Hepatic veno-occlusive disease with immunodeficiency

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Overview

Hepatic veno-occlusive disease with immunodeficiency (VODI) is characterized by (1) primary immunodeficiency and (2) terminal hepatic lobular vascular occlusion and hepatic fibrosis manifest as hepatomegaly and/or hepatic failure. Onset is before age 12 months. The immunodeficiency comprises severe hypogammaglobulinemia, clinical evidence of T-cell immunodeficiency with normal numbers of circulating T cells, absent lymph node germinal centers, and absent tissue plasma cells. Bacterial and opportunistic infections including Pneumocystis jerovici infection, mucocutaneous candidiasis, and enteroviral or cytomegalovirus infections occur. VODI is associated with 90% mortality overall and 100% mortality if unrecognized and untreated with intravenous immunoglobulin (IVIG) and Pneumocystis jerovici prophylaxis. Hepatic veno-occlusive disease with immunodeficiency (also called VODI) is a hereditary disorder of the liver and immune system. Its signs and symptoms appear after the first few months of life.

Hepatic veno-occlusive disease is a condition that blocks (occludes) small veins in the liver, disrupting blood flow in this organ. This condition can lead to enlargement of the liver (hepatomegaly), a buildup of scar tissue (hepatic fibrosis), and liver failure.

Children with VODI are prone to recurrent infections caused by certain bacteria, viruses, and fungi. The organisms that cause infection in people with this disorder are described as opportunistic because they ordinarily do not cause illness in healthy people. These infections are usually serious and may be life-threatening. In most people with VODI, infections occur before hepatic veno-occlusive disease becomes evident.

Many people with VODI live only into childhood, although some affected individuals have lived to early adulthood.

Pathophysiology

Genetics

VODI results from mutations in the SP110 gene. This gene provides instructions for making a protein called SP110 nuclear body protein, which is involved in the normal function of the immune system. This protein likely helps regulate the activity of genes needed for the body's immune response to foreign invaders (such as viruses and bacteria).

Mutations in the SP110 gene prevent cells from making functional SP110 nuclear body protein, which impairs the immune system's ability to fight off infections. It is unclear how a lack of this protein affects blood flow in the liver.

Epidemiology and Demographics

VODI appears to be a rare disorder; approximately 20 affected families have been reported worldwide. Most people diagnosed with the condition have been of Lebanese ancestry. However, the disorder has also been identified in several individuals with other backgrounds in the United States and Italy.