Dynamical System Modeling of Immune Reconstitution after Allogeneic Stem Cell Transplantation Identifies Patients at Risk for Adverse Outcomes.

Systems that evolve over time and follow mathematical laws as they evolve are called dynamical systems. Lymphocyte recovery and clinical outcomes in 41 allograft recipients conditioned using antithymocyte globulin (ATG) and 4.5-Gy total body irradiation were studied to determine if immune reconstitution could be described as a dynamical system. Survival, relapse, and graft-versus-host disease (GVHD) were not significantly different in 2 cohorts of patients receiving different doses of ATG. However, donor-derived CD3(+) cell reconstitution was superior in the lower ATG dose cohort, and there were fewer instances of donor lymphocyte infusion (DLI). Lymphoid recovery was plotted in each individual over time and demonstrated 1 of 3 sigmoid growth patterns: Pattern A (n = 15) had rapid growth with high lymphocyte counts, pattern B (n = 14) had slower growth with intermediate recovery, and pattern C (n = 10) had poor lymphocyte reconstitution. There was a significant association between lymphocyte recovery patterns and both the rate of change of donor-derived CD3(+) at day 30 after stem cell transplantation (SCT) and clinical outcomes. GVHD was observed more frequently with pattern A, relapse and DLI more so with pattern C, with a consequent survival advantage in patients with patterns A and B. We conclude that evaluating immune reconstitution after SCT as a dynamical system may differentiate patients at risk of adverse outcomes and allow early intervention to modulate that risk.

Harvesting autologous stem cells from a patient with red blood cell abnormalities of ß-thalassemia intermedia.

BACKGROUND: Autologous stem cell transplants in patients with hemoglobinopathies are limited. Previous reports used granulocyte-colony-stimulating factor (G-CSF) for mobilization of stem cells; there are no reported cases undergoing plerixafor mobilization. We report such a patient, providing guidance for peripheral blood stem cells collection when aberrant red blood cells (RBCs) disrupt normal separation. STUDY DESIGN AND METHODS: A patient with ß-thalassemia intermedia and hereditary persistence of fetal hemoglobin presented for peripheral blood stem cell collection for autologous transplant for myeloma. He underwent splenectomy for anemia secondary to hemoglobinopathy and chemotherapy, ceasing RBC transfusions. The patient was mobilized using plerixafor after collection with G-CSF failed. RESULTS: Collections were performed using an apheresis system, processing 24 L daily. Peripheral blood and apheresis product CD34 determinations were performed daily. On Day 1, the product yield was 0.04 × 10(6) CD34 cells/kg, less than expected based on white blood cell count and CD34-positive cells. Peripheral blood smear showed nucleated RBCs and RBC morphologic abnormalities. Changes in instrument variables were made after consultation with Terumo BCT to adjust for variable distribution of mononuclear and stem cells during centrifugation. Collecting stem cells at a deeper location and centrifuging faster improved collection, and a cumulative total of 4.40 × 10(6) CD34 cells/kg was achieved after four collections. The patient underwent tandem autologous transplantation and engrafted within 12 to 13 days of each transplant. CONCLUSIONS: Adjustments in apheresis variables allowed successful collection of peripheral blood stem cells from a patient with RBC anomalies of ß-thalassemia that interfered with standard stem cell harvesting.

Measurement of cancer health literacy and identification of patients with limited cancer health literacy.

Health literacy is related to a broad range of health outcomes. This study was designed to develop a psychometrically sound instrument designed to measure cancer health literacy along a continuum (CHLT-30), to develop another instrument designed to determine whether a patient has limited cancer health literacy (CHLT-6), and to estimate the prevalence of limited cancer health literacy. The Cancer Health Literacy Study involving 1,306 Black and White cancer patients was conducted between April 2011 and April 2013 in the Virginia Commonwealth University Massey Cancer Center and surrounding oncology clinics. A continuous latent variable modeling framework was adopted to dimensionally represent cancer health literacy, whereas discrete latent variable modeling was used to estimate the prevalence rates of limited cancer health literacy. Self confidence about engaging in health decisions was used as the primary outcome in external validation of new instruments. Results from a comprehensive analysis strongly supported the construct validity and reliability of the CHLT-30 and CHLT-6. For both instruments, measurement invariance tests ruled out item/test bias to explain gender and race/ethnicity differences in test scores. The limited cancer health literacy rate was 18%, a subpopulation consisting of overrepresented Black, undereducated, and low-income cancer patients. Overall, the results supported the conclusion that the CHLT-30 accurately measures cancer health literacy along a continuum and that the CHLT-6 efficiently identifies patients with limited cancer health literacy with high accuracy.

Favorable outcomes in patients with high donor-derived T cell count after in vivo T cell-depleted reduced-intensity allogeneic stem cell transplantation.

