Genetic Defect Analysis Of Thalassemia In Adults In Jiangxi Province And The Establishment Of A Differential Formula Between β-thalassemia And Iron Deficiency Anemia Using Red Blood Cell Parameters

Objective:To understand the types of gene defects in adult thalassemia in Jiangxi Province,and to explore a new formula of red blood cell parameter to identify adultβ-TT and iron deficiency anemia（iron-deficiency anemia,IDA）.Methods:Ferritin and Mediterranean anemia genes were detected in patients with small cell hypochromic anemia in the outpatient and inpatient departments of the Second Affiliated Hospital of Nanchang University from June 2013 to December2017.Meanwhile,RBC,HB,MCV,mean corpuscular hemoglobin（MCH）,mean corpuscular hemoglobin（MCH）,mean corpuscular hemoglobin concentration（MCHC）,RBC distribution width-coefficient of variation（CV）and red blood cell distribution width-standard deviation（RDW-SD）were collected from the patients of beta-TT,IDA and healthy subjects.The differences of erythrocyte parameters among different groups were analyzed.By drawing AUC curve,the sensitivity,specificity,Yoden index and the area under AUC curve of each single erythrocyte parameter in identifyingβ-TT and IDA were obtained.A new mathematical formula with the BRC indices were established using multi-parameter logistic regression analysis to identify betweenβ-TT and IDA,and the effect of differential diagnosis were compared with the other 12 formulas reported by other researchers.Results:A total of 245 cases of thalassemia were diagnosed,including 119 cases ofα-thalassemia,117 cases ofβ-TT,9 cases ofαβcomplex thalassemia.The commonα-TT in adults in Jiangxi Province is--SEA/αα,--SEA/-α3.7,-α3.7/αα.The most common genetic defects ofβ-TT are IVS-II-654,CD41/42 and CD17.The RBC parameters ofα-TT static type,standard type and HBH type were different.There was no significant difference in RBC count,Hb and MCV among the three most commonβ-TT patients.There were differences in erythrocyte parameters among normal people,β-TT and IDA groups.There were significant differences in age,RBC count,HB,MCV,MCH,MCHC,RDW-CV and RDW-SD between IDA and normal people.In the comparison of erythrocyte parameters between beta-TT and normal persons,there were statistical differences except for age and RBC count.Except for MCH,the other 6 red blood cells have significant statistical differences in IDA andβ-TT,and RDW-SD is the best parameter for identifying IDA andβ-TT.The mathematical modelforidentifyingβ-TTandIDAisLZ=-134.616+8.092×RBC-0.359×HB+1.093×MCV-2.343×MCH+0.35×MCHC+0.511×（RDW-CV）-0.215×（RD W-SD）.Compared with other identification formulas,the new formula had the highest area under the ROC curve（AUC）and Jordan index.Conclusion:--^SEA/αα,--^SEA/-α^3.7,-α^3.7/αα,IVS-II-654,CD41/42 and CD17 are the most common genetic defects of thalassemia in Jiangxi Province.Inɑ-thalassemia,there are statistical differences in red blood cell parameters in patients with static type,standard type,HBH.There were no significant differences in the RBC,Hb,and MCV of the three most commonβ-TT types.Among the single red blood cell parameters,RDW-SD was the best for identifyingβ-TT and IDA.The new red blood cell parameter formula established in this study has high application value to distinguishβ-TT from IDA.