Key messages
• Given as maintenance treatment (long-term treatment to keep symptoms under control) in people with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), subcutaneous immunoglobulin (SCIg) compared to placebo (dummy treatment) probably reduces the number of people who experience a worsening in disability. In addition, the average loss of grip strength and average worsening in disability score are probably lower among people receiving SCIg maintenance treatment compared with those receiving placebo. There is probably a higher risk of local side effects (affecting the injection site), but no difference in systemic side effects (affecting other parts of the body), in people treated with SCIg compared to those treated with placebo.
• We need more and better studies to investigate the benefits of SCIg given as induction treatment (short-term therapy) or maintenance treatment. In particular, there is a need for studies comparing SCIg maintenance treatment with other medicines, such as intravenous immunoglobulin (antibodies given through a vein).
What is chronic inflammatory demyelinating polyradiculoneuropathy (CIDP)?
CIDP is a rare disorder of the nerves that leads to gradually progressive sensory symptoms and weakness in arms and legs. CIDP is a disorder in which the body's own immune system presumably attacks the nerves (an autoimmune disease). If left untreated, people with CIDP can become severely disabled.
How is CIDP treated?
Treatment for CIDP can be divided into short-term (induction) treatment and long-term (maintenance) treatment. Most people with CIDP will require long-term treatment. The aim of induction treatment is to improve disability, whereas the goal of maintenance treatment is to keep the condition stable and prevent disability from worsening. One of the preferred treatments for both induction and maintenance treatment is intravenous immunoglobulins (IVIg). This treatment consists of purified antibodies collected from donated blood and given through a drip into a vein. Immunoglobulins can also be given by injection directly under the skin (subcutaneously). Unlike IVIg, subcutaneous immunoglobulin (SCIg) treatment does not require hospitalisation or an intravenous line.
What did we want to find out?
We wanted to know if SCIg induction treatment is better for increasing the probability of an improvement in disability, and if SCIg maintenance treatment is better for reducing the risk of worsening in disability, compared with placebo (dummy treatment) or other treatments (such as IVIg). We also wanted to know if SCIg treatment is better than placebo or other treatments for improving change in grip strength and change in disability score, and whether SCIg treatment has any side effects.
What did we do?
We searched for studies that evaluated SCIg as induction treatment or maintenance treatment compared with placebo or other treatments. We compared and summarised the results of the studies for both the induction and maintenance treatment groups, and rated our confidence in the evidence.
What did we find?
We found four studies that involved 360 people with CIDP. Most participants were men (62%), and the average age was 55 years. The studies involved people from all over the world. The smallest study involved 20 people and the largest 172. One study compared SCIg to IVIg as induction treatment. The other three compared SCIg with placebo as maintenance treatment. Studies lasted from 10 weeks to 26 weeks. All studies were partly or entirely funded by pharmaceutical companies.
Main results
We found no studies comparing SCIg to placebo as induction treatment.
The study comparing SCIg to IVIg provided very few data. There may be no difference in change in disability score after five weeks in people who receive SCIg induction treatment and those who receive IVIg induction treatment.
Compared with placebo, SCIg maintenance treatment probably reduces the number of people who experience a worsening in disability. In addition, the average loss of grip strength and average worsening in disability score are probably lower in people receiving SCIg maintenance treatment compared with those receiving placebo. SCIg maintenance treatment probably leads to more local side effects (affecting the injection site) than placebo treatment. There is probably no difference in systemic side effects (affecting other parts of the body) with SCIg maintenance treatment compared to placebo. Side effects were mostly mild in the studies, but some were more serious.
We found no studies comparing SCIg maintenance treatment to other treatments.
What are the limitations of the evidence?
In the induction treatment group, we have little confidence in the evidence because the study enroled few participants, and they were aware of the treatment they received. In the maintenance treatment group, we are only moderately confident in the evidence, because the number of included participants was relatively small.
How up to date is this evidence?
The evidence is up-to-date to July 2025.
閱讀完整摘要
Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a heterogeneous immune-mediated neuropathy that causes weakness and sensory deficits over the course of at least two months. Intravenous immunoglobulin (IVIg) is considered a first-line treatment in CIDP, both as induction and maintenance treatment. Subcutaneous immunoglobulin (SCIg) may present a viable alternative, offering potential advantages such as ease of use, participant preference, improved health-related quality of life, and cost-effectiveness, provided it is shown to be effective and safe.
目的
To assess the benefits and harms of subcutaneous immunoglobulin as induction and maintenance treatment in chronic inflammatory demyelinating polyradiculoneuropathy.
