Increased in vitro neutrophil adherence in a case of chronic idiopathic neutropenia

Summary In this report we describe a patient with persistent neutropenia whose neutrophils showed increased adhesion in a microplate assay. In three separate assays, from 12·5% to 13·7% of the patient's blood neutrophils exhibited spontaneous (unstimulated) adhesion to fetal bovine serum‐coated microplate wells, much higher than adhesion of cells from healthy controls (1·9% 2·5 SD, n= 20). The difference of spontaneous adhesion between the patient's and control neutrophils was even higher when cells from a skin‐window exudate were examined (patient: 42·1–100% adhesion: control: 3·6% 3·5 SD, n= 20). Over 80% inhibition of the increased adhesion was produced by the 60.3 anti‐CD 18 monoclonal antibody, suggesting an involvement of β2‐integrins.