Shipping blood to a central laboratory in multicenter clinical trials: effect of ambient temperature on specimen temperature, and effects of temperature on mononuclear cell yield, viability and immunologic function

cGMP-compliant transportation conditions for a prompt therapeutic use of marrow mesenchymal stromal/stem cells

We recently described conditions for safe 18-h manufacturer-to-patient transportation of freshly harvested hBM-MSC expanded under cGMP protocols using human platelet lysate (hPL), that allowed prompt use as an advanced therapeutic medicinal product. Here we outline important considerations when comparing different transportation conditions, highlighting that although cell transportation may involve a reduction in viability, this did not undermine the ultimate bone-forming regenerative potential of the cGMP-hBM-MSC population.

Effects of blood transportation on human peripheral mononuclear cell yield, phenotype and function: implications for immune cell biobanking

Human biospecimen collection, processing and preservation are rapidly emerging subjects providing essential support to clinical as well as basic researchers. Unlike collection of other biospecimens (e.g. DNA and serum), biobanking of viable immune cells, such as peripheral blood mononuclear cells (PBMC) and/or isolated immune cell subsets is still in its infancy. While certain aspects of processing and freezing conditions have been studied in the past years, little is known about the effect of blood transportation on immune cell survival, phenotype and specific functions. However, especially for multicentric and cooperative projects it is vital to precisely know those effects. In this study we investigated the effect of blood shipping and pre-processing delay on immune cell phenotype and function both on cellular and subcellular levels. Peripheral blood was collected from healthy volunteers (n = 9): at a distal location (shipped overnight) and in the central laboratory (processed immediately). PBMC were processed in the central laboratory and analyzed post-cryopreservation. We analyzed yield, major immune subset distribution, proliferative capacity of T cells, cytokine pattern and T-cell receptor signal transduction. Results show that overnight transportation of blood samples does not globally compromise T- cell subsets as they largely retain their phenotype and proliferative capacity. However, NK and B cell frequencies, the production of certain PBMC-derived cytokines and IL-6 mediated cytokine signaling pathway are altered due to transportation. Various control experiments have been carried out to compare issues related to shipping versus pre-processing delay on site. Our results suggest the implementation of appropriate controls when using multicenter logistics for blood transportation aiming at subsequent isolation of viable immune cells, e.g. in multicenter clinical trials or studies analyzing immune cells/subsets. One important conclusion might be that despite changes due to overnight shipment, highly standardized central processing (and analysis) could be superior to multicentric de-central processing with more difficult standardization.

Improvement of IFNg ELISPOT Performance Following Overnight Resting of Frozen PBMC Samples Confirmed Through Rigorous Statistical Analysis

Immune monitoring of functional responses is a fundamental parameter to establish correlates of protection in clinical trials evaluating vaccines and therapies to boost antigen-specific responses. The IFNg ELISPOT assay is a well-standardized and validated method for the determination of functional IFNg-producing T-cells in peripheral blood mononuclear cells (PBMC); however, its performance greatly depends on the quality and integrity of the cryopreserved PBMC. Here, we investigate the effect of overnight (ON) resting of the PBMC on the detection of CD8-restricted peptide-specific responses by IFNg ELISPOT. The study used PBMC from healthy donors to evaluate the CD8 T-cell response to five pooled or individual HLA-A2 viral peptides. The results were analyzed using a modification of the existing distribution free resampling (DFR) recommended for the analysis of ELISPOT data to ensure the most rigorous possible standard of significance. The results of the study demonstrate that ON resting of PBMC samples prior to IFNg ELISPOT increases both the magnitude and the statistical significance of the responses. In addition, a comparison of the results with a 13-day preculture of PBMC with the peptides before testing demonstrates that ON resting is sufficient for the efficient evaluation of immune functioning.

