Significance of anti-neutrophil antibody in chronic benign neutropenia
in Chinese children
Abstract
Background: Chronic benign neutropenia (CBN) and autoimmune neutropenia
(AIN) are notoriously difficult to differentiate in children owing to
their indistinguishable clinical course and varying availability and
accuracy in the methods of anti-neutrophil antibody detection. This
study aims to investigate whether the presence of anti-neutrophil
antibody has implications on the disease course in Chinese children with
AIN, as well as evaluating the various methods including LABScreen
MULTI, granulocyte agglutination test (GAT) and granulocyte
immunofluorescence test (GIFT) in anti-neutrophil antibody detection.
Procedure: Chinese children under 18 years of age with neutropenia ≤ 1.5
x 109/L lasting 6 months or more in our single center were recruited
into the study between 2016 to 2018. Patients with secondary causes of
neutropenia were excluded. Blood for anti-neutrophil antibody and
genotyping was taken once at the time of recruitment and subsequently
when neutropenia recovered to ≥ 1.5 x 109/L. A combination of two
in-house methods including GIFT, GAT and commercial kit LABScreenTM
multipanel were used for the detection of antibodies. The age of onset,
age of recovery, duration of neutropenia, gender, serial neutrophil
counts, incidence of invasive infection, use of G-CSF were examined.
Results: Using combined testing methods, anti-neutrophil antibody was
detected in 30.8 % of patients and positivity was associated with more
severe neutropenia, higher likelihood of infection and slower and later
recovery compared to those without antibodies. Conclusions: The presence
of anti-neutrophil antibody was useful in predicting the clinical course
of patients with AIN. The use of combined testing methods increased the
detection rate.