Posterske teme Poster topics - Biochemia Medica
Posterske teme Poster topics - Biochemia Medica
Posterske teme Poster topics - Biochemia Medica
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P7-3 Šećerna bolest<br />
P7-3<br />
Direktna automatska imunoturbidimetrijska<br />
metoda za određivanje HbA1C Ferenec-Ružić D, Kvaternik M, Svržan J, Topić E<br />
Klinički zavod za kemiju, KB Sestre milosrdnice, Zagreb, Hrvatska<br />
Cilj rada bio je analitička procjena reagencija za direktno<br />
imunoturbidimetrijsko određivanje hemoglobina A 1c (Pointe<br />
Scientifi c, Inc., MI, SAD) u punoj krvi na analizatoru<br />
Olympus 2700 (Olympus, Optical Co., Japan). Uzorci venske<br />
krvi dobiveni su od dijabetičnih bolesnika uzetih s<br />
antikoagulansom K3EDTA. Određivanje glikiranog hemoglobina<br />
(HbA 1c ) metodom turbidimetrijskog imuno testa<br />
<strong>teme</strong>lji se na izravnom određivanju HbA 1c u punoj krvi.<br />
Ukupni hemoglobin i HbA 1c imaju istu nespecifi čnu brzinu<br />
apsorpcije na lateks čestice. To je <strong>teme</strong>lj prve reakcije,<br />
gdje se miješa uzorak i R1 (lateks čestice u glicin puferu).<br />
Hemoglobin A 1c se veže na lateks IgG poliklonska antitjela.<br />
Aglutinacijski kompleks se formira u interakciji HbA 1c<br />
vezanog za lateks čestice s određenim antitjelima. Jačina<br />
apsorpcije je proporcionalna HbA 1c vezanom na lateks čestice<br />
odnosno % HbA 1c u uzorku. Reagens je kalibriran s<br />
četiri kalibratora (prema NGSP). Ispitivana je nepreciznost<br />
u seriji za 3 koncentracijske razine, nepreciznost iz dana u<br />
dan (10 dana za dvije koncentracijske razine), netočnost<br />
prema kontrolnom uzorku, netočnost procijenjena usporedbom<br />
s reagensom tvrtke Roche Diagnostics, Njemačka<br />
(Tina-Quant) uz primjenu statističke metode po Passing<br />
Bablocku (n= 50), te procjena prijenosa (carry-over). Za<br />
nepreciznost u seriji koefi cijenti varijacije CV (%) iznosili su<br />
od 1,12 do 1,87 (n=20), a za nepreciznost iz dana u dan 1,23<br />
i 2,00. Odstupanja od deklarirane koncentracije kontrolnih<br />
seruma iznosile su 0,638% i 1,584%. Usporedbom uzoraka<br />
s reagensom Roche statistička analiza je pokazala korelaciju<br />
y=0,1224x+0,9310 s koefi cijentom korelacije r=0,9680,<br />
p>0,1, što znači da su rezultati s oba reagensa usporedivi<br />
(Passing-Bablock). Konstanta K za procjenu prijenosa uzoraka<br />
iznosila je 0% do1,81%, što je manje od najviše dopuštene<br />
dvostruke vrijednosti CV za nepreciznost iz dana u<br />
dan. Kalibraciju reagensa treba provoditi svakih 7 dana.<br />
Uzorci krvi stabilni su 7 dana u hladnjaku na 2-8 °C. Pripremljeni<br />
hemolizat uzorka stabilan je do 10 dana na temperaturi<br />
2-8 °C. Rezultati ove procjene pokazuju da reagens<br />
u potpunosti zadovoljava sve analitičke kriterije standarda<br />
za kvalitetu te da je direktno određivanje HbA 1c koje ne<br />
uključuje postupak određivanja ukupnog hemoglobina i<br />
matematički zahvat izračuna HbA 1c (gdje se isključuje mogući<br />
izvor pogrješke i potrošnja reagensa) uz osiguranu<br />
preciznost i točnost metodološki napredak.<br />
E-mail: dragica.ferenec-ruzic@zg.t-com.hr<br />
<strong>Biochemia</strong> <strong>Medica</strong> 2006;16(Suppl 1):S1–S268<br />
S126<br />
P7-3<br />
A novel simplifi ed automated<br />
immunoturbidimetric assay for HbA1c determination (direct HbA ) 1C<br />
Ferenec-Ružić D, Kvaternik M, Svržan J, Topić E<br />
Diabetes mellitu<br />
Clinical Department of Chemistry, Sestre milosrdnice University<br />
Hospital, Zagreb, Croatia<br />
The aim of the study was to adapt a direct immunoassay<br />
(Pointe Scientifi c, Inc., MI, USA) for in vitro determination<br />
of hemoglobin A 1C in whole blood on an Olympus 2700<br />
autoanalyzer (Olympus Optical Co., Japan). Venous blood<br />
samples from diabetic patients are collected into K3EDTA<br />
containing vacutainer tubes. This direct determination of<br />
HbA 1c utilizes the interaction of antigen and antibody to<br />
directly determine HbA 1C in whole blood. Total hemoglobin<br />
and HbA 1c have the same nonspecifi c absorption rate<br />
to latex particles. When mouse antihuman HbA 1c monoclonal<br />
antibody is added (R2), the latex-HbA 1c -mouse anti<br />
human HbA 1c antibody complex is formed. Agglutination<br />
occurs when goat anti-mouse IgG polyclonal antibody<br />
interacts with the monoclonal antibody. The amount of<br />
agglutination is proportional to the amount of HbA 1c absorbed<br />
onto the surface of latex particles. The amount of<br />
agglutination is measured as absorbance. The HbA 1c value<br />
is obtained from calibration curve. Calibration of the<br />
procedure was performed using calibrators referenced to<br />
the NGSP value. Within-run imprecision (at three diff erent<br />
HbA 1c concentrations), between-run imprecision (in triplicate<br />
for two control hemolysates measured for 10 days),<br />
and accuracy (with control material), and by comparison<br />
with the Tina-Quant HbA 1c turbidimetric inhibition immunoassay<br />
(Roche Diagnostics, Germany; n=50) were<br />
assessed. The within-run and between-run imprecision<br />
(n=20) CV (%) was 1.12-1.87 and 1.23 and 2.00, respectively.<br />
Results of the comparison study showed no statistical<br />
diff erence according to the Passing & Bablok regression<br />
analysis (y= 0.1224+0.9310x, r=0.9680, p>0.1). Calibration<br />
of the assay was stable for at least 7 days. Refrigerated<br />
samples remained stable for HbA 1c analysis for 7 days.<br />
Stability of the hemolysate was up to 10 days at 2-8 °C.<br />
Results of the study indicate that the new automated<br />
immunoturbidimetric procedure directly determines percentage<br />
of HbA 1c adapted for routine chemistry analyzer<br />
using only one channel (a separate channel for the determination<br />
of total hemoglobin fraction for the sample is<br />
not necessary), providing a precise and accurate determination<br />
of HbA 1c .<br />
E-mail: dragica.ferenec-ruzic@zg.t-com.hr