[Characteristics of anaemia treatment in children with chronic kidney disease].

In children with chronic kidney disease anaemia is seen very often. Depending of etiology and the degree of renal insufficiency is found up to 80%. The cause is mainly because of lowered production of erythropoietin in chronically damaged kidney, but also because of insufficient intake of iron and folic acid, or intake of some drugs. Erythropoietin is a hormone which is produced in kidneys. Its main role is influence on terminal differenciation of erythroid progenitors in bone marow, and also acts on eriythropoietin receptors. In most of children with chronic kidney disease plasma level of erythropoietin is lowered, or is diminished its binding on receptors in bone marrow. New era in anaemia treatment started with developement of recombinant human erythropoietin (alfa or beta epoetin) and darbepoetin alfa (somewhat different because of higher content of sialic acid in carbohydrate moiety of molecule). Last years is developed a novel epoetin which is given 1 times monthly (metoxy polietilenglycol-epoetin beta), while earlier drugs are administered 1-3 times weekly or once in 2 weeks. These drugs are called erythropoiesis stimulating agents (ESA).They are today widely used in children with chronic renal failure before dialysis, on haemodialysis or peritoneal dialysis and in patients after kidney transplantation with deterioration of graft function. Mostly are used when glomerular filtration rate is below 35 ml/min/1 .73m2, but in some patients below 50-60 ml/min/1.73 m2. Administration is via intravenous or supcutaneous route. Efficasy of subcutaenous administration is 30- 40% higher, so this route is preferred. Dosing depends (after correction of other causes of anemia) to maintain heglobin levels between 110-120 g/L, and not to exceed 130 g/L (or haematocrit levels 33-36%, and maximum levels 39%). Theyre initiation starts when hemoglobin level falls below 80% of normal values for the age. In children older than 6 years at hemoglobin <100 g/L, or hematocrit <33%. During these therapy almost allways is need for iron supplementation intravenously or peroral. Advantages of the use of ESA are multiple: there is no need for blood transfusion, and therefore lowered risk for panel reacting antibodies (PRA) or HLA antibodies. There is also lowered risk for blood transmission of viruses. The use of erythropoietin is also in anaemia of prematurity, or in some malignant diseases to enable chemotherapy or radiation procedures. Also is used in some elective surgery procedures. Its use is safe and has proven cost-benefit, with low side effects in experienced medical team. With better hemoglobin levels there is improvement of cardiovascular system, better apetite, better growth and developement of child, so as physical and mental activity and sense of well-being.