α-Thalassemla合并冷型IgG抗-M导致新生儿重度贫血的诊断与遗传学分析

Diagnosis and genetic analysis of severe neonatal anemia caused by α-Thalassemla combined with cold IgG anti-M

目的 探讨α-Thalassemla基因的家系遗传及合并冷型IgG抗-M导致新生儿重度贫血的危害。方法 以血型血清学方法鉴定家系ABO、Rh、MN血型与意外抗体特异性,检测抗-M IgG亚型及抗体效价,结合新生儿溶血病诊断的三项试验与α-Thalassemla基因的诊断,明确病因后换血与输血治疗。结果 家系调查显示父亲:B,CCDee, MN,未检到α-Thalassemla基因;母亲:B,CcDee, NN,携带α-Thalassemla基因;先证者与弟弟均为:B,CCDee, MN,携带α-Thalassemla基因。母亲与先证者的血浆均存在冷型IgG抗-M,母亲抗体效价:128,先证者抗体效价:64。IgG抗-M亚型为IgG1与IgG3型,先证者与弟弟的直接抗球蛋白试验阴性,放散试验阴性,游离试验阳性,诊断为α-Thalassemla合并冷型IgG抗-M引起重度贫血与溶血。结论 由IgG抗-M引起新生儿溶血病的直接抗球蛋白试验可以表现为阴性或者弱阳性,α-Thalassemla基因存在家系遗传。携带α-Thalassemla基因可以引起新生儿贫血、溶血和脾肿大,合并冷型IgG抗-M可加重胎儿期及新生儿期的贫血与溶血程度,血浆中存在高效价IgG抗体时,换血合并输血可以提高疗效。

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.