Secretory IgA Secretion Rate Linked to Risk of Cancer Death
HealthDay News — Higher secretion rates of secretory immunoglobulin A (sIgA) are associated with decreased risk of cancer death, specifically non-lung cancer, according to a study published online Dec. 23 in PLOS ONE.
Anna C. Phillips, PhD, from the University of Birmingham in the United Kingdom, and colleagues examined the correlations between sIgA in saliva and mortality rates in the general population. Data were included for 639 adults from the eldest cohort of the West of Scotland Twenty-07 Study, who were aged 63 years at saliva sampling in 1995. Saliva volume and sIgA concentration were measured from unstimulated two-minute saliva samples; the sIgA secretion rate was determined as their product.
The researchers found that log sIgA secretion rate was negatively associated with all-cause mortality (hazard ratio, 0.81; P<0.001).The all-cause association was due to an underlying association with cancer mortality, especially with non-lung cancer. The hazard ratio for non-lung cancer was 0.68; for each standard deviation rise in log sIgA secretion rate there was a 32% reduction in mortality risk. There was a non-linear relationship between sIgA secretion and mortality risk for deaths from respiratory disease, with elevated risk seen for the very lowest levels of secretion. A similar, but weaker, pattern of association was seen for sIgA concentration.
"It appears that sIgA plays a protective role among older adults, and could serve as a marker of mortality risk, specifically cancer mortality," the authors write.