Evaluation of Responsiveness to Reduced-Dose Rituximab in Corticotropin/Intravenous Immunoglobulin/Rituximab Combination Immunotherapy for Opsoclonus-Myoclonus Syndrome.

Abstract

BACKGROUND:

Rituximab (anti-CD20) has been used as B-cell-targeted intervention to treat opsoclonus-myoclonus syndrome. Due to isolated reports of chronic hypogammaglobulinemia and B lymphopenia following rituximab in several disorders, and rapid B-cell depletion after a few doses, we reduced the dosage 20% in our clinical practice.

METHODS:

In this Institutional Review Board-approved retrospective study, 32 children with opsoclonus-myoclonus syndrome and cerebrospinal fluid B-cell expansion had received front-loaded adrenocorticotropic hormone, intravenous immunoglobulin, and rituximab combination immunotherapy for de novo opsoclonus-myoclonus syndrome. Parametric statistical analysis compared 10 children receiving 1200 mg/m2 of rituximab (300 mg/m2 × 4) and 22 receiving 1500 mg/m2 (375 mg/m2 × 4). Clinical response had been video documented and scored by a blinded observer.

RESULTS:

In both groups, motor severity (total score) lessened by ≥76% and cerebrospinal fluid B cells were similarly depleted (≥95%) six months after treatment. None of the treated patients remained unable to walk independently. Serum IgM depletion was analogous in the 1200 mg/m2 (-73%) and 1500 mg/m2 group (-64%). The relapse frequency was similar in both groups. Side effects were principally steroidal, tolerable, and transient. Circulating B-cell repopulation was comparable.

CONCLUSIONS:

The reduced-dose of rituximab in rituximab combination immunotherapy was as effective and well tolerated as the standard dose, and provided rapid, early therapeutic intervention in opsoclonus-myoclonus syndrome. Pending a long-term prospective study, these are proof-of-concept data in support of challenging the dose of rituximab in various disorders, which may have different dose requirements.

• Authors: Michael R Pranzatelli, Elizabeth D Tate, Nathan R McGee, Craig A MacArthur
• Journal: Pediatric neurology (Pediatr Neurol) Vol. 85 Pg. 71-75 (08 2018) ISSN: 1873-5150 [Electronic] United States
• PMID: 30197220 (Publication Type: Journal Article, Observational Study)
• Copyright: Copyright © 2018 Elsevier Inc. All rights reserved.

Chemical References

• Immunoglobulins, Intravenous
• Immunologic Factors
• Rituximab
• Adrenocorticotropic Hormone

Topics

• Adrenocorticotropic Hormone (administration & dosage)
• Child, Preschool
• Female
• Humans
• Immunoglobulins, Intravenous (administration & dosage)
• Immunologic Factors (administration & dosage)
• Immunotherapy (methods)
• Inflammation (therapy)
• Lymphopenia (therapy)
• Male
• Opsoclonus-Myoclonus Syndrome (therapy)
• Proof of Concept Study
• Retrospective Studies
• Rituximab (administration & dosage)
• Treatment Outcome