The following is the summary of “Intravenous Immunoglobulins Tapering and Withdrawal in Systemic Capillary Leak Syndrome (Clarkson Disease)” published in the November 2022 issue of Allergy and Clinical Immunology by Moyon, et al.

When a monoclonal gammopathy is present, systemic capillary leak syndrome (SCLS), called Clarkson disease, can cause potentially fatal episodes of vascular hyperpermeability. There is evidence that longer courses of intravenous immunoglobulin (IVIG) treatment are related to better outcomes, although these treatments’ optimal dosage and duration have yet to be discovered. Researchers hope to determine if reducing or stopping IVIG use is risk-free for SCLS patients.

In this retrospective multicenter analysis, researchers analyzed data from the EurêClark registry to identify all adult patients with SCLS caused by monoclonal gammopathy who had had at least one dose of IVIG. Overall survival, as measured by IVIG withdrawal, was the major endpoint. The average age of the 59 patients covered was 51±13 years. The cumulative probability of survival at 2-, 5-, 10-, and 15- years were correspondingly 100%, 85%, 72%, and 44%. 18 patients (31%) in the W+ group and 41 patients (69%) in the W- the group had their IVIG discontinued at some point. There was a statistically significant difference between the cumulative survival probability of the W+ and W- groups after 10 years: 50% for the former and 83% for the latter (log-rank test, P=.02). 

About 72% of the W+ group and 58% of the W- the group had relapsed, with the W+ group experiencing a median of 2.5 relapses (range: 0.3-4) and the W- group experiencing a median of 1 relapse (range: 0-2) (P=.03). Using a mixed linear model, researchers found no statistical evidence that IVIG tapering was related with higher attack rates per patient-year. In individuals with SCLS, discontinuing IVIG was linked to a greater risk of death and relapse. Patients with stable SCLS may want to gradually decrease their IVIG dose.