搜尋策略
We searched the Cochrane Neuromuscular Register, CENTRAL, MEDLINE, Embase, and two trials registries up to 21 July 2025. We also checked references, performed citation searching, and contacted study authors to identify additional studies.
選擇標準
We selected randomised controlled trials (RCTs) that compared SCIg with placebo or any other intervention in people with "probable" or "definite" CIDP, according to the European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) criteria.
資料收集與分析
We grouped participants based on treatment status (induction or maintenance treatment). Our primary outcome in the induction treatment group was improvement in disability (dichotomous), and our primary outcome in the maintenance treatment group was clinically significant deterioration in disability (dichotomous). Secondary outcomes included change in mean disability score, change in mean grip strength, and frequency of local and systemic adverse effects. For induction treatment, we were interested in measurements at six to 12 weeks (and also at 24 weeks for change in mean disability score), while for maintenance treatment, we were interested in measurements at 12 to 24 weeks.
Two review authors independently reviewed the literature searches, extracted data, assessed risk of bias using the Cochrane risk of bias tool RoB 1, and assessed the certainty of the evidence with GRADE. We contacted study authors where appropriate. We synthesised results using random-effects meta-analysis where possible, reporting mean differences (MDs) or standardised mean differences (SMDs) for continuous outcomes and risk ratios (RRs) for dichotomous outcomes, each with its 95% confidence interval (CI).
主要結果
Four RCTs with 360 randomised participants met our eligibility criteria. The mean age of participants was 55 (standard deviation (SD) 8.7) years, and 223 participants (62%) were men. Three studies (340 participants) had a parallel-group design and compared SCIg with placebo as maintenance treatment. One study (20 participants) had a cross-over design and compared SCIg with IVIg as induction treatment. The studies were conducted in different countries in North America, South America, and Europe, as well as Israel, Australia, and Japan. The study sites were neuromuscular clinics or general neurology departments. One study (172 participants) in the maintenance treatment group included a prestudy IVIg washout phase to determine IVIg dependency. It was the only study we rated at low risk of bias in all domains.
Induction treatment
We could not evaluate the difference between SCIg and IVIg as induction treatment in terms of rate of improvement in disability, change in grip strength, or frequency of local or systemic adverse effects, as these data were not available. SCIg compared with IVIg as induction treatment may result in little or no change in mean disability score within five weeks (MD 1.00% more improvement, 95% CI 20.94% more to 18.94% less; 1 study, 20 participants; low-certainty evidence).
We found no studies comparing SCIg to placebo for inclusion in this review.
Maintenance treatment
SCIg maintenance treatment probably reduces the risk of clinically significant deterioration in disability within 12 to 24 weeks compared to placebo (RR 0.40, 95% CI 0.28 to 0.56; 3 studies, 333 participants; moderate-certainty evidence). SCIg probably improves change in mean grip strength compared to placebo (MD 6.46 kilopascals (kPa) higher, 95% CI 2.73 higher to 10.20 higher; 2 studies, 304 participants; moderate-certainty evidence), with the CI including a clinically significant increase (8.0 kPa). SCIg probably improves change in mean disability score compared to placebo (SMD 0.65 lower, 95% CI 1.03 lower to 0.27 lower; 3 studies, 333 participants; moderate-certainty evidence). SCIg compared with placebo is probably associated with a higher risk of local adverse effects (RR 3.39, 95% CI 1.97 to 5.82; 3 studies, 333 participants; moderate-certainty evidence), but we found no difference in the risk of systemic adverse effects (RR 0.94, 95% CI 0.69 to 1.27; 3 studies, 333 participants; moderate-certainty evidence).
We found no studies comparing SCIg to other interventions for inclusion in this review.
作者結論
There is a lack of evidence on SCIg as induction treatment compared with placebo. It is unclear whether SCIg is effective as induction treatment compared to IVIg. RCTs comparing SCIg with placebo or other induction treatments are needed to provide evidence on its potential benefits.
SCIg maintenance treatment probably reduces deterioration in disability compared with placebo. SCIg probably improves mean grip strength and mean disability score compared with placebo, at the cost of a probable increase in the risk of local adverse effects and little to no difference in the risk of systemic adverse effects. Adverse effects were mostly local site reactions and were generally mild. We were unable to evaluate whether SCIg maintenance treatment is as beneficial as other maintenance treatments (such as IVIg). Future RCTs of this comparison should preferably enrol people with demonstrated active disease.
