[Clinical characteristics of 50 patients with acute intermittent porphyria]

Objective: To analyse the clinical characteristics of patients with acute intermittent porphyria (AIP) in order to improve the understanding and treatment. Methods: Patients diagnosed as AIP and admitted to the First Affiliated Hospital of Zhengzhou University were retrospectively enrolled from January 2008 to July 2018. Data of clinical manifestations, causes, laboratory data, treatment and clinical outcome were recorded. Results: Among the 50 patients, 41 patients (82%) were aged 20 to 40. The ratio of male and female was 1∶1.8. The most common symptoms were abdominal pain (94.0%), nausea, vomiting (72.0%) and constipation (42.0%). Neuropsychiatric disorders were seen in 72.0% patients, and 30.0% of the patients had dark-coloured urine. Precipitating factors included infections, menstruation, starvation, drugs, alcohol consumption, mental stimulation and so on. Laboratory tests were abnormal for urinary porphobilinogen, liver function, hyponatremia, anaemia and so on. Various mutations of hydroxymethylbilane synthase (HMBS) genes were detected in 16 patients. Management strategies included removal of risk factors, administration of glycogen and symptomatic treatment during acute episode. Most patients were discharged with improved conditions. Conclusions: The clinical manifestations of acute intermittent porphyria are complex and diverse. Misdiagnoses or malpractice may be fatal. It is critical to emphasize on its early diagnosis and treatment.