Phase 1 study of CAR-37 T cells in patients with relapsed or refractory CD37+ lymphoid malignancies.

We report on the first-in-human clinical trial using chimeric antigen receptor (CAR) T-cells targeting CD37, an antigen highly expressed in B- and T-cell malignancies (clinicaltrials.gov NCT04136275). Five patients with relapsed or refractory CD37+ lymphoid malignancies were enrolled and infused with autologous CAR-37 T-cells. CAR-37 T-cells expanded in the peripheral blood of all patients and, at peak, comprised >94% of the total lymphocytes in 4/5 patients. Tumor responses were observed in 4/5 patients, with 3 complete responses, 1 mixed response, and 1 patient whose disease progressed rapidly and with relative loss of CD37 expression. Three patients experienced prolonged and severe pancytopenia, and in two of these patients, efforts to ablate CAR-37 T-cells (which were engineered to co-express truncated EGFR) with cetuximab, were unsuccessful. Hematopoiesis was restored in these two patients following allogeneic hematopoietic stem cell transplantation. No other severe, non-hematopoietic toxicities occurred. We investigated the mechanisms of profound pancytopenia and did not observe activation of CAR-37 T-cells in response to hematopoietic stem cells in vitro or hematotoxicity in humanized models. Patients with pancytopenia had sustained high levels of IL-18, with low levels of IL-18 binding protein in their peripheral blood. IL-18 levels were significantly higher in CAR-37-treated patients relative to both cytopenic and non-cytopenic cohorts of CAR-19-treated cohorts of patients. In conclusion, CAR-37 T-cells exhibited anti-tumor activity, with significant CAR expansion and cytokine production. CAR-37 T-cells may be an effective therapy in hematologic malignancies as a bridge to hematopoietic stem cell transplant.

Four challenges to CAR T cells breaking the glass ceiling.

Cell-based therapies using chimeric antigen receptor T cells (CAR T) have had dramatic efficacy in the clinic and can even mediate curative responses in patients with hematologic malignancies. As living drugs, engineered cells can still be detected in some patients even years after the original infusion. The excitement around the cell therapy field continues to expand as recent reports have shown that CAR T cells can induce remission in patients with autoimmune disease. While these promising advances in the field garner hope for wide-spread utility of CAR T therapies across diseases, several roadblocks exist that currently limit the access and efficacy of this therapy in the clinic. Herein, we will discuss four major obstacles that the CAR T field faces, including toxicity, identifying tumor-specific antigens, improving function in solid tumors, and reducing manufacturing complexity and cost. CAR T cells have potential for a multitude of diseases, but these glass ceilings will need to be broken in order to improve clinical responses and make this potentially life-saving therapy accessible to a larger patient population.

Management of complications of chimeric antigen receptor T-cell therapy: a report by the European Society of Blood and Marrow Transplantation.

CAR-T cells are in standard clinical use to treat relapsed or refractory hematologic malignancies, such as non-Hodgkin's lymphoma, multiple myeloma and acute lymphoblastic leukemia. Owing to the rapidly progressing field of CAR-T cell therapy and the lack of generally accepted treatment guidelines, we hypothesized significant differences between European centers in prevention, diagnosis and management of short- and long-term complications. To capture the current CAR-T cell management among EBMT centers and to determine the medical need and specific areas for future clinical research the EBMT Transplant Complications Working Party performed a survey among 227 EBMT CAR-T cell centers. We received complete servey answers from 106 centers (47%) addressing questions in the areas of product selection, CAR-T cell logistics, management of cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome as well as management in later phases including prolonged cytopenias. We identified common patterns in complication management, but also significant variety in clinical management of the centers in important aspects. Our results demonstrate a high medical need for treatment harmonization and future clinical research in the following areas: treatment of steroid-refractory and very severe CRS/neurotoxicity, treatment of cytopenia, early discharge and outpatient management, as well as immunoglobulin substitution.

Genome-edited, donor-derived allogeneic anti-CD19 chimeric antigen receptor T cells in paediatric and adult B-cell acute lymphoblastic leukaemia: results of two phase 1 studies.

