Neuroimaging findings in infantile Pompe patients treated with enzyme replacement therapy

BackgroundRecombinant human acid α-glucosidase (rhGAA) enzyme replacement therapy (ERT) has prolonged survival in infantile Pompe disease (IPD), but has unmasked central nervous system (CNS) changes.MethodsBrain imaging, consisting of computed tomography (CT) and/or magnetic resonance imaging (MRI), was performed on 23 patients with IPD (17 CRIM-positive, 6 CRIM-negative) aged 2-38months. Most patients had baseline neuroimaging performed prior to the initiation of ERT. Follow-up neuroimaging was performed in eight.ResultsSixteen patients (70%) had neuroimaging abnormalities consisting of ventricular enlargement (VE) and/or extra-axial cerebrospinal fluid accumulation (EACSF) at baseline, with delayed myelination in two. Follow-up neuroimaging (n=8) after 6-153months showed marked improvement, with normalization of VE and EACSF in seven patients. Two of three patients imaged after age 10years demonstrated white matter changes, with one noted to have a basilar artery aneurysm.ConclusionsMild abnormalities on brain imaging in untreated or newly treated patients with IPD tend to resolve with time, in conjunction with ERT. However, white matter changes are emerging as seen in Patients 1 and 3 which included abnormal periventricular white matter changes with subtle signal abnormalities in the basal ganglia and minimal, symmetric signal abnormalities involving the deep frontoparietal cerebral white matter, respectively. The role of neuroimaging as part of the clinical evaluation of IPD needs to be considered to assess for white matter changes and cerebral aneurysms

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.

ObjectiveAlthough 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.MethodsWe 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.ResultsSeven 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.ConclusionsThe 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

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.

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

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

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

Representative Western gel blot showing CRIM negative status of four patients (lanes 3–6).

<p>Lane 1- protein magic marker; lane 8 -CRIM negative control cell line; lane 10 - normal human fibroblast (NHF) control; Lanes 2, 7 and 9 - left empty. 20 ug of skin fibroblast cell protein extract was loaded for each patient lane and 2.5 ug protein was loaded for NHF. Western blot was probed with anti-GAA antibody and ß-Actin was used as a protein loading control.</p

ITI treatment regimen which includes rituximab, methotrexate and intravenous immunoglobulin (IVIG).

<p>This short course of ITI regimen (5 weeks) needs to be started together with the first dose of ERT. IVIG is administered on a monthly basis for a period of 5–6 months.</p

Clinical parameters.

<p>Clinical parameters.</p

An algorithm for the management of cross-reactive immunologic material (CRIM)-negative (CN) infantile Pompe disease patients.

<p>^*Institutional review board (IRB) approved study (NCT01665326; <a href="http://www.clinicaltrials.gov" target="_blank">www.clinicaltrials.gov</a>) for rapid determination of CRIM status and long-term follow-up of response to treatment and ITI in Pompe disease. ^†CN status determination from an established CRIM negative mutation database, which allows prediction of CN status in more than 90% cases <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0067052#pone.0067052-Bali1" target="_blank">[15]</a>. ^‡ITI regimen is shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0067052#pone-0067052-g002" target="_blank">Figure 2</a>. ^§Based on the literature antibody titers sustained at ≥6,400 results in a suboptimal therapeutic response to ERT. For that reason, 6,400 was used a cutoff for further intervention <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0067052#pone.0067052-Banugaria1" target="_blank">[9]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0067052#pone.0067052-Abbott1" target="_blank">[19]</a>. **Based on the half-life of rituximab, CD19% recovery is typically noted around 5 months. ^††The decision to repeat the same ITI regimen (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0067052#pone-0067052-g003" target="_blank">figure 3</a>) or to administer ITI with a plasma-cell-targeting agent <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0067052#pone.0067052-Banugaria4" target="_blank">[20]</a> should be based on multiple factors including, but not limited to, patients clinical status, CD19% and Fc_γ receptor polymorphism. ^‡‡ITI regimen with plasma cell targeting agent such as bortezomib has been described previously <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0067052#pone.0067052-Banugaria4" target="_blank">[20]</a>.</p