Application of flow cytometry in the diagnosis of X-linked hyper-IgM syndrome

Objective To develop a flow cytometrie assay to for diagnosis of X-Linked Hyper.1gM Syndrome(XHIM).Methods Heparinized peripheral blood obtained from patient,mother and a healthy control was diluted with RPMI- 1640(unstimulated control)or with RPMI-1640 containing 15μl PMA(1 rig/μl)and 6 trl ionomycin(50 ng/μl)(stimulated cell).Using directly labeled antibodies,we have examined CD40 ligand levels on CD3+ CD8- lymphocyte surface,and CD69 levels on CD;lymphocyte Surface to determine whether the cells were activated.Results CD69 levels on CD3+ lymphocyte surface from stimulated group and from unstimulated group were above 96% and below 3%,respectively.CD40L levels Oil CD3 CDs-T lymphocyte surface from stimulated group were 0.8% (patient),60.04%(mother) and 62.87%(healthy contr01).CD40L levels on CD3+ CD8-T lymphocyte surface from unstimulated group were 0.88% (patient),4.15%(mother)and 5.51%(healthy contr01).Conclusion This flow cytometric assayis accurate and convenient,which Can be used in neonatal screening. Key words: Hypergammaglobulinemia;  Immunoglobulin M;  Flow cytometry