High Uric Acid (UA) Negatively Affects Serum Tartrate-Resistant Acid Phosphatase 5b (TRACP 5b) Immunoassay

• Published in: PloS one Vol. 11; no. 1; p. e0147554
• Main Authors: Wu, Zhi-Qi, Zhang, Yan, Xie, Erfu, Song, Wei-Juan, Yang, Rui-Xia, Yan, Cheng-Jing, Zhang, Bing-Feng, Xu, Hua-Guo
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 01.01.2016; Public Library of Science (PLoS)
• Subjects: Acid phosphatase; Acid phosphatase (tartrate-resistant); Acid Phosphatase - blood; Acid resistance; Acids; Adolescent; Adult; Aged; Biocompatibility; Biology and Life Sciences; Biomarkers, Tumor - blood; Biomedical materials; Bone cancer; Bone Neoplasms - blood; Bone resorption; Bone Resorption - blood; Breast cancer; Cancer; Care and treatment; Case-Control Studies; Complications and side effects; Diagnosis; Dilution; False Negative Reactions; Female; Glucose; Hospitals; Humans; Immunoassay; Interference; Isoenzymes - blood; Joint surgery; Laboratories; Lung cancer; Lung diseases; Male; Medical diagnosis; Medical research; Medicine; Medicine and Health Sciences; Metabolic syndrome; Metastases; Metastasis; Middle Aged; Neoplasms - blood; Neoplasms - diagnosis; Osteosarcoma; Patient outcomes; Patients; Phosphatase; Phosphatases; Physical Sciences; Prostate cancer; Sarcoma; Statistical analysis; Tartrate-Resistant Acid Phosphatase; Uric acid; Uric Acid - blood; Womens health; Young Adult; United States; China
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0147554

Bone metastases often occur in the majority of patients with advanced cancer, such as prostate cancer, lung cancer and breast cancer. Serum tartrate-resistant acid phosphatase 5b (TRACP 5b), a novel bone resorption marker, has been used gradually in the clinics as a specific and sensitive marker of bone resorption for the early diagnosis of cancer patients with bone metastasis. Here, we reported that high concentrations of uric acid (UA) lead to decrease of TRACP 5b levels and determined whether TRACP 5b level was associated with UA in interference experiment. A total of 77 patients with high concentrations of UA and 77 healthy subjects were tested to evaluate the differences in their TRACP 5b levels. Serial dilutions of UA were respectively spiked with a known concentration of TRACP 5b standard sample, then Serum TRACP 5b was detected by using bone TRAP® Assay. A correction equation was set to eliminate UA-derived TRACP 5b false-decrease. The effect of this correction was evaluated in high-UA individuals. The average TRACP level of the high-UA individuals (1.47 ± 0.62 U/L) was significantly lower than that of the healthy subjects (2.62 ± 0.63 U/L) (t-test, p < 0.0001). The UA correction equation derived: ΔTRACP 5b = -1.9751lgΔUA + 3.7365 with an R2 = 0.98899. Application of the UA correction equation resulted in a statistically non-significant difference in TRACP 5b values between the healthy subjects and high-UA individuals (p = 0.24). High UA concentrations can falsely decrease TRACP 5b levels due to a method-related systematic error. To avoid misdiagnoses or inappropriate therapeutic decisions, increased attention should be paid to UA interference, when TRACP 5b is used for early diagnosis of cancer patients with bone metastasis, evaluation of the aggressiveness of osteosarcoma or prediction of survival in prostate cancer and breast cancer with bone metastases.