Effect of Sirolimus levels between days 11 and 20 after allogeneic stem cell transplantation on the risk of hepatic sinusoidal obstruction syndrome.

Sinusoidal obstruction syndrome (SOS) is a serious complication of hematopoietic stem cell transplantation (HSCT). Sirolimus plus tacrolimus is an accepted regimen for graft-versus-host disease (GVHD) prophylaxis, with both agents implicated as risk factors for SOS. We analyzed 260 consecutive patients who underwent allogeneic HSCT following myeloablative conditioning using total body irradiation (TBI)-based (n = 151) or chemotherapy only (n = 109) regimens, with sirolimus plus tacrolimus for GVHD prophylaxis. SOS occurred in 28 patients at a median of 22 (range, 12-58) days. Mean sirolimus trough levels were higher between days 11 and 20 following transplant in patients who developed SOS (10.3 vs. 8.5 ng/ml, P = 0.008), with no significant difference in mean trough levels between days 0 and 10 (P = 0.67) and days 21-30 (P = 0.37). No differences in mean tacrolimus trough levels during the same time intervals were observed between those developing SOS and others. On multivariable analysis, a mean sirolimus trough level ≥ 9 ng/ml between days 11 and 20 increased the risk of SOS (hazard ratio 3.68, 95% CI: 1.57-8.67, P = 0.003), together with a longer time from diagnosis to transplant (P = 0.004) and use of TBI (P = 0.006). Our results suggest that mean trough sirolimus levels ≥ 9 ng/mL between days 11 and 20 post transplant may increase the risk of SOS and should be avoided.

Hypogammaglobulinemia in Adolescents and Young Adults with Acute Lymphoblastic Leukemia.

Hypogammaglobulinemia is a poorly described complication of chemotherapy in adolescents and young adults (AYAs, 15-39 years) with acute lymphoblastic leukemia (ALL). The majority of AYAs treated on a Berlin-Frankfurt-Munster-based ALL regimen experienced hypogammaglobulinemia (65.0% [13/20]). Febrile neutropenia episodes (throughout the treatment course) and infectious events during maintenance occurred more frequently in hypogammaglobulinemic patients compared with patients with normal immunoglobulin G levels (n = 7) (median 1.0 vs. 0.0, p = 0.02; 7.0 vs. 3.0, p = 0.02, respectively). Hypogammaglobulinemia did not impact overall or event-free survival. Further studies are needed to elucidate the etiology of hypogammaglobulinemia and to establish criteria for immunoglobulin replacement in these patients.

Pharmacokinetics of Basiliximab for the Prevention of Graft-versus-Host Disease in Patients Undergoing Hematopoietic Cell Transplantation with Minimal-Intensity Cyclophosphamide and Fludarabine.

STUDY OBJECTIVE: Basiliximab is an immunosuppressive monoclonal antibody used for rejection prevention following solid organ transplantation; the pharmacokinetics (PK) of basiliximab in this setting are known. Basiliximab may also be used for prophylaxis and treatment of graft-versus-host disease (GVHD) in patients undergoing allogeneic hematopoietic cell transplantation (HCT); however, the PK of basiliximab in this setting are not known. Clinical transplant providers expect variation in the volume of distribution and clearance after nonmyeloablative allogeneic transplantation (NMAT) compared with solid organ transplantation. Blood loss, organ site-specific antibody accumulation, and differences in blood product use during the two transplantation approaches may generate differences in basiliximab PK. Therefore, the objective of this study was to describe the PK of basiliximab after its addition to a minimally intense NMAT regimen, in conjunction with cyclosporine, for GVHD prophylaxis in patients with hematologic malignancies. DESIGN: Population PK analysis of a single-center, single-arm, phase II clinical trial. SETTING: Academic cancer research center. PATIENTS: Fourteen adults with hematologic malignancies (acute myeloid leukemia, acute lymphoblastic leukemia, chronic lymphocytic leukemia, myelodysplastic syndrome, non-Hodgkin's lymphoma, Hodgkin's lymphoma, myelofibrosis, or severe aplastic anemia) and undergoing NMAT with a fully HLA-matched (10 of 10 antigen matched) related or unrelated donor. MEASUREMENTS AND MAIN RESULTS: Basiliximab was used in conjunction with cyclosporine to deplete activated T cells in vivo as GVHD prophylaxis. We developed a novel competitive enzyme-linked immunosorbent assay (ELISA) method using recombinant interleukin-2 receptor alpha-chain (IL-2Ra) and a commercially available soluble sIL-2R ELISA kit to permit the quantification of serum basiliximab concentrations and characterization of the PK properties of the drug in this patient population. Using a nonlinear mixed effects model with NONMEM software, a one-compartment model with first-order elimination best described the PK, as covariate analysis using stepwise covariate modeling did not improve the base model. CONCLUSION: We suggest a one-compartment population model with first-order elimination to capture the PK profile for basiliximab for this patient population.

