Related articles: Hemolytic Anemia
Definition
Hemolytic anemias are a group of haematological diseases characterized by a shortening of the average life of red blood cells in the circulation (this usually coincides about 120 days) and their premature destruction by extra-and / or intravascular hemolysis.
The pathological picture occurs, in particular, when bone marrow production is no longer able to compensate for the reduced survival of erythrocytes.
Hemolytic anemias can be divided into two groups:
- Hemolytic anemia from intraglobular defects : the disease derives from intrinsic erythrocyte anomalies, able to induce haemolysis; these alterations can be both genetic and acquired, and can involve the cell membrane (eg spherocytosis), the metabolism or the function of red blood cells (eg hemoglobinopathies, such as sickle cell disease and thalassemia).
- Hemolytic anemia from extraglobular defects : secondary to extrinsic defects of red blood cells, which can be destroyed due to immunological alterations, mechanical damage (trauma), hyperactivity of the reticuloendothelial system (hypersplenism), toxins (poisoning with haemolytic, lead, copper and compounds with oxidizing potential, such as dapsone and phenazopyridine) or some infectious agents. The latter can cause haemolytic anemia through the direct action of toxins (as happens in the case of a- or ß-haemolytic streptococci, Clostridium perfringens and meningococci) or due to invasion and destruction of erythrocytes by the microorganism (eg Plasmodium spp. And Bartonella spp).
The most frequent forms belonging to the first group are hereditary spherocytosis, paroxysmal nocturnal hemoglobinuria and glucose-6-phosphate-dehydrogenase deficiency (G6PD); in the second, instead, autoimmune hemolytic anemias are included.
Most common symptoms and signs *
- Adynamia
- Anemia
- anisocytosis
- Asthenia
- Chills
- Cachexia
- Abdominal pain
- hemoglobinuria
- Temperature
- Hypotension
- Jaundice
- Backache
- Pallor
- splenomegaly
- thrombocytosis
- Dark urine
- Dizziness
Further indications
In hemolytic anemia, hemolysis can be acute, chronic or episodic. Systemic manifestations are similar to those of other anemias and include pallor, fatigue, dizziness and hypotension.
The patient can report the emission of dark or frankly reddish urine due to hemoglobinuria.
A haemolytic crisis (acute hemolysis) is rare; it can be accompanied by chills, fever, pain in the lumbar region and abdomen, prostration and shock. On the other hand, severe hemolysis can cause jaundice and splenomegaly.
Regarding the diagnosis, hemolysis should be suspected in patients with anemia and reticulocytosis (increase in the direct precursors of red blood cells). During the collection of anamnestic data, attention must be paid to the modalities of onset of anemic symptomatology and to the possible presence of similar pathologies in the family.
When the peripheral blood smear is evaluated, the presence of the condition may be indicated by an increase in indirect bilirubin, hypersideremia, an increase in LDH and a reduction in haptoglobin. After the first orientation, each form of haemolytic anemia is defined by further diagnostic tests (including Coombs test, quantitative Hb electrophoresis and flow cytometry).
Treatment depends on the specific underlying hemolytic mechanism; Possible approaches include martial therapy (ie the administration of iron-containing drugs), corticosteroids, use of chelating agents and splenectomy.
