Porphyrias: acute hepatic porphyria attack (suspected), porphyria cutanea tarda (blisters on exposed skin), known porphyria

Urine tests: one voiding during symptoms (no 24-hour collection), no preservative, container protected from light (aluminium foil)

• Urinary porphobilinogen (PBG) and delta-aminolaevulinic acid (ALA), expressed relative to urinary creatinine

Laboratory tests

• Serum electrolytes (sodium)
• Serum creatinine with eGFR
• Serum magnesiumif needednon-French guidelineSeizures can be accompanied by hyponatraemia and hypomagnesaemia, through hypovolaemia and inappropriate secretion of antidiuretic hormone ^[1].

Urine tests: first morning urine (20 to 50 mL), no preservative, container protected from light (aluminium foil)

• Urinary porphyrins (screening, quantification, identification)

Laboratory tests (EDTA tube protected from light for porphyrins)

• Plasma porphyrins
• FBC
• Serum ferritin
• Transferrin saturation
• AST
• ALT
• GGT
• Alkaline phosphatase
• Bilirubin
• Hepatitis C serology
• HIV serology
• HFE C282Y mutation (if transferrin saturation > 45% confirmed on a second sample)if neededIron overload with an HFE mutation is a susceptibility factor for PCT ^[11]. The NABM covers C282Y testing only after a transferrin saturation > 45% confirmed on a second sample ^[6].

Once a year (more often on givosiran or haemin)

• AST
• ALT
• Serum creatinine with eGFR
• Alpha-fetoprotein (from age 50, with liver ultrasound every 6 months)if needednon-French guidelineRisk of hepatocellular carcinoma of 1.5 to 1.8%, even without cirrhosis: ultrasound every 6 months from age 50; the AGA cites alpha-fetoprotein in the work-up, while judging its value uncertain ^[1].
• Serum ferritin and transferrin saturation (if haemin as prophylaxis)if needednon-French guidelineOn prophylactic haemin at least monthly: ferritin and iron every 3 to 6 months; consider venesection if ferritin > 1000 ng/mL ^[1].
• Serum lipase, urine protein:creatinine ratio, B12, folate, homocysteine (if givosiran)if needednon-French guidelineOn givosiran: tests before the first injection, before each monthly injection for 3 months, then every 3 months in the first year and at least every 6 months thereafter; monthly transaminases for the first 3 to 6 months (ALT > 3 ULN reported) ^[1].
• Urea (if givosiran)if needednon-French guidelineThe AGA asks for monitoring of urea and creatinine on givosiran ^[1].
• FBCif needednon-French guidelineThe 2017 American recommendations request them at baseline and then at least yearly: iron deficiency, unrelated to porphyria, is common in young women and can cause chronic symptoms ^[15]. Neither the AGA (2023), which measures ferritin on haemin ^[1], nor the page of the French Porphyria Centre ^[3] suggests this yearly check.
• Serum ferritinif needednon-French guidelineThe 2017 American recommendations request them at baseline and then at least yearly: iron deficiency, unrelated to porphyria, is common in young women and can cause chronic symptoms ^[15]. Neither the AGA (2023), which measures ferritin on haemin ^[1], nor the page of the French Porphyria Centre ^[3] suggests this yearly check.