An Integrative multi-lineage model of variation in leukopoiesis and acute myelogenous leukemia.

BACKGROUND: Acute myelogenous leukemia (AML) progresses uniquely in each patient. However, patients are typically treated with the same types of chemotherapy, despite biological differences that lead to differential responses to treatment. RESULTS: Here we present a multi-lineage multi-compartment model of the hematopoietic system that captures patient-to-patient variation in both the concentration and rates of change of hematopoietic cell populations. By constraining the model against clinical hematopoietic cell recovery data derived from patients who have received induction chemotherapy, we identified trends for parameters that must be met by the model; for example, the mitosis rates and the probability of self-renewal of progenitor cells are inversely related. Within the data-consistent models, we found 22,796 parameter sets that meet chemotherapy response criteria. Simulations of these parameter sets display diverse dynamics in the cell populations. To identify large trends in these model outputs, we clustered the simulated cell population dynamics using k-means clustering and identified thirteen 'representative patient' dynamics. In each of these patient clusters, we simulated AML and found that clusters with the greatest mitotic capacity experience clinical cancer outcomes more likely to lead to shorter survival times. Conversely, other parameters, including lower death rates or mobilization rates, did not correlate with survival times. CONCLUSIONS: Using the multi-lineage model of hematopoiesis, we have identified several key features that determine leukocyte homeostasis, including self-renewal probabilities and mitosis rates, but not mobilization rates. Other influential parameters that regulate AML model behavior are responses to cytokines/growth factors produced in peripheral blood that target the probability of self-renewal of neutrophil progenitors. Finally, our model predicts that the mitosis rate of cancer is the most predictive parameter for survival time, followed closely by parameters that affect the self-renewal of cancer stem cells; most current therapies target mitosis rate, but based on our results, we propose that additional therapeutic targeting of self-renewal of cancer stem cells will lead to even higher survival rates.

The First Report of a Pregnancy in a Patient with Purine Nucleoside Phosphorylase Deficiency.

BACKGROUND: The cause of primary immunodeficiency has expanded to nearly 200 distinct disorders. An improved understanding of these disorders has resulted in decreased morbidity and mortality with reciprocal improved life expectancy. Obstetricians should have knowledge of primary immunodeficiency, as more women with these disorders will reach reproductive age. CASE: 21-year-old G1P0 with purine nucleoside phosphorylase (PNP) deficiency delivered a viable infant vaginally at 37 weeks. Although the patient's diagnosis and pregnancy placed her at increased risk for infection, she remained asymptomatic and infection-free throughout pregnancy. CONCLUSION: The management of pregnancy complicated by PNP deficiency requires strict immune surveillance and regimented immunoglobulin replacement.

Characterization of T and B cell repertoire diversity in patients with RAG deficiency.

Recombination-activating genes 1 and 2 (RAG1 and RAG2) play a critical role in T and B cell development by initiating the recombination process that controls the expression of T cell receptor (TCR) and immunoglobulin genes. Mutations in the RAG1 and RAG2 genes in humans cause a broad spectrum of phenotypes, including severe combined immunodeficiency (SCID) with lack of T and B cells, Omenn syndrome, leaky SCID, and combined immunodeficiency with granulomas or autoimmunity (CID-G/AI). Using next-generation sequencing, we analyzed the TCR and B cell receptor (BCR) repertoire in 12 patients with RAG mutations presenting with Omenn syndrome (n = 5), leaky SCID (n = 3), or CID-G/AI (n = 4). Restriction of repertoire diversity skewed usage of variable (V), diversity (D), and joining (J) segment genes, and abnormalities of CDR3 length distribution were progressively more prominent in patients with a more severe phenotype. Skewed usage of V, D, and J segment genes was present also within unique sequences, indicating a primary restriction of repertoire. Patients with Omenn syndrome had a high proportion of class-switched immunoglobulin heavy chain transcripts and increased somatic hypermutation rate, suggesting in vivo activation of these B cells. These data provide a framework to better understand the phenotypic heterogeneity of RAG deficiency.

