Leukocytosis : Causes, Symptoms, Diagnosis & Treatment

• Classification
• Causes Of Leukocytosis
• Infections
• Systemic Diseases
• Allergy
• Blood Diseases
• Other Reasons
• Diagnostics
• Treatment For Leukocytosis
• Forecast

Leukocytosis is an increase in the content of leukocytes in the peripheral blood above 9000 in 1 μl (9x109 / l). It is observed in a wide range of nosologies, especially bacterial and viral infections, systemic inflammatory pathologies of a rheumatic nature. There are no specific clinical manifestations. Symptoms are determined by the cause, i.e. disease, against the background of which leukocytosis developed. The level of leukocytes is measured when taking venous or capillary blood in the morning 12 hours after the last meal. The white blood cell count is part of a complete blood count. To correct leukocytosis, the underlying disease is treated.

Classification

Leukocytosis is divided according to various criteria. According to the biological significance, a physiological and pathological increase in leukocytes in the blood is distinguished. Physiological leukocytosis does not cause any harm and is observed in every healthy person under certain circumstances - during intense muscular work (myogenic), 2-3 hours after a meal (alimentary), in the second trimester of pregnancy (gestational). Diseases are the cause of pathological leukocytosis. According to the degree of increase in the level of leukocytes, there are:

• Moderate leukocytosis . The number of leukocytes is from 900 to 15000.
• high leukocytosis . The content of leukocytes is from 1500 to 50000.
• Hyperleukocytosis (leukemoid reaction) . The concentration of leukocytes is over 50,000. A large number of immature forms of white blood cells are often present.

In addition to the level of leukocytosis, what type of leukocytes has gone beyond the normal range is important. Depending on the type of leukocytes, the following types of leukocytosis are distinguished:

• Neutrophilic (neutrophilia) . An increase in neutrophils above 75%. The cause is bacterial infections, suppurative processes.
• Lymphocytic (lymphocytosis) . The content of lymphocytes is more than 38% (in children under 7 years old - above 55%). Common causes are viral infections, lymphoproliferative diseases.
• Monocytic (monocytosis) . An increase in monocytes above 10%. The causes are granulomatous processes, protozoal infections, septic endocarditis.
• Eosinophilic (eosinophilia) . The content of eosinophils is more than 5%. The main causes are helminthic invasions, allergic reactions, some lung diseases.
• Basophilic (basophilia) . The increase in basophils is above 1%. A very rare condition. The cause is allergies, polycythemia vera, ulcerative colitis.

Causes of leukocytosis

infections

The most common cause of leukocytosis are various infections (bacterial, viral, parasitic). Since the main function of all leukocytes is to maintain anti-infective immunity, the presence of a foreign pathogen in the body is accompanied by a reactive increase in white blood cells in the blood. Moreover, a certain type of microorganism causes various types of leukocytosis.

• Bacterial infections. With bacterial infections, the content of neutrophils and monocytes in the blood increases, which destroy pathogens by phagocytosis and an “oxygen explosion”. With localized infections (tonsillitis, pyelonephritis, bronchitis), leukocytosis is usually insignificant. Severe purulent processes (abscess, phlegmon, osteomyelitis) and generalized infections (sepsis, endocarditis) are characterized by high leukocytosis, sometimes a leukemoid reaction occurs. A distinctive feature of leukocytosis caused by a bacterial infection is the shift of the leukocyte formula to the left, i.e. the appearance in the blood of "young", immature forms of neutrophils (metamyelocytes, promyelocytes). In acute processes, leukocytosis increases sharply and reaches a maximum on the 1-2 day of the disease, then gradually decreases and returns to normal.
• Viral infections (flu, measles, mononucleosis). They become the cause of an increase in the blood of lymphocytes, which have the ability to trigger the mechanism of apoptosis in viral cells and produce specific antibodies (immunoglobulins) against them. Lymphocytosis is most often moderate, it can persist for a long time (weeks, months, years), especially with persistent viral infections (cytomegalovirus, Epstein-Barr virus).
• Worm infestations. Infection with helminths (ascarids, pinworms, hookworms) is considered one of the most common causes of eosinophilic leukocytosis. Eosinophils contain in their granules an eosinophilic cationic protein that disrupts metabolic processes in the body of helminths. Eosinophilia occurs approximately on the 5th day of illness, grows rapidly and reaches very high values ​​by day 35-4, and then slowly (over several weeks) begins to decrease to normal numbers.

