Laboratory of Clinical Biochemistry, Department of Clinical and Toxicological Analysis, Center of Health Sciences, Federal University of Santa Maria, Santa Maria, Brazil.
Graduate Program in Pharmaceutical Sciences, Center of Health Sciences, Federal University of Santa Maria, Santa Maria, Brazil.
Scand J Clin Lab Invest. 2023 May;83(3):183-186. doi: 10.1080/00365513.2023.2191336. Epub 2023 Apr 4.
Carbamylation is a nonenzymatic post-translational modification observed during the reaction between cyanate and amino acids and/or proteins that may occur during some pathologies such as chronic kidney disease. Evidence suggests that carbamylation may interfere with the quantification of some analytes measured using immunoturbidimetric assays. C-reactive protein (CRP) is an inflammatory response protein that is commonly quantified through immunoturbidimetry in clinical laboratories. Because the presence of modified proteins in serum can lead to impaired quantification, this study aimed to verify the impact of carbamylation on the measurement of CRP in a CRP standard solution and serum pool. The samples were incubated with 150 nM, 150 µM, or 150 mM potassium cyanate (KOCN) or 20, 100, or 500 mg/dL urea at 37 °C for 24 h. CRP concentrations were measured using an immunoturbidimetric assay. The results showed a 61%-72% decrease in the CRP detection rate after incubation with KOCN. Incubation with urea resulted in a 0.7%-8% lower CRP detection rate. The results of this study indicate that high concentrations of cyanate can lead to falsely decreased CRP levels, as measured by immunoturbidimetry.
氨甲酰化是一种非酶促的翻译后修饰，在氰酸盐与氨基酸和/或蛋白质反应过程中观察到，可能发生在某些病理情况下，如慢性肾脏病。有证据表明，氨甲酰化可能会干扰免疫比浊法测定的一些分析物的定量。C 反应蛋白（CRP）是一种炎症反应蛋白，在临床实验室中通常通过免疫比浊法进行定量。由于血清中修饰蛋白的存在可能导致定量受损，因此本研究旨在验证氨甲酰化对 CRP 标准溶液和血清池测量的影响。将样品在 37°C 下与 150nM、150µM 或 150mM 氰酸钾（KOCN）或 20、100 或 500mg/dL 尿素孵育 24 小时。使用免疫比浊法测定 CRP 浓度。结果显示，与 KOCN 孵育后，CRP 的检出率下降了 61%-72%。与尿素孵育后，CRP 的检出率降低了 0.7%-8%。本研究结果表明，高浓度的氰酸盐可能导致免疫比浊法测定的 CRP 水平假性降低。
