stimulating factor (G-CSF). G-CSF use has been associated with later development of myelodysplastic syndromes/acute myelogenous leukemia (MDS/AML) in several clinical circumstances. Although clinical data to date have failed to identify any increased incidence of MDS/AML in G-CSF mobilized donors, the quality of these data are insufficient to exclude a long-term risk. Physicians should explain the potential risk to donors, and where appropriate, offer donors the option of marrow donation.

Incidence and reasons for late failure after allogeneic haematopoietic cell transplantation following BuCy2 in acute myeloid leukaemia.

The long-term follow-up is presented for 317 patients with acute myeloid leukaemia who underwent human leucocyte antigen-identical sibling marrow transplants between 1984 and 1995 following preparation with busulfan 16 mg/kg and cyclophosphamide 120 mg/kg. Among the 142 (45%) who were alive and leukaemia-free 3 years following transplantation, the leukaemia-free survival at 15 years was 72.8%. The cumulative incidence of late (>3 years beyond transplant) non-relapse mortality at 15 years was 12.9% and of late relapse was 16.5%. None of the variables considered (including age, disease stage, and graft-versus-host disease) were predictive of late failure.

CXCL12-CXCL4 heterodimerization prevents CXCL12-driven breast cancer cell migration.

Despite improvements in cancer early detection and treatment, metastatic breast cancer remains deadly. Current therapeutic approaches have very limited efficacy in patients with triple negative breast cancer. Among the many mechanisms associated that contribute to cancer progression, signaling through the CXCL12-CXCR4 is an essential step in cancer cell migration. We previously demonstrated the formation of CXCL12-CXCL4 heterodimers (Carlson et al., 2013). Here, we investigated whether CXCL12-CXCL4 heterodimers alter tumor cell migration. CXCL12 alone dose-dependently promoted the MDA-MB 231 cell migration (p < .05), which could be prevented by blocking the CXCR4 receptor. The addition of CXCL4 inhibited the CXCL12-induced cell migration (p < .05). Using NMR spectroscopy, we identified the CXCL4-CXCL12 binding interface. Moreover, we generated a CXCL4-derived peptide homolog of the binding interface that mimicked the activity of native CXCL4 protein. These results confirm the formation of CXCL12-CXCL4 heterodimers and their inhibitory effects on the migration of breast tumors cells. These findings suggest that specific peptides mimicking heterodimerization of CXCL12 might prevent breast cancer cell migration.

Heterozygous germ line CSF3R variants as risk alleles for development of hematologic malignancies.

Colony-stimulating factor 3 receptor (CSF3R) encodes the receptor for granulocyte colony-stimulating factor (G-CSF), a cytokine vital for granulocyte proliferation and differentiation. Acquired activating heterozygous variants in CSF3R are the main cause of chronic neutrophilic leukemia, a hyperproliferative disorder. In contrast, biallelic germ line hypomorphic variants in CSF3R are a rare cause of severe congenital neutropenia, a hypoproliferative condition. The impact of heterozygous germ line CSF3R variants, however, is unknown. We identified CSF3R as a new germ line hematologic malignancy predisposition gene through analysis of 832 next-generation sequencing tests conducted in 632 patients with hematologic malignancies. Among germ line CSF3R variants, 3 were abnormal in functional testing, indicating their deleterious nature. p.Trp547* was identified in 2 unrelated men with myelodysplastic syndromes diagnosed at 76 and 33 years of age, respectively. p.Trp547* is a loss-of-function nonsense variant in the extracellular domain that results in decreased CSF3R messenger RNA expression and abrogation of CSF3R surface expression and proliferative responses to G-CSF. p.Ala119Thr is a missense variant found in 2 patients with multiple myeloma and acute lymphoblastic leukemia, respectively. This variant is located between the extracellular immunoglobulin-like and cytokine receptor homology domains and results in decreased G-CSF sensitivity. p.Pro784Thr was identified in a 67-year-old man with multiple myeloma. p.Pro784Thr is a missense variant in the cytoplasmic domain that inhibits CSF3R internalization, producing a gain-of-function phenotype and G-CSF hypersensitivity. Our findings identify germ line heterozygous CSF3R variants as risk factors for development of myeloid and lymphoid malignancies.