OVERVIEW
A persistent peripheral blood leukocyte count of less than 3.5 x 109/L for various reasons is called leukopenia. Absolute peripheral blood neutrophil counts below 2 × 109/L in adults are called neutropenia. Neutrophils below 0.5 × 109/L is called granulocyte deficiency.
Etiology
The growth of neutrophils in the bone marrow can be divided into a stem cell pool, a dividing pool, and a storage pool. Mature neutrophils are mostly stored in the bone marrow and can be released into the blood at any time. After entering the blood, half of the neutrophils are attached to the walls of small blood vessels, called the marginal pool, and the other half are in the blood circulation, called the circulating pool, and the two are exchanged with each other. The half-life of neutrophils in the peripheral blood is short, 6 to 7 hours, and then they enter the tissues. Neutropenia has many causes and complex pathogenesis, and is clinically categorized into three groups:
1. Defective neutrophil generation
(1) Cytotoxic drugs, chemical poisons and radiation: the most common cause.
(2) Infection and abnormal immunity: some bacterial, viral, rickettsial or protozoal infections.
(3) Infiltration of abnormal cellular components of bone marrow: leukemia, lymphoma bone marrow invasion, metastatic cancer, etc.
(4) Bone marrow failure diseases: aplastic anemia, paroxysmal sleep hemoglobinuria, etc.
(5) Various congenital neutropenia: the specific mechanism is unknown.
(6) Neutrophil maturation disorders: folic acid, vitamin B12 deficiency, myelodysplastic syndromes, and so on.
2. Neutrophil destruction or excessive consumption
(1) Immune factors, various autoimmune diseases, certain infections such as chronic hepatitis.
(2) Non-immune factors Severe bacterial infection, sepsis, viral infection or hypersplenism.
3. Abnormal distribution of neutrophils
Certain allo-protein reactions, endotoxemia can cause neutrophils to shift to the marginal pool, and in splenomegaly, granulocytes are retained in the spleen.
Symptoms
Granulocytopenia can appear rapidly within hours or days (acute neutropenia) and can last for months or years (chronic neutropenia). Because granulocytopenia has no specific symptoms, it may not be recognized until after an infection has occurred. In acute granulocytopenia, patients may present with fever and pain (ulcers) in the mouth and perianal area. This may be followed by bacterial pneumonia and other serious infections. In chronic granulocytopenia, the condition may be mild if the granulocyte count is not too low.
Examination
1. White blood cell count < 4 x 109, white blood cell sorting count, neutrophils less than 50%. In acute granulocyte deficiency, the white blood cell count is <2×109, neutrophils are obviously reduced and lymphocytes are relatively increased.
2. Red blood cell and platelet counts are normal, bleeding and clotting times are normal.
3. Bone marrow image may be suppressed in the late stage. The bone marrow picture of acute granulocyte deficiency shows a marked reduction of the granulocyte system or maturation disorders.
Diagnosis
1. There is often a history of infection, exposure to physical and chemical substances, medication, and immunologic factors.
2. In the case of granulocyte deficiency, the onset of the disease is rapid, and symptoms of severe infection may be present.
3. Blood count: decrease in white blood cell count, decrease in neutrophils, relative increase in lymphocyte ratio. According to the degree of neutropenia, it can be divided into mild (≥1.0×109/L), moderate (0.5-1.0×109/L), and severe (<0.5×109/L).
(4) Bone marrow image: no specific changes.
Treatment
1. Treatment of etiology
Define the cause of the disease and actively treat the primary disease. If caused by drugs, stop using suspicious drugs such as antibiotics, antipyretics and painkillers.
2. Prevention of infection
Mild granulocytopenia, no special preventive measures, moderate reduction, the chance of infection increases, reduce access to public places, pay attention to skin, oral, respiratory hygiene, remove chronic foci of infection. Those with granulocyte deficiency, should take isolation measures to prevent cross-infection. For those with infection, culture of pathogenic bacteria is performed to clarify the site and type of infection. Before the causative organisms are clarified, broad-spectrum, high-efficiency and adequate antibiotic treatment should be used empirically, and attention should be paid to fungal infections.
3.Symptomatic and whitening treatment
Can apply shark liver alcohol, blood-saving, granulocyte deficiency, can be given to granulocyte colony-stimulating factor treatment.