neutropenic

Neutropenic is an adjective describing a state in which neutrophil counts are abnormally low. Neutrophils are a type of white blood cell crucial for defense against bacterial and fungal infections. Clinically, neutropenia is defined by the absolute neutrophil count (ANC). An ANC below 1.5 x 10^9/L is neutropenia; values are categorized as mild (1.0–1.5 x 10^9/L), moderate (0.5–0.99 x 10^9/L), and severe (<0.5 x 10^9/L). Profound neutropenia is often defined as ANC <0.1 x 10^9/L. The duration can be transient or chronic.

Causes include cytotoxic chemotherapy, radiation therapy damaging bone marrow, hematologic diseases such as aplastic anemia or myelodysplastic syndromes, bone marrow transplantation, autoimmune neutropenia, certain medications, severe infection, and nutritional deficiencies.

Most people with neutropenia are asymptomatic; fever is the most common presenting sign of infection, and mucositis or other infections may occur due to reduced neutrophil function.

Diagnosis relies on a complete blood count with differential to determine ANC and monitor trends, often with repeated testing. Additional tests aim to identify underlying causes and infectious etiologies.

Management depends on severity and risk. Mild neutropenia may require monitoring; severe or prolonged neutropenia increases infection risk and may prompt treatment with growth factors such as granulocyte colony-stimulating factor (G-CSF) to shorten duration in selected patients. In febrile neutropenia, prompt empiric broad-spectrum antibiotics after obtaining cultures are recommended. Preventive measures include good hand hygiene, avoidance of crowded places, and, in certain patients, prophylactic antimicrobials or G-CSF.

Prognosis relates to the degree and duration of neutropenia and the patient’s comorbid conditions; recovery of neutrophil counts typically follows improvement of the underlying condition.