Can we reduce the interference of vitamin C and PH in urinalysis?

Danqin Feng,Jianguo Cai,Jinbiao Lin,Huiming Ye,Xiaoli Chen

doi:10.1590/fst.37321

Abstract

Urinalysis is often interfered by vitamin C and PH. This study was to evaluate the interference of vitamin C and PH in urinalysis, and minimize the risk to make the effective communication. 732 leftover urine samples in which the concentration of vitamin C was 0.0 mmol/L and either of the test-strip results (Glucose, Blood, Bilirubin, Leucocyte, Nitrite, Protein, Ketone) was positive that were collected. The interference test checked out using these leftover urine samples. When the chemical protein module was positive, the sulfosalicylic acid test performed to confirm the positive results. About 27% of urine samples were vitamin C positive. Adequate vitamin C would interfere with the chemical result of GLU, BIL, and BLD, but not KET, PRO, WBC, NIT (p-value < 0.05). False-positive protein occurred at any samples, but higher when urine PH is greater than or equal to 8.0. In summary, to minimize the risk of vitamin C and PH in urinalysis, the laboratory should pay more attention to its conditions. Also, do more to help guarantee the accuracy of the urinalysis results and to give more comments to doctors to achieve effective communication.

Highlights

As we know, urine specimens are usually readily available and obtain non-invasive (Liao & Churchill, 2001)
When DIRUI dipsticks showed the concentration of vitamin C 2.8 mmol/L, it would interfere with the chemical result of GLU and BLD, p-value < 0.05 (Table 3)
When DIRUI dipsticks showed the concentration of vitamin C, either 1.4 mmol/L or 0.6 mmol/L, it would only interfere with the chemical result of BLD, p-value < 0.05 (Tables 4 and 5)

Summary

Introduction

Urine specimens are usually readily available and obtain non-invasive (Liao & Churchill, 2001). Urine tests are often used to help doctors to diagnose and evaluate diseases. Chemical tests are often interfered with by lots of factors, such as vitamin C and PH (Unic et al, 2018). To provide accurate reports to doctors, laboratory scientists should recognize and reduce false positive or false negative results (Poloni et al, 2018). Amounts of DIRUI dipsticks (FUS-12MA II) consume every day. Whether PH and vitamin C have an impact on the test results of DIRUI dipsticks? If the answer is definitely, how can we minimize or eliminate interference? Can we establish some review rulers or give some comments? Whether PH and vitamin C have an impact on the test results of DIRUI dipsticks? If the answer is definitely, how can we minimize or eliminate interference? To minimize these risks, can we establish some review rulers or give some comments?

Methods

Results

Discussion

Conclusion