Patients with hematologic malignancies were conditioned using a rabbit antithymocyte globulin-based reduced-intensity conditioning regimen for allogeneic stem cell transplantation. Donor-derived CD3(+) cell count (ddCD3), a product of CD3(+) cell chimerism and absolute CD3(+) cell count, when <110/µL at 8 weeks post-stem cell transplantation predicted a high risk of sustained mixed chimerism and relapse. Alternatively, patients with a higher ddCD3 developed graft-versus-host disease more frequently, and when partially chimeric, had higher rates of conversion to full donor chimerism after withdrawal of immunosuppression. Early data from our small cohort of patients indicate that ddCD3 at 8 weeks may be used to guide decisions regarding withdrawal of immunosuppression and administration of donor lymphocyte infusion in partially T cell-depleted reduced-intensity regimens.

Epigenetic induction of adaptive immune response in multiple myeloma: sequential azacitidine and lenalidomide generate cancer testis antigen-specific cellular immunity.

Patients with multiple myeloma (MM) undergoing high dose therapy and autologous stem cell transplantation (SCT) remain at risk for disease progression. Induction of the expression of highly immunogenic cancer testis antigens (CTA) in malignant plasma cells in MM patients may trigger a protective immune response following SCT. We initiated a phase II clinical trial of the DNA hypomethylating agent, azacitidine (Aza) administered sequentially with lenalidomide (Rev) in patients with MM. Three cycles of Aza and Rev were administered and autologous lymphocytes were collected following the 2nd and 3rd cycles of Aza-Rev and cryopreserved. Subsequent stem cell mobilization was followed by high-dose melphalan and SCT. Autologous lymphocyte infusion (ALI) was performed in the second month following transplantation. Fourteen patients have completed the investigational therapy; autologous lymphocytes were collected from all of the patients. Thirteen patients have successfully completed SCT and 11 have undergone ALI. Six patients tested have demonstrated CTA up-regulation in either unfractionated bone marrow (n = 4) or CD138+ cells (n = 2). CTA (CTAG1B)-specific T cell response has been observed in all three patients tested and persists following SCT. Epigenetic induction of an adaptive immune response to cancer testis antigens is safe and feasible in MM patients undergoing SCT.

Managing post allograft relapse of myeloid neoplasms: azacitidine and donor lymphocyte infusions as salvage therapy.

Azacitidine (Aza) may promote cytotoxic effects against hematologic tumor cells when combined with donor lymphocyte infusions (DLIs). This study sought to verify Aza-DLI's efficacy and tolerability in patients with relapsed acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) following allogeneic stem cell transplantation (SCT) and identify cohorts benefitting most from therapy. Twenty-eight patients with recurrent AML or MDS following SCT received Aza-DLI. One-year overall survival (OS) after therapy initiation was 44%; two-year OS was 35%. Molecular/cytogenetic-only relapse, the development of cGVHD after therapy initiation, and a greater number of Aza and DLI were associated with remission. There was a trend toward higher absolute CD4+ cell count in those achieving remission. This study demonstrates Aza-DLI to be effective and highlights the importance of minimal residual disease testing and alloreactivity in managing post allograft relapsed hematological malignancy.

The influence of lymphoid reconstitution kinetics on clinical outcomes in allogeneic stem cell transplantation.

Lymphoid recovery following myeloablative stem cell transplantation (SCT) displays a logistic pattern of exponential growth followed by a plateau. Within this logistic framework, lymphoid recovery is characterized by the parameters R (slope of ascent), a (time of maximal rate of ascent) and K (plateau), the 'steady-state' lymphocyte count. A retrospective analysis of allogeneic SCT performed from 2008 to 2013 was undertaken to compare lymphoid recovery and clinical outcomes in 131 patients with acute myelogenous leukemia, acute lymphocytic leukemia, and myelodysplastic syndromes. Using Prism software, a logistic curve was successfully fit to the absolute lymphocyte count recovery in all patients. Patients were classified according to the magnitude and rate of lymphoid recovery; pattern A achieved an absolute lymphocyte counts (ALC) of >1000/µL by day 45, pattern B an ALC 500 < x < 1000/µL, and pattern C an ALC <500/µL. Pattern A was characterized by a higher mean K (p < .0001) compared with patterns B and C. Patients with patterns B and C were more likely to have mixed T cell chimerism at 90 d following SCT (p = .01). There was a trend towards improved survival (and relapse-free survival) in those with pattern A and B at 1 year compared to pattern C (p = .073). There was no difference in cGVHD (p = .42) or relapse (p = .45) between pattern types. Cytomegalovirus (CMV), aGVHD, and all relapse were heralded by deviation from logistic behavior. Pattern C patients were more likely to require donor lymphocyte infusion (DLI) (p = .017). Weaning of tacrolimus post-transplant was associated with a second, separate logistic expansion in some patients. This study demonstrated that lymphoid reconstitution follows a prototypical logistic recovery and that pattern observed correlates with T cell chimerism and need for DLI, and may influence survival.

Retreatment with yttrium-90 ibritumomab tiuxetan in patients with B-cell non-Hodgkin's lymphoma.

