Laboratory findings that differentiate acute intermittent porphyria, hereditary coproporphyria, and variegate porphyria.*
| Disease . | Erythrocyte Porphobilinogen Deaminase Levels . | Urine Porphyrin Levels . | Fecal Porphyrin Levels . | Plasma Porphyrin Levels . |
|---|---|---|---|---|
| Reprinted with permission from Anderson KE, Bloomer JR, Bonkovsky HL, et al. Recommendations for the diagnosis and treatment of the acute porphyrias. Ann Intern Med . 2005 ;142 :439 –450. | ||||
| * The findings listed are considered diagnostic for acute intermittent porphyria when porphobilinogen level is increased and for hereditary coproporphyria and variegate porphyria even when porphobilinogen levels may have returned to normal. | ||||
| † Mostly coproporphyrin III | ||||
| ‡ A simple test, which consists of fluorescence scanning of diluted plasma at neutral pH, readily differentiates variegate porphyria from other porphyrias that cause elevated plasma porphyrin levels and cutaneous photosensitivity. A plasma porphyrin level determination is the most sensitive porphyrin measurement for detecting variegate porphyria, including asymptomatic cases. | ||||
| Acute intermittent porphyria | Decreased by ~ 50% (in ~ 90% of cases) | Increased, mostly uroporphyrin | Normal or slightly increased | Normal or slightly increased |
| Hereditary coproporphyria | Normal | Increased, mostly coproporphyrin | Increased, mostly coproporphyrin† | Usually normal |
| Variegate porphyria | Normal | Increased, mostly coproporphyrin | Increased, mostly coproporphyrin† and protoporphyrin | Increased, characteristic fluorescence peak‡ |
| Disease . | Erythrocyte Porphobilinogen Deaminase Levels . | Urine Porphyrin Levels . | Fecal Porphyrin Levels . | Plasma Porphyrin Levels . |
|---|---|---|---|---|
| Reprinted with permission from Anderson KE, Bloomer JR, Bonkovsky HL, et al. Recommendations for the diagnosis and treatment of the acute porphyrias. Ann Intern Med . 2005 ;142 :439 –450. | ||||
| * The findings listed are considered diagnostic for acute intermittent porphyria when porphobilinogen level is increased and for hereditary coproporphyria and variegate porphyria even when porphobilinogen levels may have returned to normal. | ||||
| † Mostly coproporphyrin III | ||||
| ‡ A simple test, which consists of fluorescence scanning of diluted plasma at neutral pH, readily differentiates variegate porphyria from other porphyrias that cause elevated plasma porphyrin levels and cutaneous photosensitivity. A plasma porphyrin level determination is the most sensitive porphyrin measurement for detecting variegate porphyria, including asymptomatic cases. | ||||
| Acute intermittent porphyria | Decreased by ~ 50% (in ~ 90% of cases) | Increased, mostly uroporphyrin | Normal or slightly increased | Normal or slightly increased |
| Hereditary coproporphyria | Normal | Increased, mostly coproporphyrin | Increased, mostly coproporphyrin† | Usually normal |
| Variegate porphyria | Normal | Increased, mostly coproporphyrin | Increased, mostly coproporphyrin† and protoporphyrin | Increased, characteristic fluorescence peak‡ |