Serum IgG levels as biomarkers for optimizing IVIg therapy in CIDP

Intravenous immunoglobulin (IVIg) is a proven effective treatment for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and Guillain-Barre syndrome (GBS). In GBS, patients show a large variability in serum immunoglobulin G (IgG) levels after standard IVIg treatment and a large increase in serum IgG levels (Delta IgG) was associated with a better outcome. Whether this is also the case in CIDP is not known. In contrast to GBS, most patients with CIDP need regular IVIg treatment for a prolonged period of time but the speed and magnitude of clinical response varies considerably between patients. Some patients with CIDP may need at least two IVIg courses before clinical signs of improvement become clear. At present, this clinical response is the only indicator used to adjust the IVIg dose and interval during maintenance treatment. Biomarkers reflecting disease activity or IVIg pharmacokinetics might be helpful to monitor patients and find the optimal dosage and frequency of IVIg treatment for individual patients. A recent prospective study in CIDP indicated that the increased Delta IgG after standard IVIg dosage during maintenance treatment was relatively constant within individual patients, but differed considerably between patients who were treated with the same stable dosage and interval of IVIg. Further studies are required to determine whether this variation in pharmacokinetics of IVIg is related with clinical recovery and whether IgG levels can be used as biomarkers to monitor and to adjust the optimal IVIg dosage in individual patients with CIDP

Protocol of a dose response trial of IV immunoglobulin in chronic inflammatory demyelinating polyradiculoneuropathy (DRIP study)

High peak levels of serum IgG may not be needed for maintenance treatment of CIDP with IVIg. More frequent dosing of IVIg leads to more stable IgG levels and higher trough levels which may be related with improved clinical efficacy. More frequent lower dosing leads to lower peak levels and may induce less systemic side-effects. The DRIP study is a double-blind randomized controlled cross-over intervention study. CIDP patients ≥ 18 years old, proven IVIg dependent and receiving an individually established but stable maintenance dose and interval of IVIg (Kiovig) can be included. One group (A) will be treated with their normal dosage and interval of IVIg and receive a placebo (albumin 0.5%) infusion in between their regular IVIg infusions, for a total of 4 infusions. The other group (B) will be treated with half their normal IVIg dosage (with the same volume of placebo to maintain the total volume) at half their interval (double their frequency) for 4 infusions. After a wash-out phase (2 infusions), patients will cross-over to the other treatment group. During the study the total dose of IVIg administered will remain unchanged as before start of the trial. The main objective is to investigate whether high frequent low dosage IVIg treatment is more effective than low frequent high dosage IVIg treatment as maintenance treatment for CIDP. Hand grip strength, as measured by the Martin Vigorimeter, will be used as the primary outcome measure. Secondary objective is to investigate whether high frequent low dosage of IVIg results in less adverse events compared to low frequent high dosage treatment. The DRIP study is currently ongoing and the protocol is presente

Health-related quality of life in Guillain-Barré syndrome patients: a systematic review

Guillain-Barre syndrome (GBS) encompasses a broad spectrum of health-related quality of life (HRQL) determinants, including mobility, fatigue, pain, and depression. We systematically reviewed the literature on functional outcome domains in which GBS patients experience limitations in the short and long terms and evaluated determinants of HRQL in GBS patients. MEDLINE and EMBASE were systematically searched by two independent reviewers for articles covering HRQL data of GBS patients. Of 730 abstracts screened, 17 articles covering data of 14 studies matched the selection criteria. The included articles showed that many GBS patients experienced physical limitations, even years after the acute phase of the disease, while results were inconsistent for perceived levels of pain, fatigue, and general mental well-being. Only three papers covered HRQL assessments at more than one time point, generally showing large improvements in HRQL in the first year after GBS onset, but not thereafter. We appraised the methodological quality of included studies using a 13-item checklist; none of the articles fulfilled all items and only seven articles presented data on correlations between HRQL and determinants. In conclusion, the majority of studies on HRQL in GBS patients are cross-sectional and of low methodological quality. This paper provides guidance for much needed high-quality studies on patterns of patient-perceived recovery after GBS onset