Korean J Pediatr.  2007 Oct;50(10):931-937. 10.3345/kjp.2007.50.10.931.

Hemolytic uremic syndrome

• Park HW

• KMID: 2279304
• DOI: http://doi.org/10.3345/kjp.2007.50.10.931

Abstract

The hemolytic uremic syndrome (HUS) is a rare disease of microangiopathic hemolytic anemia, low platelet count and renal impairment. HUS usually occurs in young children after hemorrhagic colitis by shigatoxin-producing enterohemorrhagic E. coli (D+HUS). HUS is the most common cause of acute renal failure in infants and young children, and is a substantial cause of acute mortality and morbidity; however, renal function recovers in most of them. About 10% of children with HUS do not reveal preceding diarrheal illness, and is referred to as D- HUS or atypical HUS. Atypical HUS comprises a heterogeneous group of thrombomicroangiopathy (TMA) triggered by non-enteric infection, virus, drug, malignancies, transplantation, and other underlying medical condition. Emerging data indicate dysregulation of alternative complement pathway in atypical HUS, and genetic analyses have identified mutations of several regulatory genes; i.e. the fluid phase complement regulator Factor H (CFH), the integral membrane regulator membrane cofactor protein (MCP; CD46) and the serine protease Factor I (IF). The uncontrolled activation of the complement alternative pathway results in the excessive consumption of C3. Plasma exchange or plasma infusion is recommended for treatment of, and has dropped the mortality rate. However, overall prognosis is poor, and many patients succumb to end- stage renal disease. Clinical presentations, response to plasma therapy, and outcome after renal transplantation are influenced by the genotype of the complement regulators. Thrombotic thrombocytopenic purpura (TTP), another type of TMA, occurs mainly in adults as an acquired disease accompanied by fever, neurologic deficits and renal abnormalities. However, less frequent cases of congenital or hereditary TTP associated with ADAMTS-13 (a disintegrin and metalloprotease, with thrombospondin 1-like domains 13) gene mutations have been reported, also. Recent advances in molecular genetics better allow various HUS to be distinguished on the basis of their pathogenesis. The genetic analysis of HUS is important in defining the underlying etiology, predicting the genotype-related outcome and optimizing the management of the patients.

Keyword

Hemolytic uremic syndrome; Shigatoxin-producing E. coli; Complement; Factor H; Thrombotic thrombocytopenic purpura; ADAMTS-13

MeSH Terms

Acute Kidney Injury
Adult
Anemia, Hemolytic
Antigens, CD46
Child
Colitis
Complement Factor H
Complement Pathway, Alternative
Complement System Proteins
Enterohemorrhagic Escherichia coli
Fever
Fibrinogen
Genes, Regulator
Genotype
Hemolytic-Uremic Syndrome*
Humans
Infant
Kidney Transplantation
Membranes
Molecular Biology
Mortality
Neurologic Manifestations
Plasma
Plasma Exchange
Platelet Count
Prognosis
Purpura, Thrombotic Thrombocytopenic
Rare Diseases
Serine Proteases
Thrombospondins
Antigens, CD46
Complement Factor H
Complement System Proteins
Fibrinogen
Serine Proteases
Thrombospondins