Function of neutrophils in preleukaemia

Area of Science:

• Hematology
• Immunology
• Oncology

Background:

• Preleukaemia is a condition characterized by an increased risk of developing acute myeloid leukaemia.
• Neutrophil granulocytes play a critical role in the innate immune system, primarily in combating bacterial infections.

Purpose of the Study:

• To investigate the in vitro function of blood neutrophil granulocytes in patients diagnosed with preleukaemia.
• To assess neutrophil chemotaxis, phagocytosis, and bactericidal activity in this patient cohort.
• To correlate observed neutrophil defects with chromosomal abnormalities and clinical outcomes, particularly infection susceptibility.

Main Methods:

• In vitro functional assays were performed on blood neutrophil granulocytes isolated from 17 preleukaemia patients.
• Neutrophil function parameters evaluated included chemotaxis, phagocytosis of Staphylococcus aureus, and bacterial killing capacity.
• Bone marrow karyotyping was conducted to identify chromosomal abnormalities in patients with identified neutrophil defects.

Main Results:

• Three patients exhibited cellular defects in neutrophil chemotaxis, with two having monosomy-7 and one having trisomy-8.
• A statistically significant tendency towards reduced phagocytosis and impaired Staphylococcus aureus killing was observed.
• Patients with chemotactic defects and monosomy-7 experienced recurrent infections, febrile episodes, and cutaneous abscesses, with one fatality due to sepsis.

Conclusions:

• Defects in neutrophil granulocyte function are frequently observed in patients with preleukaemia.
• These functional impairments in neutrophils may contribute to a compromised immune response and increased susceptibility to infections.
• The findings highlight the clinical significance of neutrophil dysfunction in preleukaemia and its association with adverse infectious outcomes.