title: Polarization microscopy as a tool for quantitative evaluation of collagen using picrosirius red in different stages of CKD in cats.
abstract: Chronic kidney disease (CKD) is a relevant disease in feline clinic. The tubulointerstitial damage, with collagen deposition and fibrosis, is an important result of this process. The aim of this study was to quantify and correlate the deposition of collagen and severity of interstitial fibrosis (IF) in the kidney from cats in different stages of CKD. Kidney fragments from 10 adult cats with CKD were analyzed and stained by Masson's trichrome (MT) and Picrosirius red (PSR) for circular polarized microscopy. Random quantitative analysis was performed on MT sections to classify the degree of IF, per field area, with and without circular polarization. Statistics correlations were performed by Spearman's (ρ; p < .05). There was a significant correlation of IF quantification with the area of interstitial collagen deposition by polarized PSR (PSRp) (r = .7939, p = .0098) and nonpolarized PSR (PSRn) (r = .7781, p = .0080). There was a positive correlation of serum creatinine (sCr) at different stages of CKD with PSRp (r = .7939, p = .0098), PSRn (r = .8667, p = .0027) and MT (r = .7818, p = .0117). Correlations between the percentage of quantified area was also positive from PSRp to PSRn (r = .9030, p = .0009) and PSRp to MT (r = .7939, p = .0098). The PSRN was also correlated with MT (r = .9273, p = .0001). The correlation with IF and sCr follows the disease evolution and the quantification of collagen by PSR is an excellent tool for analyzing the disease severity at different stages.
authors.affiliation: Faculdade de Veterinária, Universidade Estadual do Ceará, Ceará, Brazil.
authors.forename: G B
authors.initials: GB
authors.lastname: Morais
authors.affiliation: Faculdade de Veterinária, Universidade Estadual do Ceará, Ceará, Brazil.
authors.forename: D A
authors.initials: DA
authors.lastname: Viana
authors.affiliation: Faculdade de Veterinária, Universidade Estadual do Ceará, Ceará, Brazil.
authors.forename: F M O
authors.initials: FMO
authors.lastname: Silva
authors.affiliation: Faculdade de Veterinária, Universidade Estadual do Ceará, Ceará, Brazil.
authors.forename: F A F
authors.initials: FAF
authors.lastname: Xavier Júnior
authors.affiliation: Departamento de Fisiologia e Farmacologia, Universidade Federal do Ceará, Ceará, Brazil.
authors.forename: K M
authors.initials: KM
authors.lastname: Farias
authors.affiliation: Departamento de Fisiologia e Farmacologia, Universidade Federal do Ceará, Ceará, Brazil.
authors.forename: C D'Ó
authors.initials: CD
authors.lastname: Pessoa
authors.affiliation: Departamento de Fisiologia e Farmacologia, Universidade Federal do Ceará, Ceará, Brazil.
authors.forename: J A M
authors.initials: JAM
authors.lastname: Silveira
authors.affiliation: Faculdade de Farmácia Odontologia e Enfermagem, Universidade Federal do Ceará, Ceará, Brazil.
authors.forename: A P N N
authors.initials: APNN
authors.lastname: Alves
authors.affiliation: Faculdade de Farmácia Odontologia e Enfermagem, Universidade Federal do Ceará, Ceará, Brazil.
authors.forename: M R L
authors.initials: MRL
authors.lastname: Mota
authors.affiliation: Departamento de Geologia, Universidade Federal do Ceará, Ceará, Brazil.
authors.forename: F D O
authors.initials: FDO
authors.lastname: Silva
authors.affiliation: Centro de Ciências da Saúde, Universidade Estadual do Ceará, Ceará, Brazil.
authors.forename: C M S
authors.initials: CMS
authors.lastname: Sampaio
authors.affiliation: Instituto Cavanilles Universidad de Valencia, Valencia, Brazil.
authors.forename: J M G
authors.initials: JMG
authors.lastname: Verdugo
authors.affiliation: Faculdade de Veterinária, Universidade Estadual do Ceará, Ceará, Brazil.
authors.forename: J S A M
authors.initials: JSAM
authors.lastname: Evangelista
mesh_terms: D000818:Animals; D001391:Azo Compounds / Q000737:chemistry*; D002371:Cat Diseases / Q000175:diagnosis / Q000473:pathology*; D002415:Cats; D003094:Collagen / Q000032:analysis* / Q000648:ultrastructure; D004396:Coloring Agents / Q000737:chemistry*; D003404:Creatinine / Q000097:blood; D005260:Female; D005355:Fibrosis; D007668:Kidney / Q000737:chemistry / Q000473:pathology / Q000648:ultrastructure; D008297:Male; D008859:Microscopy, Polarization / Q000379:methods*; D051436:Renal Insufficiency, Chronic / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D012720:Severity of Illness Index
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; C009798:C.I. direct red 80; D003094:Collagen; D003404:Creatinine
keywords: chronic kidney disease; feline; fibrosis; kidney; picrosirius red