Lymphocytosis

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Lymphocytosis Classification and external resources
ICD-10	D72.8
ICD-9	288.8
DiseasesDB	7678
MeSH	D008218

Lymphocytosis is an increase in the number or proportion of lymphocytes in the blood, usually detected when a complete blood count is routinely obtained. Lymphocytes normally represent 20 to 40% of circulating white blood cells. The absolute lymphocyte count (ALC) can be directly measured by flow cytometry, or calculated by multiplying the total white blood cell (WBC) count by the percentage of lymphocytes found in the differential count^[1]. In absolute lymphocytosis, the total lymphocyte count is elevated above the population reference range (normal). In adults, absolute lymphocytosis is present when the absolute lymphocyte count is greater than 4000 per microliter, in older children greater than 7000 per microliter and in infants greater than 9000 per microliter^[2]. Relative lymphocytosis occurs when there is a higher proportion (greater than 40%) of lymphocytes among the white blood cells, however, absolute lymphocyte count (ALC) is normal (less than 4000 per microliter. Relative lymphocytosis is normal in children under age 2.

Contents 1 Symptoms 2 Causes 3 References 4 External links

[edit] Symptoms

Lymphocytosis ia a feature of infection, particularly in children. In the elderly, lymphoproliferative disorders, including chronic lymphocytic leukaemia and lymphomas, often present with lymphadenopathy and a lymphocytosis. The symptoms of the underlying disease.........

Fever, general malaise

[edit] Causes

Causes of absolute lymphocytosis include: acute viral infections, such as infectious mononucleosis (glandular fever), Epstein-Barr virus infection, and hepatitis; other acute infections such as pertussis and toxoplasmosis; chronic intracellular bacterial infections such as tuberculosis or brucellosis and Acute Lymphoblastic Leukemia.

Causes of relative lymphocytosis include: age less than 2 years; acute viral infections; connective tissue diseases, thyrotoxicosis, Addison's disease, and splenomegaly with splenic sequestration of granulocytes.

[edit] References

1. ^ For example, if the total WBC count is 30,000, and the %lymphocytes is 30, the absolute lymphocyte count is 9,000 per microliter.
2. ^ Miale, John B. Laboratory Medicine: hematology. 5th. St. Louis: C.V. Mosby, 1977.

[edit] External links

• Illustration

v • d • e Pathology: hematology, hematologic disease (primarily D50-D77, 280-289) RBCs/anemia/ hemoglobinopathy (Myeloid) nutritional anemia: Iron deficiency anemia, Plummer-Vinson syndrome, Megaloblastic anemia (Pernicious anemia) hereditary hemolytic anemia: enzyme disorders (G6PD Deficiency, Pyruvate kinase deficiency,Triosephosphate isomerase deficiency), Thalassemia, Sickle-cell disease/trait, Hereditary spherocytosis, Hereditary elliptocytosis, Hereditary stomatocytosis acquired hemolytic anemia: Autoimmune (Warm), HUS, MAHA, PNH, PCH aplastic anemia: Acquired PRCA, Diamond-Blackfan anemia, Fanconi anemia • Sideroblastic anemia Polycythemia - Methemoglobinemia Coagulation/platelets (Myeloid) coagulopathy: DIC (Congenital afibrinogenemia, Purpura fulminans) • Hemophilia (A/VII, B/IX, C/XI, XIII) • Von Willebrand disease • Hypoprothrombinemia Purpura: Henoch-Schönlein, ITP (Evans syndrome), TTP primary hypercoagulable state: Protein C deficiency - Protein S deficiency - Antithrombin III deficiency - Factor V Leiden - Activated protein C resistance - Antiphospholipid syndrome other hemorrhagic conditions: Bernard-Soulier syndrome - Glanzmann's thrombasthenia - Grey platelet syndrome - May Hegglin anomaly - Pelger-Huet anomaly Essential thrombocytosis - Thrombocytopenia Monocytes/Macrophages (Myeloid) WHO-I histiocytosis (Langerhans cell histiocytosis) WHO-II/non-Langerhans-cell histiocytosis (Juvenile xanthogranuloma, Hemophagocytic lymphohistiocytosis) WHO-III/malignant histiocytic disorders (Acute monocytic leukemia, Malignant histiocytosis, Erdheim-Chester disease) -cytosis: Monocytosis -penia: Monocytopenia Granulocytes (Myeloid) -cytosis: granulocytosis (Neutrophilia, Eosinophilia, Basophilia) -penia: Granulocytopenia/agranulocytosis (Neutropenia, Kostmann syndrome) Other/general myeloid Chronic granulomatous disease Lymphoid -cytosis: Lymphocytosis -penia: Lymphopenia Other Splenic disease (Asplenia/hyposplenism, Wandering spleen) - Pancytopenia See also hematological malignancy and immune disorders