Hypersplenism is a pathological condition characterized by increased destruction of shaped blood elements (erythrocytes, platelets, leukocytes) in the sinusoids of the spleen. It is a consequence of an enlarged spleen. The clinical picture is determined by the underlying disease, as well as cytopenic syndrome – anemia, bleeding, infections. The diagnosis is made by the presence of splenomegaly, ultrasound or CT of the abdominal cavity, laboratory confirmation of a decrease in one of the types of blood cells. Treatment depends on the disease that caused hypersplenism. With extremely pronounced cytopenia, splenectomy (removal of the spleen) is performed.
Hypersplenism is not an independent disease, but a clinical and laboratory syndrome, which is a specific natural complication of prolonged splenomegaly. However, sometimes it can develop even with the normal size of the spleen. Normally, the spleen serves as a kind of filter in which blood cells that cease to perform their functions, or abnormal cells, are delayed and destroyed. With hypersplenism, this process becomes pathological. Its occurrence indicates an unfavorable course of the underlying disease, since the syndrome is often associated with a fatal outcome.
The etiological factors of abnormally elevated spleen function are the same as in splenomegaly. However, in some patients it is not possible to accurately determine the cause (primary, idiopathic hypersplenism). The secondary process develops against the background of various pathological conditions. The most common of them are:
- Cirrhosis of the liver. Signs of hypersplenism are observed in 60% of patients with chronic liver diseases. The most common cause is cirrhosis. In this case, the syndrome is a component of portal hypertension and is accompanied by ascites, varicose veins of the esophagus and symptoms of liver failure.
- Hematological diseases. This is the second most common cause of hypersplenism. The syndrome is especially pronounced in hemoglobinopathies (sickle cell anemia, thalassemia). Also, hyperfunction of the spleen occurs in myeloproliferative, lymphoproliferative pathologies (leukemia, lymphoma), hemolytic anemia.
- Infections. Splenomegaly, complicated by hypersplenism, is quite common in infectious endocarditis. Hyperfunction of the spleen can be observed in viral (infectious mononucleosis), bacterial (typhoid fever, brucellosis) and protozoal infections (malaria, visceral leishmaniasis).
- Systemic diseases. Hypersplenism also often develops in systemic inflammatory pathologies (sarcoidosis, systemic lupus erythematosus), metabolic disorders (amyloidosis, hemochromatosis). The syndrome is most severe in people suffering from hereditary accumulation diseases (Gaucher’s disease, Niemann-Pick).
The mechanism of development of increased destruction of blood cells (sequestration) in the spleen directly depends on the pathogenesis of splenomegaly, and hence on the underlying disease. With cirrhosis of the liver, hemoglobinopathies, as well as some infections (bacterial endocarditis), there is stagnation of blood in the portal or splenic vein system, which leads to overflow of the spleen with blood. Due to the fact that a larger volume of blood passes through the spleen, the sequestration of shaped elements increases.
In infections and systemic inflammatory processes, hypersplenism is caused by hyperactivation of the reticuloendothelial system of the spleen. As a result, splenic macrophages capture blood cells in larger than usual numbers. This process is called “working hypertrophy (hyperplasia) of the spleen”. In diseases of accumulation and malignant hematological diseases, the spleen increases due to tumor proliferation and deposition of pathological proteins, lipids, etc. in it.
In the early stages of hypersplenism development, the main pathological component – cytopenic syndrome – may not be present. This is due to the compensatory enhancement of the hematopoietic function of the bone marrow. However, with the further progression of the underlying disease and hypersplenism, this mechanism becomes insufficient, which leads to a decrease in the content of cells in the peripheral blood.
The clinical picture consists of signs of splenomegaly, cytopenic syndrome and symptoms of the underlying disease. An enlarged spleen causes heaviness, aching or bursting pains in the left hypochondrium. In many pathologies, splenomegaly is accompanied by hepatomegaly, which is manifested by heaviness and pain in the right hypochondrium. Sometimes the spleen reaches such a size that it squeezes the diaphragm, and the patient begins to experience breathing difficulties (inability to take a deep breath) due to the reduced amplitude of the chest excursion. Dyspnea is especially common in patients with accumulation diseases and myeloproliferative diseases.
Cytopenic syndrome consists in a decrease in the content of shaped elements in the blood. There may be an isolated decrease in one type of cells, or all three (pancytopenia). The clinic depends on which blood cells are deficient in the patient:
A low level of red blood cells leads to anemic syndrome – the skin and mucous membranes become pale, there is an increased sensitivity to cold. In the future, symptoms of low blood pressure (weakness, dizziness, rapid heartbeat) are added.
