Lymphocytosis is a higher-than-normal amount of lymphocytes, a subtype of white blood cells, in the body. Lymphocytes are part of your immune system and work to fight off infections. Lymphocytosis results from increased numbers of lymphocytes in your blood.
Lymphocytes are a type of white blood cell. They play an important role in your immune system, helping your body fight off infection. Many underlying medical conditions can cause lymphocytosis. High lymphocyte blood levels indicate your body is dealing with an infection or other inflammatory condition.
Sometimes, lymphocyte levels are elevated because of a serious condition, like leukemia. Your doctor can order specific diagnostic tests to help pinpoint the cause of your lymphocytosis. These tests may include other laboratory tests to rule out infections or tests examining other body tissues, like bone marrow biopsy and looking at your blood under a microscope.
Lymphocytosis itself does not cause symptoms. However, you may experience symptoms from the underlying cause of lymphocytosis. Depending on the cause, symptoms may range from no symptoms to severe. Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services.
Lymphocytosis Lymphocytosis is a condition that often results from your immune system working to fight off an infection or other disease.
There is an increase in white blood cells with this condition. Though it cannot be prevented, lymphocytosis can be treated by caring for the underlying cause. What is lymphocytosis? Who is most at risk for getting lymphocytosis?
Anyone can have lymphocytosis. How common is lymphocytosis?
Lymphocytosis is very common. What are the symptoms of lymphocytosis? Show More.Lymphocytosis lim-foe-sie-TOE-sisor a high lymphocyte count, is an increase in white blood cells called lymphocytes.
Lymphocytes help fight off diseases, so it's normal to see a temporary increase after an infection. A count significantly higher than 3, lymphocytes in a microliter of blood is generally considered to be lymphocytosis in adults. In children, the threshold for lymphocytosis varies with age. It can be as high as 9, lymphocytes per microliter. The exact thresholds for lymphocytosis can vary slightly from one lab to another.
This site complies with the HONcode standard for trustworthy health information: verify here. This content does not have an English version. This content does not have an Arabic version. Make an appointment. Visit now. Explore now. Choose a degree. Get updates. Give today. Request Appointment. Symptoms Lymphocytosis. Sections Basics Definition Causes When to see a doctor.You can have a higher than normal lymphocyte count but have few, if any, symptoms.
It usually occurs after an illness and is harmless and temporary. But it might represent something more serious, such as a blood cancer or a chronic infection. Your doctor might perform other tests to determine if your lymphocyte count is a cause for concern. If your doctor determines that your lymphocyte count is high, the test result might be evidence of one of the following conditions:.
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Sign up now. Causes By Mayo Clinic Staff. Show references Bain BJ, et al. Approach to the diagnosis and classification of blood cell disorders. In: Dacie and Lewis Practical Haematology. London, Eng: Elsevier; Accessed June 20, Davids MS. Approach to the adult with lymphocytosis or lymphocytopenia. Rochester, Minn. Coates TD.To save this word, you'll need to log in. See more words from the same year Dictionary Entries near lymphocytosis lymphocyte lymphocytic choriomeningitis lymphocytic leukemia lymphocytosis lymphogranuloma lymphogranuloma inguinale lymphogranulomatosis.
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Take the quiz Spell It Can you spell these 10 commonly misspelled words? Take the quiz Syn City Build a city of skyscrapers—one synonym at a time. Play the game.Leukocytosis is white cells the leukocyte count above the normal range in the blood.
It may also occur after strenuous exercise, convulsions such as epilepsy, emotional stress, pregnancy and labor, anesthesia, as a side effect of medication e. Lithiumand epinephrine administration. There are five principal types of leukocytosis: . This increase in leukocyte primarily neutrophils is usually accompanied by a "left upper shift" in the ratio of immature to mature neutrophils and macrophages.
The proportion of immature leukocytes increases due to proliferation and inhibition of granulocyte and monocyte precursors in the bone marrow which is stimulated by several products of inflammation including C3a and G-CSF. Although it may indicate illness, leukocytosis is considered a laboratory finding instead of a separate disease. This classification is similar to that of feverwhich is also a test result instead of a disease.
