Estudo retrospectivo de hemólise e lipemia nas dosagens de creatinina de cães que realizaram exame pré-cirúrgico

Abstract

The kidney is responsible for the excretion of metabolic products, such as creatinine, which serves as an indicator of renal function in dogs and is considered a biomarker. However, pre-analytical factors can lead to the presence of interferents, such as hemolysis and lipemia, which can compromise the results of laboratory tests and affect the reliability of this biomarker. The objective of this study was to evaluate the effect of interferents related to serum appearance on creatinine measurement. The research was conducted retrospectively by selecting laboratory results of serum creatinine from clinically healthy dogs referred for pre-surgical examinations. These animals were clinically healthy and were attended at the Veterinary Hospital Superintendence Unit (SUHVU) from 2020 to 2022. Kinetic methodology with a commercial kit and automatic biochemical analyzer was used for creatinine biochemical analyses. Based on the serum appearance reported in the report, the animals were classified into three distinct groups: control (GC) - samples with normal appearance, hemolysis (GH), and lipemia (GL). The last two groups were sub-classified into mild, moderate, and intense samples. Samples from 194 dogs were analyzed, including 113 samples without alterations, 69 hemolyzed samples (43 mild, 15 moderate, 13 intense), and 12 lipemic samples (6 mild and 6 intense) No sample had a icterus appearance; therefore, this interferent was not evaluated.. Analysis of variance (ANOVA) was performed for parametric variables, and Kruskal-Wallis was used for non-parametric variables, considering significance when (p<0.05). The results of creatinine concentration (mg/dL) in median and percentiles (P25 - P75) were: GC = 1.07 (0.9 - 1.2); GH= 1.08 (1.0-1.2) and GL=1.21 (1.07-1.2). Five dogs had values above the reference range; three samples presented hemolysis, one had 2.59 mg/dL with intense hemolysis, and two exhibited moderate hemolysis, both with 1.76 mg/dL. In the control group, two animals had values of 1.97 mg/dL and 1.69 mg/dL, respectively. There was no significant difference in serum creatinine results in any group. The study demonstrated that, with the methodology used, pre-analytical interferents such as lipemia and hemolysis do not significantly interfere with serum creatinine concentration. However, this conclusion cannot be generalized to other methods of creatinine measurement.