DECTIN1 Y238X polymorphism associates with defective Dectin-1 activity. (A) Surface Dectin-1 expression in unstimulated CD14⁺ monocytes from WT or heterozygous persons for the DECTIN1 Y238X polymorphism. Dectin-1 expression was assessed in 8 WT and 4 Y238X heterozygous persons. Representative flow cytometry graphs of extracellular Dectin-1 staining (dark gray peak) and isotype control (light gray peak) are shown. (B) Cytokine production by human PBMCs from WT or heterozygous persons for the DECTIN1 Y238X polymorphism. Cytokine production (picograms per milliliter) was quantified by ELISA on culture supernatants of cells stimulated with heat-inactivated A conidia, β-glucan or phytohemagglutinin for 72 hours. Shown are the results of 8 WT and 4 Y238X polymorphic persons, assessed in triplicates. The detection limit of the assays was less than 0.5 pg/mL for each cytokine.