This fact shows suppression of bone marrow activity, as a hematological sign specific for pernicious anemia and radiation sickness. It is different from leukemia and from leukoerythroblastosisin which either immature white blood cells acute leukemia or mature, yet non-functional, white blood cells chronic leukemia are present in peripheral blood. Leukocytosis can be subcategorized by the type of white blood cell that is increased in number. Leukocytosis in which neutrophils are elevated is neutrophilia ; leukocytosis in which lymphocyte count is elevated is lymphocytosis ; leukocytosis in which monocyte count is elevated is monocytosis ; and leukocytosis in which eosinophil count is elevated is eosinophilia.
In this form there are so many WBCs that clumps of them block blood flow. This leads to ischemic problems including transient ischemic attack and stroke.
Leukocytosis is very common in acutely ill patients. It occurs in response to a wide variety of conditions, including viral, bacterial, fungal, or parasitic infection, cancer, hemorrhage, and exposure to certain medications or chemicals including steroids.
For lung diseases such as pneumonia and tuberculosis, WBC count is very important for the diagnosis of the disease, as leukocytosis is usually present. The mechanism that causes leukocytosis can be of several forms: an increased release of leukocytes from bone marrow storage pools, decreased margination of leukocytes onto vessel walls, decreased extravasation of leukocytes from the vessels into tissues, or an increase in number of precursor cells in the marrow.
Certain medications, including corticosteroidslithium and beta agonistsmay cause leukocytosis. From Wikipedia, the free encyclopedia. Redirected from Leucocytosis. This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. William, ed.
Leucocitozele; "Archived copy". Archived from the original on Retrieved Evaluation of Patients with Leukocytosis. Am Fam Physician. November ICD - 10 : DThey are comprised mainly of T, B, and natural killer NK cells, and the body typically maintains the absolute lymphocyte count ALC in a range of less than 4, lymphocytes per uL.
The mechanisms leading to an increased number of circulating lymphocytes include increased lymphocyte production, release of already formed lymphocytes into the blood, or decreased clearance of lymphocytes from the blood. A less common etiology of an elevated lymphocyte count is malignant lymphocytosis, where the lymphocyte count becomes elevated due to either an acute or chronic lymphoproliferative disorder.
An elevated lymphocyte count alone is unlikely to cause harm. Therefore, taking time to identify the underlying cause is essential, as treatment will differ substantially between reactive and malignant causes. For example, reactive lymphocytosis due to a viral infection, such as in infectious mononucleosis, requires no specific treatment other than supportive care. In contrast, acute lymphoblastic leukemia ALL may present with an elevated lymphoblast count which can easily be mistaken as a lymphocytosis.
Recognizing an elevated white blood cell count that is due to ALL is important, as this disease requires expedient treatment with intensive chemotherapy. Other causes of malignant lymphocytosis, such as chronic lymphocytic leukemia CLLexhibit a wide range of clinical behavior, and may or may not require expedient treatment depending on a variety of clinical and laboratory factors.
Most often, however, chronic lymphoproliferative disorders do not require urgent therapy. Even with highly elevated lymphocyte counts, it is unusual for patients to develop leukostasis or other signs and symptoms directly attributable to lymphocytosis. However, signs and symptoms resulting from the condition responsible for the elevated lymphocyte count may be important clues to help identify the underlying etiology.
For example, a young patient with lymphocytosis in the setting of fever, pharyngitis, fatigue, and splenomegaly would raise concern for infectious mononucleosis. In contrast, an older patient with lymphocytosis in the setting of lymphadenopathy, anemia, and thrombocytopenia would cause suspicion for CLL.
The time course of lymphocytosis can be a key discriminating factor between different etiologies. In general, lymphocytosis due to an infectious etiology such as mononucleosis will increase rapidly, and peak in the second or third week of illness. Although it may persist for up to 2 months, reactive lymphocytosis is generally self-limited. Malignant lymphocytosis may develop acutely or more gradually, and although it can wax and wane, it does not tend to resolve without specific treatment.
The rate of change of the lymphocyte count can influence treatment decisions. For example, a lymphocyte doubling time of less than 6 months is an important consideration in deciding when to initiate treatment of CLL.
Lymphocytosis: Management and Treatment
Lymphocyte morphology, as evaluated on the peripheral blood smear, can also be an important clue as to the possible cause of the lymphocytosis. For example, atypical lymphocytes with generous cytoplasm and eccentric nuclei are often seen in infectious mononucleosis. An elevated white blood cell count due to ALL may exhibit heterogeneity in the size of the malignant cells, with smaller cells being easily mistaken for lymphocytes.