Practice parameter for the diagnosis and management of primary immunodeficiency.

The American Academy of Allergy, Asthma & Immunology (AAAAI) and the American College of Allergy, Asthma & Immunology (ACAAI) have jointly accepted responsibility for establishing the "Practice parameter for the diagnosis and management of primary immunodeficiency." This is a complete and comprehensive document at the current time. The medical environment is a changing environment, and not all recommendations will be appropriate for all patients. Because this document incorporated the efforts of many participants, no single individual, including those who served on the Joint Task Force, is authorized to provide an official AAAAI or ACAAI interpretation of these practice parameters. Any request for information about or an interpretation of these practice parameters by the AAAAI or ACAAI should be directed to the Executive Offices of the AAAAI, the ACAAI, and the Joint Council of Allergy, Asthma & Immunology. These parameters are not designed for use by pharmaceutical companies in drug promotion.

Cyclophosphamide/fludarabine nonmyeloablative allotransplant for acute myeloid leukemia.

We compared survival outcomes following myeloablative allotransplant (MAT) or cyclophosphamide/fludarabine (Cy/Flu) nonmyeloablative allotransplant (NMAT) for 165 patients with acute myelogenous leukemia (AML) in remission or without frank relapse. Patients who received NMAT were more likely to be older and have secondary AML and lower performance status. At a median follow-up of 61 months, median event-free survival and overall survival survival were not different between NMAT and MAT in univariate as well as multivariate analyses. Cy/Flu NMAT may provide similar disease control and survival when compared with MAT in patients with AML in remission or without frank relapse.

Prognostic biomarkers for acute graft-versus-host disease risk after cyclophosphamide-fludarabine nonmyeloablative allotransplantation.

Five candidate plasma biomarkers (suppression of tumorogenesis 2 [ST2], regenerating islet-derived-3α [REG3α], elafin, tumor necrosis factor receptor 1 [TNFR1], and soluble IL-2 receptor-alpha [sIL2Rα]) were measured at specific time points after cyclophosphamide/fludarabine-based nonmyeloablative allotransplantation (NMAT) in patients who did or did not develop acute graft-versus-host disease (aGVHD). Plasma samples from 34 patients were analyzed at days +7, +14, +21, and +30. At a median follow-up of 358 days, 17 patients had experienced aGVHD with a median time to onset at day +36. Risk of aGVHD was associated with elevated plasma ST2 concentrations at day +7 (c-statistic = .72, P = .03), day +14 (c-statistic = .74, P = .02), and day +21 (c-statistic = .75, P = .02); elevated plasma REG3α concentrations at day +14 (c-statistic = .73, P = .03), day +21 (c-statistic = .76, P = .01), and day +30 (c-statistic = .73, P = .03); and elevated elafin at day +14 (c-statistic = .71, P = .04). Plasma concentrations of TNFR1 and sIL2Rα were not associated with aGVHD risk at any of the time points studied. This study identified ST2, REG3α, and elafin as prognostic biomarkers to evaluate risk of aGVHD after cyclophosphamide/fludarabine-based NMAT. These results need to be confirmed in an independent validation cohort.

Long-term efficacy, safety, and tolerability of Hizentra® for treatment of primary immunodeficiency disease.

Hizentra(®) (20% subcutaneous immunoglobulin [SCIG]) was administered to subjects with primary immunodeficiency disease in two extension studies in the EU and US to assess long-term efficacy and tolerability. Subjects (aged 4-69 years) were treated for 148 weeks in the EU (N = 40; 5405 infusions) and 87 weeks in the US (N = 21; 1735 infusions). Weekly doses were 116.0 mg/kg (EU) and 193.2 mg/kg (US); IgG levels were 7.97 g/L (EU) and 11.98 g/L (US). Annualized rates of serious bacterial infections were 0.05 infections/subject/year (EU) and 0.06 infections/subject/year (US). Rates of any infection were 3.33 infections/subject/year (EU) and 2.38 infections/subject/year (US). The rate of bronchopulmonary infections was higher in the EU study. No treatment-related serious AEs occurred; no subject discontinued because of treatment-related AEs. Self-administered Hizentra afforded sustained effective protection from infections and favorable tolerability during an extended treatment period of up to 3 years.

