Time Is of Essence: Utilizing Extended Hemin Treatment for a Case of Severe Acute Intermittent Porphyria

Introduction: Acute intermittent porphyria (AIP) is a disorder of heme synthesis and leads to accumulation of precursors causing abdominal and neurological symptoms. AIP can be debilitating and even fatal without correct diagnosis and timely treatment. We outline a rare case of severe AIP, masquerading as Guillain-Barre Syndrome (GBS), treated with an extended course of hemin. Case Description/Methods: 21 year-old female presented to a hospital in Ecuador 11 days after right ovarian cyst removal, for abdominal pain and convulsions. Labs showed severe hyponatremia. On exam she had abdominal tenderness with subcutaneous emphysema and lower extremity weakness. CT revealed pneumoperitoneum. She was started on anticonvulsants and underwent ex-laparotomy and lysis of adhesions. EMG revealed symmetric polyneuropathy. IVIG was initiated due to concern for GBS but she progressed with ascending polyneuropathy, developed respiratory failure due to diaphragm paralysis on day 14, was intubated and airlifted to our facility due to concerns about porphyria. Initial laboratory tests at our facility were notable for hyponatremia and elevated serum transaminases. The combination of abdominal pain, hyponatremia, and advanced motor neuropathy with quadriplegia and respiratory paralysis raised strong suspicion for acute hepatic porphyria (AHP) and she was started on hemin infusion 5 mg/kg daily while work-up was pending. Later, urine studies unveiled elevated urine PBG level 184.92 (normal < .22) mg/gCre/12h and urine ALA level 105.1 (normal < 5.4) mg/gCre/12h, consistent with AHP and most likely AIP, later confirmed by genetic test. Patient had mild improvement in neurological symptoms after 5 days of hemin and treatment was extended to14 days. ALA and PBG levels continued to downtrend (Figure 1A &1B). Patient had slow improvement in extremity strength and eventually discharged home with weekly hemin infusions. Discussion: We outline a case of severe AIP with delayed diagnosis. Fortunately, this patient received tailored treatment and eventually had full recovery. Though uniform guidelines for hemin administration exist (Table 1), they universally fail to address treatment regimens for patients with severe presentation and minimal clinical improvement within the first 4 days of treatment. In conclusion, high index of suspicion is required for timely diagnosis and extended hemin treatments should be considered for patients with AIP with refractory response to current guideline therapy.Table 1.: AIP Guidelines for Hemin Treatment Across Subspecialty Societies.Figure 1.: a: D-ALA Trend over 14-day Hemin Treatment. b: PBG Trend over 14-day Hemin Treatment.