FlowCT for the analysis of large immunophenotypic datasets and biomarker discovery in cancer immunology

Large-scale immune monitoring is becoming routinely used in clinical trials to identify determinants of treatment responsiveness, particularly to immunotherapies. Flow cytometry remains one of the most versatile and high throughput approaches for single-cell analysis; however, manual interpretation of multidimensional data poses a challenge when attempting to capture full cellular diversity and provide reproducible results. We present FlowCT, a semi-automated workspace empowered to analyze large data sets. It includes pre-processing, normalization, multiple dimensionality reduction techniques, automated clustering, and predictive modeling tools. As a proof of concept, we used FlowCT to compare the T-cell compartment in bone marrow (BM) with peripheral blood (PB) from patients with smoldering multiple myeloma (SMM), identify minimally invasive immune biomarkers of progression from smoldering to active MM, define prognostic T-cell subsets in the BM of patients with active MM after treatment intensification, and assess the longitudinal effect of maintenance therapy in BM T cells. A total of 354 samples were analyzed and immune signatures predictive of malignant transformation were identified in 150 patients with SMM (hazard ratio [HR], 1.7; P < .001). We also determined progression-free survival (HR, 4.09; P < .0001) and overall survival (HR, 3.12; P = .047) in 100 patients with active MM. New data also emerged about stem cell memory T cells, the concordance between immune profiles in BM and PB, and the immunomodulatory effect of maintenance therapy. FlowCT is a new open-source computational approach that can be readily implemented by research laboratories to perform quality control, analyze high-dimensional data, unveil cellular diversity, and objectively identify biomarkers in large immune monitoring studies. These trials were registered at www.clinicaltrials.gov as #NCT01916252 and #NCT02406144.© 2022 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved

External control of the public water supply in 29 Brazilian cities

The fluoridation of public water supplies is considered the most efficient public health measure for dental caries prevention. However, fluoride levels in the public water supply must be kept constant and adequate for the population to gain preventive benefit. The aim of this study was to analyze fluoride levels in the public water supply of 29 Brazilian municipalities during a 48-month period from November 2004 to October 2008. Three collection sites were defined for each source of municipal public water supply. Water samples were collected monthly and analyzed at the Research Laboratory of the Nucleus for Public Health (NEPESCO), Public Health Postgraduate Program, Araçatuba Dental School (UNESP). Of the 6862 samples analyzed, the fluoride levels of 53.5% (n = 3671) were within the recommended parameters, those of 30.4% (n = 2084) were below these parameters, and those of 16.1% (n = 1107) were above recommended values. Samples from the same collection site showed temporal variability in fluoride levels. Variation was also observed among samples from collection sites with different sources within the same municipality. Although 53.5% of the samples contained the recommended fluoride levels, these findings reinforce the importance of monitoring to minimize the risk of dental fluorosis and to achieve the maximum benefit in the prevention of dental caries