Association of chronic arsenic exposure with cellular immune profile in MINIMat adolescents: A birth cohort in Bangladesh

Chronic arsenic exposure is known to affect the immune system. We aimed to evaluate the association between arsenic exposure and immune cell profile in 15 years old adolescents (n=389) in rural Bangladesh, with chronic exposure to groundwater arsenic. Single blood and urine were collected. Urinary arsenic (U-As) concentration was measured using atomic absorption spectrometry. Peripheral blood mononuclear cells (PBMC) were analyzed by flow cytometry. Non-linear association was found between U-As (median, 24.9 µg/L) and immune cells with a cut-off at U-As 20 µg/L. U-As (<20 µg/L) were significantly associated with increases in CD8⁺T (21 %), na^ïve CD8⁺T (42 %) and early B cells (40 %), and classical monocytes (55 %), but reduction in CD3⁺T cells (37^%) and intermediate-monocytes (56 %). U-As (>20 µg/L) were associated with a 3 % reduction in memory B cells. Arsenic exposure was associated with altered immune cell profile in adolescents likely rendering them vulnerable to adverse health effects in later life.