Autoimmune neutropenia

Signs and symptoms

Neutropenia, which may be discovered on routine blood tests, typically causes benign infections even when the condition is severe. Ear infections (otitis media) are the most common infection seen in autoimmune neutropenia and typically infection responds to antibiotic treatment alone. Infections associated with primary AIN are usually mild and limited, including skin infections such as impetigo, gastroenteritis, upper respiratory tract infections, and ear infections. Rarely, cellulitis and abscesses may occur.
Studies of children studied for up to six years showed that most cases of autoimmune neutropenia resolved spontaneously after a median of 17 months. In 95 percent of patients, neutropenia persisted for 7 to 24 months.

Diagnosis

The diagnosis of autoimmune neutropenia is based on blood tests demonstrating neutropenia and the presence of granulocyte-specific antibodies. In some cases, tests for granulocyte-specific antibodies must be repeated several times before a positive result is seen. Bone marrow aspiration, if performed, is typically normal or it can show increased cell production with a variably diminished number of segmented granulocytes.
An association with prior parvovirus B19 has been made, but this hasn’t been confirmed. Similar to the platelet deficiency idiopathic thrombocytopenic purpura, vaccines are suspected of triggering this disorder.

Treatment

Treatment consists of corticosteroids to reduce autoantibody production, antibiotics to prevent infection and granulocyte colony-stimulating factor (G-CSF) to temporarily increase neutrophil counts. In cases of severe infection or the need for surgery, intravenous immunoglobulin therapy may be used.

Prognosis

This form of neutropenia usually disappears in two to three years of a child's life in 95% of cases.
The use of prophylactic antibiotics has been proposed.