Recent advances in transplantation for primary immune deficiency diseases: a comprehensive review.

Hematopoietic cell transplantation (HCT) is a curative therapeutic option for severe combined immunodeficiency (SCID), a group of diseases which otherwise carry life expectancies that are of limited duration and quality. Survival following HCT for SCID has improved from approximately 23 to 91 % over the last 40 years. Success with SCID prompted efforts to apply HCT to the therapeutic challenge of well over 20 molecularly defined primary immune deficiency diseases (PID). Such success is due to both early recognition of PIDs and advances in the field of transplantation. Such advances include high-resolution HLA DNA donor-recipient matching, expansion of donor sources, better tolerated conditioning, new antibiotics, and wider availability. International collaborative efforts have provided patients and caregivers information that permit better treatment decisions now, and direct clinicians and investigators to ensure progress in the future. Pioneers in screening for SCID have taken steps to correct the fundamental challenge to successful treatment, which is the rapid discovery and characterization of cases and offering the transplant option to an affected child early in life; blood spot testing for T and B cell receptor quantification is now available to a growing fraction of newborns. Organizations including the Primary Immune Deficiency Treatment Consortium in the USA, The European Society for Primary Immunodeficiency, the European Group for Blood and Marrow Transplantation, the Pediatric Blood and Marrow Transplant Consortium, the United States Immunodeficiency Network, the Immune Deficiency Foundation, and the Jeffrey Modell Foundation are contributing mightily to increase awareness and standardize optimal utilization to the benefit of patients. This review will update the allergist-immunologist concerning disease presentations, indications for transplantation, methodologies, conditioning regimens, and clinical outcomes for patients with PID for which timely HCT is critical.

A systematic analysis of recombination activity and genotype-phenotype correlation in human recombination-activating gene 1 deficiency.

BACKGROUND: The recombination-activating gene (RAG) 1/2 proteins play a critical role in the development of T and B cells by initiating the VDJ recombination process that leads to generation of a broad T-cell receptor (TCR) and B-cell receptor repertoire. Pathogenic mutations in the RAG1/2 genes result in various forms of primary immunodeficiency, ranging from T(-)B(-) severe combined immune deficiency to delayed-onset disease with granuloma formation, autoimmunity, or both. It is not clear what contributes to such heterogeneity of phenotypes. OBJECTIVE: We sought to investigate the molecular basis for phenotypic diversity presented in patients with various RAG1 mutations. METHODS: We have developed a flow cytometry-based assay that allows analysis of RAG recombination activity based on green fluorescent protein expression and have assessed the induction of the Ighc locus rearrangements in mouse Rag1(-/-) pro-B cells reconstituted with wild-type or mutant human RAG1 (hRAG1) using deep sequencing technology. RESULTS: Here we demonstrate correlation between defective recombination activity of hRAG1 mutant proteins and severity of the clinical and immunologic phenotype and provide insights on the molecular mechanisms accounting for such phenotypic diversity. CONCLUSIONS: Using a sensitive assay to measure the RAG1 activity level of 79 mutations in a physiologic setting, we demonstrate correlation between recombination activity of RAG1 mutants and the severity of clinical presentation and show that RAG1 mutants can induce specific abnormalities of the VDJ recombination process.

Establishment and characterization of a novel cell line derived from human thymoma AB tumor.

