- Autoimmune neutropenia (AIN):
Autoimmune neutropenia is most common among infants and young children. This form occurs when the body identifies the neutrophils as enemies and produces antibodies to destroy them. This type usually becomes less severe within about two years.
- AIN is further classified as either primary or secondary. In primary AIN, neutropenia is the only abnormality. In secondary AIN, other pathologies occur, including systemic autoimmune disease, infections and malignancy. Secondary AIN is extremely rare in infants.
- Congenital neutropenia: Congenital neutropenia (neutropenia at birth) is a rare form of the disease, which is usually discovered soon after birth. Individuals with this disease may experience premature loss of teeth and subsequent gum infections.
- The most severe form of chronic congenital neutropenia, known as Kostmann's syndrome, is genetically heterogeneous. In most cases, an autosomal dominant mutation in the ELA2 gene causes the disease.
- The gene responsible for many cases of the autosomal recessively inherited congenital neutropenia is HAX1. In this case, both parents have to be carriers of the recessive trait in order for the child to have congenital neutropenia. If both parents are carriers, there is a 25% chance that the child will have the disorder.
- Some evidence suggests that mutations in neutrophils' elastase or in other genes linked to the syndromic forms of neutropenia disrupt its intracellular trafficking. The mutations may also initiate the unfolded protein response.
- Other evidence suggests that there is an increase in apoptosis (cell death) of neutrophil precursors. However, these findings are controversial because some of the scientific data was falsified and retracted from publication.
- Cyclic neutropenia: Cyclic neutropenia usually occurs every three weeks and lasts for about three to six days at a time. This form is frequently present among several members of the same family. In almost all cases, cyclic neutropenia is the result of autosomal dominantly inherited mutations in ELA2 gene, which encodes neutrophils' elastase.
- Drug-induced: Many different types of drugs can cause neutropenia and agranulocytosis. Researchers estimate that about 75% of all cases of agranulocytosis in the United States are related to medication. Anti-neoplastic drugs suppress the bone marrow's production of neutrophils, which may lead to the disorder. Other drugs like clozapine, procainamide and anti-thyroid medications (like methimazole and sulfasalazine) can lead to the destruction of white blood cells. About 6-10% of drug-induced agranulocytosis cases are fatal.
- Idiopathic neutropenia: Neutropenia is considered idiopathic when the disorder cannot be attributed to any other disease or condition. This form is rare, and it often causes life-threatening infections in both children and adults.
- Mild neutropenia: When an individual's ANC is greater than 1,000, but lower than 1,500, the condition is considered mild. Individuals with mild neutropenia have a slight risk of developing infections.
- Moderate neutropenia: When an individual's ANC is greater than 500, but less than 1,000, the condition is considered moderate. Individuals have a moderate risk of developing infections.
- Severe neutropenia (Kostmann's syndrome): When an individual's ANC is less than 500, the condition is considered severe. Individuals with severe neutropenia have a serious risk of developing infections, especially in the lungs, kidneys, blood and skin because these organs are exposed to the most bacteria. If this condition is accompanied by a fever, it is known as febrile neutropenia. Severe cases of neutropenia may result in agranulocytosis, which is the complete loss of neutrophils.
Copyright © 2011 Natural Standard (www.naturalstandard.com)
The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.