EPC mobilization after erythropoietin treatment in acute ST-elevation myocardial infarction: the REVEAL EPC substudy

Erythropoietin (EPO) was hypothesized to mitigate reperfusion injury, in part via mobilization of endothelial progenitor cells (EPCs). The REVEAL trial found no reduction in infarct size with a single dose of EPO (60,000 U) in patients with ST-segment elevation myocardial infarction. In a substudy, we aimed to determine the feasibility of cryopreserving and centrally analyzing EPC levels to assess the relationship between EPC numbers, EPO administration, and infarct size. As a prespecified substudy, mononuclear cells were locally cryopreserved before as well as 24 and 48-72 h after primary percutaneous coronary intervention. EPC samples were collected in 163 of 222 enrolled patients. At least one sample was obtained from 125 patients, and all three time points were available in 83 patients. There were no significant differences in the absolute EPC numbers over time or between EPO- and placebo-treated patients; however, there was a trend toward a greater increase in EPC levels from 24 to 48-72 h postintervention in patients receiving ≥30,000 U of EPO (P = 0.099 for CD133(+) cells, 0.049 for CD34(+) cells, 0.099 for ALDH(br) cells). EPC numbers at baseline were inversely related to infarct size (P = 0.03 for CD133(+) cells, 0.006 for CD34(+) cells). Local whole cell cryopreservation and central EPC analysis in the context of a multicenter randomized trial is feasible but challenging. High-dose (≥30,000 U) EPO may mobilize EPCs at 48-72 h, and baseline EPC levels may be inversely associated with infarct size.

Viable mononuclear cell stability study for implementation in a proficiency testing program: impact of shipment conditions

The impact of shipping temperatures and preservation media used during transport of either peripheral blood mononuclear cells (PBMCs) or Jurkat cells was assessed, in view of implementing of a proficiency testing scheme on mononuclear cell viability. Samples were analyzed before and after shipment at different temperatures (ambient temperature, dry ice, and liquid nitrogen) and in different preservation media (serum with cryoprotectant, commercial cryopreservation solution, and room temperature transport medium). Sample quality was assessed by viability assays (Trypan Blue dye exclusion, flow cytometry, Cell Analysis System cell counting (CASY)), and by ELISpot functional assay. The liquid nitrogen storage and shipment were found to be the most stable conditions to preserve cell viability and functionality. However, we show that alternative high quality shipment conditions for viable cells are dry ice shipment and commercial cryopreservation solution. These were also cost-efficient shipment conditions, satisfying the requirements of a proficiency testing scheme for viable mononuclear cells. Room temperature transport medium dramatically and adversely affected the integrity of mononuclear cells.

Benznidazole treatment reduces the induction of indoleamine 2,3-dioxygenase (IDO) enzymatic activity in Chagas disease symptomatic patients

The enzyme indoleamine 2,3-dioxigenase (IDO) is critical for the regulation of immune responses in pro-tolerogenic antigen-presenting cell. To address the profile of immune responses associated with Chagas disease, we measured IDO activity of peripheral blood mononuclear cells from 168 chronic patients and 13 healthy donors. We found that IDO activity was increased in patients with Chagas disease when compared with controls. Moreover, the IDO activity of patients with Chagas disease in the symptomatic chronic phase, involving cardiac or digestive alterations, was higher than that detected in asymptomatic patients and correlated with the severity of the symptoms. Furthermore, benznidazole treatment induced a long-lasting decrease in IDO activity in symptomatic patients, reaching levels comparable with those of healthy donors. These results suggest that a pro-tolerogenic state is associated with the severity of Chagas disease and that benznidazole treatment is a valuable tool for breaking the parasite-driven immune tolerance in the symptomatic chronic phase of Chagas disease.

