OVERVIEW
Pure red cell aplastic anemia (PRCA) is an anemia resulting from a significant reduction or deficiency of red lineage cells in the bone marrow.The disease was first isolated from aplastic anemia by Kaznelson in 1922, and since then it has gradually gained widespread attention. It is closely related to autoimmunity and thymic tumors. The disease is now categorized as congenital or acquired. Acquired is subdivided into acute and chronic, with acute also called acute hematopoietic arrest, and chronic acquired pure red reentry is a rare disease. It is characterized by a significant reduction of red lineage cells in the bone marrow and is often associated with thymoma.This comorbidity was first identified by Opsahl in 1939 and has been reported repeatedly since then. It is estimated that thymoma is present in about 20%-50% of cases, which may be related to the etiology and onset of the disease.
Patients tend to be 20-67 years of age, mostly in middle-aged adults. Some of them are combined with thymoma, and thymoma combined with pure red remodeling accounts for about 7% of all thymoma patients. Women outnumbered men in the group with thymoma (2:1), but men outnumbered women in the group without thymoma. It should be noted that some pure red remodeling occurs with leukopenia and thrombocytopenia during the course of the disease and becomes generalized remodeling.
Etiology
The disease is induced by thymoma, viruses, infections, proliferative disorders of the lymphatic system, and drugs; in some cases the cause is unknown. The pathogenesis is mostly related to immunity. The combination of thymoma in some cases of this disease suggests that the role of immunity plays an important part in the pathogenesis.
Symptoms
Anemia is the only sign and symptom of the disease. If thymoma is present, the tumor is small and not easily detected on physical examination. There are usually no congenital anomalies. The blood picture shows normocytic normochromic anemia with a decrease in the absolute value of reticulocytes; the white blood cell and platelet counts are normal. The red blood cells in the bone marrow were markedly reduced, even when 500 nucleated cells were counted, but the granulocytes and megakaryocytes were not reduced. There was no obvious abnormality in the morphology of various cells, and there were occasional cases of eosinophilia.
Patients had increased serum iron, serum iron saturation, significantly prolonged clearance time of plasma 59Fe in iron kinetic studies, and decreased iron utilization, consistent with the finding of a reduced erythroid system in the bone marrow. Erythrocyte survival time was normal. Serum protein electrophoresis is normal in most patients, but gamma-globulin is increased or decreased in some. There are a variety of antibodies in the serum, such as cold agglutinin, warm agglutinin, cold hemolysin, heterophilic antibodies, antinuclear antibodies, and lupus erythematosus factor.
Examination
1. Blood routine
Hemoglobin is reduced, reticulocytes are significantly reduced, white blood cell and platelet counts are in the normal range, white blood cell classification is normal, red blood cell and platelet morphology is not abnormal, and there is no pathological hematopoietic phenomenon.
2. MCV (mean corpuscular volume of erythrocytes), MCH (mean corpuscular hemoglobin content of erythrocytes) and MCHC (mean corpuscular hemoglobin concentration of erythrocytes)
Normal.
3. Bone marrow picture
The erythroid system is significantly reduced, and the granulocyte and megakaryocyte systems are normal in all stages. There is a lack of progranulocytes and early juvenile granulocytes. There is an increase in megakaryocytes in some patients. Adipocytes are not increased.
4. Ham and Coombs test
Negative, serum iron, total iron binding capacity and ferritin are increased.
Diagnosis
Diagnosis can be made according to the patient’s age of onset, combined with clinical symptoms and laboratory tests.
Treatment
To alleviate symptoms, patients often require red blood cell transfusions, usually once every 1-2 weeks. Other common treatments are as follows:
1. Corticosteroids
The drug of choice is corticosteroids, which may provide relief in some patients. For example, prednisone, 40-60mg daily; androgens are also effective in some patients. Treatment must be continued for a long period of time, e.g. several months to six months.
2. Immunosuppressants
Antithymocyte globulin (ATG), cyclosporine A (CsA) and intravenous gammaglobulin are described in the treatment of reocclusion.
3. Thymectomy
Surgical removal of the thymus is performed when an enlarged thymus is found. The purpose of resection is to accurately diagnose the presence or absence of malignancy and to promote bone marrow hematopoiesis. It has been reported that there were 56 cases of pure red remodeling, of which 25 cases underwent thymectomy and 16 cases were ineffective. Thymic X-ray irradiation was ineffective in 5 other cases. If there is no thymus enlargement or thymoma in pure red cataract, the resection is ineffective.
4. Plasma replacement
Remove immunosuppressive substances in plasma.
5. Erythropoietin
Not very effective in this disease.
6. Splenectomy
Effective in about 14% of patients.
Questions you may be concerned about
How to regulate pure red blood cell aplastic anemia?
The treatment of pure erythrocyte aplastic anemia is mainly divided into: etiological treatment, immunosuppressant treatment and other treatments.
1. Etiological treatment: remove the causes of pure erythrocyte aplastic anemia (autoantibodies against erythroid progenitor cells; microvirus B₁₉ infections; drugs such as phenytoin sodium, azathioprine, etc.).
It also includes fighting infections, stopping drugs and removing autoantibodies against red lineage progenitor cells.
And treatment of underlying diseases related to blood (such as thymoma; chronic lymphocytic leukemia; lymphoma, etc.), removal of thymoma, leukemia and lymphoma chemotherapy, such as the use of drugs such as cyclophosphamide and vincristine.
2. Immunotherapy: Corticosteroids (such as prednisone), cyclosporine or anti-thymus/lymphocyte globulin (ATG/ALG) can play an immunosuppressive role in pure erythrocytic aplastic anemia, which can reduce the immune response caused by the disease.
3. Other treatments: Depending on the patient’s specific condition, plasmapheresis (function: to remove disease-causing antibodies; immunomodulation), gammaglobulin (function: to strengthen nutrition; reduce infection rate; neutralize antigens), or genetically recombinant human erythropoietin (rhEPO) (function: to stimulate the red lineage of hematopoiesis) and other treatments can be used.
Pure red cell aplastic anemia (also known as PRCA) is a disease characterized by hematopoietic failure of the bone marrow in the pure red lineage, and is divided into two categories: hereditary and congenital. When PRCA occurs, it is necessary to go to a regular hospital in time to prevent serious symptoms in the later stages.
Medication should be administered under the guidance of a physician.