Objectives Enzyme replacement therapy (ERT) with alglucosidase alfa (rhGAA) has changed the fatal course of infantile Pompe disease, however, development of anti rhGAA antibodies and infusion-associated reactions (IAR) restrict the tolerability and effectiveness of the treatment. Case presentation We describe a successful concomitant immune tolerance induction (ITI) and desensitization protocols in a cross-reactive immunologic material (CRIM) negative 7-month-old male patient. At the age of 5 months and eighth dose of the ERT, the patient developed IAR and his rhGAA specific IgE was negative however, his rhGAA specific IgG titer was as high as 12,800. ITI therapy to suppress antibody formation and a desensitization protocol was devised to be given concomitantly. At the end of 5-week therapy, his fatigue and weakness improved profoundly and a control antidrug antibody level decreased at 800. At the time of the patient’s follow up, he was still on ERT with desensitization at the age of 15 months without any reactions. Conclusions This is the first report in the literature applying concomitant ITI and desensitization protocols in a CRIM negative infantile-onset Pompe disease patient successfully, hence the importance of the case.

Objectives Familial hyperphosphatemic tumoral calcinosis is a rare disorder characterized by hyperphosphatemia with recurrent ectopic periarticular calcifications, in addition to other visceral and vascular manifestations, without any inflammatory or neoplastic disorder. The available treatment strategies are limited. Here we report an eight year old female patient with recurrent lesions under the chin, and bilateral hips which are painful and improving of the size of the lesions and hyperphosphatemia. Case presentation The patient was started to the treatment with peroral acetazolamide however the lesion did not regress but a new lesion appeared then we added sevelamer and topical sodium thiosulfate treatment for three months. After the three months of the combination treatment the lesions, there were no pain, no hyperphospahtemia regression/disappearance of the lesions. Conclusions This combination treatment or topical sodium thiosulfate use only may be a novel treatment strategy for the patients prospective controlled trials are needed.

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