Systemic capillary leak syndrome and autoimmune diseases: A case series.

Objectives: Systemic capillary leak syndrome (Clarkson's disease) is a rare entity characterized by recurrent and unpredictable attacks of capillary leakage of plasma fluid and proteins throughout the endothelium. Some cases are secondary. We describe the rare association between secondary capillary leak syndrome (SCLS) and autoimmune diseases.

Methods: We conducted a nationwide, retrospective, observational, and collaborative study throughout the hospital units of the Club des Rhumatismes et Inflammations network (CRI) between March and August 2015. Inclusion criteria were patients with (1) capillary leakage episodes characterized by edema and elevated hematocrit, low albumin count without proteinuria, or other cause of protein loss; and (2) definite autoimmune diseases according to international classification criteria.

Results: The clinical and biological data of five patients (three women) were reviewed. Median age was 43.2 (17-55) years. Four patients had Sjögren syndrome. One of them also fulfilled the criteria for systemic sclerosis (n = 1). The fifth patient had polymyositis. During the 37.2 months of median follow-up (5.4-201), we recorded a total of 24 attacks, yielding an attack incidence of 91/100 patient-years. Laboratory tests revealed that three patients had anti-SSA/Ro antibodies. Only one patient had a monoclonal blood component (IgGκ). Three patients needed ICU support; one died during a flare.

Conclusions: We reported the first case series of a rare association of SCLS and autoimmune diseases, supporting the idea of some immune mediation in the pathogenesis of the former disease.