Vrednotenje vpliva hemolize na koncentracijo nevronsko specifične enolaze v vzorcih seruma in plazme

Šimnovec, Leja (avtor), Jerin, Aleš (mentor)

Nevronsko specifična enolaza je encim, ki se v telesu pojavlja v dveh izoformnih oblikah. Homodimer γγ je prisoten v celicah centralnega živčnega sistema, heterodimer αγ pa tudi v drugih telesnih celicah, med drugim v eritrocitih in trombocitih. Zaradi prisotnosti nevronsko specifične enolaze v eritrocitih lahko že blaga, praktično nevidna hemoliza povzroči lažno povišane koncentracije nevronsko specifične enolaze. To vodi v napačno interpretacijo kliničnega stanja bolnika in posledično v neustrezne diagnostične ter terapevtske odločitve. Z raziskavo smo nameravali razviti korekcijsko enačbo za popravek izmerjenih koncentracij nevronsko specifične enolaze v hemoliziranih vzorcih oziroma vsaj prilagoditi obstoječe modele iz literature. V študiji je sodelovalo 22 preiskovancev. Za vsakega smo pripravili šest serij redčitev hemoliziranega vzorca in štiri hemolizirane vzorce polne krvi. Koncentracijo nevronsko specifične enolaze smo določili z elektrokemiluminiscenčno metodo, indeks hemolize pa s fotometrično meritvijo. Trem znanim enačbam smo prilagodili regresijske koeficiente in numerične konstante, eno izmed njih pa smo nadgradili ter razvili novo različico korekcijske enačbe: c_(NSE popravljena)=c_(NSE izmerjena) -HI ×0,34× (1-0,07/0,34 )^(1/2). Rezultati so pokazali, da nobena izmed štirih testiranih enačb ne omogoča popolne odprave vpliva hemolize. Na redčenih hemoliziranih vzorcih sta pri nizkih indeksih hemolize najboljše popravke omogočili nova razvita enačba in prilagojena enačba po Ruiz modelu, pri čemer slednja zaradi metodoloških omejitev ni primerna za klinično uporabo. Ugotovili smo, da obstoječi modeli na hemoliziranih vzorcih polne krvi niso ustrezni, kar nakazuje na prisotnost dodatnega dejavnika, ki vpliva na koncentracijo nevronsko specifične enolaze v teh vzorcih. Potrdili smo, da obstaja linearna povezava med koncentracijo nevronsko specifične enolaze in indeksom hemolize (R2 = 0,8647) ter da vsaka enota hemolize (1 HI = 1 mg/dL) prispeva 0,34 ± 0,06 μg/L nevronsko specifične enolaze, sproščene iz eritrocitov. Povezave med maso nevronsko specifične enolaze v eritrocitu in starostjo, spolom, povprečnim volumnom eritrocita, povprečno maso hemoglobina v eritrocitu ter povprečno koncentracijo hemoglobina v eritrocitu nismo potrdili.

• Jezik: Slovenski jezik
• Ključne besede: hemoliza, indeks hemolize, nevronsko specifična enolaza, korekcijska enačba
• Vrsta gradiva: Magistrsko delo/naloga
• Tipologija: 2.09 - Magistrsko delo
• Organizacija: FFA - Fakulteta za farmacijo
• Leto izida: 2025
• PID: 20.500.12556/RUL-176405
• COBISS.SI-ID: 259822083
• Datum objave v RUL: 29.11.2025

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Evaluation of the impact of hemolysis on the concentration of neuron-specific enolase in serum and plasma samples

Izvleček

Neuron-specific enolase is an enzyme present in the body in two isoforms. The γγ homodimer is found in cells of the central nervous system, while the αγ heterodimer can also be detected in other body cells, including red blood cells and platelets. Because neuron-specific enolase is present in red blood cells, even mild, practically invisible hemolysis can cause falsely elevated concentrations of neuron-specific enolase. This may lead to misinterpretation of the patient’s clinical condition and consequently to inappropriate diagnostic and therapeutic decisions. The aim of our study was to develop a correction equation to adjust the measured concentrations of neuron-specific enolase in hemolyzed samples, or alternatively, to modify existing models from the literature. The study included 22 participants. For each participant, six dilution series of hemolyzed samples and four hemolyzed whole-blood samples were prepared. Neuron-specific enolase concentrations were determined using an electrochemiluminescence method, while the hemolysis index was measured photometrically. Regression coefficients and other numerical constants of three known equations were adjusted, and one of them was upgraded to develop a new version of the correction equation: c_(NSE corrected)=c_(NSE measured) -HI×0,34× (1-0,07/0,34 )^(1/2). The results showed that none of the four tested equations completely eliminated the influence of hemolysis. In diluted hemolyzed samples the best corrections at low hemolysis index were obtained using the newly developed equation and the equation adjusted according to the Ruiz model, however the latter is not suitable for clinical use due to methodological limitations. It turned out that none of the four tested equations were suitable for hemolyzed whole-blood samples, suggesting the presence of an additional factor influencing the concentration of neuron-specific enolase in these samples. We demonstrated a linear relationship between neuron-specific enolase concentration and the hemolysis index (R² = 0.8647) and that each unit of hemolysis (1 HI = 1 mg/dL) contributes 0.34 ± 0.06 μg/L of neuron-specific enolase released from red blood cells. No correlation was found between the mass of neuron-specific enolase in a red blood cell and age, sex, mean corpuscular volume, mean corpuscular hemoglobin, or mean corpuscular hemoglobin concentration.

• Ključne besede: hemolysis, hemolysis index, neuron-specific enolase, correction equation