Application of bone marrow indirect Coombs test and its clinical significance in diagnosis of immuno-related pancytopenia / 中国实验血液学杂志

ABSTRACT

This study was purposed to applicate the bone marrow indirect Coombs test and investigate its clinical significancies in diagnosis of immuno-related pancytopenia (IRP). 30 patients with pancytopenia including 22 cases of IRP and 8 cases of idiopathic cytopenia of undetermined significance (ICUS), and 15 patients with iron-deficiency anemia as controls were enrolled in this study. After incubation of the bone marrow supernatant of IRP patients and bone marrow nucleated cell (BMNC) of controls was used as experiment group, while the incubation of BMNC and bone marrow supernatant of controls was used as control group. After incubation for 45 min, the positive rate of membrane antibodies in bone marrow hematopoietic cells (CD15(+), GlyCoA(+) and CD34(+)cells) was detected by flow cytometry, and correlation analysis of positive rate with clinical data of patients were analyzed. The results showed that among 30 patients with pancytopenia (16 positive and 14 negative for bone marrow direct Coombs test) 16 cases showed positive for bone marrow indirect Coombs test, with positive rate 53.33. In the experiment group, the median positive rate of CD15(+)IgM was 0.34, which was significantly higher than that in control group (0.20, P < 0.05); the median positive rates of CD34(+) IgG and IgM were 0.64 and 0.21 respectively, which were significantly higher than those in control group (0.00, P < 0.05) and (0.00, P < 0.05); the positive rates of GlyCoA(+)IgG and IgM were (0.83 ± 0.75) and (2.12 ± 1.98) respectively, which were significantly higher than those in control group [(0.47 ± 0.43), P < 0.05, (0.68 ± 0.64), P < 0.01]; the positive rates of CD15(+) IgG and IgM were positively correlated with the ratio of CD5(+)B cells. The positive rates of GlyCoA(+) IgG and IgM negatively correlated with the Hb level, percentage of reticulocytes, the ratio of bone marrow erythroid lineage and DC1/DC2 positively correlated with the ratio of CD5(+)B cells and indirect bilirubin level. It is concluded that antibodies (IgG or IgM) aiming at the bone marrow hematopoietic cells exist in the supernatant of some IRP and ICUS patients, and may act on the membrane protein of the normal BMNC. These antibodies correlate with the prognosis of IRP.