Two years' long-term follow up in chronic inflammatory demyelinating polyradiculoneuropathy: efficacy of intravenous immunoglobulin treatment

Outcome in chronic inflammatory demyelinating polyneuropathy: A systematic review and meta-analysis

INTRODUCTION/AIMS

Outcomes in chronic inflammatory demyelinating polyneuropathy (CIDP) have been reported in longitudinal and cross-sectional studies. A considerable variation in long-term disease outcome has appeared in those reports. To overcome this uncertainty, a systematic review and meta-analysis was conducted on CIDP outcomes, including the parameters of case fatality rate, ambulation, physical ability, and remission.

METHODS

In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic search was conducted in PubMed and EMBASE (OVID) for reports with at least 2 years of follow-up on patients with active or previously active CIDP that were published no later than May 12, 2022. Studies were appraised for quality using the Joanna Briggs Institute Critical Appraisal Checklist for studies reporting prevalence data. Pooled analyses were conducted and the results were visualized using forest plots. The study protocol was registered prospectively on PROSPERO (CRD42021266903).

RESULTS

A total of 1290 titles were identified. Sixty-nine full-text articles were screened and 21 studies with 1199 patients were selected for the data analysis. The pooled case fatality rate was 3.3% (95% confidence interval [CI], 1.9% to 5.7%). The pooled fraction of nonambulatory patients was 8.2% (95% CI, 5.7% to 11.6%) and, overall, 47.1% (95% CI, 39.5% to 54.9%) of CIDP patients had a good outcome without disability. The pooled rate of remission was 40.8% (95% CI, 30.6% to 51.8%).

DISCUSSION

Future research is warranted on how to prevent long-term impairment in CIDP. Care should be taken in developing clinical strategies to avoid immunomodulating therapy in the many patients in remission.

Fatigue, depression, and product tolerability during long-term treatment with intravenous immunoglobulin (Gamunex® 10%) in patients with chronic inflammatory demyelinating polyneuropathy

INTRODUCTION/AIMS

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is characterized by progressive weakness and sensory loss, often affecting patient's ability to walk and perform activities of daily living independently. Furthermore, patients often report fatigue and depression which can affect their quality of life. These symptoms were assessed in CIDP patients receiving long-term intravenous immunoglobulin (IVIG) treatment.

METHODS

GAMEDIS was a multi-center, prospective, non-interventional study in adult CIDP patients treated with IVIG (10%) and followed for two years. Inflammatory Neuropathy Cause and Treatment (INCAT) disability score, Hughes Disability Scale (HDS), Fatigue Severity Scale (FSS), Beck Depression Inventory II (BDI), Short Form-36 health survey (SF-36) and Work Productivity and Activity Impairment Score Attributable to General Health (WPAI-GH) were assessed at baseline and quarterly. Dosing and treatment intervals, changes in outcome parameters, and adverse events (AEs) were analyzed.

RESULTS

148 evaluable patients were followed for a mean of 83.3 weeks. The mean maintenance IVIG dose was 0.9 g/kg/cycle (mean cycle interval 38 days). Disability and fatigue remained stable throughout the study. Mean INCAT score: 2.4 ± 1.8 at baseline and 2.5 ± 1.9 at study end. HDS: 74.3% healthy/minor symptoms at baseline and 71.6% at study end. Mean FSS: 4.2 ± 1.6 at baseline and 4.1 ± 1.7 at study end. All patients reported minimal/no depression at baseline and throughout. SF-36 and WPAI-GH scores remained stable. Fifteen patients (9.5%) experienced potentially treatment-related AEs. There were no AEs in 99.3% of infusions.

DISCUSSION

Long-term treatment of CIDP patients with IVIG 10% in real-world conditions maintained clinical stability on fatigue and depression over 96 weeks. This treatment was well-tolerated and safe.

Posturography as a biomarker of intravenous immunoglobulin efficacy in chronic inflammatory demyelinating polyradiculoneuropathy

INTRODUCTION/AIMS

Imbalance is a common feature of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Intravenous immunoglobulin (IVIg) exerts clinical benefit in CIDP, including improving balance, although objective markers of efficacy are lacking. Posturography is an established objective marker of balance; therefore, this study aimed to determine the utility of posturography as an objective marker of treatment efficacy in CIDP.