There is no data on safety and efficacy of a second course of ibritumomab tiuxetan. In this work, data on patients with B-cell NHL who were treated with two courses of ibritumomab tiuxetan were analyzed. Eighteen such patients were analyzed (age: 58 years, 48 - 91), with a median of four prior regimens (1 - 7), stem cell transplantation (n = 5), and radiation therapy (n = 6). After the first course, G3/4 neutropenia and thrombocytopenia was 35% and 41%; overall response rate (ORR) was 89%; time between courses was 16.6 months (6.0 - 42.7). After the second course, the incidence of G3/4 neutropenia and thrombocytopenia was 28% and 44%; and ORR 77%. There were no infectious or bleeding complications, secondary myelodysplastic syndromes, or leukemias. Retreatment with the ibritumomab tiuxetan regimen was well tolerated, with a safety profile similar to that of the first course. To conclude, patients who benefited from the first course of ibritumomab tiuxetan can benefit from retreatment.

Stem cell transplantation as a dynamical system: are clinical outcomes deterministic?

Outcomes in stem cell transplantation (SCT) are modeled using probability theory. However, the clinical course following SCT appears to demonstrate many characteristics of dynamical systems, especially when outcomes are considered in the context of immune reconstitution. Dynamical systems tend to evolve over time according to mathematically determined rules. Characteristically, the future states of the system are predicated on the states preceding them, and there is sensitivity to initial conditions. In SCT, the interaction between donor T cells and the recipient may be considered as such a system in which, graft source, conditioning, and early immunosuppression profoundly influence immune reconstitution over time. This eventually determines clinical outcomes, either the emergence of tolerance or the development of graft versus host disease. In this paper, parallels between SCT and dynamical systems are explored and a conceptual framework for developing mathematical models to understand disparate transplant outcomes is proposed.

Distinct oligoclonal T cells are associated with graft versus host disease after stem-cell transplantation.

BACKGROUND: In patients with hematologic malignancies who receive stem-cell transplantation, donors' T cells can recognize minor histocompatibility antigens on recipient cells and generate an objective response against the tumor. However, a major side effect of such therapy is graft-versus-host disease (GVHD). The purpose of this study was to characterize distinct T-cell clones that were frequently and exclusively involved in GVHD or graft-versus-tumor (GVT) effects. METHODS: We hypothesized that distinct GVHD-associated T-cell clones can be identified during the disease progression. To test this, we conducted comparative analysis of T-cell receptor (TCR) Vßs in donor-recipient pairs of patients with GVHD versus those with GVHD-free and relapse-free survival using quantitative reverse-transcriptase polymerase chain reaction and spectratyping analyses. RESULTS: We identified three sets of T-cell clones that were either frequently involved in GVHD (TCR Vß4, 11, and 23) or GVT effect (TCR Vß9, 16, and 20), or were increased at the time of GVHD and GVT effects in a patient-specific manner (TCR Vß2, 3, 7, 12, 15, and 17). Spectratyping analysis showed restricted clonality of the identified TCR Vßs. Polymerase chain reaction analysis also confirmed the presence of GVHD-associated T-cell clones at the site of the disease. CONCLUSIONS: These data suggest that GVHD- and GVT-associated clones can be distinguished by molecular analysis of TCR Vß to develop targeted therapy for GVHD.

Shaping your career to maximize personal satisfaction in the practice of oncology.

The practice of oncology can be a source of both great satisfaction and great stress. Although many oncologists experience burnout, depression, and dissatisfaction with work, others experience tremendous career satisfaction and achieve a high overall quality of life. Identifying professional goals, optimizing career fit, identifying and managing stressors specific to practice type, and achieving the optimal personal work-life balance can increase the likelihood of individual oncologists' achieving personal and professional satisfaction. In this article, we will explore how oncologists can accomplish these tasks and will examine several pervasive professional myths that often distort perspective. The article concludes in a conversation with four oncologists regarding what they find most meaningful about their work, how they manage career-specific stressors, and how they achieve balance between their personal and professional lives.

Antibody-mediated pure red cell aplasia due to epoetin alfa during antiviral therapy of chronic hepatitis C.

Anemia frequently complicates the treatment of chronic hepatitis C with interferon and ribavirin (RVN), requiring dose reduction and jeopardizing sustained virologic response. Increasingly, epoetin alfa is used to prevent anemia in this setting. Below, we report the first case of pure red cell aplasia (PRCA) in a patient with chronic hepatitis C who received epoetin alfa (Procrit) to manage anti-viral treatment-induced anemia. Red blood cell transfusion-dependence developed 16 wk after the patient was started on peginterferon alfa-2b and RVN for chronic hepatitis C despite the simultaneous administration of epoetin alfa and subsequent discontinuation of the antiviral medications. Bone marrow biopsy was consistent with PRCA. High-titer erythropoietin antibodies, assayed by two methods, appeared shortly after epoetin alfa was administered, and were associated with a decline in serum erythropoietin to undetectable levels. Erythropoietin antibodies directed toward epoetin alfa were shown to cross react with darbepoetin alfa (Aranesp), and a neutralization assay confirmed that they inhibited cell growth in the presence of erythropoietin. Transfusion-dependence resolved approximately 16 wk after discontinuing epoetin alfa, and 6 wk after starting danazol. PRCA caused by the development of erythropoietin antibodies is a potentially life-threatening complication of administering epoetin alfa to prevent the anemia associated with antiviral therapy in patients with chronic hepatitis C.