NATURAL COURSE OF AN ACUTE ATTACK IN ACUTE INTERMITTENT PORPHYRIA

E.Pishick, A. Yrjönen, R.Kauppinen

Research Program in Molecular Medicine, Biomedicum-Helsinki, University of Helsinki, Finland

Objective: To assess the course of an acute attack by studying correlation of clinical manifestations with precipitating factors, and treatment of patients with acute intermittent porphyria (AIP).

Patients and methods: The study group included 15 Russian and Finnish AIP patients experiencing totally 41 acute attacks in 1995-2004, who were assessed clinically and biochemically during an acute attack and in remission.

Results: An acute attack could be dissected into several distinct phases. An initial phase of an acute attack included dysautonomia and mental symptoms lasting 3-29days (mean 14 days). If an additional precipitating factor was administrated, the second phase of an acute attack developed including paresis, epileptic seizures, unconsciousness and hyponatremia. If an attack was treated early and precipitating factors were eliminated, acute attacks rarely proceeded to the second phase. After pareses had developed, intensity of abdominal pain usually declined, but myalgia increased. Tachycardia correlated with activity of an acute attack. Mechanical lung ventilation, bulbar paresis, severe consciousness impairment and arrhythmia appeared only at the late stage of an acute attack (mean 45 days, range 13-83 days) and reflected the most severe impairment of the nervous system. In the majority of the cases it was provoked by additional precipitating factors and could be attributed to a separate phase of an acute attack. Transaminases were usually normal during early days of an acute attack but increased in the majority of cases when an acute attack proceeded. Heme arginate was more effective than glucose infusion leading to a plateau phase significantly earlier (mean 7.6±1.0 vs. 12.3±2.0 days in patients treated conventionally, p=0.001) even in severely affected patients.

Conclusions: Precipitating factors appeared usually in combination, and were responsible for several distinct phases of an acute attack, which could be observed in severe cases. Heme therapy should be started early but it is efficient even in severely affected patients. The delay of diagnosis and administration of additional precipitating factors were responsible for a poor outcome of an acute attack.