METHODS

Posturography was performed on 18 CIDP patients, established on IVIg infusions, and results were compared to age-matched healthy controls. CIDP patients were assessed just prior to IVIg infusion and at the mid-point of the cycle. Center of pressure (CoP) was measured and the total path traveled by CoP (Sway Path, SP) was calculated for five different conditions: feet placed in parallel 16 cm apart at the medial border with eyes open (16cmEO) and eyes closed (16cmEC); medial borders of the feet touching with eyes open (0cmEO) and eyes closed (0cmEC); and tandem stance.

RESULTS

The sway path (SP) was significantly increased in CIDP patients (mean SP 1191 ± 104 mm) when compared to healthy controls (mean SP 724 ± 26 mm, P < .001). The increase was most prominent during eyes closed and tandem stance conditions. Treatment with IVIg significantly reduced SP when assessing 0cmEC (1759 ± 324 mm vs. 1081 ± 134 mm, P = .019) and tandem stance (1775 ± 290 mm vs. 1152 ± 113 mm, P = .027).

DISCUSSION

Posturography detected significant improvements in balance following IVIg in CIDP patients established on maintenance therapy. As such, posturography may be considered an objective marker of treatment response in clinical management and therapeutic trials.

Corneal inflammatory cell infiltration predicts disease activity in chronic inflammatory demyelinating polyneuropathy

The assessment of disease activity is fundamental in the management of chronic inflammatory demyelinating polyneuropathy (CIDP). Previous studies with small patient numbers found an increase of corneal immune cell infiltrates as a potential marker of inflammation in patients with CIDP. However, its clinical relevance remained unclear. The present study aimed to determine whether the amount of corneal inflammatory cells (CIC) measured by corneal confocal microscopy (CCM) detects disease activity in CIDP. CIC were measured in 142 CCM-investigations of 97 CIDP-patients. Data on clinical disease activity, disability (INCAT-ODSS) and need for therapy escalation at the timepoint of CCM, 3 and 6 months later were analyzed depending CIC-count. Pathological spontaneous activity during electromyography was examined as another possible biomarker for disease activity in comparison to CIC-count. An increased CIC-count at baseline was found in patients with clinical disease activity and disability progression in the following 3-6 months. An increase to more than 25 CIC/mm² had a sensitivity of 0.73 and a specificity of 0.71 to detect clinical disease activity and a sensitivity of 0.77 and a specificity of 0.64 to detect disability progression (increasing INCAT-ODSS) in the following 6 months. An increase to more than 50 CIC/mm² had a sensitivity of about 0.51 and a specificity of 0.91 to detect clinical disease activity and a sensitivity of 0.53 and a specificity of 0.80 to detect disability progression. CIC count is a non-invasive biomarker for the detection of disease activity in the following 6 months in CIDP.

Individualizing Therapy in CIDP: A Mini-Review Comparing the Pharmacokinetics of Ig With SCIg and IVIg

Immunoglobulin (Ig) therapy is a first-line treatment for CIDP, which can be administered intravenously (IVIg) or subcutaneously (SCIg) and is often required long term. The differences between these modes of administration and how they can affect dosing strategies and treatment optimization need to be understood. In general, the efficacy of IVIg and SCIg appear comparable in CIDP, but SCIg may offer some safety and quality of life advantages to some patients. The differences in pharmacokinetic (PK) profile and infusion regimens account for many of the differences between IVIg and SCIg. IVIg is administered as a large bolus every 3–4 weeks resulting in cyclic fluctuations in Ig concentration that have been linked to systemic adverse events (AEs) (potentially caused by high Ig levels) and end of dose “wear-off” effects (potentially caused by low Ig concentration). SCIg is administered as a smaller weekly, or twice weekly, volume resulting in near steady-state Ig levels that have been linked to continuously maintained function and reduced systemic AEs, but an increase in local reactions at the infusion site. The reduced frequency of systemic AEs observed with SCIg is likely related to the avoidance of high Ig concentrations. Some small studies in immune-mediated neuropathies have focused on serum Ig data to evaluate its potential use as a biomarker to aid clinical decision-making. Analyzing dose data may help understand how establishing and monitoring patients' Ig concentration could aid dose optimization and the transition from IVIg to SCIg therapy.

