Pro-LL-37 and neutrophil count sharpen childhood autoimmune neutropenia diagnosis

The wire

1. 01In 214 suspected autoimmune neutropenia cases, children positive on all three assays had significantly higher pro-LL-37 levels and lower absolute neutrophil counts, a pattern the authors read as preserved granulopoiesis with peripheral destruction.
2. 02The findings question use of the bead-based assay as a standalone test and position pro-LL-37 as an adjunct marker separating antibody-mediated neutropenia from congenital and idiopathic forms.
3. 03LL-37 here is a diagnostic readout rather than a therapy; the British Journal of Haematology study is retrospective assay comparison and needs prospective validation before changing workups.

From the source

Autoimmune neutropenia in children: Test cells versus beads and a role for pro-LL-37 and absolute neutrophil count

British journal of haematology · 2026 Aug 26 · Ratcliffe P, Löfstedt AH, Sundin M et al.