Thymomas are low-grade epithelial tumors of the anterior mediastinum. The complexity of the disease and the lack of in vitro and in vivo models hamper the development of better therapeutics. In this study, we report a novel cell line, designated as IU-TAB-1, which was established from a patient with stage II thymoma (World Health Organization-type AB). The IU-TAB-1 cell line was established in vitro and characterized using histological and immunohistochemical staining, fluorescence-activated cell sorting, cytogenetic analyses and functional assays including in vitro and a NOD/SCID xenograft model. A whole-genome gene expression analysis (Illumina) was performed on the IU-TAB-1 cell line and 34 thymomas to determine the clinical relevance of the cell line. The IU-TAB-1 cell line was positive for epithelial markers (pan-cytokeratin and EpCAM/CD326) including thymic epithelial (TE) surface markers (such as CD29, CD9, CD54/ICAM-1, CD58 and CD24) and p63, and negative for B- and T-cell lineage markers. Gene expression profiling demonstrated overlapping and distinct genes between IU-TAB-1 and primary thymomas including the primary tumor (from which the cell line was derived). IU-TAB-1 cells are tumorigenic when implanted in immunodeficient mice with tumors reaching a volume of 1000 mm³ at around 130 days. The established cell line represents a biologically relevant new tool to investigate the molecular pathology of thymic malignancies and to evaluate the efficacy of novel therapeutics both in vitro and in vivo.

Molecular analysis of thymoma.

Histologic classification of thymomas has significant limitations with respect to both subtype definitions and consistency. In order to better understand the biology of the disease processes, we performed whole genome gene expression analysis. RNA was extracted from fresh frozen tumors from 34 patients with thymomas and followup data was available. Using the Illumina BeadStudio® platform and Human Ref-8 Beadchip, gene expression data was analyzed with Partek Genomics Suite®, and Ingenuity Pathways Analysis (IPA). Unsupervised clustering of gene expression data, representing one of the largest series in literature, resulted in identification of four molecular clusters of tumors (C1-C4), which correlated with histology (P = 0.002). However, neither histology nor clusters correlated with clinical outcomes. Correlation of gene expression data with clinical data showed that a number of genes were associated with either advanced stage at diagnosis or development of recurrence or metastases. The top pathways associated with metastases were amino acid metabolisms, biosynthesis of steroids and glycosphingolipids, cell cycle checkpoint proteins and Notch signaling. The differential expression of some of the top genes related to both metastases and stage was confirmed by RT-PCR in all cases of metastases and matched nonmetastatic cases. A number of potential candidates for therapeutics were also identified.

Comparison of pulmonary complications after nonmyeloablative and conventional allogeneic hematopoietic cell transplant.

Nonmyeloablative conditioning before allogeneic hematopoietic cell transplant (HCT) is an alternative to conventional conditioning in older patients and those with comorbidities. It is not known whether the decreased tissue injury associated with nonmyeloablative conditioning lowers the risk of pulmonary complications. The medical records of patients who underwent transplantation were reviewed and all pulmonary complications documented. Sixty-two consecutive patients with hematologic malignancies who underwent minimally intensive HCT (subjects) were compared to 48 consecutive patients who received conventional myeloablative allogeneic peripheral blood HCT (controls) over the same period at Indiana University Hospital. Pulmonary complications were categorized according to the type of complication and the time of onset after transplantation. Median follow-up times were similar between groups (P = .70). The study population (minimal intensity recipients) was older (P < .01), and the incidence of chronic graft-versus-host disease (cGVHD) was higher in subjects than controls (P = .02). Sixty-nine percent of subjects and 73% of controls developed pulmonary complications (P = .70). There was a trend in the minimally conditioned patients towards a lower incidence of pulmonary complications in older patients in the early posttransplantation period and a higher incidence of infectious pneumonias and bronchiolitis obliterans syndrome at later time points. The frequency of pulmonary complications seems to be similar after minimally intensive or myeloablative conditioning and allotransplantation. There was no difference in overall mortality or pulmonary-related mortality between the 2 groups.

Thymic carcinoma: outcomes after surgical resection.

