Quantifying Treatment-Related Fluctuations in CIDP: Results of the GRIPPER Study

Jeffrey A. Allen, Mamatha Pasnoor, Mazen M. Dimachkie, Senda Ajroud-Driss, Thomas H. Brannagan, Albert A. Cook, Timothy Walton, Mark B. Fiecas, John T. Kissel, Ingemar Merkies, Kenneth C. Gorson, Richard A. Lewis

Research output: Contribution to journalArticlepeer-review

11 Scopus citations


OBJECTIVE: The objective of this study was to explore the extent of IV immunoglobulin (IVIG) treatment-related fluctuations (TRFs) by using home collection of daily grip strength in patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and to use that information to develop evidence-based treatment optimization strategies. METHODS: This prospective observational study included 25 patients with well-defined CIDP. Participants recorded grip strength daily for 6 months. Disability and gait metrics were collected weekly. Serum immunoglobulin G levels were obtained at peak, trough, and midcycle IVIG intervals. Day-to-day grip strength changes <10% were considered random. To identify patients with TRFs, 3-day averaged grip strength was calculated on each consecutive day after an IVIG infusion. TRFs were defined as ≥10% 3-day averaged grip strength difference compared to the pre-IVIG baseline. RESULTS: Participants successfully recorded grip strength on all but 9% of recordable days. Twelve patients (48%) were classified as low/no fluctuaters and 13 (52%) as frequent fluctuaters. In the frequent fluctuating group, grip strength improved over 1 week and thereafter was relatively stable until the third week after infusion. Grip strength was significantly correlated with measures of disability. CONCLUSIONS: Grip strength collection by patients at home is reliable, valid, and feasible. A change in grip strength by ≥10% is a useful, practical, and evidence-based approach that may be used to identify clinically meaningful TRFs. From these data, we propose a treatment optimization strategy for patients with CIDP on chronic IVIG that may be applied to routine clinic care during both face-to-face and virtual video or telephone patient encounters. TRIAL REGISTRATION INFORMATION: ClinicalTrials.gov Identifier: NCT02414490.

Original languageEnglish (US)
Pages (from-to)e1876-e1886
Issue number14
StatePublished - Apr 6 2021

Bibliographical note

Publisher Copyright:
© 2021 American Academy of Neurology.


  • Adult
  • Aged
  • Disability Evaluation
  • Female
  • Hand Strength
  • Humans
  • Immunoglobulins, Intravenous/therapeutic use
  • Male
  • Middle Aged
  • Patient Reported Outcome Measures
  • Polyradiculoneuropathy, Chronic Inflammatory Demyelinating/drug therapy
  • Recovery of Function
  • Young Adult

PubMed: MeSH publication types

  • Research Support, Non-U.S. Gov't
  • Observational Study
  • Journal Article


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