Classification and general characteristics
Colony-stimulating factors are classified into a specific group of immunotropic drugs. Their key pharmacological target is hemopoiesis (the process of blood formation). It is important to understand that agents of this group do not have a direct effect on antibody production, phagocytosis (as a primary action of the entire group), or the complement system. Their main task is the regulation of the cellular composition of the blood.
Acting as hematopoietic growth factors, they stimulate bone marrow activity. In clinical practice, three main representatives are used: filgrastim, lenograstim, and molgramostim.
Filgrastim — the baseline representative of G-CSF
Filgrastim is an analogue of granulocyte colony-stimulating factor (G-CSF). Chemically, it is a non-glycosylated protein.
The drug is produced using modern genetic engineering methods as a recombinant drug. The production technology involves introducing a plasmid containing the human gene into the genetic material of the bacterium E. coli. As a result of this intervention, the bacterium begins to independently produce human G-CSF.
Pharmacodynamics:
- Regulates neutrophil production directly in the bone marrow.
- Stimulates the release of functionally active neutrophils from the bone marrow into the peripheral blood.
Indications for use: The drug is prescribed for the treatment of neutropenia, a pathological decrease in neutrophil count. Such clinical situations most frequently arise after bone marrow transplantation or aggressive chemotherapy courses, when it is urgently necessary to restore suppressed hematopoiesis.
Contraindications: Pregnancy, lactation (breastfeeding), and leukemias. In leukemias, the drug is dangerous due to the high risk of stimulating the growth of myeloid malignant cells.
Lenograstim and its features
Lenograstim also belongs to the G-CSF group; however, in terms of its chemical nature, it is a recombinant human glycosylated granulocyte colony-stimulating factor.
Its mechanism of action is similar to filgrastim: it specifically stimulates bone marrow activity, accelerates the maturation of neutrophils specifically (rather than lymphocytes, eosinophils, or monocytes) and their release into the systemic circulation. As a result of using lenograstim, the absolute neutrophil count in the peripheral blood reliably increases.
Clinical application, including all indications and strict contraindications, completely corresponds to that of filgrastim.
Molgramostim — a broad-spectrum drug (GM-CSF)
Unlike the previous agents, molgramostim is a recombinant analogue of human granulocyte-macrophage colony-stimulating factor (GM-CSF).
Its pharmacodynamics is more extensive and includes three main directions:
- Regulation of hemopoiesis: the drug potently stimulates the proliferation (reproduction) and differentiation of progenitor cells.
- Effect on mature cells: affects the growth and function not only of granulocytes, but also of macrophages and eosinophils.
- Functional activation: significantly enhances phagocytosis, oxidative metabolism, and leukocyte cytotoxicity. Due to this, blood cells are able to fight threats more effectively, including exhibiting cytotoxicity against malignant cells.
Application: Molgramostim is indicated for the treatment and prevention of leukopenia, accelerating the recovery of myeloid hematopoiesis, and preventing severe infectious complications arising against the background of leukopenia.
Contraindications: Like other CSFs, it is contraindicated in leukemias due to the risk of stimulating malignant cells, as well as during lactation.
Briefly: answers to topical questions
What side effects are characteristic of filgrastim?
Characteristic side effects of filgrastim include:
- Bone and muscle pain — a specific effect of bone marrow stimulation.
- Dysuria.
- Transient arterial hypotension.
To avoid confusing the drugs, pay attention to their suffixes: "-grastim" (granulocyte-stimulating) and "-gramostim" (granulocyte-macrophage-stimulating). Filgrastim and lenograstim act only on granulocytes (G-CSF), while molgramostim acts on both granulocytes and macrophages (GM-CSF).
Class and exam questions
What is the difference between filgrastim and lenograstim?
Both drugs are G-CSF analogues and have identical indications. The main difference lies in their chemical structure: filgrastim is a non-glycosylated protein, while lenograstim is glycosylated.
Which cells does molgramostim act on?
Unlike G-CSF, molgramostim affects the growth and function of several cell pools simultaneously: granulocytes, macrophages, and eosinophils. In addition, it enhances their phagocytosis, oxidative metabolism, and cytotoxicity.
Why are CSFs strictly contraindicated in leukemias?
These drugs are potent growth factors for myeloid cells. In leukemias, they can trigger rapid growth of both healthy and malignant cells, worsening the course of the disease.
In which clinical situations is filgrastim most commonly prescribed?
The main indication is the treatment of neutropenia. Most often, the drug is required to restore normal hematopoiesis after aggressive courses of chemotherapy or after bone marrow transplantation.
What else to study on this topic
- Structural features of glycosylated and non-glycosylated recombinant proteins.
- Mechanisms of leukocyte functional activation (oxidative metabolism, phagocytosis).
- The process of introducing a plasmid with a human gene into E. coli bacteria.
- Differences between myeloid and lymphoid hematopoiesis.
- Prevention of infectious complications in severe leukopenia.
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