Editor-In-Chief: C. Michael Gibson, M.S., M.D. ; Associate Editor(s)-in-Chief: Lakshmi Gopalakrishnan, M.B.B.S. 
Synonyms and keywords: Neutrophilia, congenital neutrophilia
Granulocytosis is defined as the presence of an increased number of granulocytes, a category of white blood cells present in the peripheral blood. Often, the word refers to an increased neutrophil granulocyte count, as neutrophils are the main granulocytes. An increase in eosinophil granulocyte is known as eosinophilia. In cardiovascular disease, increased white blood cell counts have been shown to indicate a worse prognosis.
Granulocytosis can be a feature of a number of diseases:
- Infection, especially bacterial
- Malignancy, most notably leukemia (it is the main feature of chronic myelogenous leukemia, CML)
- Autoimmune disease
Causes by Organ System
Causes in Alphabetical Order
- Acute intermittent porphyria
- Acute myeloid leukemia
- Acute pancreatitis
- Acute promyelocytic leukemia
- Adult-onset Still's disease
- Bronchiolitis obliterans organizing pneumonia
- Chronic myeloid leukaemia
- Congenital syphilis
- Extrinsic allergic alveolitis
- Gallbladder empyema
- Granulocyte colony stimulating factor
- Granulocyte-macrophage colony stimulating factor
- Hereditary neutrophilia
- Hyperimmunoglobulinemia D and periodic fever syndrome
- Leukocyte adhesion deficiency type 1
- Leukocyte adhesion deficiency type 2
- Leukocyte adhesion deficiency type 3
- Leukemoid reaction
- Mast cell leukemia
- Polycythaemia rubra vera
- Recurrent hereditary polyserositis
- Severe acute respiratory syndrome
- Thrombin human
- Urate crystal arthropathy
- Wegener granulomatosis
A "left shift" refers to the presence of increased proportions of younger, less well differentiated neutrophils and neutrophil-precursor cells in the blood. This generally reflects early or premature release of myeloid cells from the bone marrow, the site where neutrophils are generated. A severe neutrophilia with left shift is referred to as a leukemoid reaction. The leukocyte alkaline phosphatase (LAP) score, which refers to the amount of alkaline phosphatase per neutrophil, will increase. In a severe infection, toxic granulation changes happen to the neutrophils.
This can resemble Pelger-Huet anomaly.
- ↑ Mohamed IS, Wynn RJ, Cominsky K; et al. (June 2006). "White blood cell left shift in a neonate: a case of mistaken identity". J Perinatol. 26 (6): 378–80. doi:10.1038/sj.jp.7211513. PMID 16724080.
- ↑ Shmuely H, Pitlik SD, Inbal A, Rosenfeld JB (June 1993). "Pelger-Huët anomaly mimicking 'shift to the left'". Neth J Med. 42 (5–6): 168–70. PMID 8377874.