Guidelines for monitoring late-onset Pompe disease Summary. Although treatment with alglucosidase alfa has helped improve the prognosis of patients with late-onset Pompe disease, both the development of the disease and the effectiveness of the treatment need to be monitored on a regular basis. This is the reason that has led a committee of Spanish experts to draw up a series of guidelines on how to follow up these patients. The committee proposes a model of follow-up tests for late-onset Pompe disease. First of all, the nutritional status and swallowing function must be evaluated. Second, and due to the variability of the clinical features, the committee recommends the simultaneous use of several scales to measure different functions and parameters. Thus, muscular force is assessed with the Medical Research Council scale; motor functioning, with the six-minute walk test and timed tests; disability, with the Rasch-built Pompe-specific Activity scale; respiratory functioning, with measurement of the forced vital capacity and oxygen saturation; and fatigue, with the fatigue intensity scale. Lastly, the safety and tolerability of enzyme replacement therapy are controlled by registering and treating the potential side effects and measurement of the anti-alglucosidase alfa antibodies. A number of different general recommendations are also included.