Molecular Classification
Other
Other Names
Systemic capillary leak syndrome, Vascular leak syndrome, Clarkson disease
Disease Roles
InflammationInfectionCardiovascular disease (due to hypotension and shock)

Capillary leak syndrome Overview

Capillary leakage is not a single molecule or receptor but rather a pathophysiological process characterized by the escape of plasma from small blood vessels into surrounding tissues. This leads to symptoms such as rapid drop in blood pressure, swelling, thickened blood, hypoalbuminemia, and potentially life-threatening complications like organ failure and pulmonary edema. The most well-known clinical entity is systemic capillary leak syndrome (SCLS), also called Clarkson disease. SCLS can be idiopathic or secondary to triggers such as sepsis, autoimmune diseases, viral infections including COVID‑19, certain medications like interleukins or chemotherapy agents. The underlying mechanism involves transient increases in vascular permeability due to dysfunction of the endothelial barrier—possibly mediated by inflammatory cytokines and factors like VEGF and angiopoietin‑2—but no specific molecular target has been identified. Treatment focuses on supportive care during acute episodes; some patients benefit from prophylactic use of beta agonists or phosphodiesterase inhibitors. Capillary leakage itself is not considered a therapeutic target but rather an endpoint resulting from upstream molecular events; thus it does not fit standard definitions for drug targets such as receptors or enzymes[1][3][4][5].

Mechanism of Action

For preventive/treatment drugs: - Beta agonists increase endothelial barrier function. - Phosphodiesterase inhibitors stabilize endothelium. - Leukotriene receptor antagonists reduce inflammation-mediated permeability[5]. For causative drugs/agents: - Chemotherapy agents and monoclonal antibodies may disrupt endothelial integrity.

Biological Functions

Other (specifically, pathological increase in vascular permeability)

Disease Associations

Inflammation
Infection
Cardiovascular disease (due to hypotension and shock)
Other (multi-organ dysfunction, kidney failure, etc.)

Safety Considerations

  • Rapid onset of shock and organ failure if untreated
  • Risk of pulmonary edema during fluid resorption phase
  • High mortality risk without prompt intervention

Interacting Drugs

Terbutaline
Theophylline
Montelukast sodium
Gemcitabine
Tagraxofusp/Elzonris

Associated Biomarkers

Biomarker
Monoclonal “M” protein in blood (>50% of primary cases)
Hypoalbuminemia during episodes
Hemoconcentration during episodes