Chediak-Higashi syndrome is a rare autosomal recessive defect of the immune system that usually develops symptoms after birth. Children affected by this syndrome are particularly vulnerable to infections caused by Gram-positive bacteria, Gram-negative bacteria and fungi. The prognosis is poor - most patients die before the age of 10.
Chediak-Higashi syndromedevelops against the background of immunodeficiency, which is associated with the presence of mutations in the CHS1 (or LYST1) gene coding for the CHS protein in patients. It has been shown that this protein, found in the cytoplasm of many different cells, can interfere with the intracellular transport of proteins. The effect of disturbing this transport is incorrect synthesis and storage of secretory granules of various types of cells. This is especially true of leukocyte and fibroblast lysosomes, dense blood platelets, neutrophil eosinophilic granules or melanosomes of melanocytes.
Chediak-Higashi syndrome: symptoms
Chediak-Higashi syndrome is characterized by a very serious course. This is due to the presence of recurrent purulent infections as a result of neutropenia or the so-called "lymphoma-like syndrome". Viral infections, especially infection with the Epstein-Barr virus, contribute to the development of this phase. In the "lymphoma-like syndrome", abnormal white blood cells divide uncontrollably and invade many organs, causing them to become dysfunctional. Characteristic are fever, periods of excessive bleeding resulting in anemia, pancytopenia and associated infections that are extremely difficult to control. These infections most often affect the respiratory system and the skin and are especially caused by bacteria such asStaphylococcus aureus(golden staph),Streptococcus pyogenesandPneumococcus species . The defect of melanosome melanization is manifested by the presence of oculocutaneous albinism in patients.
In addition, Chediak-Higashi syndrome sufferers may complain of a tendency to bruise, hypersensitivity to sunlight, photophobia, lymphadenopathy, liver enlargement and spleen enlargement, as well as oral mucositis and periodontitis. Peripheral progressive disease may occur in older patientsneuropathy, both axonal and demyelinating.
It is very important that patients with Chediak-Higashi syndrome have been shown to be more prone to neoplasms originating from the reticuloendothelial system.
Chediak-Higashi syndrome: diagnosis
The diagnosis of Chediak-Higashi syndrome is conditioned by finding giant, granular inclusions in the cytoplasm of peripheral blood neutrophils. This is done by staining by the Wright method. Additionally, one can notice a slow movement of these cells caused by the presence of the above-mentioned granules.
It is also possible to demonstrate decreased neutrophil chemotaxis and NK (Natural Killers) lymphocyte activity as well as low levels of lysosomal enzymes. You can also check the presence of a mutation in the CHS1 (LYST1) gene.
It's good to know that Chediak-Higashi syndrome can be diagnosed prenatally. For this purpose, hair samples are taken from the fetal scalp by biopsy or leukocytes are tested from a sample of its blood.
Chediak-Higashi syndrome: treatment
Treatment includes the use of appropriately selected antibiotics in the event of an infection and blood or platelet transfusion during periods of anemia. Vitamin C can be administered prophylactically. Bone marrow stem cell transplantation has proven successful in only a few patients worldwide.