BACKGROUND: Genome-edited donor-derived allogeneic anti-CD19 chimeric antigen receptor (CAR) T cells offer a novel form of CAR-T-cell product that is available for immediate clinical use, thereby broadening access and applicability. UCART19 is one such product investigated in children and adults with relapsed or refractory B-cell acute lymphoblastic leukaemia. Two multicentre phase 1 studies aimed to investigate the feasibility, safety, and antileukaemic activity of UCART19 in children and adults with relapsed or refractory B-cell acute lymphoblastic leukaemia. METHODS: We enrolled paediatric or adult patients in two ongoing, multicentre, phase 1 clinical trials to evaluate the safety and antileukaemic activity of UCART19. All patients underwent lymphodepletion with fludarabine and cyclophosphamide with or without alemtuzumab, then children received UCART19 at 1·1-2·3 × 106 cells per kg and adults received UCART19 doses of 6 × 106 cells, 6-8 × 107 cells, or 1·8-2·4 × 108 cells in a dose-escalation study. The primary outcome measure was adverse events in the period between first infusion and data cutoff. These studies were registered at ClinicalTrials.gov, NCT02808442 and NCT02746952. FINDINGS: Between June 3, 2016, and Oct 23, 2018, seven children and 14 adults were enrolled in the two studies and received UCART19. Cytokine release syndrome was the most common adverse event and was observed in 19 patients (91%); three (14%) had grade 3-4 cytokine release syndrome. Other adverse events were grade 1 or 2 neurotoxicity in eight patients (38%), grade 1 acute skin graft-versus-host disease in two patients (10%), and grade 4 prolonged cytopenia in six patients (32%). Two treatment-related deaths occurred; one caused by neutropenic sepsis in a patient with concurrent cytokine release syndrome and one from pulmonary haemorrhage in a patient with persistent cytopenia. 14 (67%) of 21 patients had a complete response or complete response with incomplete haematological recovery 28 days after infusion. Patients not receiving alemtuzumab (n=4) showed no UCART19 expansion or antileukaemic activity. The median duration of response was 4·1 months with ten (71%) of 14 responders proceeding to a subsequent allogeneic stem-cell transplant. Progression-free survival at 6 months was 27%, and overall survival was 55%. INTERPRETATION: These two studies show, for the first time, the feasibility of using allogeneic, genome-edited CAR T cells to treat patients with aggressive leukaemia. UCART19 exhibited in-vivo expansion and antileukaemic activity with a manageable safety profile in heavily pretreated paediatric and adult patients with relapsed or refractory B-cell acute lymphoblastic leukaemia. The results this study are an encouraging step forward for the field of allogeneic CAR T cells, and UCART19 offers the opportunity to treat patients with rapidly progressive disease and where autologous CAR-T-cell therapy is unavailable. FUNDING: Servier.

Reduced grey matter perfusion without volume loss in early relapsing-remitting multiple sclerosis.

BACKGROUND: Grey matter (GM) pathology in multiple sclerosis (MS) is associated with progressive long-term disability. Detection of GM abnormalities in early MS may therefore be valuable in understanding and predicting the long-term course. However, structural MRI measures such as volume loss have shown only modest abnormalities in early relapsing-remitting MS (RRMS). We therefore investigated for evidence of abnormality in GM perfusion, consistent with metabolic dysfunction, in early RRMS. METHODS: 25 RRMS patients with ≤5 years disease duration and 25 age-matched healthy controls underwent 3 Tesla MRI with a pseudo-continuous arterial spin labelling sequence to quantify GM perfusion and a volumetric T1-weighted sequence to measure GM volume. Neurological status was assessed in patients and neuropsychological evaluation undertaken in all subjects. Voxel-based analysis was used to compare regional GM perfusion and volume measures in patients and controls. RESULTS: There was reduced global GM perfusion in patients versus controls (50.6±5.8 mL/100 g/min vs 54.4±7.6 mL/100 g/min, p=0.04). Voxel-based analysis revealed extensive regions of decreased cortical and deep GM perfusion in MS subjects. Reduced perfusion was associated with impaired memory scores. There was no reduction in global or regional analysis of GM volume in patients versus controls. CONCLUSIONS: The decrease in GM perfusion in the absence of volume loss is consistent with neuronal metabolic dysfunction in early RRMS. Future studies in larger cohorts and longitudinal follow-up are needed to investigate the functional and prognostic significance of the early GM perfusion deficits observed.

