Neutropenia corresponds to the decrease in the amount of neutrophils, which are the blood cells responsible for fighting infections. Ideally, the amount of neutrophils should be between 1500 and 8000 / mm³, however, due to changes in the bone marrow or in the maturation process of these cells, the amount of circulating neutrophils may decrease, characterizing neutropenia.
According to the amount of neutrophils found, neutropenia can be classified according to its severity into:
- Mild neutropenia, in which neutrophils are between 1000 and 1500 / µL; Moderate neutropenia, in which neutrophils are between 500 to 1000 / µL; Severe neutropenia, in which neutrophils are less than 500 / µL, which can favor the proliferation of fungi and bacteria that live naturally in the body, resulting in infection;
The smaller the amount of circulating neutrophils, the greater the person's susceptibility to infections. It is important that neutropenia is carefully evaluated, as the result may have been influenced by problems at the time of collection, sample storage or changes in the equipment where the analysis is performed, for example. Therefore, it is recommended that the total neutrophil count be evaluated to see if, in fact, there is a neutropenia.
In addition, when the number of red blood cells and platelets is normal and the number of neutrophils is low, it is recommended that repeated blood counts be performed to confirm neutropenia.
Causes of neutropenia
The decrease in the amount of neutrophils may be due to insufficient production or changes in the maturation process of neutrophils in the bone marrow or due to the higher rate of destruction of neutrophils in the blood. Thus, the main causes of neutropenia are:
- Megaloblastic anemia; Aplastic anemia; Leukemia; Enlarged spleen; Cirrhosis; Systemic lupus erythematosus; Paroxysmal nocturnal hemoglobinuria; Viral infections, mainly by the Epstein-Barr virus and the hepatitis virus; Infection by bacteria, especially when there is tuberculosis and septicemia.
In addition, neutropenia can happen as a consequence of treatment with some drugs, such as Aminopyrine, Propiltiouracil and Penicillin, for example, or due to vitamin B12 or folic acid deficiency, for example.
Learn more about neutrophils.
Cyclic neutropenia
Cyclic neutropenia corresponds to an autosomal dominant genetic disease characterized by decreased levels of neutrophils in cycles, that is, every 21 days, most of the time, there is a decrease in the amount of circulating neutrophils.
This disease is rare and happens due to a mutation in a gene on chromosome 19 that is responsible for the production of an enzyme, elastase, in neutrophils. In the absence of this enzyme, neutrophils are more frequently destroyed.
Febrile neutropenia
Febrile neutropenia occurs when there is a small amount of neutrophils, usually less than 500 / µL, favoring the occurrence of infections and leading to an increase in body temperature, usually above 38ºC.
Therefore, treatment for febrile neutropenia involves taking fever-lowering drugs, antibiotics orally or through the vein, according to what the doctor tells you to control the infection and injections with neutrophil growth factors, to fight neutropenia. In addition, it may also be necessary to add a second antimicrobial to the treatment if the patient continues to have a fever after 5 days of starting treatment.
