DISEASES OF Neutrophils

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Neutrophils are small cells with a nucleus with 2-5 lobes has short life span 6-8 hours.

   Function of neutrophils:

•          The prime function of neutrophils is to ingest and kill bacteria, fungi and damaged cells.

•          Neutrophils are released into the circulation in response to stimuli e.g infections and corticosteriods therapy.

•          Neutrophil leucocytosis (neutrophillia)
A rise in the number of circulating neutrophils to >10x10⁹ occur in bacterial infections or as a result of tissue damage, pregnancy, during excersise and corticosteriod therapy.

Causes of neutrophil leucocytosis

•          Bacterial infection

•           Tissue necrosis in myocardial infarction

•          Inflammation

•          Corticosteriod therapy

•          Hematological , myelofibrosis, Leukomoid reaction, Leukoerythroblastic reaction

•          Pregnancy, excersise

•          Malignant (breast,bronchial-gastric)

•          Metabolic ,renal failure

•           Congenital, neutrophil adhesion deficiency.

•          Neutropenia and agranulocytosis
Neutropenia is defined as a circulating neutrophil count below 1.5x10⁹/l. Absence of neutrophil is called agranulocytosis.

Causes of Neutropenia:

A- Congenital : is rare in which there is a defect in maturation and release of neutrphils from the bone marrow  (Kostman’s syndrome, cyclic neutropenia every 2-3 weeks).

•          Acquired causes
Viral infections, severe bacterial infections (typhoid)., Felty’s syndrome, immune neutropenia and pancytopenia.

•          Leukemia, myelosuppressive drugs, antiviral drugs, hypersplenism.

•          Clinical features:
Infections may be frequent when neutrophil count is below 0.5 (severe neutropenia) and may be associated with septicemia and may be associated with pneumonia and septicemia.

•          Patients presented by glazed mucositis in the mouth and ulceration.

•          Disseminated infection are usually occurred with septicemia, fungemia and deep abscesses, local infections ,mouth, perianal, skin damage and vascular catheters.

•          Treatment
Growth factors also used successfully in the treatment of chronic neutropenia.

•          Steroids and high dose intravenous immunoglobulins are used to treat patients with severe autoimmune neutropenia and recurrent infections.

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•          Causes of neutrophil dysfunction
A-Congenital:

•          1-Leucocyte adhesion defect: autosomal recessive disorder impaired leukocyte tissue localization,locomotion,and endocytosis.

•          2-Hyper-IgE syndrome: the syndrome characterized by very high levels of IgE,impaired neutrophil locomotion,severe eczema with frequent staphylococcal secondary infections, abscesses and fungal infections.            

•          Shwachman’s syndrome
Exocrine pancreatic insufficiency and Pyogenic infections, defects in neutrophil migration.

•          Chronic granulomatous disease

•          This is a congenital defect of neutrophil and monocyte killing.

•          Clinical features:

•          Patients have chronic suppurative granulommas or abccess affecting skin, lymph nodes, liver, lung as well as osteomyelitis.

Treatment: Antimicrobial therapy, surgical measures, regular gamma interferon can reduce the frequency of infection.

•          Acquired neutrophil dysfunction
Causes:

•          Corticosteriods therapy, affect neutrophil function and cell mediated immunity.