Acute intermittent porphyria (AIP) patients who have recurrent attacks are more likely to be sicker and unemployed, yet face higher medical costs than patients with occasional attacks, researchers in The Netherlands report.
Their study, “Medical and financial burden of acute intermittent porphyria,” was published in the Journal of Inherited Metabolic Disease.
Only a small fraction of patients with AIP, a rare genetic disease, experience recurrent attacks, defined as several attacks during a year.
These patients also report lower quality of life, including difficulties holding a job and long-term disability. The impact of recurrent attacks on other aspects of a patient’s life, namely financial and personal struggles, is less clear.
To get a better insight into the burden of AIP, researchers performed a retrospective analysis to assess the prevalence of porphyria symptoms and complications in three patient subgroups: those with recurrent attacks each year, one or occasional attacks, and in individuals that carry a mutation in the HMBS gene but show no symptoms, so-called asymptomatic carriers who served as a control group.
They analyzed medical records of patients followed at a single clinic, the Erasmus Medical Center, in Rotterdam, The Netherlands, between 1960 and 2016.
“We collected symptoms related to porphyria, porphyria related complications, attack frequency, hospitalisation frequency, hospitalisation days related to acute porphyric attacks, frequency of heme infusions and medical healthcare costs based on hospitalisations and heme therapy,” the researchers wrote.
In total, the analysis included 11 recurrent cases, 24 symptomatic cases and 53 asymptomatic carriers.
Results showed that patients with recurrent attacks have significantly higher burden of porphyria-related symptoms, namely pain and neurological deficits, compared to controls.
Nearly all patients developed hypertension and chronic kidney disease, but the prevalence of both symptoms was higher in both recurrent and symptomatic patients compared to asymptomatic cases. Around 70% of recurrent and symptomatic patients developed hypertension compared to 26% of the asymptomatic control group. Kidney disease was prevalent in 64% of recurrent patients and 46% of symptomatic ones, and 13% of those who were asymptomatic.
Patients with recurrent attacks underwent frequent and long hospitalization periods, with a median of 82 days, and received a median of 399 total ampoules of heme per person. Those in the symptomatic non-recurrent group were hospitalized for a median of seven days due to acute attacks, and required a median of three ampoules of heme per person.
Total medical cost for recurrent patients was €5.8 million (about $6.3 million), while for symptomatic ones it was €300,000 (about $360,000).
Unemployment affected 63.6% of recurrent attacks patients, compared to 33.3% and 20.8% in symptomatic patients and asymptomatic carries, respectively.
“AIP [acute intermittent porphyria] patients with recurrent attacks have a high mortality and morbidity, compared to other symptomatic AIP patients and to asymptomatic carriers. Recurrent attacks result in high medical costs and high unemployment rates,” the study concluded.
“In future studies, these different AIP groups should therefore be analysed separately, as our study clearly demonstrated that patients with recurrent attacks are different than sporadical symptomatic patients and asymptomatic HMBS gene carriers,” the researchers suggested.