Cystine, Urine (Cystinuria Panel)

Sample type

Urine (24-hour)

Uses

Measures levels of cystine in urine to detect presence of cystinuria and nephrolithiasis.

Precautions

Cystatin C has not been shown to be affected by factors such as muscle mass and nutrition, factors which have been demonstrated to affect creatinine values. In addition, a rise in creatinine does not become evident until the GFR has fallen by approximately 50%.

Interfering factors

Specimen other than serum or heparinized plasma; grossly hemolyzed (>1,000 mg/dL Hgb) samples; excessive turbidity and clots in samples

Pre-analytical errors

Collect the sample in a non-sterile tube.

The corrective action

The sample should be rejected and another sample requested

Post-analytical errors

Write an other patient`s name in the report

If the patient’s gender is written wrong in the report, the reference range was written incorrectly

The corrective action

If the report is not delivered to the patient and this error is discovered, the correct name must be written, but if the report is delivered to the patient, you must communicate with him, apologise to him, and tell him that an error has occurred and replace it with the correct report

If the report is not delivered to the patient and this error is discovered, fix it, but if the report is delivered to the patient, apologise to him, tell him that an error has occurred, and replace it with the correct report. And next time, Be careful when you write down the gender and reference range.

Reference range

2.1−58.0 mg/24 hours