Low blood cell count

Blood cells are the most important cells in the human body. Their content in the human body is very high. The main function of blood cells is to help blood regeneration. Therefore, whether the total blood cell count is within the normal range has a great impact on people. When people find that the total blood cell value in the body is relatively low, it will have a significant impact on the regeneration of the blood, and it will easily cause symptoms such as aplastic anemia. It can be seen how serious the harm of low total blood cell count is.

Corresponding symptoms will appear within a short period of time, and very professional treatment is required to cure it. Try not to delay and seek treatment immediately.

Pancytopenia, also known as aplastic anemia (AA), is a pancytopenia syndrome caused by bone marrow hematopoietic failure. Cause of disease: About 50% to 75% of cases are idiopathic and have unknown causes, while secondary cases are mainly related to drugs and other chemical substances, infection and radiation. The following is a brief summary:

Drugs are the most common risk factor. There are two types of drug-induced aplastic anemia:

Pancytopenia is dose-related and is a drug toxicity effect. When a certain dose is reached, it will cause bone marrow suppression, which is generally reversible, such as various anti-tumor drugs. Cell cycle-specific drugs such as cytarabine and methotrexate mainly act on more mature pluripotent stem cells that are easy to divide. Therefore, when pancytopenia occurs, the bone marrow still retains a certain amount of pluripotent stem cells, and aplastic anemia can be recovered after drug withdrawal. Busulfan and nitrosoureas act not only on stem cells entering the proliferation cycle, but also on stem cells in the non-proliferation cycle, thus often leading to long-term bone marrow suppression that is difficult to recover from. In addition, phenytoin sodium, phenothiazines, thiouracil and chloramphenicol can also cause dose-related bone marrow suppression.

Only a few patients develop hematopoietic disorders, mostly due to allergic reactions to drugs, which often lead to persistent aplastic anemia. There are many types of drugs of this type, the most common ones are chloramphenicol, organic arsenic, atilapine, trimethoprim-sulfamethoxazole, phenylbutazone, gold preparations, aminopyrine, piroxicam (piroxicam), sulfonamides, thiamphenicol, carbimazole (carbimazole), methimazole (thimazole), chlorpropamide, etc. Drug-induced aplastic anemia is most commonly caused by chloramphenicol. According to a domestic survey, the risk of aplastic anemia in patients who took chloramphenicol within six months was 33 times that of the control group, and there was a dose-response relationship. Chloramphenicol can cause the above two types of drug-induced aplastic anemia. The chemical structure of chloramphenicol contains a nitrobenzene ring, and its bone marrow toxicity is related to nitroso-chloramphenicol. It can inhibit mitochondrial DNA polymerase in bone marrow cells, leading to reduced DNA and protein synthesis. It can also inhibit heme synthesis, and vacuoles and increased sideroblasts may appear in the erythroblasts. This inhibitory effect is reversible, and blood counts recover once the drug is discontinued.

Chloramphenicol can also cause allergic reactions that are not related to the dose. Bone marrow suppression often occurs weeks or months after taking chloramphenicol, or it may occur suddenly during treatment. The mechanism may be that it directly inhibits hematopoietic stem cells through autoimmunity or directly damages the chromosomes of stem cells. These effects are often irreversible, even if the drug is stopped. People with genetic defects in stem cells have increased sensitivity to chloramphenicol.

Chloramphenicol is a nitrobenzene compound with dichloroacetyl side chains. Chloramphenicol is closely related to the onset of aplastic anemia, with the actual risk being 1/20,000 to 1/30,000, which is 10 to 20 times higher than those who have not been exposed. Domestic multifactorial analysis research data show that the risk of developing aplastic anemia in patients who have a history of taking chloramphenicol (combination) within one year or six months before the onset of the disease is 6 times or 33 times that of the control group, respectively. Data from the American Medical Association's Adverse Drug Event Registry show that 50% of people develop symptoms within 38 days of using the drug.