Systemic diseases

The cause of leukocytosis is often chronic systemic inflammatory processes. The exact pathogenetic mechanisms of the increase in leukocytes in these pathologies are still unknown. It is assumed that the mediators and cytokines formed during rheumatic inflammation stimulate the production of leukocytes in the bone marrow. This mainly applies to the following rheumatic diseases:

• Joint diseases : rheumatoid arthritis, ankylosing spondylitis.
• Diffuse connective tissue diseases : systemic lupus erythematosus, dermatomyositis, scleroderma.
• Systemic vasculitis: nonspecific aortoarteritis, granulomatosis with polyangiitis, giant cell arteritis.

In arthritis and diffuse connective tissue diseases, leukocytosis is usually moderate. With systemic vasculitis with necrotizing inflammation in the vascular wall, leukocytosis can reach high numbers.

Allergy

This is the main cause of eosinophilic leukocytosis. Ingestion of an allergen causes IgE-mediated degranulation of mast cells with the release of mediators of allergic inflammation - leukotrienes, histamine, etc. One of the main functions of eosinophils is to suppress the production of inflammatory mediators, so any allergic reaction is accompanied by an increase in the level of eosinophils.

The maximum level of eosinophilia is reached at the moment of exacerbation of the allergic reaction, then it gradually decreases as the symptoms regress and returns to normal levels in remission. In most allergic diseases (bronchial asthma, rhinoconjunctivitis), moderate leukocytosis is observed. Only with the development of systemic reactions (Stevens-Jones syndrome, DRESS syndrome) can high leukocytosis occur.

Blood diseases

Malignant myeloproliferative (leukemia, polycythemia) and lymphoproliferative (lymphoma) pathologies are considered the main cause of hyperleukocytosis. It is caused by oncological transformation of bone marrow and lymphatic tissue stem cells, followed by overproduction of leukocytes. With leukemia, neutrophilic, monocytic or eosinophilic leukocytosis is observed, with lymphomas - lymphocytosis.

In acute leukemia, in addition to leukocytosis, there are signs such as leukemic failure, which implies the presence of only mature leukocytes and blast cells and the absence of intermediate forms (metamyelocytes), basophilic-eosinophilic association (a simultaneous sharp increase in basophils and eosinophils). Leukocytosis increases slowly over several years. It reaches high numbers (up to 10,000) and gradually decreases under the influence of chemotherapy.

Other reasons

• Massive tissue breakdown : myocardial infarction, ischemic stroke, pancreatic necrosis, extensive burns.
• Toxic effects on the bone marrow : lead poisoning, organic hydrocarbon compounds, ionizing radiation.
• Endocrine disorders : chronic adrenal insufficiency, autoimmune polyglandular syndromes, congenital dysfunction of the adrenal cortex.
• Primary immunodeficiencies : Wiskott-Aldrich syndrome, Job's syndrome (hyper-IgE syndrome).
• Malignant neoplasms : small cell lung cancer, breast cancer, colon adenocarcinoma.
• Pulmonary diseases : pulmonary eosinophilia (eosinophilic pneumonia), Langerhans cell histiocytosis, allergic bronchopulmonary aspergillosis.
• Dermatological diseases : eczema, Dühring's dermatitis herpetiformis, scabies.
• Condition after removal of the spleen (splenectomy) : as a component of post-splenectomy syndrome.

