Chronic benign neutropenia among Chinese children.
OBJECTIVE
To delineate the clinical behaviour of chronic benign neutropenia in Chinese children in Hong Kong.


METHODS
Retrospective study.


METHODS
University teaching hospital, Hong Kong.


METHODS
All infants and children with absolute neutrophil count of 1.5 x 10(9) /L or lower for more than 3 months.


METHODS
Development of significant infection, and achievement of remission.


RESULTS
Twenty-four children with chronic benign neutropenia were identified between 1992 and 2001. Their median age of diagnosis was 9 months. The mean (standard deviation) initial absolute neutrophil count was 0.28 x 10(9) /L (0.24 x 10(9) /L). Twenty-three patients presented with infection. Of the 19 patients tested, four (21%) were positive for anti-neutrophil antibodies. Bone marrow examination was performed in 17 patients: nine had normal results, but six showed evidence of peripheral consumption, one showed late maturation arrest at band stage, and one showed phagocytosis of myeloid cells by histiocytes. The overall hospitalised infection rate was 51.6 episodes per 1000 patient-months. Ten percent of cases were considered 'significant' infections and required hospital admission with either surgical intervention or intravenous therapy (antibiotics or fluid replacement). In the first year of diagnosis, more than 80% of patients had their lowest absolute neutrophil count (mean, 0.16 x 10(9) /L; standard deviation, 0.11 x 10(9) /L). Granulocyte-colony stimulating factor was used to treat three patients and induced transient elevation of absolute neutrophil count in all three. The projected remission rate was 55.4% at 3 years. Even for those with persistent disease, there was significant recovery in absolute neutrophil count to a mean of 0.5 x 10(9) /L (P<0.01).


CONCLUSIONS
Patients with chronic benign neutropenia experienced a relatively benign clinical course regardless of their remission status. Only a small proportion of patients developed significant infections. A multi-centre prospective study may help identify predictive factors of remission.
Department of Paediatrics and Adolescent Medicine, The University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong.
B H Y
BH
Chung
G C F
GC
Chan
T  L
T
Lee
J S Y
JS
Kwok
A K S
AK
Chiang
H K
HK
Ho
S Y
SY
Ha
Y L
YL
Lau
D001327:Autoimmune Diseases / Q000453:epidemiology / Q000208:ethnology*; D001424:Bacterial Infections / Q000453:epidemiology / Q000208:ethnology*; D002675:Child, Preschool; D002908:Chronic Disease; D015331:Cohort Studies; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D008297:Male; D009503:Neutropenia / Q000453:epidemiology / Q000208:ethnology*; D012189:Retrospective Studies