Acute intermittent porphyria presenting with rhabdomyolysis and polyneuropathy with severe quadriparesis and respiratory failure: A case report.

BACKGROUND: Acute intermittent porphyria (AIP) is the most common form of acute porphyria, a group of rare inherited disorders of heme biosynthesis. Severe attacks may be associated with life-threatening complications, including peripheral motor neuropathy, encephalopathy and seizures. Very rarely, an acute AIP attack can be complicated by rhabdomyolysis as illustrated in this case report. CASE SUMMARY: A 28-year-old female presented with severe abdominal pain and muscle weakness, which progressed to severe rhabdomyolysis and acute kidney injury requiring dialysis. The disease course was further complicated by an acute severe axonal peripheral motor neuropathy with quadriparesis and respiratory muscle weakness requiring prolonged invasive mechanical ventilation. An important clue for diagnosis was red urine without hematuria. The diagnosis was established by the finding of elevated δ-aminolevulinic acid and porphobilinogen in a random urine sample and later confirmed by genetic testing. The patient was initially treated with hemin and parenteral glucose. However, since she needed prolonged treatment, givosiran was commenced and continued after discharge. When the period between givosiran administrations was extended to two months, this led to a new (milder) attack. After 40 months of givosiran treatment and continued physical rehabilitation, the patient is ambulatory and without acute attacks. CONCLUSION: Our case illustrates that treatment with hemin and givosiran for longer than two years may be needed for neurological recovery after an AIP attack with severe motor polyneuropathy and multisystem involvement.