Diagnostics

Leukocytosis is detected during a clinical blood test. Since there are quite a few reasons for an increase in the level of leukocytes, you should first consult a general practitioner. The doctor collects a detailed history, conducts a physical examination of the patient, including measuring body temperature, examining the skin and mucous membranes, etc. Based on the data obtained, in order to confirm the disease that caused leukocytosis, the following studies are prescribed:

• Blood tests . Markers of inflammation are determined in the blood - high ESR and CRP, autoantibodies (rheumatoid factor, ACCP, antibodies to the cytoplasm of neutrophils). Be sure to calculate the leukocyte formula (percentage of leukocyte forms). A blood smear is being studied for the presence of toxic granularity of neutrophils, atypical mononuclear cells, Botkin-Gumprecht shadows. If a septic condition is suspected, presepsin is measured.
• Identification of the pathogen . To identify the infectious agent as the cause of leukocytosis, a bacterial culture of blood, sputum, and urine is performed. Antibodies (class G and M immunoglobulins) to bacteria, viruses, helminths are determined by enzyme immunoassay, and their DNA is detected using polymerase chain reaction.
• Allergy diagnostics . In order to confirm the allergic nature of the disease, the level of immunoglobulin E (IgE) is measured by ELISA. To identify the causative allergen, basophilic tests, various allergological tests are performed - skin (scarification, application, prick tests), provocative (nasal, inhalation, conjunctival) tests.
• Radiography . In case of pneumonia, chest x-rays show infiltrates in the lungs, foci of blackout, and x-rays of the joints in patients with arthritis show narrowing of the joint space, osteoporosis, and bone erosion. In osteomyelitis, x-rays of the bones reveal thickening of the periosteum, sequestration foci (areas of bone necrosis).
• ultrasound . In pyelonephritis, an ultrasound examination of the OBP reveals an increase in the size of the kidneys, expansion and compaction of the pelvicalyceal system. Hepatosplenomegaly is characteristic of infectious mononucleosis. Echocardiography may show vegetations on the valves, pericardial effusion.
• Histological studies . If leukemia is suspected, a trepanobiopsy or sternal puncture is performed, the material of which reveals hyperplasia of the granulocytic germ, a large number of blast cells. For the diagnosis of lymphomas, an aspiration biopsy of an enlarged lymph node is performed, the biopsy reveals lymphocytic hypercellularity, collagen proliferation, Berezovsky-Sternberg giant cells.

The leukocyte formula allows you to determine the percentage of different types of leukocytes

Treatment for leukocytosis

There is no symptomatic treatment for leukocytosis. To normalize the level of white blood cells, it is necessary to fight the underlying pathology that caused leukocytosis. With a slight leukocytosis during the recovery period from an infectious disease, no medical intervention is needed. However, even a moderate increase in leukocytes in the blood, which persists for a long time, requires a specialist consultation to find out the cause.

For the treatment of diseases accompanied by leukocytosis, antibacterial, antiviral, anthelmintic drugs are used. If the high content of leukocytes is due to rheumatological pathology, agents that suppress the inflammatory process (glucocorticosteroids, immunosuppressants) are used. Allergic reactions are effectively stopped by antihistamines and corticosteroids.

If the cause of leukocytosis was malignant hematological diseases, a long course of chemotherapy is required, and in some cases, allogeneic bone marrow transplantation. Suppurative processes (phlegmon, abscesses) are subject to surgical intervention, which involves dissection of soft tissues, washing and drainage of the focus. Endocarditis may require valve repair or replacement.

Forecast

Leukocytosis alone cannot be a predictor of sequelae or complications. It is impossible to predict the prognosis and risk of death from it. The outcome directly depends on the cause, i.e. the disease that caused leukocytosis, as well as the degree of its severity. For example, an acute respiratory viral infection almost always proceeds benignly, ends in complete recovery and does not affect life expectancy in any way. Pathologies such as systemic vasculitis, hemoblastoses are characterized by a high percentage of mortality. Therefore, at any level of increase in leukocytes in the blood, a thorough examination is indicated, aimed at finding out the cause and timely initiation of treatment.