An early economic evaluation of Kooth, a web-based mental health platform for children and young people with emerging mental health needs.

Background: "Kooth" is a web-based mental health platform commissioned by the National Health Service (NHS), local authorities, charities, and businesses in the UK. The platform gives children and young people (CYP) access to an online community of peers and a team of counsellors. This study reports an early economic evaluation of the potential benefits of Kooth in the UK. Methods: An early evidence cost calculator was built to estimate the potential costs and savings of implementing Kooth from a UK NHS and crime sector perspective. A decision tree structure was used to track the progress of CYP with emerging mental health needs (EMHN), comparing CYP with access to Kooth to CYP without access to Kooth. The model implemented a 12-month time horizon and followed a typical Kooth contract in relation to costing, engagement, and CYP demographics. Results: The base case results followed a cohort of 2160 CYP. The results of the cost calculator estimated that engagement with Kooth is associated with a cost saving of £469,237 to the NHS across a 12-month time horizon, or £236.15 per CYP with an EMHN. From a combined NHS and UK crime sector perspective, the cost savings increased to £489,897, or £246.54 per CYP with an EMHN. The largest cost savings were provided by an estimated reduction of 5346 GP appointments and 298 antidepressant prescriptions. For this cohort, the model predicted that engagement with Kooth averted 6 hospitalisations due to suicidal ideation and 13 hospitalisations due to self-harm. Furthermore, the number of smokers and binge drinkers was reduced by 20 and 24, respectively. When a crime sector perspective was taken, 3 crimes were averted. Discussion: This early model demonstrates that Kooth has the potential to be a cost-saving intervention from both an NHS and a combined NHS and UK crime sector perspective. Cost savings were provided through aversion in clinical and social outcomes. The model used a conservative approach to balance the uncertainty around assumptions of the intermediate outcomes (GP and medication use). However, it is limited by a paucity of costing data and published evidence relating to the impact of digital mental health platforms.

Optimization of a flow cytometry test for routine monitoring of B cell maturation antigen targeted CAR in peripheral blood.

Chimeric antigen receptor (CAR) modified T cell therapies targeting BCMA have displayed impressive activity in the treatment of multiple myeloma. There are currently two FDA licensed products, ciltacabtagene autoleucel and idecabtagene vicleucel, for treating relapsed and refractory disease. Although correlative analyses performed by product manufacturers have been reported in clinical trials, there are limited options for reliable BCMA CAR T detection assays for physicians and researchers looking to explore it as a biomarker for clinical outcome. Given the known association of CAR T cell expansion kinetics with toxicity and response, being able to quantify BCMA CAR T cells routinely and accurately in the blood of patients can serve as a valuable asset. Here, we optimized an accurate and sensitive flow cytometry test using a PE-conjugated soluble BCMA protein, with a lower limit of quantitation of 0.19% of CD3+ T cells, suitable for use as a routine assay for monitoring the frequency of BCMA CAR T cells in the blood of patients receiving either ciltacabtagene autoleucel or idecabtagene vicleucel.

Biophysical characterization of the structure of a SARS-CoV-2 self-amplifying RNA (saRNA) vaccine.

The current SARS-Covid-2 (SARS-CoV-2) pandemic has led to an acceleration of messenger ribonucleic acid (mRNA) vaccine technology. The development of production processes for these large mRNA molecules, especially self-amplifying mRNA (saRNA), has required concomitant development of analytical characterization techniques. Characterizing the purity, shape and structure of these biomolecules is key to their successful performance as drug products. This article describes the biophysical characterization of the Imperial College London Self-amplifying viral RNA vaccine (IMP-1) developed for SARS-CoV-2. A variety of analytical techniques have been used to characterize the IMP-1 RNA molecule. In this article, we use ultraviolet spectroscopy, dynamic light scattering, size-exclusion chromatography small-angle X-ray scattering and circular dichroism to determine key biophysical attributes of IMP-1. Each technique provides important information about the concentration, size, shape, structure and purity of the molecule.

