When HLH patients are initially being worked up for a diagnosis, they often hear from their doctors to hope for leukemia because it has a higher survival rate of 80-90% while HLH has a survival rate of 30-50% at best..... this is why research is important... because of all the leukemia research they have improved the survival rate significantly because of new treatments etc. One day we hope the same for HLH.
What is HLH?
HLH stands for Hemophagocytic Lymphohistiocytosis and is a life-threatening immunodeficiency. It affects people of all ages and ethnic groups. Common symptoms are fevers, enlarged spleen, low blood counts and liver abnormalities. At least half of the patients with HLH will also experience inflammation of the brain which can lead to a wide variety of neurological problems.
HLH has traditionally been divided into genetic forms (Familial HLH or FHLH) or acquired forms which may be associated with infections, autoimmune conditions or cancer. HLH patients have overactive histiocytes and lymphocytes, which are white blood cells that normally control infections, but when overactivated can cause swelling, redness, heat, pain and malfunction/damage of organs when they attack and accumulate in healthy lymph tissue (ed: Liver, Spleen, Lymph Nodes). To date, 7 genetic causes of FHLH have been discovered, accounting for 60% of childhood HLH cases in the U.S.A. FHLH can be inherited in either an autosomal recessive manner (where both parents are carriers) or in an x-linked manner affecting only males. HLH is considered rare, but specific incidence is unknown.
The symptoms of HLH result from an overactive and poorly controlled immune response involving T lymphocytes and macrophages. This abnormally intense immune response results in prolonged and highly elevated levels of cytokines (molecules which, in minute quantities, normally regulate immune functions). This so-called "hypercytokinemia" is potentially damaging to all the major vital organs. The hallmark of hypercytokinemia is Hemophagocytosis, the process for which the disorder is named. Hemophagocytosis is an abnormal consumption of blood cells by macrophages which are turned on by the high cytokine levels, resulting in the low blood counts.
While some patients experience HLH symptoms which can wax and wane or respond well to steroids initially, many patients suffer from progressive illness which can lead to death if appropriate immune suppressive treatment is not begun in time. Ultimately, children and young adults who have HLH on the basis of known genetic defects will require a hematopoietic cells transplant (BMT) to cure them. Patients without a known genetic cause who experience progressive HLH or recurrent episodes are also considered for BMT. At present, with the more widespread use of Reduced Intensity Conditioning (RIC) protocols accompanied by careful selection of donor and stem cell product to be used - long term survival rates after HCT have improved from 50-70% up to 90% in experienced HCT centers.
HLH is not a cancer. Over the years cancer treatments have been used in patients with HLH. Consequently, Hematologists and Oncologists who treat cancer also treat children with HLH.
Because the disease is relatively new from a research perspective (1985) and causes as well as symptoms are still being discovered, many cases go undiscovered (or too late) and lead to fatality for the patient. It is important to catch the illness early.
The Doctors at Cincinnati Children's Hospital treat more cases of HLH each year than any other pediatric hospital in North America. Dr. Lisa Filipovich leads a collaborative team of doctors, researchers, nurse managers and social workers who support the diagnosis and clinical care for HLH patients at Cincinnati Children’s.
HLH has traditionally been divided into genetic forms (Familial HLH or FHLH) or acquired forms which may be associated with infections, autoimmune conditions or cancer. HLH patients have overactive histiocytes and lymphocytes, which are white blood cells that normally control infections, but when overactivated can cause swelling, redness, heat, pain and malfunction/damage of organs when they attack and accumulate in healthy lymph tissue (ed: Liver, Spleen, Lymph Nodes). To date, 7 genetic causes of FHLH have been discovered, accounting for 60% of childhood HLH cases in the U.S.A. FHLH can be inherited in either an autosomal recessive manner (where both parents are carriers) or in an x-linked manner affecting only males. HLH is considered rare, but specific incidence is unknown.
The symptoms of HLH result from an overactive and poorly controlled immune response involving T lymphocytes and macrophages. This abnormally intense immune response results in prolonged and highly elevated levels of cytokines (molecules which, in minute quantities, normally regulate immune functions). This so-called "hypercytokinemia" is potentially damaging to all the major vital organs. The hallmark of hypercytokinemia is Hemophagocytosis, the process for which the disorder is named. Hemophagocytosis is an abnormal consumption of blood cells by macrophages which are turned on by the high cytokine levels, resulting in the low blood counts.
While some patients experience HLH symptoms which can wax and wane or respond well to steroids initially, many patients suffer from progressive illness which can lead to death if appropriate immune suppressive treatment is not begun in time. Ultimately, children and young adults who have HLH on the basis of known genetic defects will require a hematopoietic cells transplant (BMT) to cure them. Patients without a known genetic cause who experience progressive HLH or recurrent episodes are also considered for BMT. At present, with the more widespread use of Reduced Intensity Conditioning (RIC) protocols accompanied by careful selection of donor and stem cell product to be used - long term survival rates after HCT have improved from 50-70% up to 90% in experienced HCT centers.
HLH is not a cancer. Over the years cancer treatments have been used in patients with HLH. Consequently, Hematologists and Oncologists who treat cancer also treat children with HLH.
Because the disease is relatively new from a research perspective (1985) and causes as well as symptoms are still being discovered, many cases go undiscovered (or too late) and lead to fatality for the patient. It is important to catch the illness early.
The Doctors at Cincinnati Children's Hospital treat more cases of HLH each year than any other pediatric hospital in North America. Dr. Lisa Filipovich leads a collaborative team of doctors, researchers, nurse managers and social workers who support the diagnosis and clinical care for HLH patients at Cincinnati Children’s.