Hemophagocytic lymphohistiocytosis (HLH)

For further information and help in relation to HLH please go to hrtrust.org - The Histiocytosis Research Trust
Please take a look at the Cavan Hoey Trust, set up by his grandafther Terry http://the-cavan-tommy-hoey-trust.org
Camerons Smile - a group on facebook set up by Anne Devenney in memory of her son Cameron. Cameron passed away after a brave battle with HLH in April 2008. Anne now raises awareness of this disease and funds for research into HLH.
CDC - Centres for disease control and prevention - information on HLH, click here
http://www.tcf.org.uk TCF is a charitable organisation of bereaved parents, siblings and grandparents dedicated to the support and care of other bereaved parents, siblings and grandparents who have suffered the death of a child/children.

Hemophagocytic lymphohistiocytosis (HLH) is a rare disorder of the immune system that mainly affects young babies and children. According to the HAA, HLH occurs in 1.2 in every 1,000,000 children under the age of 15 (if these figures are correct, approximately 15-20 children in the UK are affected per year). In rare cases it can affect adolescents and adults. Patients with HLH have an abnormally regulated immune system, and specific white blood cells, called macrophages, grow abnormally and accumulate in the body's organs, including the liver, spleen, bone marrow, central nervous system and skin.

There are two main types of HLH: primary and secondary. Primary HLH, also known as familial or relapsing HLH, is an inherited condition (FHL). Affected individuals may have an abnormality in a gene that is important in regulation of immune response; some of these gene defects are now known and can be detected.

A similar illness, called secondary Hemophagocytic syndrome (HLH or sHLH), may be triggered by certain types of infection, auto-immune diseases and/or by cancer. A macrphophage activation syndrome (MAS) develops as the result of the severe infection. The condition has also been described in immuno-compromised hosts in association with viral infections and the term, virus-(infection) associated hemophagocytic syndrome ,(VAHS, or IAHS) is also used, but most patients are not immuno-surpressed!

Secondary HLH can also be induced by bacteria, as well as rheumatoid conditions.

For a detailed explanation of FHL and sHLH, treatment plans, incidence of this disease, survival rates and causes, please read the HLH 2004- protocol
For a full description of HLH from the HIstiocytosis Association of America, please click here
Diagnosis and treatment click here