Science News: An Approach to Assessing Immunoglobulin Dependence in Chronic Inflammatory Demyelinating Inflammatory Polyneuropathy

Submitted by: Francisco Gomez, MD
Edited by: Niranjan Singh, MD

Kapoor M, Compton L, Rossor A, et al. An approach to assessing immunoglobulin dependence in chronic inflammatory demyelinating inflammatory polyneuropathy. J Peripher Nerv Syst. 2021;26(4): 461- 468. doi:10.1111/jns.12470

Summary: Chronic inflammatory demyelinating polyneuropathy (CIDP) is a peripheral nerve disease coursing with weakness and impaired sensation. The course tends to be relapsing-remitting or progressive if left untreated. While there is evidence to support treatment with IVIg, plasma exchange, or steroid therapy and consensus on how to identify and monitor patients needing a protracted treatment course, data on when and how to stop therapy and identify remission is lacking.
 
The consensus is that CIDP patients necessitate close monitoring via validated tools, of which there are several: minimum clinically important differences (MCID) for Inflammatory Rasch-built Overall Disability Scale (I-RODS), Medical Research Council Sum Score (MRC-SS), Inflammatory Neuropathy Cause and Treatment (INCAT), sensory sum score, Overall Neuropathy Limitation Score (ONLS), hand dynamometry, I-RODS, 10-m walk, up and go 10 m walk, and Berg Balance scale.
 
Overall in the study’s cohort, patients who were deemed IVIg dependent were younger at age of onset (43.4 vs 50.6 years) had a 1 year longer delay in diagnosis, and had been on the treatment longer (6.8y vs 4.8y).
 
Herein, the authors sought to elucidate IVIg treatment cessation strategies in CIDP. They included 33 CIDP patients, 16 underwent cessation and 17 gradual dose reduction. There were 12 out of 33 patients with CIDP who went off IVIg remained stable for more than 2 years without treatment, while the remaining required reinstitution of IVIg with rapid return to baseline. Outcomes and IVIg dependency were determined via MRC-SS and I-RODs scores.
 
Comments: This is a small but important study looking to determine disease activity while on IVIg with optimal control. It appears the only way to know would be discontinuation of IVIg. The study did not find predictors of disease activity. Since IVIg is expensive with side effects, studies will help to stop unnecessary treatment.
 
This paper suggests there is clinical difference in degree of recrudescence or relapse rates in IVIg cessation vs tapering, which may be helpful to the readership when selecting a course of action.
 
Article of Similar Interest:
England NHS. Updated Commissioning Guidance for the use of therapeutic immunoglobulin (Ig) in immunology, haematology, neurology and infectious diseases in England. December 2019.