Scientists have found that some treatments for cancer and sickle cell disease can destroy the germ cells, which are transformed into sperm in males. Some children prepubertal treatment of sickle cell disease leads to complete destruction of the germ cells, spermatogonia.
The study, published in the journal Human Reproduction, describes the effect of the treatment on the number of spermatogonial cells.
The researchers concluded that the removal and freezing testicular tissue for fertility preservation should be carried out before the boys will take a course of chemotherapy, which uses high-dose "alkylating agents". This would allow them to restore fertility to achieve adulthood. Before puberty, boys can not produce sperm samples, which can freeze and store until such time as the patients do not want to start a family. Transplantation of testicular tissue after treatment - one of the possible ways to restore fertility, but at the moment how the generation of sperm preserved tissues are experimental and still did not result in pregnancy.
Under the leadership of Dr. Jan-Bernd Shtukenborga, associate professor at the Karolinska Institute, an international team of researchers analyzed the tissue of the testes obtained from 32 boys (average six years) from Sweden, Finland and Iceland. Boys suffer from a high risk of infertility due to prescribed therapy: testicular irradiation, chemotherapy or radiation therapy in preparation for bone marrow transplantation. Patients suffering from diseases such as cancer and blood disorder (sickle cell disease, thalassemia and Fanconi anemia).
Sickle cell disease is a major cause of bone marrow transplant in children without cancer. Twenty boys tissue samples after the initial chemotherapy were taken, and in the twelve - before treatment. The scientists also looked at 14 healthy testicular tissue samples stored in a biobank Karolinska Hospital.
They counted the number of germ cells in the cross-sections of the seminiferous tubules and found that the number tends to zero for patients receiving alkiriruyuschie agents. Germ Cell Foundation in five boys with sickle cell disease has been completely exhausted, and one very low - all six received hydroxyurea. This was not observed in patients who have not started treatment or were treated nealkiriruyuschimi agents.
Alkiriruyuschie agents used in some chemotherapy damage DNA and kill cancer cells. Hydroxyurea - a chemotherapeutic agent commonly used to treat blood disorders. For example, in the case of sickle cell anemia it improves the function of the erythrocytes. Bone marrow transplantation provides the greatest chance of cure or long-term remission. However, before the transplant patient's bone marrow is necessary to destroy and suppress the immune system to radio or chemotherapy, so that the body has not rejected the transplant.
"Our data on the sharp decline in the germ cells in males receiving alkiriruyuschie agents, and patients with sickle cell disease receiving hydroxyurea, show that the preservation of frozen testicular tissue should be carried out before starting treatment. This should be aware of the doctors, patients and their caregivers "- reported the scientists.
They also noted that in the case of some patients, the disease may have been influenced by the number of spermatogonia before treatment started, and the preservation of testicular tissue can not affect fertility.