Screening for Porphyrias
Testing | In Patients With Acute Neurovisceral Symptoms | In Patients With Photosensitivity |
|---|---|---|
Screening | Urinary ALA, PBG, creatinine (random urine sample)‡ | Plasma porphyrins* |
Confirmation (when screening test results are significantly abnormal) | Urinary ALA, PBG, and creatinine (quantitative)‡ Fecal and urinary porphyrins† Red blood cell PBG deaminase Plasma porphyrins* | Red blood cell porphyrins Urinary ALA, PBG, porphyrins, and creatinine (quantitative)‡ Fecal porphyrins† Plasma porphyrins* |
* The preferred method is by direct fluorescent spectrophotometry. | ||
† Urinary and fecal porphyrins are fractionated only if the total is increased. | ||
‡ Results are corrected according to urine creatinine level. | ||
ALA = delta-aminolevulinic acid; PBG = porphobilinogen. | ||