It is a group of syndromes with clinical manifestations of anemia, bleeding, infection and other symptoms due to biological, chemical, physical and other factors that lead to hypofunction or failure of hematopoietic tissues, and is a relatively common disease of the hematopoietic system. Acute anemia is progressive, often accompanied by severe infection and internal bleeding, while chronic anemia, infection and bleeding are relatively mild. Although the disease can occur in all age groups, it is more common in young adults, with an annual incidence of 7.4 per 100,000 in China.
Causes
1, chemical factors: chemicals such as benzene and its derivatives, organophosphorus pesticides are common, and the drugs that commonly cause this disease are chloramphenicol, antipyretics and analgesics, sulfonamides, tetracyclines, antitumor drugs, anti-tuberculosis drugs (such as isoniazid), insecticides, anti-thyroid drugs (such as tabazol, methylthiouracil), etc.
2. Physical factors: mainly ionizing radiation, such as X-rays, radioisotopes, gamma rays, etc. Receiving radiation treatment or too frequent diagnostic irradiation, the risk of developing reoccurrence is 10 times higher than that of the control group.
3. Biological factors: Closely related to the development of reoccurrence is viral infection. The most common one is hepatitis virus. The mechanism of hepatitis causing reoccurrence is due to the direct toxic effect of hepatitis virus on bone marrow hematopoietic stem cells; from the perspective of embryogenesis, both liver and bone marrow belong to the monocyte-macrophage system, and such inhibitory factors may have a cross effect with liver-bone marrow.
4, other factors Long-term untreated anemia, chronic renal failure, anterior pituitary and hypothyroidism, immune factors, genetic factors can cause reocclusion, and some paroxysmal sleep hemoglobinuria (PNH) can also be transformed into reocclusion, called “AA-PNH syndrome”. There is no satisfactory explanation for the pathogenesis, which is generally summarized as the interaction of seeds (hematopoietic stem cells), soil (hematopoietic microenvironment) and worms (immune abnormalities).
The pathogenesis is misintegrated and complex, with some patients due to stem cell defects, others due to damage to the hematopoietic microenvironment, and others due to the presence of inhibitory factors or cells in the blood. Recanalization is a group of multiple lesions that differ in their nature and in the approach to treatment and the efficacy they produce.
Typing
There are acquired aplastic anemia and congenital aplastic anemia.
Clinical manifestations
The clinical manifestations of aplastic anemia are anemia, bleeding and infection. Scholars in China divide reblastosis into acute and chronic.
1. Acute type has rapid onset, heavy disease and rapid progress.
(1) Anemia: Most of them are progressively aggravated, and symptoms such as pallor, weakness, dizziness, palpitation and shortness of breath are obvious.
2) Infection: Most patients have fever with body temperature above 38 degrees, and individual patients are in uncontrollable high temperature from onset to death. Respiratory tract infections are the most common, and other infections of the gastrointestinal tract, genitourinary tract and skin. The infections are mainly Gram-negative bacilli, Staphylococcus aureus and fungi, often combined with sepsis.
(3) Bleeding: There are varying degrees of bleeding from the skin, mucous membranes and internal organs. Skin bleeding is manifested as bleeding spots or large petechiae, small blood blisters in the oral mucosa; epistaxis, gingival blood, bleeding from the conjunctiva of the eye, etc. may be present. Bleeding can occur in all organs, but only bleeding from organs with external openings is clinically detectable. Clinically, hematemesis, blood in the stool, blood in the urine, vaginal bleeding in women, followed by fundus bleeding and intracranial bleeding, the latter often life-threatening. The site of bleeding increases from less to more, with a subtle shift from surface to visceral, often foreshadowing more serious bleeding.
2, the chronic type has a slower onset and progression, and the disease is lighter than the acute type.
(1), anemia: chronic process, common pallor, weakness, dizziness, palpitations, shortness of breath after activity, etc.. Symptoms improve with blood transfusion but are not maintained for long. (2), infection: hyperthermia is less common than the acute type, and infection is relatively easy to control.
(3) Bleeding: bleeding tendency is mild, mainly skin bleeding, and visceral bleeding is rare. Cerebral hemorrhage occurs in advanced patients who have been treated for a long time. At this time, the patient may have severe headache and vomiting.
Diagnostic criteria
1.Domestic diagnostic criteria The domestic diagnostic criteria for reblastosis have been discussed for many times, and the final revision of the Fourth Academic Conference on Aplastic Anemia in 1987 was as follows
(1) Decrease in whole blood cells and decrease in the absolute value of reticulocytes.
(2) Generally no hepatosplenomegaly.
(3) Bone marrow is hypoproliferative or severely hypoproliferative in at least 1 site (if proliferation is active, there must be a significant decrease in megakaryocytes), and there is an increase in small granular nonhematopoietic cells in the bone marrow (bone marrow biopsy and other tests, if available, show a decrease in hematopoietic tissue and an increase in adipose tissue).
(4) Other diseases that cause allogeneic cytopenia can be excluded, (PNA, refractory anemia in MDS (MDS-RA), acute hematopoietic arrest, myelofibrosis, acute leukemia, malignant histiocytosis, etc.)
(5) General anti-anemia drug therapy is ineffective.