Anti-TACI single and dual-targeting CAR T cells overcome BCMA antigen loss in multiple myeloma.

Chimeric Antigen Receptor (CAR) T cells directed to B cell maturation antigen (BCMA) mediate profound responses in patients with multiple myeloma, but most patients do not achieve long-term complete remissions. In addition, recent evidence suggests that high-affinity binding to BCMA can result in on-target, off-tumor activity in the basal ganglia and can lead to fatal Parkinsonian-like disease. Here we develop CAR T cells against multiple myeloma using a binder to targeting transmembrane activator and CAML interactor (TACI) in mono and dual-specific formats with anti-BCMA. These CARs have robust, antigen-specific activity in vitro and in vivo. We also show that TACI RNA expression is limited in the basal ganglia, which may circumvent some of the toxicities recently reported with BCMA CARs. Thus, single-targeting TACI CARs may have a safer toxicity profile, whereas dual-specific BCMA-TACI CAR T cells have potential to avoid the antigen escape that can occur with single-antigen targeting.

Tumor-activated lymph node fibroblasts suppress T cell function in diffuse large B cell lymphoma.

Recent transcriptomic-based analysis of diffuse large B cell lymphoma (DLBCL) has highlighted the clinical relevance of LN fibroblast and tumor-infiltrating lymphocyte (TIL) signatures within the tumor microenvironment (TME). However, the immunomodulatory role of fibroblasts in lymphoma remains unclear. Here, by studying human and mouse DLBCL-LNs, we identified the presence of an aberrantly remodeled fibroblastic reticular cell (FRC) network expressing elevated fibroblast-activated protein (FAP). RNA-Seq analyses revealed that exposure to DLBCL reprogrammed key immunoregulatory pathways in FRCs, including a switch from homeostatic to inflammatory chemokine expression and elevated antigen-presentation molecules. Functional assays showed that DLBCL-activated FRCs (DLBCL-FRCs) hindered optimal TIL and chimeric antigen receptor (CAR) T cell migration. Moreover, DLBCL-FRCs inhibited CD8+ TIL cytotoxicity in an antigen-specific manner. Notably, the interrogation of patient LNs with imaging mass cytometry identified distinct environments differing in their CD8+ TIL-FRC composition and spatial organization that associated with survival outcomes. We further demonstrated the potential to target inhibitory FRCs to rejuvenate interacting TILs. Cotreating organotypic cultures with FAP-targeted immunostimulatory drugs and a bispecific antibody (glofitamab) augmented antilymphoma TIL cytotoxicity. Our study reveals an immunosuppressive role of FRCs in DLBCL, with implications for immune evasion, disease pathogenesis, and optimizing immunotherapy for patients.

Arterial spin labelling reveals an abnormal cerebral perfusion pattern in Parkinson's disease.

There is a need for objective imaging markers of Parkinson's disease status and progression. Positron emission tomography and single photon emission computed tomography studies have suggested patterns of abnormal cerebral perfusion in Parkinson's disease as potential functional biomarkers. This study aimed to identify an arterial spin labelling magnetic resonance-derived perfusion network as an accessible, non-invasive alternative. We used pseudo-continuous arterial spin labelling to measure cerebral grey matter perfusion in 61 subjects with Parkinson's disease with a range of motor and cognitive impairment, including patients with dementia and 29 age- and sex-matched controls. Principal component analysis was used to derive a Parkinson's disease-related perfusion network via logistic regression. Region of interest analysis of absolute perfusion values revealed that the Parkinson's disease pattern was characterized by decreased perfusion in posterior parieto-occipital cortex, precuneus and cuneus, and middle frontal gyri compared with healthy controls. Perfusion was preserved in globus pallidus, putamen, anterior cingulate and post- and pre-central gyri. Both motor and cognitive statuses were significant factors related to network score. A network approach, supported by arterial spin labelling-derived absolute perfusion values may provide a readily accessible neuroimaging method to characterize and track progression of both motor and cognitive status in Parkinson's disease.

CAR T Cells Contend with Myeloma in the Bone Marrow Microenvironment.

