Treatment of sickle-cell disease Increasing the body's production of<unk>  is used as a strategy to treat sickle-cell disease. The discovery that hemoglobin F alleviated the symptoms of sickle cell disease occurred in 1948. Janet Watson observed that red blood cells from infants with the disease took longer to sickle and did not deform as much compared to their mother's cells, which carried the disease trait. Later, it was noted that patients with sickle cell trait as well as hereditary persistence of hemoglobin F (HPFH) didn't have symptoms. Additionally, in sickle cell patients, F-cells were found to be more long living than non-F cells as they contain hemoglobin F. When<unk>  production is switched off after birth, normal children begin producing adult hemoglobin (HbA). Children with sickle-cell disease begin producing a defective form of hemoglobin called hemoglobin S instead, which form chains that cause red blood cells to change their shape from round to sickle-shaped. These defective red blood cells have a much shorter life span than normal red blood cells (10–20 days compared to up to 120 days). They also have a greater tendency to clump together and block small blood vessels, preventing blood supply to tissues and organs. This leads to the so-called vaso-occlusive crisis, which is a hallmark of the disease. If<unk>  remains relatively high after birth, the number of painful episodes decreases in patients with sickle-cell disease and they have a better prognosis.<unk> 's role in reducing disease severity comes from its ability to disrupt the formation of hemoglobin S chains within red blood cells. Interestingly, while higher levels of hemoglobin F were associated with improvement of some symptoms, including the frequency of painful episodes, leg ulcers and the general severity of the disease, it had no correlation to others. A few examples are priapism, stroke and systemic blood pressure. As hemoglobin F are only produced by some red blood cells, in different quantities, only a subpopulation of cells are protected against sickling. It could be that the symptoms that high hemoglobin F doesn't prevent are quite sensitive to the rupture of the sickled non-F cells. Hydroxyurea is a chemical that promotes the production of<unk>  and reduces the premature rupturing of red blood cells. Combination therapy with hydroxyurea and recombinant erythropoietin — rather than treatment with hydroxyurea alone — has been shown to further elevate hemoglobin F levels and to promote the development of<unk> -containing F-cells. Hemoglobin F as a marker for cancers There have been some studies evaluating the possibility of using hemoglobin F as an indicator of the prognosis for cancer. It has been suggested that elevated concentrations of haemoglobin F can be found in main kinds of solid tumours and blood cancers. Examples include acute lymphoblastic leukemia and myeloid leukemia in children, where higher concentrations of hemoglobin F were associated with a worse outcome, including a higher risk of relapse or death. Other cancer types where higher hemoglobin F levels have been observed are transitional cell cancer, colorectal carcinoma and various types of blastomas. In fact, in several types of blastomas, including neuroblastoma and retinoblastoma (affecting the nerve cells and the eyes, respectively), F-cells were found in newly formed blood vessels and spaces in between tumour cells. Clusters of F-cells were also present in the bone marrow of some of these patients. Interestingly, hemoglobin F is not directly produced by tumour cells, but seems to be induced by the biological environment of the cancer in nearby blood cells. A reason suggested for this increase in hemoglobin F is that it may favor cancer growth by providing better oxygen supply to the developing cancerous cells. In adults, increased hemoglobin F production is thought to be caused by factors leading to the activation of the gene coding for the γ subunit, such as DNA demethylation (which can activate normally silent genes and is a hallmark of cancer.
Fetal hemoglobin
Hemoglobin
Ferritin
Beta-2 transferrin
Mean corpuscular hemoglobin
Indoxyl sulfate
Fetal fibronectin
Neopterin