ABSTRACT
【Objective】 To investigate the family inheritance of α-Thalassemla gene and the risk of severe anemia in neonates caused by cold IgG anti-M. 【Methods】 ABO, Rh, MN blood groups and the specificity of unexpected antibody were identified by blood group serology. The IgG subtype and antibody titer of anti-M antibody were detected. The etiology of neonatal hemolytic disease was identified by three tests and α-Thalassemla gene diagnosis. 【Results】 Family investigation showed that father was B, CCDee, MN with no α-Thalassemla gene detected; Mother B, CcDee, NN, carrying α-Thalassemla gene; both the proband and his brother were B, CCDee, MN, carrying α-Thalassemla gene. Cold IgG anti-M was present in plasma of both the mother and the proband. The titer of the mother was 128 and that of the proband was 64. The subtype of IgG anti-M was IgG1 and IgG3. The direct anti-globulin test, release test and free test of the proband and his brother were negative, and the diagnosis was severe anemia and hemolysis caused by α-Thalassemla combined with cold IgG anti-M. 【Conclusion】 The direct antiglobulin test of neonatal hemolytic disease caused by IgG anti-M can be negative or weakly positive, and α-Thalassemla gene could be hereditary in families. The presence of α-Thalassemla gene can cause anemia, hemolysis and splenomegalysis in neonates, which could be aggravated when accompanied by cold-type IgG anti-M. In the presence of high-valency IgG antibody in plasma, blood exchange combined with transfusion can improve the curative effect.
