Early diagnosis and timely implementation of enzyme replacement therapy are the most important determinants of Pompe disease, doctors remind. Unfortunately, the late form of the disease, which is predominant, is often detected at a late stage. Several factors contribute to this, but what could solve the problem and lead to diagnosis as early as the pre-symptomatic stage is newborn screening.
We need screening for Pompe disease, doctors warn
Published April 17, 2023 21:24
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Pompe disease is a rare genetic disease. It has two forms. In the early form, associated with infancy, the diagnosis is usually made fairly quickly, because the disease has a very turbulent course. In the late form, it initially manifests with many unrelated symptoms, such as muscle pain, breathing problems, headaches and insomnia. Over time, these symptoms worsen, sometimes becoming life-threatening. The late form occurs in the largest group of patients.
- What should raise suspicion of the disease are abnormalities in the laboratory test. The enzyme in question is creatine kinase. Its level is elevated, even before symptoms appear. Added to this are symptoms related to weakness of the leg muscles in particular. Walking up stairs or standing up from a squatting position is difficult. It's also the early onset of respiratory failure, shortness of breath, to which patients adapt relatively well for a long time. However, there can be dramatic symptoms, for example, with a theoretically harmless upper respiratory tract infection," says Professor Anna Kostera-Pruszczyk, head of the Department of Neurology at the University Clinical Center of Warsaw Medical University.
Although doctors' awareness of the disease has increased in recent years, many patients are still diagnosed at a late stage. This is because the symptoms build up very slowly and many people struggling with the disease do not pay much attention to them until the course becomes severe.
Meanwhile, early diagnosis and implementation of available treatment can halt progression. The drug program, run at the Institute of Psychiatry and Neurology, among others, uses enzyme replacement therapy (ERT), consisting of recombinant enzyme supplementation, for treatment.
- The treatment itself is somewhat cumbersome for patients, as the drug is administered intravenously every two weeks. However, the drug is very well tolerated and patients feel very good after its administration, with no reports of side effects. Based on observations, it can be concluded that the effect of administering this drug is to stop the progression of the disease in most patients, or to slow it down significantly," says Dr. Grzegorz Witkowski of the 1st Neurology Clinic of the IPiN PAN.
As doctors emphasize, the effect of administering this drug depends on when the patient receives it. The less severe the symptoms are at the beginning of therapy, the better the effect of this treatment.
- We also received patients with much more severe symptoms, late diagnosed. In these patients, we may not see very spectacular results from this therapy, but we see that the disease is not getting worse," adds Dr. Witkowski.
In 2022, the European Medicines Agency registered another therapeutic option with a new recombinant enzyme, avalglucosidase alfa. This is the first new therapy in 15 years.
- It is an enzyme that is very similar to the one already in place. However, due to the modifications made to the molecule, it is a drug that is better absorbed by muscle cells and may contribute to better maintenance of motor skills, says Dr. Grzegorz Witkowski.
Better absorption of the drug translates into up to five times more efficient removal of glycogen from cells. The therapy is intended for use in adults and children 6 months and older.
An opportunity to avoid severe symptoms and implement treatment early could be newborn screening. Detecting Pompe disease in the pre-symptomatic stage would allow monitoring the patient and implementing enzyme replacement therapy at the optimal time, that is, when the first symptoms appear.
- It's an enzyme whose absence is detected, so with reduced enzyme activity we can tell if a patient is suspected. Screening is supposed to detect a group of suspects and refer them for further diagnosis, usually for genetic testing," says Dr. Ewa Glab-Jabłońska of the Department of Screening and Metabolic Diagnostics at the Mother and Child Institute.
- This needs to be fought for. Diagnosis of rare diseases is, unfortunately, a hole in Poland and takes a long time. Screening and early diagnosis in this disease would give patients a good chance, because we have treatment, and that's the most important thing," adds Dr. Mariusz Oltarzewski, head of IMiD's Department of Screening and Metabolic Diagnostics.
Przemysław Burmer, CEO of the Rare Diseases Foundation, affected by Pompe disease, which his sister also faces, heard the diagnosis 12 years ago, and has been on enzyme replacement therapy for 11. Patients need access to early diagnosis and treatment, he says, but not only that.
- What we went through before we got to the right diagnosis was the inspiration for starting the foundation and spreading awareness of the disease. People look for information on the Internet, call, ask about symptoms. I was initially diagnosed with muscular dystrophy. Getting to the right diagnosis is difficult, but now things are better in that regard. Often, however, it ends there and with the administration of medicine. What we lack is at least psychological support, dietary support or easier access to rehabilitation," Przemysław Burmer mentions.
