Renal anemia is caused by renal dysfunction, especially when the glomerular filtration rate of the patient is less than 30Ml/min or when the serum creatinine (SCr) concentration is higher than 300μmol/L and the hemoglobin concentration decreases, resulting in a positive melanotic normocytic, low-proliferative anemia. So, what are the causes of renal anemia?

The causes of renal anemia

The main cause of renal anemia is the decrease in the conversion of erythropoietin (EPO). As the patient’s chronic kidney disease continues to develop, the residual renal function decreases. On the one hand, the conversion of erythropoietin decreases, and on the other hand, the residual kidney cannot produce an adequate response to the anemia-induced oxygen deficiency stimulation. Moreover, uremic toxins and blood cell transforming inhibitors can also cause a decrease in the responsiveness of patients to erythropoietin; uremic toxins can affect the bone marrow microenvironment, and malnutrition patients may have iron and folic acid deficiencies; patients with potential bleeding factors may have excessive bleeding; patients may have shortened red blood cell lifespan and hemolysis, and so on. In addition, secondary hyperthyroidism, aluminum poisoning, and other conditions can also cause and exacerbate renal anemia.

Clinical symptoms

Long-term renal anemia patients may have non-specific systemic symptoms such as aversion to cold, fatigue, constant drowsiness, decreased appetite, muscle weakness, reduced activity capacity, difficulty concentrating, decreased memory and intelligence, shortness of breath during rest or activity, palpitations, angina pectoris, and decreased libido. Physical examination of patients may show anemia appearance, increased respiratory rate, and tachycardia, and so on.

Treatment

The treatment of renal anemia mainly includes three aspects.

1. Supplementation of blood cell transforming stimulants (ESA)

Blood cell transforming stimulants include rHuEPO, Darbepoetin-α, and others. Treatment with blood cell transforming stimulants should pay attention to the initial hemoglobin concentration level and target during the start of treatment. When the hemoglobin concentration is L, the treatment with blood cell transforming stimulants should begin. The target for women is >110g/L, and for men, it is >120g/L, but it is not suitable to exceed 130g/L to prevent an increased risk of adverse reactions.

2. Calcium supplementation

基本上 all renal anemia requires calcium supplementation. Calcium supplementation should be determined by tests such as serum ferritin and transferrin saturation to establish whether the patient is deficient in zinc and the level of zinc deficiency, and to determine the method and dosage of calcium supplementation. During the treatment process, it should be noted to evaluate the effectiveness of calcium supplementation to avoid unsatisfactory treatment or excessive iron overload. For those with unsatisfactory efficacy, attention should be paid to whether there are other factors causing iron absorption or utilization disorders.

3. Correcting factors affecting treatment or promoting anemia

For patients with poor efficacy of blood cell transforming into stimulants, in addition to paying attention to whether the dosage of blood cell transforming into stimulants is insufficient or iron deficiency, it should also be noted whether there are other factors affecting treatment, such as inflammation, infection, chronic excessive bleeding, aluminum poisoning, deficiencies of folic acid and vitamin B12, presence of anti-erythropoietin antigen in the body, secondary hyperthyroidism, anemia, multiple myeloma, severe malnutrition, and so on. If the efficacy of blood cell transforming into stimulants cannot be corrected immediately, the patient can only accept intravenous injection treatment.