Neutropenia

Neutropenia is a hematologic condition characterized by an abnormally low concentration of neutrophils, the most abundant type of white blood cell essential for combating bacterial and fungal infections. This deficiency compromises the immune system's first line of defense, significantly increasing susceptibility to recurrent and potentially severe infections.ncbi.nlm.nih+3

Definition and Classification

Neutropenia is clinically defined as an absolute neutrophil count (ANC) below 1,500 cells per microliter (1,500/µL) of blood. The condition is stratified by severity: mild (1,000–1,500/µL), moderate (500–1,000/µL), severe (<500/µL), and agranulocytosis (near-complete absence). Severity directly correlates with infection risk, with severe cases requiring immediate medical intervention.

Causes and Pathophysiology

Common etiologies include chemotherapy, radiation therapy, bone marrow disorders (e.g., leukemia, aplastic anemia), autoimmune diseases (e.g., lupus), viral infections (e.g., HIV, hepatitis), and certain medications (e.g., clozapine, antibiotics). Mechanisms involve decreased neutrophil production in bone marrow, increased peripheral destruction, or abnormal sequestration.

Symptoms and Management

Neutropenia often presents asymptomatically until infection occurs. Fever, oral ulcers, skin abscesses, and respiratory infections are typical manifestations. Diagnosis involves complete blood count (CBC) and differential. Treatment addresses underlying causes, administers antibiotics for infections, and may include granulocyte-colony-stimulating factors (G-CSF) to stimulate neutrophil production.