BACKGROUND: Thymic carcinoma is a rare malignancy with little information regarding outcomes after therapy with curative intent. We undertook a retrospective analysis of all patients who underwent resection of thymic carcinoma at 2 hospitals. METHODS: From 1990 to 2011, 16 patients (9 men, 7 women) underwent surgical resection of thymic carcinoma at a mean age of 52 years. Patient demographics, extent of surgical resection, and outcomes were compiled. RESULTS: The distribution of Masaoka stages at presentation was I in 3 (19%), II in 4 (25%), III in 8 (50%), and IV in 1 (6%). Neoadjuvant chemotherapy was administered to 6 patients (38%) whose tumors were deemed to be more locally invasive. Surgical resection included en bloc extrapleural pneumonectomy in 1, lobectomy in 2, and superior vena cava resection and reconstruction in 4. There were no perioperative deaths. Complete resection was achieved in 14 (88%), and of these patients, only 1 experienced local recurrence. At last follow-up, 10 patients were alive and well, 1 patient was alive with disease, and 5 patients had died. Mean survival was 4.2 years. CONCLUSIONS: Although considered to have greater malignant potential, long-term survival can be achieved in patients with thymic carcinoma who are amenable to surgical therapy. With increased use of computed tomography imaging, patients with early-stage disease are being identified more frequently, and complete surgical resection appears to have favorable cure rates in these patients. Select patients with locally advanced disease can experience long-term survival with a multimodality approach.

Immune-mediated diseases and immunodeficiencies associated with thymic epithelial neoplasms.

INTRODUCTION: This retrospective study aimed to characterize the clinical hematological and immunological features of patients with thymic epithelial neoplasms. METHODS: From a cohort of 512 patients with thymic epithelial neoplasms, 79 patients diagnosed with autoimmune/immunodeficiency conditions or signs and/or symptoms suggesting an autoimmune or immunodeficiency state were evaluated by standard immunological and hematological testing. RESULTS: Elevated percentages of CD2+, CD3+, and CD8+ lymphocytes were observed in 44 (57.1%), 33 (41.8%), and 32 (40.5%) patients. Low CD4+ and CD19+ percentages were observed in 25 (31.6%) and 36 (46.2%), respectively; CD4+:CD8+ ratios were inverted in 18 (22.8%). IgG, IgA, and IgM levels were low in 12 (15.8%), 9 (11.7%) and 15 (19.7%) patients, respectively. Patients with immunodeficiency condition(s) were more likely to have high CD8+ percentages (p = 0.040), low CD19+ percentages (p = 0.025), and/or inverted CD4+/CD8+ ratios (p = 0.034). Patients with autoimmune condition(s) were more likely to have a high/normal CD4+ percentage (p = 0.038). High CD2+ percentages were associated with lower mean IgG and IgA levels (p = 0.030 and p = 0.017, respectively). High CD3+ and CD8+ percentages were associated with lower mean IgA levels (p = 0.046 and p = 0.013, respectively). Low CD19+ percentages were associated with lower mean IgG and IgA levels (p = 0.004 and p < 0.001, respectively). CONCLUSION: Signs/symptoms and history of autoimmune and immunodeficiency conditions among patients with thymic epithelial neoplasms are associated with high frequencies of abnormalities in immunoglobulin levels and lymphocyte immunophenotypes, suggesting a role for their assessment.

A unique posterior segment manifestation of whipple disease.

PURPOSE: To report a novel posterior segment manifestation of Whipple disease. METHOD: Single observational case study. RESULTS: The white crystalline deposit in the retina, choroiditis, and vitritis resolved with treatment of Whipple disease. CONCLUSION: Whipple disease can be associated with panuveitis, multifocal choroiditis, and white crystalline deposits in the anterior segments and retina, a unique clinical finding.

Whipple's disease-associated pulmonary hypertension with positive vasodilator response despite severe hemodynamic derangements.

Pulmonary hypertension (PH) associated with Whipple's disease (WD-PH) is extremely rare, and the underlying pathophysiological processes are incompletely understood. Alterations in hemodynamics can be severe, with right ventricular (RV) dysfunction being common. A case involving a 23-year-old man with WD-PH who exhibited a dramatic vasodilator response during right heart catheterization despite severely altered pulmonary hemodynamics and concomitant RV dysfunction is reported. While the patient's symptoms responded poorly to treatment with nifedipine and sildenafil, significant improvement in dyspnea, RV dysfunction and pulmonary pressures were noted following antibiotic therapy. The present report highlights that despite severely elevated pulmonary artery pressures and RV dysfunction in WD-PH patients, a highly significant vasodilator response and dramatic improvement with antibiotic therapy may be observed. Furthermore, the case highlights the phenomenon of PH in the setting of inflammation, suggesting that adequate control of the inflammatory response can be accompanied by a marked improvement in hemodynamics in certain types of PH.