In this issue of Blood Cancer Discovery, Dhodapkar and colleagues find that myeloid, dendritic, and endogenous T-cell populations in the bone marrow microenvironment are associated with progression-free survival (PFS) in multiple myeloma patients responding to B-cell maturation antigen-targeted CAR T cells. Immunosuppressive myeloid cells are associated with short PFS, but a diverse T-cell receptor repertoire and more dendritic cells are associated with a longer PFS, suggesting a potential role for epitope spreading. See related article by Dhodapkar et al., p. 490 (6).

Mitochondrial ROS signalling requires uninterrupted electron flow and is lost during ageing in flies.

Mitochondrial reactive oxygen species (mtROS) are cellular messengers essential for cellular homeostasis. In response to stress, reverse electron transport (RET) through respiratory complex I generates high levels of mtROS. Suppression of ROS production via RET (ROS-RET) reduces survival under stress, while activation of ROS-RET extends lifespan in basal conditions. Here, we demonstrate that ROS-RET signalling requires increased electron entry and uninterrupted electron flow through the electron transport chain (ETC). We find that in old fruit flies, ROS-RET is abolished when electron flux is decreased and that their mitochondria produce consistently high levels of mtROS. Finally, we demonstrate that in young flies, limiting electron exit, but not entry, from the ETC phenocopies mtROS generation observed in old individuals. Our results elucidate the mechanism by which ROS signalling is lost during ageing.

Clinical Pharmacology and Determinants of Response to UCART19, an Allogeneic Anti-CD19 CAR-T Cell Product, in Adult B-cell Acute Lymphoblastic Leukemia.

Background: UCART19 is an "off-the-shelf" genome-edited anti-CD19 chimeric antigen receptor (CAR)-T cell product, manufactured from unrelated healthy donor cells. Methods: UCART19 was administered to 25 adult patients with relapsed or refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL) in the CALM trial. All patients underwent lymphodepletion with fludarabine and cyclophosphamide ± alemtuzumab and received one of three ascending doses of UCART19. Given the allogeneic nature of UCART19, we analyzed the impact of lymphodepletion, HLA disparities, and host immune system reconstitution on its kinetics, along with other factors known to affect autologous CAR-T cell clinical pharmacology. Results: Responder patients (12/25) had higher UCART19 expansion (C max) and exposure (AUCTlast) than nonresponders (13/25), as measured by transgene levels in peripheral blood. The persistence of CAR+ T cells did not exceed 28 days in 10/25 patients and lasted beyond 42 days in 4/25. No significant correlation was found between UCART19 kinetics and administered cell dose, patient and product characteristics or HLA disparities. However, the number of prior lines of therapy and absence of alemtuzumab negatively impacted UCART19 expansion and persistence. Alemtuzumab exposure positively affected IL7 and UCART19 kinetics, while negatively correlating with host T lymphocyte AUC0-28. Conclusions: UCART19 expansion is a driver of response in adult patients with R/R B-ALL. These results shed light on the factors associated with UCART19 kinetics, which remain highly affected by the impact of alemtuzumab on IL7 and host-versus-graft rejection. Significance: First description of the clinical pharmacology of a genome-edited allogeneic anti-CD19 CAR-T cell product showing the crucial role of an alemtuzumab-based regimen in sustaining UCART19 expansion and persistence through increased IL7 availability and decreased host T lymphocyte population.

Allogeneic Anti-BCMA CAR T Cells Are Superior to Multiple Myeloma-derived CAR T Cells in Preclinical Studies and May Be Combined with Gamma Secretase Inhibitors.

