Antimicrobial use before chronic lymphocytic leukemia: a retrospective cohort study

Area of Science:

• Hematology
• Immunology
• Epidemiology

Background:

• Chronic lymphocytic leukemia (CLL) is associated with a higher risk of severe infections.
• The underlying reasons for infection susceptibility in CLL patients, beyond disease-related immune dysfunction, are not fully understood.

Purpose of the Study:

• To investigate whether individuals with Chronic lymphocytic leukemia (CLL) have a constitutional susceptibility to infections.
• To explore the timeline of infection susceptibility preceding a CLL diagnosis.

Main Methods:

• Utilized nationwide Danish registers to link data for CLL patients and matched controls.
• Assessed antimicrobial use as a proxy for infection susceptibility up to 22 years before diagnosis.
• Examined antimicrobial use in children and grandchildren of CLL patients.

Main Results:

• CLL patients exhibited increased use of macrolides, antimycotics, and antivirals for up to 22 years before diagnosis compared to controls.
• Antimicrobial use began a gradual increase in CLL patients approximately six years prior to their leukemia diagnosis.
• A similar pattern of increased antimicrobial use was observed in the children and grandchildren of CLL patients.

Conclusions:

• The findings suggest that increased infection susceptibility precedes CLL diagnosis by decades.
• This prolonged period of susceptibility is consistent with a potential role for immune dysfunction or infections in CLL pathogenesis.
• A constitutional predisposition to infections may be linked to the risk of developing CLL.