Hyposplenism is a temporary or permanent hypofunction of the spleen caused by the absence, atrophy or functional failure of its parenchyma. It is manifested by frequent severe infectious diseases, dyspeptic disorders, in the later stages — skin hyperemia, severe headaches, dizziness, increased blood pressure, asthenia. It is diagnosed taking into account the data of a general blood test, ultrasound, CT, MRI, spleen scintigraphy, esophagogastroduodenoscopy. Antibiotics, vaccines are used for treatment, etiopathogenetic therapy of diseases that are complicated by lienal insufficiency is carried out.
ICD 10
D73.0 Hyposplenism
Meaning
The term “hyposplenism” to describe atrophic splenic hypofunction in a patient with gluten-sensitive celiac disease was first used by the American hematologist William Dameshek in 1955. The disorder is rare, which is due to the high regenerative ability of the lienal parenchyma (splenosis), which allows partially or completely compensating for the functions of the organ even after its removal.
In most patients, the occurrence of hyposplenism is associated with posttraumatic splenectomy. According to statistics in the field of traumatology, hematology, abdominal surgery, the spleen is damaged in 17-30% of abdominal injuries and is removed in 90% of such cases. The urgency of timely detection and therapy of splenic insufficiency is associated with a high risk of fatal infectious complications, especially often occurring in postsplenectomy disorder.
Causes of hyposplenism
Lienal insufficiency develops in the complete absence of an organ, anatomical reduction in volume and a decrease in the functional viability of tissues. Extremely rarely, the pathological condition has a congenital character and becomes a consequence of agenesis, combined with dextrocardia, transposition of abdominal organs, vascular anomalies (Ivemark syndrome). In most patients, hyposplenism is acquired, its causes in gastroenterology are considered:
- Surgical removal of the spleen. Emergency splenectomy is performed for severe injuries accompanied by massive crushing of the lienal parenchyma and profuse bleeding. Segmental resection and total organ removal are used as methods of treatment of cysts, abscesses, heart attacks, tuberculous lesions of the spleen, portal hypertension, a number of hematological diseases — hereditary microspherocytosis, thalassemia, autoimmune hemolytic anemia, idiopathic thrombocytopenia.
- Lienal pathology. Decreased functionality often results from general parenchymal atrophy due to involutive changes, hypovitaminosis, starvation, prolonged parenteral nutrition. The development of hyposplenism is possible with partial destruction of white and red pulp caused by traumatic injuries, vascular thrombosis, infarction, necrosis with spleen inversion. Hypofunction is observed when the organ is involved in primary systemic lymphoproliferative processes (lymphogranulomatosis, non-Hodgkin’s lymphomas).
- Damage to the spleen in other diseases. According to observations in the field of gastroenterology, functional lienal insufficiency is noted in gastrointestinal pathology (celiac disease, ulcerative colitis, Crohn’s disease, abdominal toad, chronic hepatitis, liver cirrhosis). Hyposplenism complicates the course of autoimmune processes (rheumatoid arthritis, systemic lupus erythematosus, amyloidosis, autoimmune thyroiditis). Splenic functions decrease with hereditary anemia, leukemia, and other hematological diseases.
In rare cases, the cause of hyposplenism is endocrine disorders (hypoparathyroidism). The disease may also have an iatrogenic origin — the function of the organ is inhibited when a “graft versus host” reaction occurs after bone marrow transplantation, when high doses of corticosteroids are prescribed. Prolonged immunosuppressive therapy can provoke atrophy of the splenic parenchyma.
Pathogenesis
For various causes of hyposplenism, there is a common mechanism for the development of a hypofunctional state based on the loss of the main functions of the spleen. Despite the fact that the organ has a high functional and regenerative reserve, while maintaining less than 30% of the volume of active tissue, the antigen-dependent proliferation and differentiation of T-lymphocytes is disrupted, the production of opsonins (primarily taftsin, which has an immunogenic and antitumor effect) decreases, the phagocytic reaction is inhibited, which ultimately leads to the development of severe immune insufficiency.
Due to violations of the filtering function, the utilization of aging blood elements suffers and indirectly – the exchange of pigments, iron, bile production by liver cells. Since when hyposplenism occurs, the spleen ceases to cope with the function of depositing blood elements, their content in peripheral blood increases.
Hyposplenism symptoms
Lienal hypofunction, provoked by non-surgical causes, may be latent for a long time. Patients with hyposplenism have frequent bacterial lesions of various organs (pneumonia, otitis, sinusitis, furunculosis), which are characterized by a torpid course and resistance to therapy.
Late signs of the disorder are dyspeptic disorders caused by damage to the gastrointestinal mucosa — decreased appetite, epigastric pain, nausea, heartburn, intestinal motility disorders. With the progression of hyposplenism, hyperemia of the skin, dilation of subcutaneous veins, severe headaches and dizziness are detected, there is a significant increase in blood pressure, asthenic syndrome increases with weakness, fatigue, decreased performance.
Complications
Against the background of a decrease in the reactivity of the body, lesions associated with the activation of conditionally pathogenic microflora occur. Due to the violation of antigen-dependent production of B and T lymphocytes in hyposplenism, generalized forms of bacterial infections caused by pneumococci, meningococci, hemophilic bacillus type B are often diagnosed. In 30% of patients suffering from splenic insufficiency of surgical origin, severe septic conditions with high mortality are detected, antiblastoma resistance decreases, predisposition to fungal, viral diseases, and parasitic invasions increases.
