Neutropenia can occur due to the presence of autoantibodies.
Diagnostic features:
(1) absolute neutrophil count less than 1,500 per µL
(2) presence of antibodies to neutrophil antigens that are present on the patient's neutrophils
(3) bound IgM or IgG antibodies to neutrophils
(4) no other causes (myelodysplasia, hypoplasia, etc) that can explain the neutropenia better
The condition may be primary or secondary.
Secondary causes include:
(1) autoimmune disease
(2) malignancy
(3) infection (viral infection, other)
(4) associated with neurological diseases
(5) drug exposure
