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

Abstract

Background: Administration of intravenous immunoglobulins (IVIgs) is established for long-term treatment of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Prevention of secondary axonal loss going along with permanent clinical disability and muscular atrophy is a major aim in CIDP therapy. To assess long-term clinical efficacy of IVIg treatment despite heterogenous disease course and variable complaints reported by the patients, long-term electrophysiological monitoring was performed for systematic evaluation of therapeutic efficacy of IVIg.

Methods: A total of 21 patients with CIDP treated with IVIg 1 g/kg bodyweight every 3-6 weeks were examined electrophysiologically every 12 months over a period of 2 years.

Results: Assessment of clinical symptoms, using the Inflammatory Neuropathy Cause and Treatment (INCAT) and Hughes functional grading score (F-score) revealed improvement of motor and sensory symptoms over a period of 2 years. As electrophysiological results remained stable, IVIg treatment seems to be suitable to prevent axonal loss in CIDP.

Conclusions: This study confirms efficacy of IVIg as firstline therapy in CIDP. Doses and frequency of IVIg application should be adapted based on clinical evaluation and analysis of long-term electrophysiological findings.

Keywords: INCAT; chronic inflammatory demyelinating polyradiculoneuropathy; intravenous immunoglobulins; long-term treatment; nerve conduction study.

Figure 1.

Concomitant treatment at baseline and after two-years-treatment. Six patients had two or more substances for pre-treatment (A) which explains the n- number > 21. One patient had a rapid progression of disease and treatment was adjusted several times also using off-label therapies like fumarates. In the end, this patient died one year after observation period.

Figure 2.

Start of treatment after first symptoms. We analyzed the latency (in months) until IVIg were initially applied after first manifestation of disease. Based on this, patients were divided into three groups (initiation of IVIg treatment within one year (A), lately after 3.5 years (B) and ⩾ 3.5 years (C). INCAT for lower extremity (LE) was evaluated over time (baseline, after 12 months and 24 months).

Figure 3.

Clinical course. All patients (n=21) were examined at baseline and after 12 and 24 months. INCAT disability score was evaluated for the upper extremity. Scale range is from 0 (=no upper limp problems/ walking not affected) to 5 (inability to use either arm for any purposeful movement/restricted to wheelchair). In our cohort the most affected patients had a score of 4. Patients also underwent Hughes functional grading score (n=21); LE, lower extremity; UE, upper extremity.

Figure 4.

Electrophysiological data. Median (A,C), tibial (B) and sural nerve (D) were analyzed at three time points: baseline, follow-ups after 12 months and after 24 months. Number of values differs indicated by (n=) in each bar as some patients reject single measurements; CMAP, compound motor action potential; DML, distal motor latency; mCV, motor conduction velocity; SNAP, sensory nerve action potential; sCV, sensory conduction velocity.