Long-Term Outcome for Patients with CIDP

By Michael Rubin, MD

Professor of Clinical Neurology, Weill Cornell Medical College

SYNOPSIS: In a careful meta-analysis of published series of treated patients with chronic inflammatory demyelinating polyneuropathy (CIDP), about one-half of patients achieved a good long-term remission with independent function and only about 8% were unable to walk independently.

SOURCE: Al-Zuhairy A, Jakobsen J. Outcome in chronic inflammatory demyelinating polyneuropathy: A systematic review and meta-analysis. Muscle Nerve 2023; Mar 16. doi: 10.1002/mus.27820. [Online ahead of print].

Chronic inflammatory demyelinating polyneuropathy (CIDP) may be treated with a panoply of immunosuppressive or immunomodulatory medications, as well as intravenous immunoglobulin (IVIG) and plasma exchange. The initial rate of response to treatment is approximately 65%, with up to 15% of patients remaining treatment-resistant. However, because of variations in methodology, patient populations, treatment strategies, follow-up length, and outcome severity, long-term outcome data remain limited. To address these shortcomings, a systematic literature review and meta-analysis were undertaken.

PubMed and EMBASE (OVID) searches were conducted using terms including CIDP, prognosis, outcome, disability, mortality, long-term, and follow-up, with citation lists then searched manually for articles not identified in the original database searches. Inclusion criteria required patients 18 years of age or older of any sex or ethnic group, followed for at least two years, with a diagnosis of CIDP based on criteria proposed by Dyck et al, the Ad Hoc Subcommittee, the European Neuro Muscular Centre (ENMC), and the European Federation of the Neurological Societies/Peripheral Nerve Society (EFNS/PNS). Excluded were reports with a high risk of bias, such as case reports, with fewer than 10 patients; reports of uncommon CIDP variants (pure motor or sensory CIDP, Lewis-Sumner disease); and patients with concomitant diabetes, paraproteinemia, or human immunodeficiency virus. Duplication of data was prevented by screening for studies overlapping in terms of study site and recruitment window, in which case the larger study sample was retained. Studies were appraised and rated for quality using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist for studies reporting prevalence data, with pooled analyses performed using a random intercept logistic regression model of the generalized linear mixed model, Clopper-Pearson 95% confidence intervals calculated for individual studies, and between-study heterogeneity addressed using the Higgins and Thompson I² statistic.

Among 1,290 study titles identified, 21 studies comprising 1,199 patients were selected for review, with 11 studies, comprising 62% of the pooled fraction, reporting that most patients had typical CIDP. The long-term CIDP pooled case fatality rate was 3.3%, including 37 CIDP-associated deaths, comprising 14 deaths caused by respiratory insufficiency or swallowing difficulties resulting from disease progression or relapse, two deaths caused by cerebral infarction, one death each from pneumonia or pulmonary embolism, and 19 deaths considered a complication of CIDP, with no further information provided. Based on six studies comprising 209 patients, the pooled remission rate was 40.8%, while nine studies, comprising 443 patients, indicated that a good outcome without disability was seen in 47.1% with long-term CIDP. Based on 15 reports comprising 708 patients, the pooled fraction of non-ambulatory patients was 8.2%. A good outcome without disability, as well as remission, was present in almost half the CIDP patients, indicating that a favorable long-term prognosis may be expected for many CIDP patients, warranting that clinical care strategies take this into consideration to avoid overtreatment.

COMMENTARY

Do treatment-related fluctuations of IVIG-treated CIDP patients negatively affect long-term prognosis? In a retrospective observational cohort study of 23 CIDP patients followed for a mean of 44.7 months, no difference in strength, disability, or IVIG use was found, regardless of whether patients experienced a low or high number of
treatment-related fluctuations. Drug-free remission was seen in one-third of both groups.

Treatment-related fluctuations do not predict poor prognosis or status of long-term disease activity. Periodic IVIG taper efforts in CIDP patients to determine if remission has been achieved or if ongoing therapy is warranted do not pose a risk of increasing disability.¹

REFERENCE

Cook M, Pasnoor M, Ajroud-Driss S, et al. CIDP prognosis in patients with IVIG treatment-related fluctuations. Muscle Nerve 2023;67:69-73.