Diagnosis and Management of Porphyria

Diagnostic Criteria

The diagnosis of porphyria requires demonstration of elevated levels of porphyrins and porphyrin precursors (ALA and PBG) in urine, stool, and blood, with values at least 5 times above the upper normal limit during acute attacks, as recommended by the European Association for the Study of the Liver and the American Gastroenterological Association 1, 2
Diagnostic values of PBG >10 mg/g creatinine (>5 times the upper normal limit) in a random urine sample are recommended as the first-line test by the American Gastroenterological Association 2

Plasma, urine, and stool porphyrin analysis can determine the specific type of porphyria, according to the European Association for the Study of the Liver 1
Genetic testing can identify mutations in the HMBS (AIP), CPOX (HCP), or PPOX (VP) genes, as recommended by the American Gastroenterological Association 2
The Watson-Schwartz test can be used for rapid detection of elevated urinary PBG 2
Initial biochemical testing should measure ALA, PBG, porphyrins, and creatinine in a random urine sample, with both ALA and PBG elevated at least 5-fold above the upper limit of normal during acute attacks 2

Intravenous hemin is recommended as first-line treatment, administered at 3-4 mg/kg body weight once daily for 4 days, preferably into a high-flow central vein, with heme bound to human serum albumin to reduce vein irritation, as recommended by the American Gastroenterological Association 2
Supportive care includes discontinuing potential triggering medications, carbohydrate loading, pain management with safe analgesics, antiemetics for nausea and vomiting, and monitoring and correcting electrolyte abnormalities, as recommended by the American Gastroenterological Association 2
Givosiran (RNAi therapeutic targeting hepatic ALAS1) is considered for patients with ≥4 attacks per year, as recommended by the American Association for the Study of Liver Diseases and the American Gastroenterological Association 3, 2

Patients with recurrent attacks should be monitored every 3-6 months, while those with sporadic attacks should be monitored annually, as recommended by the American Gastroenterological Association 2
Urinary ALA and PBG levels, renal function, liver enzymes, and serum ferritin (in patients receiving prophylactic hemin) should be monitored regularly, as per the American Gastroenterological Association and the European Association for the Study of the Liver 2, 3
Hepatic ultrasound and alpha-fetoprotein every 6 months after age 50 are recommended for hepatocellular carcinoma screening, as recommended by the American Gastroenterological Association 2

Chronic hypertension, chronic kidney disease, and hepatocellular carcinoma (particularly in patients over 50 years) are potential complications of AIP, as recommended by the American Gastroenterological Association 2
Psychiatric evaluation and pain management are essential components of care, and addressing chronic symptoms including nausea, fatigue, anxiety, and insomnia is crucial, as recommended by the American Association for the Study of Liver Diseases 3
Liver transplantation may be considered for severe, disabling, intractable attacks refractory to hemin therapy, and renal transplantation may be beneficial for AIP patients with advanced renal disease, with combined liver-kidney transplantation for patients with both recurrent attacks and ESRD, as recommended by the American Association for the Study of Liver Diseases 3
Pre-conception evaluation is recommended, and high-risk obstetrical care should be provided during pregnancy, with caution advised when using hormonal contraceptives (progestins may trigger attacks), according to the American Association for the Study of Liver Diseases 3