title: Estimating the concentration of urea and creatinine in the human serum of normal and dialysis patients through Raman spectroscopy.
abstract: Urea and creatinine are commonly used as biomarkers of renal function. Abnormal concentrations of these biomarkers are indicative of pathological processes such as renal failure. This study aimed to develop a model based on Raman spectroscopy to estimate the concentration values of urea and creatinine in human serum. Blood sera from 55 clinically normal subjects and 47 patients with chronic kidney disease undergoing dialysis were collected, and concentrations of urea and creatinine were determined by spectrophotometric methods. A Raman spectrum was obtained with a high-resolution dispersive Raman spectrometer (830 nm). A spectral model was developed based on partial least squares (PLS), where the concentrations of urea and creatinine were correlated with the Raman features. Principal components analysis (PCA) was used to discriminate dialysis patients from normal subjects. The PLS model showed r = 0.97 and r = 0.93 for urea and creatinine, respectively. The root mean square errors of cross-validation (RMSECV) for the model were 17.6 and 1.94 mg/dL, respectively. PCA showed high discrimination between dialysis and normality (95 % accuracy). The Raman technique was able to determine the concentrations with low error and to discriminate dialysis from normal subjects, consistent with a rapid and low-cost test.
authors.affiliation: Instituto Esperança de Ensino Superior - IESPES, Rua Coaracy Nunes, 3315, Caranazal, 68040-100, Santarém, PA, Brazil.
authors.forename: Maurício Liberal
authors.initials: ML
authors.lastname: de Almeida
authors.affiliation: Instituto Esperança de Ensino Superior - IESPES, Rua Coaracy Nunes, 3315, Caranazal, 68040-100, Santarém, PA, Brazil.
authors.forename: Cassiano Junior
authors.initials: CJ
authors.lastname: Saatkamp
authors.affiliation: Biomedical Engineering Institute, Universidade Camilo Castelo Branco - UNICASTELO, Parque Tecnológico de São José dos Campos, Estr. Dr. Altino Bondesan, 500, Eugênio de Melo, São José dos Campos, 12247-016, SP, Brazil.|Center for Innovaton, Technology and Education - CITÉ, Parque Tecnológico de São José dos Campos, Estr. Dr. Altino Bondesan, 500, Eugênio de Melo, São José dos Campos, 12247-016, SP, Brazil.
authors.forename: Adriana Barrinha
authors.initials: AB
authors.lastname: Fernandes
authors.affiliation: Biomedical Engineering Institute, Universidade Camilo Castelo Branco - UNICASTELO, Parque Tecnológico de São José dos Campos, Estr. Dr. Altino Bondesan, 500, Eugênio de Melo, São José dos Campos, 12247-016, SP, Brazil.|Center of Biophotonics, School of Dentistry, Federal University of Bahia - UFBA, Av. Araújo Pinho, 62, Canela, Salvador, 40110-150, BA, Brazil.
authors.forename: Antonio Luiz Barbosa
authors.initials: AL
authors.lastname: Pinheiro
authors.affiliation: Biomedical Engineering Institute, Universidade Camilo Castelo Branco - UNICASTELO, Parque Tecnológico de São José dos Campos, Estr. Dr. Altino Bondesan, 500, Eugênio de Melo, São José dos Campos, 12247-016, SP, Brazil. landulfo.silveira@gmail.com.|Center for Innovaton, Technology and Education - CITÉ, Parque Tecnológico de São José dos Campos, Estr. Dr. Altino Bondesan, 500, Eugênio de Melo, São José dos Campos, 12247-016, SP, Brazil. landulfo.silveira@gmail.com.
authors.forename: Landulfo
authors.initials: L
authors.lastname: Silveira
mesh_terms: D000328:Adult; D003404:Creatinine / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D025341:Principal Component Analysis; D006435:Renal Dialysis; D013059:Spectrum Analysis, Raman / Q000379:methods*; D014508:Urea / Q000097:blood*
chemical_list: D014508:Urea; D003404:Creatinine
keywords: Creatinine; Human serum; Partial least squares (PLS); Principal components analysis (PCA); Raman spectroscopy; Urea