Detection of autoantibodies to neutrophils in a subset of individuals with ADAN and lower pro-LL-37 levels than in controls. (A) The outcome of tests for anti-neutrophil antibodies in 64 individuals with ADAN tested. (B) Fractions of healthy female and male blood donors with antibodies against either HLA class I or human neutrophil antigen (HNA). One of the 40 males and 6 of the 62 females were positive for GIFT. GIFT-positive samples were subjected to LabScreen Multi (LSM), a bead-based screening method on the Luminex platform (Thermo Fisher Scientific) capable of differentiating HNA and HLA class I antibodies in setting of alloimmunization. GIFT reactivity in all donors except 1 could be explained by HLA class I antibodies and only 1 of the female donors showed weak reactivity against HNA in LSM. (C) Plasma levels of hCAP-18/pro-LL-37 in the ADAN group and in healthy donors. Pos, positive result; neg, negative result.