Treatment of myeloid leukemia: the hunt for the Philadelphia chromosome
Elizaveta Alekseeva, Independent Newspaper
Once this disease was called whiteblood: patients had a huge amount of white blood cells in their blood, and this meant an inevitable quick death. Now the forecast is not so hopeless at all. In recent decades, medicine has achieved impressive success in hematology. Methods of treatment have also been found for such a formidable type of white blood, or, in modern terms, leukemia, as chronic myeloid leukemia.
The cause of the disease has not been reliably clarified, but the mechanism of its development has been established: an abnormal, so-called Philadelphia chromosome appears in the body as a result of the fusion of normal 9th and 22nd chromosomes (it was discovered by scientists in Philadelphia), which prevents apoptosis ("self-destruction") of cells that have completed their life cycle. Pathological cells actively multiply and gradually displace normal hematopoietic cells.
When the mechanism of the disease was established, a search began in laboratories around the world for a remedy that would stop the increased production of damaged leukocytes by the bone marrow. Imatinib turned out to be such a remedy. The medicine created on its basis became a salvation for the sick. It became possible not only to radically prolong their lives, but also to fundamentally change the quality of this life and the forecast for the future. Hematologists believe that a new era has begun in their clinical practice, when they got their hands on such a powerful opportunity for targeted targeted drug therapy.
At the International Conference on Chronic Myeloid Leukemia held in Moscow, new methods of treating it were discussed, in particular in those patients who do not tolerate imatinib or in whom it is ineffective. In order to suppress the activity of pathological leukocytes, which is necessary to preserve the life of patients, they require the so-called second-line therapy. To do this, since 2007, nilotinib has been used – a substance that blocks the transmission of a signal from the Philadelphia chromosome, which causes the bone marrow to produce a huge number of damaged leukocytes.
Experts distinguish three stages of the effect. The first is the achievement of hematological remission, normalization of the blood test and the patient's condition (spleen size). But the Philadelphia chromosome remains in the cells. The second stage is the achievement of cytogenetic remission, when the Philadelphia chromosome will not be detected in cells. The third stage is when, as a result of exposure to thyroxine kinase inhibitors in the body, a pathological gene is not detected in the molecular study of blood cells, bone marrow.
"Leading hematology centers in Russia take part in all international studies," says Olga Vinogradova, PhD, Senior Researcher at the Hematology Research Center of the Russian Academy of Medical Sciences. – Modern drugs are included in the developed standards of treatment of patients. Receiving them, patients can lead a lifestyle of practically healthy people, work, raise children."
It is very important that therapy begins as early as possible. Unfortunately, often the disease is detected by accident, during the production of blood tests, when, for example, a person for some reason gets to the hospital. The time between diagnosis and the start of treatment should be as short as possible. Doctor of Medical Sciences Anna Turkina stressed that breaks in therapy are detrimental to patients. Drugs used in chronic myeloid leukemia are included in the program "Seven nosologies". Every patient is taken into account. Member of the Russian Academy of Medical Sciences, Professor Alexander Rumyantsev urged doctors to submit timely and full applications for medicines to the relevant regional structures of the Ministry of Health and Social Development in order to avoid or minimize interruptions in treatment.
Perhaps in the future, a remedy will be created that cures myeloid leukemia definitively, but in the meantime, therapy should continue for life.
Portal "Eternal youth" www.vechnayamolodost.ru22.10.2008