Question

A urine specimen is collected from a 19- year-old brittle diabetic patient. She currently takes 2000 mg of Vitamin C every day.

UA results are as follows:
pH = 5.0
Urobilinogen - Normal
Protein - Negative
Glucose - Negative
Ketones - Negative
Bilirubin - Negative
Blood - Negative
Nitrite - Negative
Leukocyte esterase - Negative
Clinitest - 1000 mg/dL
1. Identify any abnormal results.
2. Explain any discrepancies.
3. What other tests are affected by high levels of Ascorbic Acid?
4. If these results were obtained on a newborn who had NOT received any Ascorbic Acid, what disease process might be occurring?

Answer 1

The abnormal test result is a Clinitest reading of 1000 mg/dL, indicating high levels of reducing sugars. The negative routine glucose test may be a false negative due to Vitamin C intake. Without Vitamin C intake, such results in a newborn could indicate galactosemia.

Step-by-step explanation:

Analysis of Urinalysis Results

The abnormal result in the urinalysis is the Clinitest reading of 1000 mg/dL, which is indicative of high levels of reducing sugars in the urine, most likely glucose. However, there are discrepancies present since the urine glucose test came back negative. This inconsistency may be due to the high intake of Vitamin C (Ascorbic Acid) by the patient, which can cause false negatives in the routine glucose checks that use glucose oxidase methods. Ascorbic Acid is known to interfere with the accuracy of some urine tests, including tests for glucose, blood (hemoglobin), and bilirubin.

If these results were obtained from a newborn who had not received any Ascorbic Acid, it would be suggestive of a possible inborn error of metabolism such as galactosemia, where the infant is unable to properly break down the sugar galactose, leading to the presence of reducing substances in the urine.