IgA deficiency and mortality: a population-based cohort study

Area of Science:

• Immunology
• Clinical Epidemiology
• Public Health

Background:

• Selective IgA deficiency is the most common primary immunodeficiency.
• While linked to increased morbidity, data on mortality risk in IgA deficiency is limited.
• Understanding long-term outcomes is crucial for patient management.

Purpose of the Study:

• To investigate the all-cause mortality risk in individuals diagnosed with IgA deficiency.
• To compare mortality rates between IgA deficient patients and matched general population controls.
• To analyze mortality trends over time and by age group.

Main Methods:

• Population-based prospective cohort study utilizing Swedish national registers.
• Identified 2,495 individuals with IgA deficiency (≤0.07 mg/L) from 1980-2012.
• Matched each patient with up to 10 general population controls (n=24,509) on age, sex, residence, and diagnosis year.
• Used Cox regression to estimate hazard ratios, adjusting for education level.

Main Results:

• A total of 260 deaths occurred in the IgA deficiency group versus 1,599 in controls.
• The conditional mortality hazard ratio was 1.8 (95% CI 1.6–2.1), indicating a significantly increased risk.
• Higher relative mortality was observed in the first 10-15 years post-diagnosis and in younger patients.

Conclusions:

• Patients with IgA deficiency have a substantially increased risk of all-cause mortality.
• The elevated mortality risk is most pronounced in the initial 10-15 years following diagnosis.
• Age at diagnosis also modifies the mortality risk, with younger individuals facing higher relative risks.