Lienal hypofunction is accompanied by erythrocytosis, which can be complicated by ulcers of the stomach and 12-pestle intestine, pulmonary, uterine, gastrointestinal bleeding, thrombosis and thromboembolism, the development of heart failure. Patients with hyposplenism who live in a tropical climate have an increased risk of malaria.
Diagnostics
Diagnosis of hyposplenism is usually difficult only in cases where the development of the disease is not associated with the removal of the spleen. This is due to the scarcity of early clinical manifestations of nonsurgical splenic hypofunction and the absence of pathognomonic signs of the disorder. Diagnostic search involves not only an assessment of the structural and functional state of the organ, but also a comprehensive examination of the patient to identify possible complications. The most informative are such laboratory and instrumental methods as:
- Blood test. With hyposplenism, an increase in the number of red blood cells and platelets is detected. A characteristic sign of the disease is an increase in the number of abnormal cells (target—shaped erythrocytes, schistocytes, siderocytes), the appearance of pathological inclusions – Howell-Jolly corpuscles (represent the remains of the cell nucleus) and Papenheim corpuscles.
- Echography. Ultrasound of the spleen is a non-invasive examination method that allows you to obtain information about the topography and size of the organ, confirm the presence of inflammatory or degenerative processes, visualize cysts, neoplasms. Sonography is always performed when closed parenchymal lesions are suspected, not accompanied by organ rupture, which often lead to hyposplenism.
- Esophagogastroduodenoscopy. EGDS is performed in the presence of persistent dyspeptic symptoms in order to exclude gastrointestinal pathology. The method allows you to visualize the state of the mucous membrane of the upper digestive tract, to identify erosions, ulcers, neoplasms. Additionally, a biopsy is performed for histological analysis.
Also, with hyposplenism, blood tests for vitamin B12 and folic acid are recommended (usually there is a decrease in indicators). When studying the coagulogram, an increase in blood clotting ability is often detected. To assess the state of the cardiovascular system, an ECG or echocardiography is prescribed. In case of insufficient information content of ultrasound examination, CT and MRI of the spleen are performed, which allow to examine in detail the internal structure of the organ, assess the state of perfusion, and conduct a densitometric analysis. A fairly sensitive method is radioscintigraphy, the value of which is particularly significant for detecting splenic parenchyma (splenosis) residues in operated patients.
Differential diagnosis of hyposplenism is carried out with primary and secondary immunodeficiency conditions, congenital erythrocytosis, true polycythemia, inflammatory bowel diseases, peptic ulcer, heart failure, thrombophlebitis. Due to the frequent association of the disease with gastrointestinal diseases and the location of the organ in the abdominal cavity, in addition to the observation of a hematologist, the patient may need consultations with a gastroenterologist and an abdominal surgeon.
Hyposplenism treatment
Therapeutic tactics depend on the causes that caused the development of splenic insufficiency. The main tasks are the complete or partial restoration of the functions of the organ with its anatomical preservation, the prevention of severe infectious complications. The patient is recommended to follow the daily routine, exclude stress and significant physical activity, sufficient motor activity, proper nutrition, folic acid intake and other vitamins.
If hyposplenism is caused not by oncological diseases, but by another somatic or endocrine pathology, etiopathogenetic treatment of the underlying pathological process is often accompanied by a decrease in splenic hypofunction. Drug therapy for the prevention of generalized infections involves the use of drugs such as:
- Antibiotics. Broad—spectrum antibacterial agents are recommended – beta-lactam penicillins, clavulanic acid derivatives, diaminopyrimidines, cephalosporins of the second generation. In postoperative hyposplenism, antibiotic therapy begins immediately after surgery and can last up to 2 years.
- Immunobiological preparations. For immunization, a polyvalent pneumococcal vaccine, a polysaccharide meningococcal vaccine in conjugation with diphtheria toxoid, a hemophilic conjugated vaccine of type B. Vaccination is performed from 8 to 14 days after emergency splenectomy, 2 weeks before the planned one, revaccination — every 3-6 years.
A promising direction for strengthening immunity in the symptoms of hyposplenism caused by the removal of the spleen is the appointment of tafcin-containing drugs in the postoperative period. Analogues of splenic peptides stimulate phagocytosis, proliferation of T-dependent zones in lymph nodes, improve the elimination of circulating immune complexes. Although attempts to transplant the spleen have been made since 1963, the transplantological method of correcting hyposplenism has not been widely used.
Prognosis and prevention
The probability of a full recovery depends on the root cause of the disease. The prognosis is unfavorable if the occurrence of hyposplenism is associated with tumors of the blood system (leukemia, Hodgkin’s lymphoma). Prevention of the disease consists in performing organ-preserving operations on the spleen, autotransplantation of the splenic parenchyma when it is impossible to preserve the organ, timely detection and treatment of predisposing conditions: thalassemia, thrombocytemia, sickle cell anemia, gluten intolerance, lymphoproliferative diseases.
To prevent infectious complications of hyposplenism, it is recommended to inform splenectomized patients about increased susceptibility to infections, vaccination. Patients should avoid visiting countries with a high prevalence of malaria.