Overview of Benign Erythrocytosis
Benign erythrocytosis, which includes benign familial polycythemia and pseudoerythrocytosis, is a condition with normal or decreased red blood cell volume and increased red blood cell pressure volume and normal arterial oxygen saturation. It is an autosomal disorder with different epitopes and is relatively rare.
Etiology
1. Decreased blood volume
The most common causes, such as repeated diarrhea, excessive sweating, excessive urination, severe dehydration, extensive burns, chronic hypoadrenocorticism, etc., due to the loss of excessive water, resulting in blood concentration.
2. Physical factors
Benign erythrocytosis, its etiology and pathogenesis may be: ① aldosterone excretion is reduced; ② uneven blood distribution. The red blood cell volume varies between different vascular beds, and the capillary bed is lower than the large vessel pool. When the total erythrocyte pressure product obtained from direct measurement of erythrocyte volume and blood volume is normal, it is lower than the erythrocyte pressure product of large vessels or venous blood, which may be caused by the transfer of erythrocytes to the pool of large vessels or the transfer of plasma out of the pool of large vessels.
3. Family factors
If hypertension, hyperlipidemia and thromboembolic cardiovascular disease, there is often a family history of erythrocytosis, so it is considered that this disease is genetically related.
Symptoms
Symptoms are mild, often with headache, drowsiness, dizziness and easy fatigue, or no symptoms at all. The patient has a deep red color and conjunctival congestion, but there is often no splenomegaly. The same patient is found in the family.
1. Erythrocytosis due to decreased blood volume
Characterized by primary disease, e.g., shock, chronic hypoadrenocorticism.
2. Erythrocytosis due to somatic factors
Most common in middle-aged men. It manifests as polyneuroticism with headache, dizziness, fatigue, mild to moderate hypertension, may have angina attack, skin itching and sweating.
Examination
Blood tests show erythrocytosis, hemoglobin up to 200 g/L or more, increased erythrocyte pressure volume, and normal white blood cells and platelets. Serum erythropoietin (EPO) is normal, and the JAK2 gene and other myeloproliferative tumor driver genes are negative.
Diagnosis
1. Headache, dizziness, and fatigue are common, but there may be no conscious symptoms, no hepatosplenomegaly, and increased blood volume.
2. Hemoglobin may be over 200g/L, white blood cells and platelets are normal.
3. The same patient is found in the family.
4. Genetic examination of many people in the family can help to confirm the diagnosis.
Treatment
For erythrocytosis due to decreased blood volume, the cause of the disease should be treated, and the blood volume should be supplemented according to the condition. For somatic patients, the main symptomatic treatment, myelosuppressive drugs are generally not used.