Posterske teme Poster topics - Biochemia Medica

P13-2 Endokrinologija
P13-3
Usporedba triju potpuno automatiziranih
imunokemijskih metoda za mjerenje
ukupnog HCG u serumu
Kačkov S, Rogić D, Fressl G, Kralik S, Fuček M
Klinički zavod za laboratorijsku dijagnostiku, KBC Zagreb, Zagreb,
Hrvatska
Mjerenje ukupnog HCG rabi se u ranom otkrivanju i praćenju
normalne i patološke trudnoće te specifi čnih malignih
bolesti. Danas na tržištu postoje brojne potpuno automatizirane
imunokemijske metode za mjerenje ovoga analita.
U ovoj studiji uspoređene su tri homogene imunokemijske
metode s dva protutijela i to: A. metoda s elektrokemiluminiscentnom
detekcijom (Roche, Elecsys 2010), B.
metoda s fl uorescentnom detekcijom (BioMerieux, Vidas)
te C. biotin-streptavidinska metoda s luminiscentnom detekcijom
(Johnson&Johnson, Vitros). Nepreciznost (CV%)
unutar i između serija bila je prihvatljiva za sve tri ispitane
metode i to: A: 2,1 i 4,1; B: 4,5 i 5,7 i C: 3,2 i 6,1. Funkcionalna
osjetljivost izražena kao najniža koncentracija s CV
20% bila je: A 0,7 U/L, B: 2,5 U/L i C: 1,4 U/L. Poznato je
da se beta-HCG u serumu, s obzirom na stadij trudnoće
ili prisutnost maligne bolesti, može nalaziti u vrlo širokom
rasponu mjernih koncentracija. U tom smislu, veći raspon
linearnosti metode omogućuje brži i jednostavniji rad uz
manji utrošak reagenasa. Linearnost ispitanih metoda bila
je kako slijedi: A: 0,1-10.000 U/L, B: 2-1500 U/L i C: 0,5-1000
U/L. Usporedba rezultata dobivenih svim trima ispitanim
metodama (N=50) ukazala je na visoku razinu korelacije
(r>0.96 za sva tri para vrijednosti), s obzirom na to da se
radi o imunokemijskim metodama. Međutim, zapaženo je
izrazito pozitivno odstupanje rezultata dobivenih metodom
B, i to samo u području visokih vrijednosti koje prelaze
linearnost te zahtijevaju prethodnu diluciju za sve tri
metode. Ovaj podatak još jednom ukazuje na nemogućnost
bilo kakvog praćenja bolesnika primjenom različitih
imunokemijskih metoda.
E-mail: sanjakackov@net.hr
P13-3
Comparison of three fully automated
immunassays for serum total HCG
determination
Kačkov S, Rogić D, Fressl G, Kralik S, Fuček M
Endocrinology
Clinical Institute of Laboratory Diagnosis, Zagreb University Hospital
Center, Zagreb, Croatia
HCG determination in serum is used for detection and follow
up of early pregnancy and some specifi c malignancies.
There are numerous fully automated beta-HCG immunoassays
available. In this study, we compared three
methods, all of them homogeneous sandwich immunassays:
A) electrochemiluminescence detection method
(Roche, Elecsys 2010), B) fl uorescence detection method
(BioMerieux, Vidas), and C) biotin-streptavidin method
with luminescent signal detection (Johnson&Johnson,
Vitros). Imprecision (expressed as CV%) both within- and
between-run was within acceptable limits: A) 2.1 and 4.1,
B) 4.5 and 5.7, and C) 3.2 and 6.1, respectively. Functional
sensitivity, expressed as the lowest beta-HCG concentration
that could be measured with a CV 20%, was as
follows: A) 0.7 U/L, B) 2.5 U/L and C) 1.4 U/L. As it is commonly
known, serum HCG concentrations, depending
on the stage of pregnancy or the presence of malignant
growth, can vary within several orders of magnitude.
Thus, methods with higher linearity are highly preferable,
since they allow for ease of operation and cost reduction.
Linearities of the three methods studied were as follows:
A) 0.1-10,000 U/L, B) 2-1500 U/L and C) 0.5-1000 U/L. Comparison
of results obtained by all three methods (N=50)
revealed a high degree of correlation, taking into account
the diff erent antibodies and signal detection used (r>0.96
for all three pairs of results). However, we noticed a substantial
positive bias in the results obtained by method B,
not throughout the concentration range but only in the
results that required prior dilution. This fi nding confi rms
the known fact that patient follow-up should always be
performed by using the same immunochemistry method.
E-mail: sanjakackov@net.hr
Biochemia Medica 2006;16(Suppl 1):S1–S268
S155