Hemin Prophylaxis for Patients with Frequently Recurring Acute Porphyric Attacks: Experience with Five Cases.

Background

The acute porphyrias are a group of four clinically indistinguishable diseases characterized by sudden, acute episodes of neurovisceral symptoms that can be life-threatening. Attacks are precipitated by a genetic deficiency in one of the enzymes involved in heme biosynthesis, acting in concert with one or more endogenous or exogenous triggers. The resultant stimulation of hepatic heme results in overproduction of highly reactive heme intermediaries - porphyrins and porphyrin precursors - which accumulate in the liver, blood, and bone marrow. A small percentage of patients have attacks that recur every several weeks, even after all known triggers are eliminated. Although hemin prophylaxis has been recommended for such patients (Anderson K, et al. Recommendations for the Diagnosis and Treatment of the Acute Porphyrias. Annals of Internal Medicine. 2005 Mar; 142(6):439–50), no adequate and well-controlled clinical studies have been conducted.

Methods

We report on five patients, all diagnosed with acute porphyria on the basis of elevated levels of urinary aminolevulinic acid and porphobilinogen (4 with acute intermittent porphyria, 1 with hereditary coproporphyria). All had a history of recurring acute porphyric attacks and received hemin prophylaxis for at least one year in an out-patient setting and were previously treated for a minimum of one year in a hospital setting. The dosage and frequency of prophylactic hemin was based on each patient’s clinical picture, and ranged from a one-day course of 1–4mg/kg/day every 10 to 40 days to a four day-course of 1–4 mg/kg/day every 30 days. The outcome of prophylaxis hemin treatment was determined on the basis of frequency of severe attacks requiring hospitalization and both physician and patient assessment of the severity of symptoms.

Results

Five patients (3 female, 2 male), ranging in age from 25–61 years old suffered from frequently recurring acute porphyric attacks, with symptoms that included abdominal pain (5), psychological disturbances (2), peripheral motor neuropathy (2), and nausea (2). Two patients had a significant reduction in the frequency of their acute attacks and three reported a moderate decrease with prophylactic hemin treatment. All five patients experienced a marked improvement in the reduction of the severity of their attacks. Overall, the occurrence of severe acute attacks requiring hospitalization declined by 66%. Three of the five patients did not require hospitalization over the 12 month period of time. One patient experienced phlebitis during one course of hemin treatment.

Conclusions

Hemin prophylaxis can be an effective disease management strategy in acute porphyria patients with frequently recurring acute attacks.