anemia of chronic disease in the elderly
Introduction
Introduction to chronic disease anemia in the elderly Chronic disease anemia is one of the anemia caused by iron in a certain part of the metabolism of the human body. Chronic disease anemia, the current clinical incidence is second only to iron deficiency anemia, in hospitalized patients It is the most common. basic knowledge The proportion of illness: 0.005% Susceptible people: the elderly Mode of infection: non-infectious Complications: renal failure, hypovolemic shock, hypoglycemia
Cause
The cause of chronic disease anemia in the elderly
Red blood cell life is shortened (30%):
In chronic anemia, 20% to 30% of patients have shortened red blood cell life, which may be due to:
(1) Fecal damage The erythrocyte membrane is easily swallowed.
(2) Non-specific stimulation of the mononuclear-macrophage system, which enhances phagocytic activity.
(3) Increased hemolysin in tumor patients.
(4) Hemolysis caused by bacterial toxins.
(5) vascular injury, red blood cells tend to stay in the local area and cause damage. It is observed in the experiment that the red blood cells of normal rheumatoid arthritis patients are normal, and the red blood cell life is normal, such as the red blood cells of normal people. In patients with rheumatoid arthritis, the red blood cell life is shortened, which also indicates that this type of hemolysis is caused by factors other than red blood cells.
Insufficient compensation for bone marrow for anemia (20%):
In chronic anemia, bone marrow lacks the compensatory capacity for anemia, which may be the main cause of chronic disease anemia. When chronic inflammation occurs, interleukin (IL-1), tumor necrosis factor (TNF) and Increased cytokines such as interferon (TNF) can not only inhibit the production of EPO in the body, but also affect the response of bone marrow to EPO, inhibit the formation of erythroid progenitor cells, and the utilization of iron, further the formation of bone marrow erythrocytes. influences.
Another explanation for the lack of EPO secretion in chronic disease anemia is that in some patients, the conversion rate of T4 to T3 is reduced, protective thyroid function is reduced, oxygen consumption in tissues is reduced, and the signal of hypoxia is not obvious. Therefore, it is not possible to stimulate a sufficient amount of EPO like other anemia.
Iron release and utilization barriers (20%):
The cause of low iron in chronic disease anemia is not very clear. One explanation is the nutrition and immunity formula of the body. Since both bacteria and tumor cells require iron nutrition, low iron is considered as the reaction of the body to the growth of bacteria or tumor tissue. Another explanation is that when inflammation or infection occurs, macrophages are activated, macrophages over-feed iron, resulting in low serum iron and increased storage iron. IL-1 increases in inflammation and stimulates release of lactoferrin from neutrophils. Lactoferrin is easier to bind to iron than ferritin (especially when pH is lowered), resulting in a decrease in transferrin concentration. Because of the lack of lactoferrin receptor on immature red blood cells, iron bound to lactoferrin cannot be The utilization of red blood cells can only be swallowed by macrophages, resulting in excessive iron storage in macrophages.
Insufficient secretion of EPO and slow response of bone marrow to EPO may be the main cause of chronic disease anemia. At present, the treatment of chronic disease anemia with EPO can improve the anemia of patients, which also indicates that EPO secretion is the main, low iron. This is not the main reason, because supplementation of iron in patients with chronic disease anemia does not improve anemia.
Pathogenesis
1. The role of cytokines
ACD is stimulated by the cellular immune system to cause a complex and wide-ranging response of the body's cells, resulting in increased inflammatory cytokines, including tumor necrosis factor (TFN) interleukin-1 (IL-1) and interferon ( IFN), etc., lead to erythroid hematopoietic inhibition, manifested as decreased production of erythropoietin (EPO) and slow response of bone marrow to EPO. Reduced EPO production is also associated with increased NO production. Patients with rheumatoid arthritis still have IL-6 liters. High, the latter can increase blood volume leading to blood thinning.
2. Red blood cell life is shortened
Factors such as enhanced phagocytic activity, bacterial toxins, hemolysin of the tumor, vascular damage, and damage to the erythrocyte membrane by fever in the patient shorten the lifespan of the red blood cells.
3. Iron metabolism abnormalities
The mechanism of AHP's hypoferremia is still unclear, probably due to excessive uptake of iron after macrophage activation. IL-1 stimulates the release of lactoferrin by neutrophils during inflammation, which is easy to bind to iron, resulting in reduced transferrin concentration. At the time of ACD, the transferrin receptor on the erythrocyte membrane is also reduced, which makes the iron utilization disorder. It is also believed that hypoferremia is a reaction of the body to the growth of bacteria and tumor tissues, because the latter also needs iron nutrition, eventually causing serum. Iron is reduced and iron is increased.
Prevention
Elderly chronic anemia prevention
Because this disease is a secondary factor, the prevention of this disease is mainly to actively control the treatment of primary disease, to prevent the occurrence of chronic disease anemia, the cause of this disease involves more primary diseases, such as chronic liver disease, chronic kidney Disease, chronic endocrine diseases and various chronic infections lead to abnormal iron metabolism, and small cell hypochromic anemia occurs.
Complication
Chronic disease anemia complications in the elderly Complications, renal failure, hypovolemic shock, hypoglycemia
Common infections and bleeding, blood loss, kidney failure.
Symptom
Chronic disease anemia symptoms in the elderly Common symptoms Shock fatigue Low blood volume shock Dizziness Myelosuppression Renal failure Hypoglycemia Heart palpitations with fatigue, pale
Anemia of chronic disease anemia is generally mild or moderate, slow progress, anemia symptoms are not heavy, often masked by the clinical manifestations of the primary disease, often accompanied by chronic infection, inflammation or tumor symptoms, so clinical manifestations A variety of hemoglobin, less than 90g / L, HCT is generally not less than 32%, normal cell normal anemia, 1/3 ~ 1/2 patients with hypopigmentation or small cell anemia, serum iron And total iron binding capacity is lower than normal, iron saturation is normal or slightly lower than normal, serum ferritin is increased, red blood cell free protoporphyrin is increased, erythroid cells in bone marrow may have mild compensatory hyperplasia, iron staining shows iron The granulocyte is reduced and the stored iron in the macrophage is increased.
Examine
Examination of chronic disease anemia in the elderly
Anemia is normal cell, normal pigmentation, small cell and hypochromic anemia, decreased serum iron (SI), decreased total iron binding capacity (TIBC), increased serum ferritin (SF), serum soluble transferrin Receptors did not increase, red blood cell free protoporphyrin (FEP) and zinc protoporphyrin (ZPP) only slightly increased, bone marrow iron staining can increase iron, but the number of iron red blood cells decreased, serum EPO levels decreased.
When the tumor invades the bone marrow, the bone X-ray shows abnormality.
Diagnosis
Diagnosis and diagnosis of chronic disease anemia in the elderly
diagnosis
Diagnosis of chronic disease anemia must first rule out the blood loss caused by these diseases, renal failure, drug-induced myelosuppression and tumor invasion of bone marrow or dilute anemia in advanced tumors.
Differential diagnosis
In the differential diagnosis, it is mainly distinguished from iron deficiency anemia. Although the serum iron is also low in chronic disease anemia, the total iron binding capacity is often lower than normal, so the transferrin saturation is normal or slightly lower, serum ferritin and bone marrow iron. Normal or increased, FEP is increased in chronic anemia and iron deficiency anemia, but the latter increases higher, faster, and the increase in FEP in chronic anemia is often slow, only obvious when anemia is severe .