The presence of large lymphoblasts with prominent nucleoli and pale blue cytoplasm suggests ALL and not true lymphocytosis. A complete blood count with manual differential should be ordered to accurately quantify the total white blood cell WBC and absolute lymphocyte count ALC. With patients in whom a reactive lymphocytosis is suspected, a thorough infectious work-up should be performed.Changes in total and differential leukocyte count are usually grouped into patterns, which facilitate interpretation.
These patterns are:. We have also provided useful tips on identifying the type of leukogram that is occurring see below. This is due to increased endogenous or exogenous administered corticosteroids. The classic leukogram pattern from increased corticosteroids either exogenous or endogenous includes a neutrophilia, lymphopenia, monocytosis, and eosinopenia.
Not all of these changes will be present in any given animal. The most consistent finding is lymphopenia, followed by a mature neutrophilia increase in segmented neutrophils, but not usually bands. Monocytosis from corticosteroids is fairly common in dogs, seen occasionally in cats, and seen only rarely in horses and cattle.
In one study, 8 ponies were given 2 mg dexamethasone IV likely not a good mimic of a stress response and leukocyte kinetics were monitored over several days Targowski Lymphocyte counts began to decrease at by 4 hours with the nadir 1. The eosinophil count rebounded by 72 hours. In another study, 2 horses given mg prednisolone IV roughly 0. In 8 thoroughbred horses given 1. In 3 calves given 0. The mechanisms for corticosteroid-related leukogram changes are as follows:.
A stress leukogram is specifically referring to the results of corticosteroids. It is tempting to use the term stress leukogram when describing a nervous animal, but these animals are likely to have an epinephrine response rather than a corticosteroid response. Changes on the leukogram due to epinephrine responses are most commonly seen in cats of any ageyoung horses 1 year of age or lessand possibly younger animals of other breeds. These changes are usually transient, and will diminish within about 30 minutes after the animal calms Rose et al Other changes in clinical pathologic results that may be seen with a physiologic leukocytosis are:.
The blood neutrophil count with inflammation represents the balance between tissue demand and bone marrow supply. The leukogram pattern can be variable depending on the source and severity of the inflammation. This occurs particularly with localized inflammation that is not inciting a systemic inflammatory response with associated clinical and clinical pathologic manifestations, such as fever, an inflammatory leukogram, hypoferremia and increased globulins.
If there is other clinical or laboratory evidence of inflammation in an animal, do not let the lack of an inflammatory leukogram dissuade you from considering that an inflammatory process may be occurring.
Since changes in the hemogram can occur frequently, monitoring hemogram results frequently every 12 to 24 hours can be very helpful in determining the course of an inflammatory response and response to treatment.
Regardless, never treat laboratory data, always treat the patient. With the classic inflammatory leukogram, the bone marrow senses an increased demand for neutrophils through cytokine stimulation. The bone marrow initially responds to this demand by releasing the storage pool of post-mitotic mature and band neutrophils, which results in a neutrophilia with a left shift with fewer band than segmented neutrophils, i.
Cytokines such as granulocyte and granulocyte-monocyte stimulating factor also kick in and stimulate granulopoiesis within days. Thus, the following changes are seen with a classic inflammatory leukogram:. With overwhelming inflammation, the bone marrow is unable to release enough leukocytes to keep up with peripheral demand, leading to leukopenia.
The typical leukogram pattern is:. Sequestered inflammation, such as a closed pyometra or an abscess, can result in a moderate to marked neutrophilia with or without a left shift and usually with little or mild toxic change mimicking a paraneoplastic leukocytosis.
There may be a concurrent monocytosis. Rupture of the lesion will result in a more severe inflammatory leukogram and corresponding clinical signs i.
Acute endotoxemia results in a different hematologic pattern, which may vary between species. Infusion of endotoxin int0 neonatal foals results in a rapid, transient neutropenia within hours, potentially without a left shift or toxic change, likely due to rapid margination of neutrophils and lymphopenia mechanism unclear within a few hours, followed by a neutrophilia by hours likely due to release of bone marrow stores.
The lymphopenia is too acute to be attributed to a stress response, being seen within hours after endotoxin infusion Lavoie et al