Aplastic anemia in children: new concepts in etiology and therapy. Introduction

The progression risk factors of children with transfusion-independent non-severe aplastic anemia

Non-severe aplastic anemia (NSAA) in children is a rare, idiopathic condition of bone marrow insufficiency that can resolve spontaneously, persist for months or years, or progress to severe aplastic anemia (SAA). We reviewed clinical and laboratory data of patients diagnosed with transfusion-independent non-severe aplastic anemia (NSAA) from 1996 to 2009 at the Institute of Hematology and Blood Diseases Hospital, Peking Union Medical College, and analyzed the clinical course and outcomes in these patients. NSAA was defined as bone marrow cellularity <50 % and two or three cytopenias that persisted for 6 weeks or more: absolute neutrophil count (ANC) <1.5 × 10(9)/L, absolute reticulocyte count (ARC) <40 × 10(9)/L, platelet count <100 × 10(9)/L, without meeting criteria for SAA (bone marrow cellularity <30 % and two or three cytopenias: ANC <0.5 × 10(9)/L, ARC <20 × 10(9)/L, platelet count <20 × 10(9)/L). All patients were treated with reasonable supportive care, cyclosporine A, and stanozolol (0.1 mg/kg/day). Of a total of 284 patients, 117 (41.2 %) were female, and 167 (58.8 %) were male. With a median follow-up of 43 months (range 2-196 months), 38 patients (13.4 %) progressed to transfusion-dependent NSAA and among them 26 patients (9.2 %) progressed to SAA. One hundred and ninety-eight patients (69.7 %) had persistent NSAA. Forty-eight patients (16.9 %) showed the complete resolution of NSAA. The Kaplan-Meier estimates of all patients for progression-free survival were 86 ± 2.7 % and 66 ± 7.3 % at 60 and 120 months after diagnosis, respectively. Patients with ANC <1.0 × 10(9)/L or female had a higher probability of progression to transfusion-dependent NSAA (18.5 vs. 5.4 %, respectively; p = 0.002, and 17.1 vs. 10.8 %, respectively; p = 0.022). The patients with ARC <60 × 10(9)/L or with ANC <1.0 × 10(9)/L had a higher probability of progression to SAA (11.5 vs. 3.6 %, respectively; p = 0.035, and 12.7 vs. 3.6 %, respectively; p = 0.011). A categorical risk factor analysis showed that patients with ANC <1 × 10(9)/L had a higher probability of progression to SAA (p = 0.03) and had a higher probability of progression to transfusion-dependent AA (p = 0.007). NSAA patients may be benefited from early intervention with cyclosporine A and stanozolol.

Natural history of moderate aplastic anemia in children

BACKGROUND

Moderate aplastic anemia (MAA) in children is a rare, idiopathic condition of bone marrow insufficiency that can resolve spontaneously, persist for months or years, or progress to severe aplastic anemia (SAA). We evaluated the rate of progression to SAA.

METHODS

We reviewed the records of 136 children referred for evaluation of bone marrow failure from 1978 to 2002 at St. Jude Children's Research Hospital. MAA was defined by a hypocellular bone marrow (<50%) and 2 or 3 cytopenias (absolute neutrophil count <1,500/mm(3), absolute reticulocyte count <40,000/mm(3), platelet count <100,000/mm(3)) lasting at least 6 weeks.

RESULTS

Twenty-four patients met the criteria for MAA. At a median follow-up of 66 months (range, 10-293), 16 patients (67%) progressed to SAA, 5 (21%) had persistent MAA, and 3 (12%) had complete resolution of MAA. No risk factors for progression could be identified.

CONCLUSIONS

When childhood MAA is treated with supportive care alone, 2/3 of patients progress to SAA.