A drop in the concentration of platelets in the blood causes hemorrhagic syndrome. There are nosebleeds, bleeding gums. In women, menstruation becomes abundant and prolonged. The skin is covered with petechial rashes, ecchymoses, both spontaneously and with the slightest mechanical damage.
Due to a decrease in the content of leukocytes, namely granulocytes, the body’s resistance to various bacterial infections decreases. Pustular formations (boils, carbuncles) often appear on the skin. Constantly recurrent inflammatory infectious processes develop ‒ pneumonia, pyelonephritis, otitis media.
Hypersplenism is characterized by a large number of complications. The most frequent adverse effects are associated with thrombocytopenia. Extensive internal bleeding develops. The most dangerous of them is hemorrhagic stroke, which has a high mortality rate (about 30%). Severe rapidly progressing anemia leads to decompensation of chronic heart failure (pulmonary edema, cardiogenic shock), aggravation of coronary heart disease in the form of unstable angina and myocardial infarction. Due to granulocytopenia, infectious diseases acquire a severe lightning-fast course, rapidly turning into a septic state and septic shock.
The profile of a specialist who oversees a patient with hypersplenism is determined by the underlying pathology. Mainly, such patients are treated by hepatologists and hematologists, since the most frequent etiological factors are cirrhosis of the liver and hematological diseases. During the general examination, the enlarged and painful spleen during palpation attracts attention. Additional examination includes:
- Blood test. The main laboratory study for the diagnosis of hypersplenism is a clinical blood test. There is a decrease in the indicators of erythrocytes, platelets, granulocyte leukocytes (neutrophils). Usually erythrocytopenia is much more pronounced than thrombocytopenia and neutropenia. Reticulocytosis is characteristic.
- Instrumental research. The main imaging method is ultrasound of the abdominal organs. An enlarged spleen with diffuse changes is detected, the liver is often enlarged. Sometimes the spleen can maintain its normal size. For a more detailed study of the structure of the spleen, CT is used.
- Biopsy. In rare cases, when it is necessary to identify latent hypersplenism or differentiate the causes of cytopenic syndrome, sternal puncture or trepanobiopsy is resorted to to obtain a bone marrow sample. Microscopy shows hyperplasia of bone marrow sprouts – granulocytic, erythrocytic, megakaryocytic.
Differential diagnosis of hypersplenism is carried out taking into account the component of cytopenic syndrome. Erythrocytopenia should be distinguished from other types of anemia (iron deficiency, chronic diseases). With thrombocytopenia, it is necessary to differentiate hypersplenism from other hemorrhagic diathesis caused by low platelet levels (immune thrombocytopenia, thrombocytopenic purpura). The development of pancytopenia requires the exclusion of aplastic anemia, severe deficiency of cyancobalamin (vitamin B12).
Patients are subject to mandatory hospitalization in the inpatient department (hematology, gastroenterology). The main condition for successful therapy is the treatment of the underlying disease, against the background of which there was a pathological increase in the sequestration function of the spleen – anti-cirrhotic, antibacterial therapy, chemotherapy, etc. Since hypersplenism itself is characterized by a persistent progressive course, treatment is a difficult task. Various methods are used to eliminate the manifestations of the syndrome.
There are no medications that allow you to completely get rid of the signs of hypersplenism. Since the main danger to life is cytopenic syndrome, measures are used to maintain blood cells at the proper level. First of all, these are transfusions of whole blood or its individual components (thawed, washed erythrocyte mass, platelet concentrate).
Sometimes pharmacological drugs are prescribed that affect individual bone marrow sprouts – erythropoietin, filgrastim, thrombopoietin. These medications are resorted to very rarely and only when other methods have proved unsuccessful, because the bone marrow in hypersplenism is already in a state of hyperplasia. Therefore, the additional use of medicinal stimulators of hematopoiesis is pathogenetically poorly justified.
Splenectomy (surgical removal of the spleen) is the most radical way to treat hypersplenism, which allows to achieve normalization of blood cell parameters. However, this operation is associated with a large number of complications – thrombosis, increased sensitivity of the body to bacteria such as pneumococcus, meningococcus, Hemophilus bacillus. In this regard, minimally invasive endovascular interventions ‒ embolization of the splenic artery or its branches – have been performed more often recently. This allows you to eliminate hypersplenism and preserve the normal function of the spleen.
Prognosis and prevention
The survival rate and frequency of adverse effects depend on the underlying pathology that caused hypersplenism. The main cause of death is hemorrhagic stroke, extensive bleeding, septic condition. Primary prevention of hypersplenism consists in timely diagnosis and competent treatment of the underlying disease. Patients who have had spleen removal are subject to mandatory vaccination against hemophilic bacillus, meningococcus, pneumococcus. Children under 6 years old who have undergone splenectomy should receive prophylactic doses of penicillin antibiotics for a long time.