Sinusoidit

Sinusoidit is an inflammation of the hepatic sinusoids, the small capillary-like vessels that run between liver cells. It is distinct from sinusitis, which describes inflammation of the nasal or paranasal sinuses. Sinusoidit can arise as part of broader hepatic injury or vascular conditions and may affect liver perfusion and function.

The hepatic sinusoids are lined by specialized endothelial cells and are integral to filtrating blood from the portal vein and hepatic artery. In sinusoidit, inflammation can cause endothelial injury, dilation or disruption of the sinusoidal lining, and accumulation of inflammatory cells. This can contribute to altered blood flow, congestion, and, in severe cases, portal hypertension or reduced liver function. It can occur in isolation or as a component of other liver diseases.

Causes of sinusoidit include drug-induced liver injury (notably certain chemotherapeutic agents and other hepatotoxic drugs), viral or autoimmune hepatitis, graft-versus-host disease, sepsis, and congestive heart failure. It may also be seen in the setting of sinusoidal obstruction syndrome (veno-occlusive disease), where obstruction of hepatic sinusoids worsens blood flow.

Clinical features are variable and may include right upper quadrant discomfort, hepatomegaly, mild jaundice, and signs of portal hypertension such as ascites in advanced cases. Laboratory findings often show elevated liver enzymes with possible cholestatic patterns.

Diagnosis relies on clinical context, laboratory testing, and imaging. Liver biopsy can reveal sinusoidal dilation, inflammatory cell infiltration within the sinusoids, and related vascular changes, helping distinguish sinusoidit from other hepatic conditions.

Treatment focuses on addressing the underlying cause, removing offending agents, and providing supportive liver care. Prognosis depends on the severity and reversibility of the underlying injury; in some cases, symptoms resolve with cessation of the offending factor, while others may progress to chronic liver disease. See also hepatic veno-occlusive disease and sinusoidal obstruction syndrome.