Clinical Application Of Glycosylated Hemoglobin Combined With MCV,MCH And RDW-SD In The Diagnosis Of Thalassemia

Objective:Analyze the value of glycosylated hemoglobin,MCV,MCH,and RDW-SD in the diagnosis of thalassemia,find reliable and simple indicators,and establish a diagnostic model for screening thalassemia.Methods:From January 2020 to December 2022,520 patients with thalassemia（confirmed by gap-PCR technology combined with PCR-RDB technology）from the affiliated hospital of Youjiang Medical College for Nationalities were collected as the thalassemia group,and 676 patients in our hospital during the same period were selected as the control group,including 271 patients with iron deficiency anemia and 405 healthy people;All the patients used electrical impedance method and HPLC to detect red blood cell parameters and glycosylated hemoglobin,analyzed the detailed clinical data and relevant examination results of each subject,compared the differences and correlations of the general situation,glycosylated hemoglobin and red blood cell parameters among the groups,screened out the relevant indicators with statistical differences,and used binary logistic regression analysis,Establish a diagnostic model for the combined detection of thalassemia by glycosylated hemoglobin and red blood cell parameters,draw the receiver operating characteristic（ROC）curve of the subjects,compare the area under the curve（AUC）between single and combined indicators,and evaluate the value of relevant indicators in the diagnosis of thalassemia.Results:（1）RBC,Hb,HCT,MCV,MCH and MCHC in thalassemia group were lower than those in normal healthy group（P<0.05）,and RDW-SD,RDW-CV,Hb A_1a and Hb A_1b were higher than those in healthy group（P<0.05）;RBC,Hb,HCT and Hb A_1a in thalassemia group were higher than those in iron deficiency anemia group（P<0.05）;There was no significant difference in Hb A_1c among the groups（P>0.05）.（2）In thalassemia group,Hb A_1a was positively correlated with RBC and RDW-CV（P<0.05）,and negatively correlated with Hb,MCV and MCH（P<0.01）;Hb A_1c was positively correlated with Hb and MCHC（P<0.05）,and significantly negatively correlated with RDW-CV and RDW-SD（P<0.01）;There was no significant correlation between Hb A_1b and erythrocyte parameters.（3）Compared with the healthy group,RBC,Hb and MCH were the protective factors of thalassemia（OR<1,P<0.05）,while RDW-CV and Hb A_1b were the independent risk factors of thalassemia（OR>1,P<0.05）;Compared with iron deficiency anemia group,RBC,MCV and RDW-SD were protective factors of thalassemia（OR<1,P<0.05）;MCH,RDW-CV and Hb A_1a were independent risk factors for thalassemia（OR>1,P<0.05）.（4）Single indicator ROC curve results.Assign a value of 0 to the healthy group and 1 to the thalassemia group.The optimal cutoff value for thalassemia by Hb A_1a is 1.35%,sensitivity 82.5%,specificity 70.7%,AUC=0.830,P<0.001;The optimal cutoff value of Hb A_1b for thalassemia was 1.85%,sensitivity 93.7%,specificity16.6%,AUC=0.546,P<0.05;The optimal cutoff value of Hb A_1c for thalassemia is 6.05%,sensitivity 99.3%,specificity 19.5%,AUC=0.542,P<0.05;The optimal cutoff value of MCV for thalassemia is 82.55 f L,with sensitivity of 95.1%,specificity of 81.9%,AUC=0.911,P<0.001;The optimal cutoff value of MCH for thalassemia is 26.85 pg,with sensitivity of97.5%,specificity of 86.3%,AUC=0.946,P<0.001;The best cutoff value of RDW-CV for thalassemia is 14.05%,with sensitivity of 85.7%,specificity of 90.8%,AUC=0.933,P<0.001;The AUC of each single indicator is ranked in descending order:MCH>RDW-CV>MCV>Hb A_1a>Hb A_1b>Hb A_1c;Assign a value of 0 to the iron deficiency anemia group and1 to the thalassemia group:The AUC of MCV,MCH,and RDW-CV were 0.536,0.511,and0.508,respectively,with sensitivity of 88.1%,86.9%,and 87.1%,and specificity of 23.6%,28.4%,and 22.1%,respectively.There was no statistically significant difference（P>0.05）;The best cutoff value of RDW-SD for distinguishing thalassemia from iron deficiency anemia is41.05 f L,with a sensitivity of 50.0%,a specificity of 79.0%,AUC=0.640,P<0.001;The best cutoff value for Hb A1a in distinguishing thalassemia from iron deficiency anemia is 1.25%,sensitivity 80.8%,specificity 44.3%,AUC=0.668,P<0.001.（5）Joint indicator ROC curve results.Serial test for diagnosis of thalassemia:The sensitivity of the combined index of MCV+RDW-CV（model 1）was 81.5%,the specificity was 98.3%,AUC=0.958,P<0.001;The sensitivity of the combined index of MCV+MCH+RDW-CV（Model 2）was 79.4%,the specificity was 98.8%,AUC=0.970,P<0.001;The sensitivity and specificity of the combined index of MCV+RDW-CV+Hb A_1b（model 3）were 76.4%,98.6%,AUC=0.960,P<0.001,respectively;The AUC of the three models is ranked in descending order:Model 2>Model3>Model 1.The AUC of models 1,2,and 3 was higher than that of MCH（P<0.05）,and there was a statistically significant difference in AUC between model 2 and models 1,3（P<0.05）;The sensitivity of RDW-SD+Hb A_1a combined index（model 4）was 65.6%,the specificity was69.4%,AUC=0.701,P<0.001;The sensitivity of MCV+MCH+Hb A_1a combined index（model5）was 67.1%,the specificity was 70.8%,AUC=0.740,P<0.001.The AUC of model 4 and model 5 was higher than that of RDW-SD and Hb A_1a single index（P<0.05）,and the AUC of model 5 was higher than that of model 4（P<0.05）.Conclusion:（1）The value of combined indicators in distinguishing thalassemia from iron deficiency anemia is higher than that of single indicators.（2）For the screening of thalassemia in counties,townships,and towns,the combined indicator MCV+RDW-CV（Series test）has important value.（3）Model RDW-SD+Hb A_1a and model MCV+MCH+Hb A_1a have certain value in distinguishing thalassemia from iron deficiency anemia,and model MCV+MCH+Hb A_1a has greater value.