Leucocytosis

Definition

An increase in numbers of circulating leucocytes to greater than 11x 10x9/l

Neutrophilia (>7.5 x10x9/l)

Commonest cause of leucocytosis

Often associated with toxic granulation, shift to the left with band forms and occasional metamyelocytes, and Dohle bodies. Seeen in association with the following condition:

1- Acute infection-e.g. abscesses, septicaemia

2- Tissue damage-e.g. myocardial infarction, burns, gangrene, vasculitis

3- Neoplasia

4- Haemorrhage and haemolysis

5- Chronic myeloid leukaemia, chronic myelomonocytic leukaemia, myelofibrosis

6- Metabolic disorders e.g. diabetes, gout, uraemia

7- Drugs-e.g. predenisolone, lithium

8- Strenuous exercise

Eosinophilia

Seen in association with:

1- Allergy-e.g. hay fever, athma, urticaria

2- Parasitic infections, especially if there is tissue invasion

3- Skin diseae-e.g. eczema, dermatitis herpetiforms, psoriasis

4- Myeloproliferative disease, e.g. PRV, CML, chronic eosinophilic leukaemia

5- Neoplasia-especially Hodgkin`s disease (5% patients)

6- Miscellaneous-e.g. polyarteritis nodisa, plmonary eosinophilia (parasitic infiltraton; loeffler`s syndrome), sarcoidosis, hypereosinophilic syndrome, post irradiation

Monocytosis

Seen in association with the following conditions:

1- Infection-e.g. tuberculosis, brucellosis, subacute bacterial endocarditis, typhus, malaria, kala-azar

2- Inflammatory disorders-e.g. rheumatoid arthritis, SLE, Crohn`s disease, ulcerative colitis

3- Neoplasia

4- Haematological malignancy-e.g.CMML, AML-M4 ansd M6

Basophilia

Seen in association with:

1-Myxoedema

2- Chickenpox

3- Myeloproliferative disorders, especially PRV oR CML (may herald blastic transformation)

Lymphocytosis

Seen in association with:

1- Acute infection-e.g. infectious mononucleosis, rubella, pertussis, mumps, infectious lymphocytosis

2- Chronic infections-e.g. brucellosis, tuberculosis, syphilis, hepatitis

3- Haematological disorders-e.g. chronic lymphocytic leukaemia, hairy cell leukaemia, chronic T-cell lymphocytosis (large granular lymphocytes)

Leukamoid reaction

Extremely high leucocyte count (>50x10x9/l) seen in non leukaemic condition, simulating myeloid or lymphatic leukaemia. Seen in association with severe infections, especially in children and splenectomised patients.