Multiple myeloma remains an incurable plasma cell malignancy despite the rapidly evolving treatment landscape. Chimeric antigen receptor T cells targeted against BCMA have recently shown great promise in relapsed refractory multiple myeloma; however, all patients ultimately still progress from their disease. Lack of CAR T-cell persistence, impaired T-cell fitness in autologous CAR T-cell products and the presence of an immunosuppressive bone marrow (BM) microenvironment are contributory factors to treatment failure. We generated anti-BCMA CAR T cells from healthy donors (HD) and patients with multiple myeloma at different stages of disease to compare their T-cell profile, fitness, and cytotoxic activity in preclinical studies. We also used an ex vivo assay with multiple myeloma BM biopsies from distinct genomic subgroups to test the efficacy of HD-derived CAR T cells in a clinically relevant model. HD volunteers showed increased T-cell counts, higher CD4/CD8 ratio, and expanded naïve T-cell population compared with patients with multiple myeloma. After anti-BCMA CAR T-cell production, patients with relapsed multiple myeloma had lower frequencies of CAR+ T cells, decreased central memory phenotype, and increased checkpoint inhibitory markers compared with HD-derived products, which compromised their expansion and cytotoxicity against multiple myeloma cells in vitro. Importantly, HD-derived CAR T cells efficiently killed primary multiple myeloma cells within the BM microenvironment of different multiple myeloma genomic subgroups and their cytotoxic activity could be boosted with gamma secretase inhibitors. In conclusion, allogeneic anti-BCMA CAR T cells are a potential therapeutic strategy for patients with relapsed multiple myeloma and should be further developed in the clinic. Significance: Multiple myeloma is an incurable cancer of the plasma cells. A new therapy with anti-BCMA CAR T cells - the patient's own T cells genetically engineered to find and kill myeloma cancer cells - has shown encouraging results. Unfortunately, patients still relapse. In this study, we propose to use T cells from HD volunteers, which have a stronger T-cell fitness, higher cancer killing capacity, and are ready to be administered when needed.

UCART19, a first-in-class allogeneic anti-CD19 chimeric antigen receptor T-cell therapy for adults with relapsed or refractory B-cell acute lymphoblastic leukaemia (CALM): a phase 1, dose-escalation trial.

BACKGROUND: The prognosis for adults with relapsed or refractory B-cell acute lymphoblastic leukaemia remains poor. UCART19, an allogeneic genome-edited anti-CD19 chimeric antigen receptor (CAR) T-cell product derived from healthy donors and available for immediate clinical use, offers a potential therapeutic option for such patients. The CALM trial is a first-in-human study evaluating the safety and antileukaemic activity of UCART19 in adult patients with relapsed or refractory B-cell acute lymphoblastic leukaemia. METHODS: This phase 1, open-label study was conducted at eight centres across France, the UK, the USA, and Japan. Adult patients aged 16-70 years with CD19-positive relapsed or refractory B-cell acute lymphoblastic leukaemia who had morphological relapse or a minimal residual disease level of at least 1 × 10-3 and had exhausted standard treatment options were enrolled in the study, which comprised a dose-escalation phase of up to three UCART19 doses followed by a safety expansion phase. Patients underwent lymphodepletion with fludarabine (30 mg/m2 per day intravenously for 3 days) and cyclophosphamide (500 mg/m2 per day intravenously for 3 days) with or without alemtuzumab (1 mg/kg or 40 mg or 60 mg over 5 days) and received UCART19 doses of 6 × 106, 6-8 × 107, or 1·8-2·4 × 108 total CAR T cells intravenously, followed by safety evaluation and disease response assessments. The primary endpoint was incidence and severity of adverse events. Secondary endpoints were the overall response rate, duration of response, relapse-free survival, progression-free survival, and overall survival. This trial is registered with ClinicalTrials.gov (NCT02746952) and is complete. FINDINGS: Between Aug 1, 2016, and June 30, 2020, 25 patients were enrolled in the study and treated with UCART19. Median duration of follow-up was 12·8 months (IQR 2·8-24·8). Median age was 37 years (IQR 28-45). 14 (56%) patients were male and 11 (44%) female. 17 (68%) patients were White, two (8%) Black, two (8%) Asian, and four (16%) from other racial or ethnic groups. Three patients developed dose-limiting toxicities (one at each dose level); one had grade 4 cytokine release syndrome and two had grade 4 prolonged cytopenias. Grade 3 or higher cytokine release syndrome was reported in six (24%) patients and grade 3 or higher neurological toxicity in one (4%) patient. Grade 3 or higher infections occurred in seven (28%) patients, and grade 4 prolonged cytopenia in four (16%) patients. Two (8%) patients developed grade 1 acute cutaneous graft-versus-host disease. 14 patients died, nine from progressive disease and five from infections or other complications, of which four were considered to be related to UCART19 or lymphodepletion, or both. After a median of follow-up of 12·8 months (IQR 2·8-24·8), overall response rate was 48% (95% CI 28-69; 12 of 25 patients), duration of response and median relapse-free survival were 7·4 months (95% CI 1·8 to not calculable), progression-free survival was 2·1 months (95% CI 1·2-2·8), and overall survival was 13·4 months (95% CI 4·8-23·0). INTERPRETATION: UCART19 had a manageable safety profile, and showed evidence of antileukaemic activity in heavily pretreated adult patients with relapsed or refractory B-cell acute lymphoblastic leukaemia. This study shows that allogeneic off-the-shelf CAR T cells can be used safely to treat patients with relapsed B-cell acute lymphoblastic leukaemia. FUNDING: Servier.