Longer-term effects of intravenous immunoglobulin treatment in chronic inflammatory demyelinating polyneuropathy: Who benefits?

Intravenous immunoglobulins (IVIg) represent an established cornerstone for the immunotherapy of chronic inflammatory demyelinating polyneuropathy (CIDP). Efficacy of IVIg for CIDP was proven in a large phase III trial. Yet, data on longer-term efficacy and effects in distinct subgroups are scarce. Our trial investigates the long-term efficacy of IVIg treatment in CIDP patients. In this observational real-world study, we retrospectively analyzed 49 CIDP patients receiving continuous IVIg treatment with a mean initial dosage of 87 g (1 g/kg body weight) every 4 weeks over a mean time of 45 months between 2010 and 2018. INCAT-Scores before the start of treatment and at the end of the observation period were compared. Over the observation period, IVIg treatment led to a median improvement of one INCAT score point. Subgroup analyses revealed a more pronounced improvement of INCAT scores in female CIDP patients, individuals with relapsing disease courses, patients with more pronounced motor impairment (higher initial INCAT scores) and in the cohort without need for concomitant other immunotherapies. These data argue for sustained beneficial effects of longer-term immunotherapy with IVIg in CIDP, particularly in females and relapsing disease forms with higher disease activity.

Measuring disease activity and predicting response to intravenous immunoglobulin in chronic inflammatory demyelinating polyneuropathy

Chronic inflammatory demyelinating polyneuropathy (CIDP) is characterised by significant clinical heterogeneity and as such reliable biomarkers are required to measure disease activity and assess treatment response. Recent advances in our understanding of disease pathogenesis and the discovery of novel serum-based, electrophysiologic and imaging biomarkers allow clinicians to make more informed decisions regarding individualised treatment regimes.

As a chronic immune-mediated process typified by relapse following withdrawal of immunomodulatory therapy, a substantial proportion of patients with CIDP require long term treatment with intravenous immunoglobulin (IVIg), a scarce and expensive donor-derived resource. The required duration and intensity of immunoglobulin treatment vary widely between individuals, highlighting both the heterogeneous nature of the underlying disease process as well as the variable pharmacologic properties of IVIg.

This review outlines the use of multimodal biomarkers in the longitudinal evaluation of nerve injury and how recent developments have impacted our ability to predict both response to immunoglobulin administration and its withdrawal.

Clinical, Sonographic, and Electrophysiologic Longitudinal Features of Chronic Inflammatory Demyelinating Polyneuropathy

BACKGROUND AND PURPOSE

Several studies have aimed to find potential biomarkers to simplify the diagnosis of chronic inflammatory demyelinating polyneuropathy (CIDP) and to monitor and predict the disease course. However, reliable markers are still lacking. We aimed to investigate whether high-resolution nerve ultrasound (HRUS) is suitable for monitoring the long-term clinical course of CIDP.

METHODS

Twenty patients fulfilling the definite diagnostic criteria of CIDP received clinical examination, evaluation of the INCAT (inflammatory neuropathy cause and treatment) overall disability sum score (ODSS) as well as nerve conduction studies, and HRUS every 6 months over a median follow-up time of 34 months. Patients were divided into clinically stable/regressive disease course or progressive disease course according to the development of the ODSS.

RESULTS

The intranerve cross-sectional-area (CSA) variability of the nerves of the lower extremity increased with disease progression, whereas it remained unchanged in patients with a stable or remitting disease course.

CONCLUSION

Nerve ultrasound can be used as a method to objectify the long-term disease course in CIDP patients. The intranerve CSA variability is suitable for monitoring the clinical course of patients with CIDP.