title: Algorithm for the early diagnosis and treatment of patients with cross reactive immunologic material-negative classic infantile pompe disease: a step towards improving the efficacy of ERT.
abstract: OBJECTIVE
  Although enzyme replacement therapy (ERT) is a highly effective therapy, CRIM-negative (CN) infantile Pompe disease (IPD) patients typically mount a strong immune response which abrogates the efficacy of ERT, resulting in clinical decline and death. This study was designed to demonstrate that immune tolerance induction (ITI) prevents or diminishes the development of antibody titers, resulting in a better clinical outcome compared to CN IPD patients treated with ERT monotherapy.
  
  
  METHODS
  We evaluated the safety, efficacy and feasibility of a clinical algorithm designed to accurately identify CN IPD patients and minimize delays between CRIM status determination and initiation of an ITI regimen (combination of rituximab, methotrexate and IVIG) concurrent with ERT. Clinical and laboratory data including measures of efficacy analysis for response to ERT were analyzed and compared to CN IPD patients treated with ERT monotherapy.
  
  
  RESULTS
  Seven CN IPD patients were identified and started on the ITI regimen concurrent with ERT. Median time from diagnosis of CN status to commencement of ERT and ITI was 0.5 months (range: 0.1-1.6 months). At baseline, all patients had significant cardiomyopathy and all but one required respiratory support. The ITI regimen was safely tolerated in all seven cases. Four patients never seroconverted and remained antibody-free. One patient died from respiratory failure. Two patients required another course of the ITI regimen. In addition to their clinical improvement, the antibody titers observed in these patients were much lower than those seen in ERT monotherapy treated CN patients.
  
  
  CONCLUSIONS
  The ITI regimen appears safe and efficacious and holds promise in altering the natural history of CN IPD by increasing ERT efficacy. An algorithm such as this substantiates the benefits of accelerated diagnosis and management of CN IPD patients, thus, further supporting the importance of early identification and treatment initiation with newborn screening for IPD.
authors.affiliation: Division of Medical Genetics, Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, United States of America.
authors.forename: Suhrad G
authors.initials: SG
authors.lastname: Banugaria
authors.forename: Sean N
authors.initials: SN
authors.lastname: Prater
authors.forename: Trusha T
authors.initials: TT
authors.lastname: Patel
authors.forename: Stephanie M
authors.initials: SM
authors.lastname: Dearmey
authors.forename: Christie
authors.initials: C
authors.lastname: Milleson
authors.forename: Kathryn B
authors.initials: KB
authors.lastname: Sheets
authors.forename: Deeksha S
authors.initials: DS
authors.lastname: Bali
authors.forename: Catherine W
authors.initials: CW
authors.lastname: Rehder
authors.forename: Julian A J
authors.initials: JA
authors.lastname: Raiman
authors.forename: Raymond A
authors.initials: RA
authors.lastname: Wang
authors.forename: Francois
authors.initials: F
authors.lastname: Labarthe
authors.forename: Joel
authors.initials: J
authors.lastname: Charrow
authors.forename: Paul
authors.initials: P
authors.lastname: Harmatz
authors.forename: Pranesh
authors.initials: P
authors.lastname: Chakraborty
authors.forename: Amy S
authors.initials: AS
authors.lastname: Rosenberg
authors.forename: Priya S
authors.initials: PS
authors.lastname: Kishnani
mesh_terms: D000465:Algorithms; D058846:Antibodies, Monoclonal, Murine-Derived / Q000494:pharmacology / Q000627:therapeutic use; D019411:Clinical Laboratory Techniques; D003429:Cross Reactions; D042241:Early Diagnosis; D056947:Enzyme Replacement Therapy / Q000009:adverse effects / Q000379:methods*; D005260:Female; D006009:Glycogen Storage Disease Type II / Q000175:diagnosis* / Q000188:drug therapy* / Q000276:immunology; D006801:Humans; D007136:Immunoglobulins / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D007165:Immunosuppression Therapy; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008727:Methotrexate / Q000494:pharmacology / Q000627:therapeutic use; D000069283:Rituximab; D012449:Safety; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; D007136:Immunoglobulins; D000069283:Rituximab; D008727:Methotrexate