Large-scale prospective T cell function assays in shipped, unfrozen blood samples: experiences from the multicenter TRIGR trial

Broad consensus assigns T lymphocytes fundamental roles in inflammatory, infectious, and autoimmune diseases. However, clinical investigations have lacked fully characterized and validated procedures, equivalent to those of widely practiced biochemical tests with established clinical roles, for measuring core T cell functions. The Trial to Reduce Insulin-dependent diabetes mellitus in the Genetically at Risk (TRIGR) type 1 diabetes prevention trial used consecutive measurements of T cell proliferative responses in prospectively collected fresh heparinized blood samples shipped by courier within North America. In this article, we report on the quality control implications of this simple and pragmatic shipping practice and the interpretation of positive- and negative-control analytes in our assay. We used polyclonal and postvaccination responses in 4,919 samples to analyze the development of T cell immunocompetence. We have found that the vast majority of the samples were viable up to 3 days from the blood draw, yet meaningful responses were found in a proportion of those with longer travel times. Furthermore, the shipping time of uncooled samples significantly decreased both the viabilities of the samples and the unstimulated cell counts in the viable samples. Also, subject age was significantly associated with the number of unstimulated cells and T cell proliferation to positive activators. Finally, we observed a pattern of statistically significant increases in T cell responses to tetanus toxin around the timing of infant vaccinations. This assay platform and shipping protocol satisfy the criteria for robust and reproducible long-term measurements of human T cell function, comparable to those of established blood biochemical tests. We present a stable technology for prospective disease-relevant T cell analysis in immunological diseases, vaccination medicine, and measurement of herd immunity.

Practical guidance for implementing predictive biomarkers into early phase clinical studies

The recent U.S. Food and Drug Administration (FDA) coapprovals of several therapeutic compounds and their companion diagnostic devices (FDA News Release, 2011, 2013) to identify patients who would benefit from treatment have led to considerable interest in incorporating predictive biomarkers in clinical studies. Yet, the translation of predictive biomarkers poses unique technical, logistic, and regulatory challenges that need to be addressed by a multidisciplinary team including discovery scientists, clinicians, biomarker experts, regulatory personnel, and assay developers. These issues can be placed into four broad categories: sample collection, assay validation, sample analysis, and regulatory requirements. In this paper, we provide a primer for drug development teams who are eager to implement a predictive patient segmentation marker into an early clinical trial in a way that facilitates subsequent development of a companion diagnostic. Using examples of nucleic acid-based assays, we briefly review common issues encountered when translating a biomarker to the clinic but focus primarily on key practical issues that should be considered by clinical teams when planning to use a biomarker to balance arms of a study or to determine eligibility for a clinical study.

Immune monitoring in cancer vaccine clinical trials: critical issues of functional flow cytometry-based assays

The development of immune monitoring assays is essential to determine the immune responses against tumor-specific antigens (TSAs) and tumor-associated antigens (TAAs) and their possible correlation with clinical outcome in cancer patients receiving immunotherapies. Despite the wide range of techniques used, to date these assays have not shown consistent results among clinical trials and failed to define surrogate markers of clinical efficacy to antitumor vaccines. Multiparameter flow cytometry- (FCM-) based assays combining different phenotypic and functional markers have been developed in the past decade for informative and longitudinal analysis of polyfunctional T-cells. These technologies were designed to address the complexity and functional heterogeneity of cancer biology and cellular immunity and to define biomarkers predicting clinical response to anticancer treatment. So far, there is still a lack of standardization of some of these immunological tests. The aim of this review is to overview the latest technologies for immune monitoring and to highlight critical steps involved in some of the FCM-based cellular immune assays. In particular, our laboratory is focused on melanoma vaccine research and thus our main goal was the validation of a functional multiparameter test (FMT) combining different functional and lineage markers to be applied in clinical trials involving patients with melanoma.

