Is subcutaneous immunoglobulin (injection of antibodies into the fatty tissue under the skin) effective and safe for people with chronic inflammatory demyelinating polyradiculoneuropathy (a long-term autoimmune condition causing nerve damage and weakne...
• 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).
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 resultsWe 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.