Worse Disease Burden for VP Patients Than Those With HCP, Israeli Study Finds
People with variegate porphyria (VP), one of a group of related disorders, carry a significantly heavier disease burden — the overall impact of a medical disorder on a patient’s life — than those with hereditary coproporphyria (HCP), primarily due to more frequent body-wide and skin symptoms.
Disease burden is the measure of a medical condition’s impact. In patients, this assessment is based on symptoms and poor health, and other quality of life factors such as financial cost and the likelihood of an earlier death.
The study, “Greater disease burden of variegate porphyria than hereditary coproporphyria: An Israeli nationwide study of neurocutaneous porphyrias,” was published in the journal Molecular Genetics and Metabolism Reports.
VP and HCP are two forms of porphyria caused by mutations in genes of the pathway that synthesizes heme, an integral part of the hemoglobin protein that carries oxygen inside red blood cells.
People with either of these conditions, together known as neurocutaneous porphyrias (NCPs), can experience both body-wide, or systemic, symptoms — including abdominal pain, muscle weakness, and neurological complications such as anxiety and confusion — and skin involvement (cutaneous) such as painful skin blisters.
However, data on these two conditions are limited, and there has been no comparison between VP and HCP using a relevant number of patients.
Now, researchers in Israel designed a study to investigate the type and frequency of clinical manifestations of both of these porphyrias.
The study included 40 people with VP (48% female), with a mean age of 49, and 21 HCP patients (55% female), whose average age was 48. Most patients reported a porphyria family history and were Sephardi Jews. Interviews to collect data were conducted by a medical professional.
The results revealed the primary systemic symptom was abdominal pain, reported by 64% of those with VP and 69% of HCP patients.
Most patients with VP (68%) experienced abdominal symptoms as well as musculoskeletal or psychiatric manifestations on a daily or weekly basis. Musculoskeletal symptoms included limb pain, limb numbness, and muscle weakness. In contrast, participants with HCP reported less than one symptom overall per week.
No differences were found between VP and HCP regarding rates of hospitalization. Additionally, there was no correlation identified between the odds of frequent systemic symptoms and at least one hospitalization.
The VP group used medications for pain more frequently than HCP patients, but the difference did not reach statistical significance.
Skin involvement was seen in 58% of VP patients and 5% — representing one individual — of the HCP group. Having both systemic and cutaneous symptoms was more prevalent in VP patients (40%) than people with HCP (5%). There was no correlation between the occurrence of systemic and skin symptoms in either group.
“Taking into account that cutaneous presentation in VP patients is similarly more substantial and affect a much greater portion of patients, these characteristics point to a more considerable disease burden of VP than HCP,” the researchers wrote.
Alcohol consumption, which can induce porphyria symptoms, was much less common in VP patients than among those in the HCP group (36% vs. 69%). However, most participants in both groups reported infrequent consumption of less than one drink per week — one bottle of beer or half a glass of wine, or a small glass of spirits.
The majority of VP patients who reported alcohol consumption (78%) also reported one or more systemic symptoms per week, but there was no significant association between these two factors. A similar trend was found for drug use, such as cannabis, with 80% of such VP patients also reporting frequent systemic symptoms.
“This trend might be attributable to the higher frequency of reported painful manifestations in the VP group and efforts of patients with VP to self-medicate,” the team wrote.
Among women, hormonal changes due to menstruation commonly triggered systemic symptoms, in particular abdominal pain, as reported in 38% of people with VP and 50% in the HPC group.
Finally, a previous infusion of hematin was reported only by VP patients (12%), whereas glucose treatments — to reduce porphyrin production in the liver — were reported by 20% of VP participants and 23% of those with HCP.
“This nationwide study elicits a much heavier disease burden in VP patients compared to HCP patients with more frequent [systemic] and cutaneous manifestations,” the scientists wrote.
“Our study expands the current understanding of the presentation and disease burden of HCP and VP and has implications for improving diagnosis and patient management by generating greater awareness of the disease burden and impact on patients’ lives,” they added.