Porphyrins Evaluation, Whole Blood

Casandra

Casandra Test Code MC73093Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID PEECPT Codes 82542, 84311

Porphyrins Evaluation, Whole Blood

Clinical Use

Use

The porphyrins evaluation test is pivotal in establishing a biochemical diagnosis for disorders such as erythropoietic protoporphyria (EPP) and X-linked dominant protoporphyria (XLDPP). It is particularly useful for screening and diagnosing individuals suspected to have these conditions, as both involve porphyrin accumulation manifesting as heightened protoporphyrin levels in erythrocytes, plasma, and feces. This test is also applied to evaluate iron-deficiency anemia and chronic lead intoxication, with elevated zinc-complexed protoporphyrin levels often indicative of these conditions. The evaluation aids in differentiating these inherited porphyrias from other causes of elevated porphyrins and facilitates early detection for appropriate patient management.

Special Instructions

For optimal results, patients should abstain from alcohol intake 24 hours prior to specimen collection. The test should be performed on one collection tube of whole blood, placed on wet ice immediately after drawing. Ensure the test is ordered with a complete list of current medications, and use the preferred container tubes for accurate results. If ordering manually, complete and send a Biochemical Genetics Test Request form with the specimen.

Limitations

False positives may occur if alcohol is consumed within 24 hours prior to specimen collection due to enzyme suppression, potentially leading to erroneous results. The protoporphyrin measurements are conducted through spectrofluorometric analysis, and certain conditions such as improper specimen collection or handling might result in diagnostic confusion or inaccurate interpretations. Additionally, the test does not distinguish genetic variants of XLDPP and EPP and may require further genetic testing for comprehensive diagnosis.

Test Details

New York Approved