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The causes of increase and decrease in monocytes
Last reviewed: 22.11.2021
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Monocytosis - an increase in the number of monocytes in the blood more than 0.8 × 10 9 / l - accompanies a number of diseases. Monocytes are elevated in tuberculosis; the appearance of monocytosis is considered a proof of the active spread of the tuberculosis process. An important indicator is the ratio of the absolute number of monocytes to lymphocytes, which is normally 0.3-1.0. This ratio is more than 1 in the active phase of the disease and decreases with recovery, which is used to assess the course of tuberculosis.
Diseases and conditions in which monocytosis is possible
Main reasons | Clinical forms |
| Infections |
Subacute infective endocarditis; period of recovery after acute infections; viral ( infectious mononucleosis ), fungal, rickettsial and protozoal infections ( malaria, leishmaniasis ) |
| Granulomatosis |
Tuberculosis, especially active; syphilis; brucellosis; sarcoidosis; ulcerative colitis |
| Diseases of the blood | Acute monoblastic and myelomonoblastic leukemia; chronic monocytic, myelomonocytic and myeloid leukemia; lymphogranulomatosis |
|
Collagenoses |
Systemic lupus erythematosus, rheumatoid arthritis, nodular polyarteritis |
Also, monocytes are elevated in infectious endocarditis, sluggish sepsis, which is often observed in the absence of leukocytosis. Relative or absolute monocytosis is noted in 50% of patients with systemic vasculitis. Short-term monocytosis can develop in patients with acute infections during convalescence.
Monocytopenia - a decrease in the number of monocytes less than 0.09 × 10 9 / l. Monocytes are lowered by hypoplasia of hematopoiesis.