Primerjava izračunov ocene glomerulne filtracije z uporabo beta-2-mikroglobulina in kreatinina

Hodalj, Lucija (author), Osredkar, Joško (mentor)

Rutinska metoda za merjenje glomerulne filtracije (GF) običajno vključuje uporabo serumskega kreatinina za izračun GF. Najpogosteje uporabljena enačba za ta izračun je CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration). Ta enačba upošteva serumsko raven kreatinina, starost, spol in raso za izračun GF. CKD-EPI enačba je natančnejša od starejših metod, kot je MDRD, predvsem pri višjih vrednostih GF. Izračun omogoča zgodnejše in bolj natančno odkrivanje kronične ledvične bolezni (KLB), kar pomaga pri boljšem upravljanju in zdravljenju bolezni. Vendar pa ima izračun GF na podlagi kreatinina določene omejitve, zaradi katerih ni vedno najbolj natančen. Zaradi tega je treba iskati druge možne parametre za GF. Namen dela je bil, da preverimo drugi biološki označevalec za stanje ledvic, beta-2-mikroglobulin (β2M). Pri skupini pacientov smo za izračun GF uporabili dve enačbi za serumski β2M. Nato smo rezultate GF primerjali z rezultati izračuna (CKD-EPI) glede na koncentracijo kreatinina. Preverjali smo, če oba izračuna podata enako oceno glede na stopnjo ledvične okvare. Za potrebe raziskave smo zbrali podatke o 610 bolnikih, ki so bili sprejeti v obdobju treh mesecev. Med njimi jih je največ imelo stopnjo okvare ledvic G1, najmanj pa G4. Primerjava obeh enačb, ki vpoštevata vrednosti β2M, med skupinami glede na stopnjo okvare ledvic, je pokazala zelo različne korelacije (od 0,04 do 0,53). Skupna korelacija, dobljena z uporabo obeh enačb, je znašala 0,84. Na drugi strani je bil delež odstopanja rezultatov, pridobljenih z uporabo obeh enačb za β2M in rezultatov standardne metode, precej visok. Pri uporabi prve enačbe (GF = 149,0 * 1/serum β2M (mg/L) + 9,153) je skupni delež odstopanja znašal 50,8 %, medtem ko pri drugi enačbi (GF = 133* β2M -0,852) 45 %. Dobljeni rezultati nam kažejo, da obstaja neskladje med β2M in standardnimi metodami za določanje GF s pomočjo kreatinina. Nasprotno pa v praksi pogosto ugotavljamo, da izračun GF na podlagi kreatinina bolj pomakne oceno v nižje območje okvare ledvic (višjo stopnjo KLB). Zato so rezultati z β2M, ki kažejo manjšo okvaro KLB, morda bolj natančni, bolnike pa lahko ocenimo nekje vmes med obema vrednostma. Zaključek naloge je, da je β2M obetaven biološki označevalec, vendar bi se morali osredotočiti na raziskovanje vzrokov za neskladje med njim in standardnimi metodami. Natančnost diagnoze bi lahko izboljšali s kombinacijo β2M z drugimi kazalniki ali metodami (npr. cistatin C, albuminurija, sečnina, MRI...).

• Language: Slovenian
• Keywords: glomerulna filtracija, beta-2-mikroglobulin, kreatinin
• Work type: Master's thesis/paper
• Organization: FFA - Faculty of Pharmacy
• Year: 2024
• PID: 20.500.12556/RUL-164673
• Publication date in RUL: 07.11.2024

Secondary language

• Language: English
• Title: Comparison of glomerular filtration rate estimation calculations using beta-2-microglobulin and creatinine

Abstract

The routine method for measuring glomerular filtration rate (GFR) typically involves using serum creatinine to calculate the estimated GFR (eGFR). The most used formula for this calculation is CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration). This method uses serum creatinine levels, age, sex, and race to calculate the eGFR. The CKD-EPI formula is more accurate than older methods, such as MDRD, especially at higher eGFR values. The calculation allows for earlier and more precise detection of chronic kidney disease, aiding in better management and treatment of the condition. However, the calculation of GFR based on creatinine has certain limitations, which means it is not always the most accurate. Therefore, other possible parameters for assessing GFR need to be explored. The aim of this study was to evaluate another biomarker for kidney function, beta-2-microglobulin (β2M). In a group of patients, we used two formulas for serum β2M to calculate glomerular filtration. We then compared the GFR results with the calculation results (CKD-EPI) based on creatinine concentration. We examined whether both calculations provided the same assessment regarding the stage of kidney impairment. For the purposes of the research, we collected data on 610 patients who were admitted over a three-month period. Among them, the majority had kidney impairment stage G1, while the least had stage G4. Correlations within the groups varied significantly (0.53, 0.04, 0.39, 0.33, and 0.36). The overall correlation obtained using both formulas was 0.84. On the other hand, the discrepancy rate of results obtained using both formulas for β2M was quite high. Using the first formula, the overall discrepancy rate was 50,8 %, while with the second formula it was 45 %. The obtained results indicate a discrepancy between β2M and the standard methods for determining GFR using creatinine. Conversely, in practice, we often find that the creatinine-based eGFR calculation tends to be skewed towards a lower range of kidney impairment, and therefore, those results which are classified in an earlier stage with β2M might not be incorrect but could place these patients somewhere in between. The conclusion of the study is that β2M is a promising marker, but we should focus on investigating the causes of the discrepancy between it and the standard methods. Improving diagnostic accuracy could be achieved by combining β2M with other indicators or methods (e.g. cystatin C, albuminuria, urea, MRI, etc.).

• Keywords: glomerular filtration rate, beta-2-microglobulin, creatinine