Treatment Benefit for Chronic Inflammatory Demyelinating Polyneuropathy Observed With Intravenous Immunoglobulin, Corticosteroids

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP, also called chronic inflammatory demyelinating polyneuropathy) is an immune-mediated polyneuropathy involving nerve roots and peripheral nerve inflammation and characterized by segmental demyelination and remyelination. Typical clinical presentation includes symmetric, motor-predominant weakness and sensory impairment, primarily affecting vibration and position sense often more than pain or temperature sense along with areflexia.¹

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CIDP may have atypical variants and can be monophasic, relapsing, or progressive. Symptoms must persist for at least 8 weeks before establishing a diagnosis. CIDP variants differ from typical CIDP due to different immunopathogeneses and treatment responses.¹

Supportive laboratory features for individuals who do not meet theEuropean Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) demyelinative nerve conduction criteria include albuminocytologic dissociation in spinal fluid, enlarged proximal nerve segments or ultrasound (US) nerve root or plexus hypertrophy, increased signal intensity, contrast enhancement on magnetic resonance imaging (MRI), or histologic features of demyelination on nerve biopsy.²

A group of investigators at the University of Rochester Medical Center (URMC), evaluated treatment response in individuals with laboratory features supportive of CIDP. Their study had two aims. First, the focus was on individuals who did not meet the EFNS/PNS demyelinative nerve conduction criteria. Second, they wanted to determine whether any pre-treatment laboratory supportive characteristics were associated with a positive treatment response.²

The researchers selected all patients with presumed CIDP through an electronic medical database search at URMC from October 1995 to October 2021. They screened these patients to identify a sub-group of individuals with clinical features of CIDP without evidence of demyelination on nerve conduction studies (NCS). Study inclusion criteria requirements for patients included the following²:

• Had chronic polyneuropathy progression over at least 2 months consistent with typical or variant CIDP clinically;
• Had evaluation at URMC before treatment;
• Had evidence of polyneuropathy on NCS but did not meet EFNS demyelinative criteria;
• Had one or more supportive laboratory features for CIDP;
• Received treatment with intravenous immunoglobulin (IVIg), corticosteroids, or plasma exchange (PLEX); and
• Received follow up for at least 6 months after treatment.

Exclusion criteria requirements included the following²:

• Evidence of hereditary or other acquired neuropathies; and
• Inability to determine Rankin or Medical Research Council (MRC) outcome measures on chart review.

The investigators collected data at baseline pre-treatment and then post-treatment at 3 months, 6 months, 1 year, and each year thereafter until their last follow-up visit. They defined a positive treatment response as a one-or-more point improvement on the modified Rankin scale (mRS), or a 4-or-more point improvement in the MRC sum score (MRCSS).²

The researchers evaluated and treated 232 patients for presumed CIDP from 1995 to 2021. Eventually, 20 patients satisfied all study criteria. The supportive laboratory features for CIDP among these patients included the following: 94% (17/18) with cerebrospinal fluid (CSF) protein > 45 mg/dL, 43% (6/14) with MRI lumbosacral root or plexus enhancement, and 67% (4/6) with enlarged proximal nerves on US.²

Patients received the following therapies: IVIg (18 patients), corticosteroids (10), PLEX (1), and other immunomodulatory agents (6). The investigators observed a positive treatment response on the MRCSS or mRS for 12 patients. They noted the presence of MRI lumbosacral root or plexus enhancement correlated with a positive treatment response.²

Immunomodulatory therapies, such as IVIG, can make an impact in limiting underdiagnosis of and delays in treatment for CIDP that can lead to the accumulation of disabling effects. Of the 12 patients that had a positive treatment response on either scale, 11 of them were treated with IVIG, offering potential in treatment with this therapy.²

The authors concluded that patients with clinical features of CIDP without NCS evidence of demyelination, especially in the presence of MRI lumbosacral root or plexus enhancement, require consideration for a trial of immunomodulating therapy.² IVIG could be an ideal therapy in that category for further research.

REFERENCES

1. Gogia B, Rocha Cabrero F, Khan Suheb MZ, et al. Chronic Inflammatory Demyelinating Polyradiculoneuropathy. In: StatPearls. Treasure Island (FL): StatPearls Publishing; March 4, 2024.

2. Curry P, Herrmann DN, Stanton M, et al. Treatment response in patients with clinical and supportive laboratory features of chronic inflammatory demyelinating polyneuropathy without demyelinative findings on nerve conduction studies: A retrospective study. Muscle Nerve. Published online July 3, 2024. doi:10.1002/mus.28198