Luis Rello Varas

@article{GARCIAGONZALEZ20161,

title = {Serum sample containing endogenous antibodies interfering with multiple hormone immunoassays. Laboratory strategies to detect interference},

author = {Elena García-González and Maite Aramendía and Diego Álvarez-Ballano and Pablo Trincado and Luis Rello},

url = {https://www.sciencedirect.com/science/article/pii/S2352551715300020},

doi = {https://doi.org/10.1016/j.plabm.2015.11.001},

issn = {2352-5517},

year  = {2016},

date = {2016-01-01},

journal = {Practical Laboratory Medicine},

volume = {4},

pages = {1-10},

abstract = {Objectives 

Endogenous antibodies (EA) may interfere with immunoassays, causing erroneous results for hormone analyses. As (in most cases) this interference arises from the assay format and most immunoassays, even from different manufacturers, are constructed in a similar way, it is possible for a single type of EA to interfere with different immunoassays. Here we describe the case of a patient whose serum sample contains EA that interfere several hormones tests. We also discuss the strategies deployed to detect interference. 

Subjects and methods 

Over a period of four years, a 30-year-old man was subjected to a plethora of laboratory and imaging diagnostic procedures as a consequence of elevated hormone results, mainly of pituitary origin, which did not correlate with the overall clinical picture. 

Results 

Once analytical interference was suspected, the best laboratory approaches to investigate it were sample reanalysis on an alternative platform and sample incubation with antibody blocking tubes. Construction of an in-house ‘nonsense’ sandwich assay was also a valuable strategy to confirm interference. In contrast, serial sample dilutions were of no value in our case, while polyethylene glycol (PEG) precipitation gave inconclusive results, probably due to the use of inappropriate PEG concentrations for several of the tests assayed. 

Conclusions 

Clinicians and laboratorians must be aware of the drawbacks of immunometric assays, and alert to the possibility of EA interference when results do not fit the clinical pattern.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid26327185,

title = {Lead screening in DBS by solid sampling high-resolution continuum source graphite furnace atomic absorption spectrometry: application to newborns and pregnant women},

author = {Luis Rello and Maite Aramendía and Miguel A Belarra and Martín Resano},

doi = {10.4155/bio.15.124},

issn = {1757-6199},

year  = {2015},

date = {2015-01-01},

journal = {Bioanalysis},

volume = {7},

number = {16},

pages = {2057--2070},

abstract = {BACKGROUND: DBS have become a clinical specimen especially adequate for establishing home-based collection protocols. In this work, high-resolution continuum source graphite furnace atomic absorption spectrometry is evaluated for the direct monitoring of Pb in DBS, both as a quantitative tool and a screening method.



METHODOLOGY: The development of the screening model is based on the establishment of the unreliability region around the threshold limits, 100 or 50 μg l(-1). More than 500 samples were analyzed to validate the model.



CONCLUSION: The screening method demonstrated high sensitivity (the rate of true positives detected was always higher than 95%), an excellent LOD (1 µg l(-1)) and high throughput (10 min per sample).},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{C4JA00313F,

title = {Direct analysis of dried blood spots by femtosecond-laser ablation-inductively coupled plasma-mass spectrometry. Feasibility of split-flow laser ablation for simultaneous trace element and isotopic analysis},

author = {M. Aramendía and L. Rello and S. Bérail and A. Donnard and C. Pécheyran and M. Resano},

url = {http://dx.doi.org/10.1039/C4JA00313F},

doi = {10.1039/C4JA00313F},

year  = {2015},

date = {2015-01-01},

journal = {J. Anal. At. Spectrom.},

volume = {30},

issue = {1},

pages = {296-309},

publisher = {The Royal Society of Chemistry},

abstract = {This work describes a novel procedure based on the use of a 1030 nm femtosecond (fs) laser ablation (LA) device operating at a high repetition rate (30 000 Hz) coupled to a sector field-inductively coupled plasma-mass spectrometer (ICP-MS), enabling the complete ablation of dried blood spot (DBS) specimens in a reasonable time (200 s for samples of 5 μL). The integration of the complete signal obtained, in combination with the use of Pt as an internal standard (which can be added to the clinical filter paper prior to the blood deposition, ensuring compatibility with unsupervised sample collection schemes), permits obtaining an analytical response that is independent of the particular characteristics of every sample. On the basis of this methodology, an analytical method was developed for the direct determination of several elements (Cd, Co, Cu and Pb) in four blood reference materials as well as in three real samples, providing accurate results in all cases evaluated, at concentration levels ranging from 0.1 to hundreds of μg L−1. Detection limits of 0.043 (Cd), 0.42 (Co), 0.54 (Cu), and 0.040 (Pb) μg L−1 are achieved, and precision values most often range between 3 and 9% RSD. Finally, the potential to couple the LA device simultaneously to a multicollector-ICP-MS and a sector field-ICP-MS unit by split-flow is also demonstrated, thus allowing us to obtain both elemental (Co, Cu, Cd and Pb) and isotopic (Cu isotopic composition) information from every particular DBS, and therefore maximizing the amount of information that can be drawn from a single DBS specimen. Still, the precision of the approach is limited at this point, as RSD values of approx. 1500 ppm and delta variations of almost 4‰ were observed for five DBS specimens created from the same blood sample.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pmid25012579,

