Lack HLA-A Allele Expression In Severe Aplastic Anemia

Objective To investigate lack HLA-A allele antigen expression in patients with aplastic anemia,and the response to IST in HLA-LL+ and HLA-LL-patients with AA,then explore the correlation between clinical indexes and HLA-LL+.Methods A total of 36 cases AA diagnosed in Hematology Department of Tianjin Medical University General Hospital were enrolled in this study from April 2017 to March2018.Of these,17 cases were newly diagnosed and pretreated,including 8 males and 9 females,aged 17 to 73 years,with an average median age of 39 years.19 cases were posttreated,including 10 males and 9 females,aged 13-68 years,with an average median age of 41 years.The health controls group whose gender,race and age were same as those patients with AA were assessed in this study,above of all this sample were collected from patients with AA peripheral blood.diagnosis and effect of treatment were assessed according to Chinese expert consensus on the diagnosis and treatment of aplastic anemia(2017).Part 1 the expression of HLA-A antigen on leukocyte surface in AA and healthy controls was detected using Flow cytometry(FCM)with using specific monoclonal antibody HLA-A2 and A9 respectively in neutrophil,monocyte,B and T lymphocytes,Natural killer cell surface antigen.Part 2 To compare the response to IST in HLA-LL+ and HLA-LL-patients with AA and explore the correlation between clinical indexes and HLA-LL+.Results1.Expression of HLA-A allele in peripheral blood in patients with AA and healthy controls(1)Expression of HLA-A2 and A9 allele in peripheral blood in patients with AA and healthy controls 36 AA patients were enrolled in this study,HLA-LLs accounted for 1.85%–90.66% in each leukocyte population.of these in the newly diagnosed and pretreated group were 17 cases totally.HLA-LL+ were detected in 7of 17(41.17%)newly diagnosed and pretreated group and HLA-LL-were 10 of17(58.82%).Of these,Lack of HLA-A2 was 85.71% in 6 AA patients(4 males and 2females)in the newly diagnosed and pretreated group,while HLA-A9 was 14.28% in 1 cases(0 male and 1 female).There were 19 cases enrolled in the posttreated group,HLA-LL+ were detected in 8 of 19(42.10%)protreated group and HLA-LL-were 11 of19(57.89%).Lack of HLA-A2 were 5 AA patients(2 males and 3 females),and the expression-lacking rate was 62.5%,while HLA-A9 was 37.5%.However,the positive expression rate of HLA-A2 and A9 was completely found in controls.(2)Specific monoclonal antibody HLA-A2 and HLA-A9 by FCM showed the sensitivity was different,of which HLA-A2 was 73.33% and HLA-A9 was26.66%.The expression-lacking rate of HLA-A on neutrophils was 40.00% in AA.Monocytes was40%.B and T lymphocytes was 33.33% and 53.33%,respectively.and natural killer cells was 40%.2.Compare the response to IST in HLA-LL+ and HLA-LL-patients with AA and explore the correlation between clinical indexes and HLA-LL+ In the newly diagnosed and pretreated group,the response to IST in HLA-LL+ was 71.4%,and that in HLA-LL-was 40%.While in posttreated group the response to IST in HLA-LL+ was62.5%,and in HLA-LL-was 45.45%.The expression-lacking rate of HLA-A2 allele was significantly negatively correlated with the absolute neutrophil cells(P =-0.645,P =0.032)in AA patients,while that was significantly positively correlated with Hemoglobin(r = 0.691,P = 0.019)in AA patients,but was not correlated with White blood cell(r =-0.0091,P = 0.979),platelet(r =-0.173,P = 0.612),absolute monocyte cell(r =-0.173,P = 0.612),erythrocyte(r = 0.388,P = 0.238),absolute lymphocyte cell(r = 0.513,P = 0.107),reticulocyte percentage(r = 0.082,P = 0.811),absolute reticulocyte value(r = 0.068,P = 0.842).The expression-lacking rate of HLA-A9 allele was not correlated with WBC(r =-0.195,P = 0.754)?RBC(r =-0.300,P = 0.624)?HB(r =-0.600,P = 0.285)?PLT(r =-0.700,P = 0.188)?ANC(r =-0.311,P = 0.611)?LNC(r =-0.216,P = 0.727)?Ret%(r = 0.100,P = 0.873)?AMC(r = 0.036,P = 0.955)?Ret#(r =0.603,P = 0.282).Conclusion1.There was the lack of HLA-A2 and HLA-A9 in peripheral blood in some AA patients,while the expression-lacking of that was not found in controls.HLA-LL+ was found in both the pretreated and the posttreated group,but the reponse to IST was higher in AA patients with HLA-LL+ than in HLA-LL-,In the posttreated group,the response to IST was similar in AA patients with HLA-LL+ and HLA-LL-.It was suggested that HLA-LL+ in the newly diagnosed and pretreated group had a good effect on IST and provided a predictor for the response to IST AA in clinical treatment.2.This study analyzed the correlation between the lack of HLA-A2 and HLA-A9 in AA patients and the clinical indexs.It was found that the expression-lacking of HLA-A2 was significantly negatively correlated with ANC and positively correlated with HB.There was no correlation with White blood cell,platelet,absolute monocyte cell,erythrocyte,absolute lymphocyte cell,reticulocyte percentage,absolute reticulocyte value.There was no correlation between the loss of HLA-A9 expression and the clincal indexs,including absolute neutrophil cells,Hemoglobin,White blood cell,platelet,absolute monocyte cell,erythrocyte,absolute lymphocyte cell,reticulocyte percentage,absolute reticulocyte value.