Characterizing mild cognitive impairment in Parkinson's disease.

There is growing interest in identifying Parkinson's disease (PD) patients with mild cognitive impairment (PD-MCI), but widely disparate criteria have been used. We assessed 143 PD patients and 50 matched controls on 20 measures across 4 cognitive domains (executive function, attention and working memory, learning and memory, visuoperception). Twenty-four patients met criteria for dementia (PD-D); nondementia patients were classified as either with normal cognition or MCI for 12 neuropsychological criteria. We compared the influence of these criteria on the distribution of global cognitive performance in the resulting PD-MCI groups relative to the control and PD-D groups. Different criteria produced substantial variation in the proportion of PD-MCI cases identified. Fourteen percent PD-MCI was found when using 2 scores in 1 domain at 2 standard deviations (SD) below normative scores, with no controls identified as MCI, through to 89% PD-MCI with 1 score in 1 domain at 1 SD below normative scores, when 70% of controls were identified as MCI. The balance of cases with impaired cognition but not those with generally intact cognition was better served by using criteria that required 2 specific deficit scores or deficits across 2 domains. As comparisons with external normative data may have greater applicability across centers, we suggest that 2 scores at -1.5 SD within any single domain (30% PD-MCI) or 1 score at -1.5 SD in each of 2 domains (37% PD-MCI) provide suitable criteria to minimize the inclusion of cognitively well patients. Clinical dementia rating did not improve the relative identification of cognitively impaired and unimpaired nondementia PD patients.

Erythrocytes as Biomarkers for Dementia: Analysis of Protein Content and Alpha-Synuclein.

BACKGROUND: Discovering biomarkers for dementia is a pivotal step toward successful early diagnosis and treatment. Although plasma biomarkers have been explored, no consensus has been reached. Alpha-synuclein (AS), a 14 kDa synaptic protein associated with several neurodegenerative diseases, exists natively within erythrocytes (ERC). This protein is characteristic of Lewy body diseases, in which it aggregates into toxic Lewy bodies. As ERC are implicated in dementia, they are a potential target for future biomarkers. OBJECTIVE: The aims of this study were to assess AS levels within ERC and whether AS can be used as a peripheral biomarker to differentiate between dementia and aged matched healthy control subjects. METHODS: A total of 114 samples (60 aging controls, 36 Alzheimer's disease, 12 vascular dementia (VaD) and 6 dementia with Lewy bodies (DLB) subjects) were analyzed. We used Bradford assay to measure protein concentration, indirect ELISA to detect levels of AS, and immunoblotting to identify AS composition. Data were analyzed with nonparametric tests. RESULTS: AS oligomers were present in dementia blood samples, whereas in controls, AS was largely monomeric. There was a significant increase in AS levels in DLB whole blood (p = 0.005; Kruskal-Wallis test), with a sensitivity and specificity of 100.0% and 93.9%. Protein concentrations in ERC isolated at pH 5.7 were significantly increased in dementia patients compared to controls (17.58 versus 40.33µg/ml; p≤0.005; Mann-Whitney test). In the VaD group, the protein concentration in the pH5.7 ERC fraction had sensitivity and specificity of 91.7% and 62.1%. CONCLUSIONS: ERC protein concentration and AS levels have a potential for development of a novel diagnostic dementia blood test.