Severe Chronic Neutropenia in Korean Children.

Severe chronic neutropenia (SCN) is a rare hematologic disorder defined by an absolute neutrophil count less than 0.5×10⁹/L for several months or years. They usually suffer from recurrent infections. Principal subtypes of SCN are congenital, cyclic, idiopathic and primary autoimmune neutropenia (AIN).

Medical records collected from a national survey were retrospectively analyzed on newly diagnosed SCN patients in Korea between January, 1999 and December, 2008 in respect to the diagnosis, clinical manifestations, treatments and prognosis of the patients.

There were 64 patients (Male, 20; Female 44) reported from 16 hospitals: congenital, 19; cyclic, 16; idiopathic, 25; and immune in origin, 4. The main clinical manifestation was various types of bacterial infections. Two cases (1 congenital, 1 cyclic) were diagnosed by family histories. The median age at diagnosis was 12 months (11 days-158 months). A bone marrow examination was done in 45 patients (70.3 %) at the median age of 26 months (1 day-158 months), with the interval between the initial CBC and BM study being 7.3 months (9 days-138 months). The ELA2 mutation, done in 6 patients, was not detected. Only one patient with congenital SCN evolved to AML at 54 months after diagnosis, who is under chemotherapy. Most patients were treated with G-CSF (5-10 μg/kg/day) during infection episodes. The median follow up duration was 23 months (11 days – 176 months). Two patients of congenital SCN died of infection (pneumonia, meningitis) and 8 patients were lost to follow up, and the remaining are alive.

SCN is a rare hematologic disease with inherent vulnerability to infections, thus early detection with proper management should be important for survival of SCN patients. We propose a nation-wide, prospective study to delineate the prevalence, molecular diagnosis, natural history, the optimal use of G-CSF, and prognostic factors in Korean patients with SCN.

No relevant conflicts of interest to declare.