The Effects Of Liver And Cardiac Iron Overload On Hematopoietic Stem Cell Transplantation In Children With β-thalassemia Major:MRI Detection

Objective: To explore whether liver and cardiac iron overload have an impact on hematopoietic stem cell transplantation(HSCT)in children withβ-thalassemia major by T2*level of magnetic resonance imaging(MRI).Methods: Before HSCT,the results of liver and cardiac MRI T2*,serum ferritin(SF),liver function,coagulation function,myocardial enzyme,troponin I and ejection fraction(EF)in 34 patients with β-thalassemia major who were between the ages of 2 and 14 were detected.After HSCT,the results of hematopoietic reconstruction time,mortality,chimerism rate and incidence of complications(such as graft-versus-host disease(GVHD),thrombocytopenia,infection,sepsis,etc)were recorded.Finally,there was a correlation analysis between the results of liver and cardiac iron overload and the above factors.Results:(1)There were 33 cases of liver iron overload(22 of them were severe,about 67%)and 15 cases of cardiac iron overload(7 of them were severe,about 47%).(2)No significant correlation between cardiac MRI T2* and SF(r=-0.210,P=0.234).No significant correlation between liver MRI T2* and SF(r=-0.059,P=0.741).(3)No children with abnormal heart and liver function was found before HSCT.No significant correlation between cardiac MRI T2*and EF(r=-0.210,P=0.234).(4)No significant correlation between the result(including cardiac MRI T2*,liver MRI T2* and SF)and NEU implantation time(the result were “r=0.026 P=0.884”,“r=-0.026 P=0.883” and “r=-0.001 P=0.994”respectively).(5)No significant correlation between the result(including cardiac MRI T2*,liver MRI T2* and SF)and PLT implantation time(the result were“r=-0.285 P=0.103”,“r=0.096 P=0.588 and “r=-0.018 P=0.919” respectively).(6)The incidence of sepsis was significantly negatively correlated with cardiac MRI T2*(r=-0.392 P=0.022)and positively correlated with SF(0.402P=0.018).The incidence of thrombocytopenia was significantly positively correlated with SF(r=0.370 P=0.031).MRI T2* and SF both had no significant correlation with other observed indicators(such as GVHD,etc.).(7)Six deaths of all(3 cases for severe GVHD,2 cases for severe infection and 1case for diffuse alveolar hemorrhage).The difference of survival distribution was not statistically significant(P>0.05).Conclusions:(1)Cardiac and liver iron overload degree were not balanced.Higher incidence and heavier degree in liver iron overload.(2)It was more comprehensive and effective to evaluate iron overload by combining MRI and SF.(3)The degree of cardiac and liver iron overload was not correlated with the degree of damage of heart and liver function.(4)Iron overload was the risk factor of children with β-thalassemia major in HSCT,which mainly increases the risk of severe infection and reduces the stability of hematopoiesis.(5)The single evaluation results of cardiac or liver MRI should not be regarded as the deterministic standards for HSCT.