title = {Birth Prevalence of Fatty Acid β-Oxidation Disorders in Iberia},

author = {Hugo Rocha and Daisy Castiñeiras and Carmen Delgado and José Egea and Raquel Yahyaoui and Yolanda González and Manuel Conde and Inmaculada González and Inmaculada Rueda and Luis Rello and Laura Vilarinho and José Cocho},

doi = {10.1007/8904_2014_324},

issn = {2192-8304},

year  = {2014},

date = {2014-01-01},

journal = {JIMD Rep},

volume = {16},

pages = {89--94},

abstract = {Mitochondrial fatty acid β-oxidation disorders (FAOD) are main targets for newborn screening (NBS) programs, which are excellent data sources for accurate estimations of disease birth prevalence. Epidemiological data is of key importance for the understanding of the natural history of the disorders as well as to define more effective public health strategies. In order to estimate FAOD birth prevalence in Iberia, the authors collected data from six NBS programs from Portugal and Spain, encompassing the screening of more than 1.6 million newborns by tandem mass spectrometry (MS/MS), and compared it with available data from other populations. The participating NBS programs are responsible for the screening of about 46% of all Iberian newborns. Data reveals that Iberia has one of the highest FAOD prevalence in Europe (1:7,914) and that Portugal has the highest birth prevalence of FAOD reported so far (1:6,351), strongly influenced by the high prevalence of medium-chain acyl-CoA dehydrogenase deficiency (MCADD; 1:8,380), one of the highest ever reported. This is justified by the fact that more than 90% of Portuguese MCADD patients are of Gypsy origin, a community characterized by a high degree of consanguinity. From the comparative analysis of various populations with comparable data other differences emerge, which points to the existence of significant variations in FAOD prevalences among different populations, but without any clear European variation pattern. Considering that FAOD are one of the justifications for MS/MS NBS, the now estimated birth prevalences stress the need to screen all Iberian newborns for this group of inherited metabolic disorders. },

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{C2JA30262D,

title = {Direct determination of Cu isotope ratios in dried urine spots by means of fs-LA-MC-ICPMS. Potential to diagnose Wilson's disease},

author = {Martín Resano and Maite Aramendía and Luis Rello and Mª Luisa Calvo and Sylvain Bérail and Christophe Pécheyran},

url = {http://dx.doi.org/10.1039/C2JA30262D},

doi = {10.1039/C2JA30262D},

year  = {2013},

date = {2013-01-01},

journal = {J. Anal. At. Spectrom.},

volume = {28},

issue = {1},

pages = {98-106},

publisher = {The Royal Society of Chemistry},

abstract = {This work investigates the potential of a 257 nm femtosecond (fs) laser ablation (LA) device operating at a high repetition rate (10 000 Hz) coupled to a multicollector (MC)-ICPMS to develop a method for the direct determination of Cu ratios in dried urine spots, prepared by deposition of urine (300 μL) onto precut clinical filter paper discs (16 mm diameter). The sampling capabilities offered by the fs LA system, permitting ablation of 150 μm thick coronas in the rim area of the filter, together with the use of admixed Ni as an internal standard, the proper optimization of the MC-ICPMS conditions (e.g., use of pseudo high-resolution mode to avoid interferences) and the use of a data processing approach particularly suitable for short transient signals (linear regression fit) enabled analysis of real urine samples with precision values around 500 ppm (RSD) for urinary Cu contents of a few hundred μg L−1. The methodology developed could prove to be useful for implementing screening protocols to detect Wilson's disease (WD), a well-known disorder related to Cu metabolism. In fact, the use of this analytical methodology permitted us to observe significant differences between (i) untreated WD patients and (ii) WD patients that are under treatment and control samples. This work represents the first time that determination of 65Cu/63Cu ratios has been used in the context of WD research, and serves as a proof of principle, suggesting that Cu isotope analysis could help in developing earlier and more reliable means to diagnose WD.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}