Erythrocyte antigens Lewis a/b

Heparinized blood, 1ml

About 80% of the population are so-called secretors and about 20% are so-called non-secretors.
The secretor status can be detected with the help of the Lewis blood group system, since the same gene is responsible for the secretor status and the Lewis system.
Secretors are Lewis(a-b+)
Non-secretors are Lewis(a+b-)
About 2-5% of the population are so-called "double" Lewis-negative (a-b-). For this minority, the Lewis blood group system is useless for determining secretor status.

Allegedly, non-secretors have poor defences and thus more frequent infections, Graves' disease, allergies, fibromyalgias, diabetes, reactive arthritis, liver problems, heart disease and more tooth decay.