Infantile-onset Pompe disease presents during the first few months of life with hypotonia, generalised muscle weakness, and hypertrophic cardiomyopathy. Enzyme replacement therapy (ERT) with alglucosidase alfa (Myozyme) is the established first-line intervention — but in some infants the expected cardiac and electrophysiological improvements are not achieved, requiring an escalation step that targets the underlying immunological barrier.
After initiating enzyme replacement therapy with alglucosidase alfa, the following cardiac and electrophysiological endpoints were not reached: significant regression of left ventricular hypertrophy (expected within approximately two months of ERT); resolution of left ventricular outflow tract obstruction (expected within one month); and normalisation of the shortened PR interval and elevated QRS voltages. Non-achievement of these benchmarks is the trigger for the next management step described here.
Infantile-onset Pompe disease presents during the first few months of life with symptoms of hypotonia, generalized muscle weakness and hypertrophic cardiomyopathy.
The immune-modulating protocols can involve a combination of rituximab, methotrexate, and support with gamma globulins during the period of induced immunocompromise.
In small case series, some patients have responded with reduction of anti-GAA titres after the use of ITI or have failed to develop high antibody titres when treated with ITI prior to commencement of ERT.
DOI: 10.1017/cjn.2016.37