Measurement of holotranscobalamin in assessing vitamin B12 status

Cilj istraživanja bio je ispitati je li holotranskobalamin osjetljiviji pokazatelj deficita vitamina B12 u odnosu na kobalamin, te postoji li povezanost između kobalamina i holotranskobalamina s homocisteinom. Ispitanici i metode U istraživanje je bilo uključeno 54 ispitanika koji su na temelju nalaza koncentracije homocisteina podjeljeni u dvije skupine. U prvoj skupini je bio 31 ispitanik s povišenom razinom homocisteina te neurološkim simptomima, a u drugoj 23 ispitanika s normalnim vrijednostima homocisteina i različitim uputnim dijagnozama. Koncentracije kobalamina, holotranskobalamina i homocisteina izmjerene su u uzorcima seruma kemiluminiscentnom mikročestičnom imunoanalizom (CMIA) (Abbot Laboratories) na Arhitect i1000SR imunokemijskom analizatoru (Abbott Diagnostics, Lake Forest, SAD). Rezultati su obrađeni statističkim programom MedCalc (MedCalc Software, Mariakerke, Belgium). Za ispitivanje osjetljivosti i specifičnosti koristila se ROC analiza, za usporedbu među skupinama Mann-Whitney test i Fisher egzaktni test, a za ispitivanje povezanosti koeficijent korelacije. Rezultati Ispitivanje je pokazalo da holotranskobalamin nije osjetljiviji pokazatelj deficita B12 vitamina od kobalamina (AUC=0.596 vs. AUC= 0.511), te da postoji vrlo slaba povezanost između holotranskobalamina i kobalamina (r=0.333). Međutim, između holotranksobalamina, te kobalamina i homocisteina nema povezanosti (r=0.032 vs r= -0.103). Zaključak Rezultati istraživanja su pokazali da holotranskobalamin nije osjetljiviji pokazatelj statusa vitamina B12 u odnosu na kobalamin. Može se reći da holotranskobalamin i kobalamin, 22 zasebno ili u kombinaciji imaju gotovo jednaku dijagnostičku učinkovitost u dijagnozi deficita B12 vitamina kao rani pokazatelji.The aim of the study was to examine whether holotranscobalamin is a more sensitive indicator of vitamin B12 deficiency in relation to cobalamin, and whether there is a significant correlation between cobalamin, holotranscobalamin and homocysteine levels. Patients and methods The study included 54 subjects who were divided into two groups according to the findings of homocysteine. The first group included 31 patients with elevated homocysteine values and with neurological symptoms, whereas 23 patients with normal homocysteine values and different diagnoses which represented controls. The cocentrations of cobalamin, holotranscobalamin and homocysteine were measured in serum samples with chemiluminescent microparticle immunoassay (CMIA) (Abott Laboratories) on the Architect i1000SR analyzer ( Abbott Diagnostics , Lake Forest , United States ). The results were processed using MedCalc Software (MedCalc Software, Mariakerke, Belgium). ROC curve was used to test sensitivity and specificity, while Mann-Whitney test and Fisher exact test were used for groups comparision. For testing the connection, correlation coefficient was used. Results The test showed that holotranscobalamin is not a more sensitive indicator of vitamin B 12 deficiency than cobalamin (AUC= 0.511 vs. AUC= 0.596), and that there is a weak connection between holotranscobalamin and cobalamin (r= 0.333). However, between holotranscobalamin, and cobalamin and homocysteine there is no correlation (r= 0.032 vs. r= -0.103). Conclusion Research shows that holotranscobalamin is not a more sensitive indicator of vitamin B 12 deficiency than cobalamin. It can be said that holotranscobalamin and cobalamin, separately or in combination have almost equal diagnostic efficiency in the diagnosis of vitamin B12 deficiency as early indicators