Low serum lipids suggest severe bone marrow failure in children with aplastic anemia

Significantly low serum lipid levels are occasionally seen at the time of diagnosis in children with aplastic anemia (AA). The aim of the present study was to clarify the pathologic and clinical significance of pretreatment serum lipid levels in AA.

A questionnaire seeking precise data about AA in pediatric patients, including the initial laboratory data at the time of onset of AA and the clinical course of these patients, was sent to 18 institutes in Japan; 13 institutes responded to the questionnaire. In this retrospective study, data concerning hematologic examination and serum lipids were available for analysis in 127 children with AA. Serum lipoprotein patterns were analyzed using conventional agarose electrophoresis in eight patients. In order to elucidate the cause of hypolipidemia in AA, we assayed serum macrophage colony stimulating factor (M-CSF), which is well known to have apparent cholesterol-lowering activity, by using an enzyme-linked immunosorbent assay in seven patients with hypocholesterolemia and compared the results with those obtained in patients with iron-deficiency anemia (IDA).

We found that pretreatment total cholesterol (TC) and triglyceride levels in the serum correlated well with counts of both nucleated cells and hemopoietic cells in the bone marrow (BM) and were inversely correlated with the lymphocyte ratio in both the BM and peripheral blood. Patients with serum TC lower than 150 mg/dL showed a poor response to any form of therapy except BM transplantation. There was no difference in the serum lipoprotein patterns between the controls and patients examined. The serum M-CSF level was significantly higher in patients with TC levels lower than 150 mg/dL compared with controls.

These results indicate that the pretreatment serum lipid level may reflect hematopoietic activity within the BM and can help to predict the therapeutic response of each case of AA to treatment with immunosuppressive drugs, corticosteroids and anabolic steroids. These results also indicate that M-CSF may be one of the contributing causes of the hypocholesterolemia that occurs in both AA and IDA.