2. Diagnostic criteria for domestic acute reoccurrence (also called SAA-I type) (1) Clinical manifestations: rapid onset, progressive increase in anemia; often accompanied by severe infection and internal bleeding. (2) Blood picture: In addition to a rapid decrease in hemoglobin, two of the following must be present: ① reticulocytes less than 1%, absolute value less than 15×109/L; ② leukocytes significantly reduced, absolute value of neutrophils less than 0.5×109/L; ③ platelets less than 20×109/L. (3) Bone marrow picture: ① multi-site hypoplasia, three lines of hematopoietic cells significantly reduced, non-hematopoietic cells increased. If the proliferation is active, there must be lymphocytes increase; ② the non-hematopoietic cells and adipocytes in the small granules of bone marrow increase.
3.Diagnostic criteria of chronic reoccurrence in China
(1) Clinical manifestations: slow onset, anemia, infection and bleeding are mild.
(2) Blood picture: hemoglobin decreases slowly, reticulocytes, leukocytes, neutrophils and platelets are often higher than those of acute reoccurrence.
(3) Bone marrow picture.
(1) Decrease in lineage 3 or 2, with at least 1 site of dysplasia and marked decrease in megakaryocytes.
(2) Increase in non-hematopoietic cells and adipocytes in bone marrow granules.
(4) If the disease worsens during the course of the disease, the clinical, blood and bone marrow images are the same as those of acute reoccurrence, which is called SAA-II.
Conventional treatment
1. Remove the cause of the disease and prohibit the use of drugs that affect hematopoietic function; avoid contact with radiation except for necessary examinations; actively treat hepatitis if there is viral hepatitis.
2.Supportive treatment: Blood transfusion should be given in case of severe anemia. At present, component transfusion is more common. According to the lack of blood-forming components and bleeding, infection and other conditions, the corresponding component transfusion is used.
For non-gastrointestinal bleeding, dexamethasone or hydrocortisone can be added intravenously. Infection: due to neutropenia, infection is inevitable when <0.5×109/L. Pathogens mostly come from the skin, mucous membranes, respiratory tract, but also from conditional pathogens of the gastrointestinal tract, common bile duct, and urinary tract. Pay attention to skin, oral and anal hygiene and dietary hygiene. Avoid contamination of various punctures and cannulae. Granulocyte deficiency, severe infection and antibiotic treatment is ineffective, can be infused with granulocytes at least (1 to 2) × 1010 granulocytes per day for 3-5 days to control the infection.
4.Treatment of chronic aplastic hormone
Androgenic hormone drugs : Testosterone propionate: 50~100mg each time, injected intramuscularly once a day.
Conilon: 2~4mg per time, 3 times daily, orally.
Oxycodone: 15～60mg per day, divided into 2～3 times orally.
Bone marrow stimulants.
①Nitragynine: by intramuscular injection for 5 days, with 2 days interval, repeated until remission.
② Ichiban c-base, 8-16mg daily by intramuscular injection in adults and at the discretion of children. Continuous use for 1.5 to 2 months may show efficacy, and the course of treatment should not be less than 4 months.
③ Scopolemic drugs mainly release the vasospasm of the bone marrow microenvironment and adjust its blood perfusion, thus improving the hematopoietic microenvironment.
Trace element drugs.
①Cobalt chloride: Cobalt can inhibit fine enzymes and make cells hypoxic, thus stimulating the kidney to increase erythropoietin production.
②Immunomodulators The main drug is levamisole. The course of treatment is more than 3 months.
③Adrenocorticotropic hormone.
5.Treatment of acute aplastic anemia
Immunosuppressive therapy.
①Anti-lymphocyte globulin (ALG), anti-thymocyte globulin (ATG): This product has the function of mediating immunity against immunoreactive T suppressor cells, and they can induce T cell proliferation and restore hematopoiesis.
②Cyclosporin A (CSA): It is a killing agent for Ts cell Tc cell clone, corrects the immune disorder in patients with remittent disease and induces the recovery of bone marrow hematopoiesis in severe remittent disease.
Bone marrow transplantation: Bone marrow transplantation for reblastosis has gained much experience abroad. Since it is not easy to find HLA tissue-matched donors for bone marrow transplantation, and it is labor-intensive and resource-intensive, the indications should be strictly selected, and there are the following views on the indications: severe reblastosis (except for the elderly), granulocytes below 0.5×109/L, platelets below 20×109/L, bone marrow Lymphocytes above 75%; preferably within 3 months from diagnosis; under 20 years of age; few transfusions prior to transplantation (preferably no transfusions); and identical HLA type.
Chronic reoccurrence has a relatively mild onset and the symptoms of complicated infections and bleeding are not very serious, but the treatment takes a longer time to show effect. If Chinese herbal medicine and/or androgen therapy are given to tonify the kidney and activate blood, most patients can have remission with an efficiency of about 80% and a good prognosis. Acute reoccurrence is a group of bone marrow failure diseases with rapid onset and progression, often accompanied by internal bleeding and serious infection, often life-threatening and with poor prognosis; in treatment, we can save the lives of a considerable number of patients by providing heat-clearing and blood-cooling herbal medicines, actively cooperating with western medicine such as component blood transfusion, broad-spectrum antibiotics, propecia, hematopoietic stimulating factor and other supportive therapies, or with immunosuppressive therapy.