Cardiovascular toxicity and titin cross-reactivity of affinity-enhanced T cells in myeloma and melanoma

An obstacle to cancer immunotherapy has been that the affinity of T-cell receptors (TCRs) for antigens expressed in tumors is generally low. We initiated clinical testing of engineered T cells expressing an affinity-enhanced TCR against HLA-A*01-restricted MAGE-A3. Open-label protocols to test the TCRs for patients with myeloma and melanoma were initiated. The first two treated patients developed cardiogenic shock and died within a few days of T-cell infusion, events not predicted by preclinical studies of the high-affinity TCRs. Gross findings at autopsy revealed severe myocardial damage, and histopathological analysis revealed T-cell infiltration. No MAGE-A3 expression was detected in heart autopsy tissues. Robust proliferation of the engineered T cells in vivo was documented in both patients. A beating cardiomyocyte culture generated from induced pluripotent stem cells triggered T-cell killing, which was due to recognition of an unrelated peptide derived from the striated muscle-specific protein titin. These patients demonstrate that TCR-engineered T cells can have serious and not readily predictable off-target and organ-specific toxicities and highlight the need for improved methods to define the specificity of engineered TCRs.

Vaccine against autoimmune disease: antigen-specific immunotherapy

Recent interest in testing whether the success of antigen-specific immunotherapy (ASIT) for autoimmune diseases in mice can be translated to humans has highlighted the need for better tools to study and understand human autoimmunity. Clinical development of ASIT for allergy has been instructive, but limited understanding of CD4 T cell epitope/determinant hierarchies hampers the rational design and monitoring of ASIT. Definitive identification of pathogenic T cell epitopes as is now known in celiac disease and recent initiatives to optimize immune monitoring will facilitate rational design, monitoring and mechanistic understanding of ASIT for human autoimmune diseases.

Functional characterization of T cell populations in a mouse model of chronic obstructive pulmonary disease

Cigarette smoke (CS) exposure is the primary risk factor for the development of chronic obstructive pulmonary disease (COPD). COPD is characterized by chronic peribronchial, perivascular, and alveolar inflammation. The inflammatory cells consist primarily of macrophage, neutrophils, and lymphocytes. Although myeloid cells are well studied, the role of lymphocyte populations in pathogenesis of COPD remains unclear. Using a mouse model of CS-induced emphysema, our laboratory has previously demonstrated that CS exposure causes changes in the TCR repertoire suggestive of an Ag-specific response and triggers a pathogenic T cell response sufficient to cause alveolar destruction and inflammation. We extend these findings to demonstrate that T cells from CS-exposed mice of the BALB/cJ or C57B6 strain are sufficient to transfer pulmonary pathology to CS-naive, immunosufficient mice. CS exposure causes a proinflammatory phenotype among pulmonary T cells consistent with those from COPD patients. We provide evidence that donor T cells from CS-exposed mice depend on Ag recognition to transfer alveolar destruction using MHC class I-deficient recipient mice. Neither CD4(+) nor CD8(+) T cells from donor mice exposed to CS alone are sufficient to cause inflammation or pathology in recipient mice. We found no evidence of impaired suppression of T cell proliferation among regulatory T cells from CS-exposed mice. These results suggest that CS exposure initiates an Ag-specific response that leads to pulmonary destruction and inflammation that involves both CD8(+) and CD4(+) T cells. These results are direct evidence for an autoimmune response initiated by CS exposure.

Comparison of hematologic measurements between local and central laboratories: data from the BABY HUG trial

OBJECTIVES

To investigate the concordance of blood count indices measured locally and at a central laboratory.

DESIGN AND METHODS

In a multi-center clinical trial of hydroxyurea therapy in infants with sickle cell anemia (BABY HUG), the concordance between blood count indices measured locally and at a central laboratory was investigated.

RESULTS

Local laboratory measurements of neutrophil and monocyte counts were significantly higher (44% and 37%, respectively) compared to the central measurements (p<0.0001), and mean corpuscular volume (MCV) was higher centrally.

CONCLUSION

Overnight shipping with processing delay causes spurious reductions in absolute neutrophil count (ANC) and absolute monocyte count (AMC) that may result in incorrect monitoring decisions in multicenter clinical trials.