Clinical Course of Neutropenia in Previously Healthy Children / 임상소아혈액종양

ABSTRACT

BACKGROUND: Neutropenia can be easily found in previously healthy children associated with various medical conditions, and the clinical course ranges from transient benign to life threatening. This study aimed to investigate the etiology, clinical characteristics, and clinical courses of neutropenia in previously healthy children. METHODS: We evaluated 215 previously healthy children under aged 18 years who diagnosed with neutropenia in two hospitals. Clinical and laboratory features were analyzed retrospectively based on the medical records. RESULTS: Transient infectious neutropenia (TIN) accounted for 97.7% of cases and chronic neutropenia (CN), for 2.3%. An infectious agent was identified in 128/210 (61%) patients with TIN, and the most frequent agents were viruses (46.5%). The most common viral agent was respiratory syncytial virus (RSV) (29%). TIN subgroups exhibited no differences in severity according to infectious agent (virus, bacteria, Mycoplasma); however, neutropenia severity differed among viral agents [mild-to-moderate neutropenia in the RSV group (857.3±293.3/µL) and moderate-to-severe neutropenia in the parainfluenza group (567.3±198.1/µL); P=0.017]. All patients with CN had anti-neutrophil antibody positivity (autoimmune neutropenia, AIN), and moderate-to-severe neutropenia predominated. The median duration of TIN was 8 days (range, 3–286 days), and it was significantly longer for AIN at 330 days (range, 217–730 days) (P=0.000). The median duration of neutropenia was also different according to each viral agent, with 4 days (range, 3–11 days) for the RSV group and longer durations for 3 other groups (influenza, parainfluenza, other respiratory viruses) (P=0.015). CONCLUSION: Neutropenia in previously healthy children is usually of transient infectious origin, with mild-to-moderate severity, and it resolves spontaneously without complications.