Myelofibrosis

Myelofibrosis is a chronic disease caused by a disruption of the normal process of hematopoiesis in the bone marrow, which is characterized by the replacement of hematopoietic tissue with fibrous tissue. This leads to a decrease in the production of all types of formed elements of the blood, which is most often manifested by anemia, thrombocytopenia and leukopenia. This disease can be primary, occurring as an independent pathology, or secondary, developing against the background of other diseases, such as chronic myeloproliferative processes. The key aspect of myelofibrosis is the excessive formation of connective tissue, which significantly reduces the functional capacity of the bone marrow and can lead to various complications, including an enlarged spleen and liver, as well as increased vulnerability to infectious diseases.

History of the disease and interesting historical facts

The first mention of myelofibrosis dates back to the 19th century, when it was established that this disease is associated with a disorder of hematopoiesis. In the 1930s, scientists began to distinguish myelofibrosis as an independent nosological unit. For decades, researchers have tried to understand the pathogenesis of the disease and its relationship with other myeloproliferative disorders. In 2005, a link was identified between myelofibrosis and a mutation in the JAK2 gene, which significantly affected the diagnosis and treatment of this pathology. Also, in recent years, new therapeutic strategies have been developed aimed at improving the quality of life of patients and slowing the progression of the disease.

Epidemiology

Myelofibrosis is a relatively rare disease, but its prevalence increases with age. According to one large study, the incidence of myelofibrosis is approximately 0.5–1 case per 100,000 people per year. The disease is most often diagnosed in people over 50 years of age, while its incidence is significantly lower in young people. In addition, differences in the incidence of the disease in men and women have been established, which can be explained by both genetic and hormonal factors.

Genetic predisposition to this disease

It has now been established that myelofibrosis can develop in patients with certain genetic mutations. The main ones are mutations in the JAK2 gene (in approximately 50-60% patients), as well as mutations in the CALR and MPL genes. These mutations lead to activation of signaling in cells, which contributes to the proliferation of myeloid precursors and, as a consequence, to bone marrow fibrosis. In addition, some patients have chromosomal abnormalities, in particular, deletions of chromosomes 5 and 7, which may also indicate a more unfavorable prognosis.

Risk factors for the development of this disease

There are several factors that can contribute to the development of myelofibrosis, among them are:

• Age: Incidence increases with age.
• Gender: Men are affected more often than women.
• Family history: presence of myeloproliferative diseases in close relatives.
• Exposure to chemicals such as benzene may increase the risk of developing.
• Pre-existing blood disorders such as polycythemia vera or essential thrombocythemia.

Diagnosis of this disease

Diagnosis of myelofibrosis is based on a comprehensive approach, including the following methods:

• Main symptoms: fatigue, weakness, enlarged spleen and liver, night sweats.
• Laboratory tests: complete blood count, which shows anemia and thrombocytopenia, as well as biochemical tests.
• Radiological examinations: ultrasound and CT of the abdominal organs to assess the size of the spleen and liver.
• Other types of diagnostics: bone marrow puncture followed by histological examination.
• Differential diagnosis: Other causes of splenomegaly, such as lymphomas or infectious diseases, must be excluded.

Treatment

Myelofibrosis therapy involves a multidisciplinary approach:

• General treatment: supportive therapy, including blood transfusions in case of severe anemia.
• Pharmacological treatment: use of JAK2 inhibitors such as rojosiquiba to reduce symptoms and slow disease progression.
• Surgical treatment: if the spleen is very large, surgical removal may be possible.
• Other treatments: experimental therapy and participation in clinical trials.

List of medications used to treat this disease

The main groups of drugs used in the treatment of myelofibrosis:

• JAK2 inhibitors (rohosikib, fanganib).
• Immunomodulators (eg, thalidomide).
• Medicines that improve hematopoiesis (erythropoietin).
• Antibiotics and antifungal drugs to prevent infections.

Disease monitoring

Monitoring of patients with myelofibrosis includes:

• Regular blood tests to assess hemoglobin and platelet levels.
• Assessment of the size of the spleen and liver using ultrasound.
• Prognosis: moderate to poor, depending on the patient's mutational profile.
• Complications: infection, thrombosis, risk of developing leukemia.

Age-related features of the disease

Myelofibrosis manifests itself differently depending on the patient's age:

• In older patients, the disease may progress more aggressively, with severe symptoms.
• In young people, the disease often has a more favorable course and less pronounced clinical manifestations.
• In childhood, myelofibrosis is extremely rare, but requires a special approach to treatment.

Questions and Answers

• What is myelofibrosis? Myelofibrosis is a chronic disease associated with impaired hematopoiesis in the bone marrow, manifested by tissue fibrosis and impaired blood cell production.
• What are the symptoms of myelofibrosis? Systemic weakness, anemia, enlarged spleen and liver, night sweats and suspicious palpable tumors.
• How is myelofibrosis diagnosed? Diagnosis includes blood tests, ultrasound of organs, bone marrow puncture and genetic tests for mutations.
• What are the main treatments for myelofibrosis? Treatment includes supportive care, JAK2 inhibitors, and surgery if needed.
• What is the outlook and prognosis for patients with myelofibrosis? The outlook is highly dependent on the individual mutation profile, but the average survival is reduced compared to the general population.