Study On The Incidence And Treatment Strategy Of Aplastic Anemia

Objective:To assess the outcomes of a novel immunosuppressive strategy of a combination of cyclosporine, levamisole and danazol for severe aplastic anemia.Methods:A cohort of 261 patients with SAA received a novel immunosuppressive strategy of cyclosporine alternately combined with levamisole plus danazol (CSA&LMS-based regimen), which included 70 VSAA and 191 moderate SAA [initial absolute neutrophil count (ANC)> 200/μL] cases. CSA&LMS-based regimen was orally administrated with the initial dose of CSA 3 mg/kg in adults or 5 mg/kg in children every other day, and LMS 150 mg in adults or 2.5 mg/kg in children every other day, danazol (5.0-10.0) mg/kg daily, continued for 12 more months, followed by a slow tapering. rhuG-CSF was administered in all VSAA patients or if clinically indicated, usually for severe systemic infection. Red blood cells (RBCs) were transfused when the hemoglobin level was< 6g/dL, and platelets were transfused when the blood platelet count was< 10×1003/μL, or< 20×103/μL in the presence of bleeding and/or fever. All the analyses were performed using statistical package SPSS 16.0. The Chi-square test or Fisher exact test and the Mann Whitney-U test were used to compare the differences between groups. The Logistic regression was used to assess the predicted factors for response at 6 months in multivariate analysis. Survival curves were calculated using the Kaplan-Meier method and compared using the log-rank test.Results:There were 92 (35.2%) and 118 (45.2%) patients achieved response at 3 and 6 months, respectively. After stratification for pre-treatment neutrophil counts (<200, 200-500,>500/μL), the response rates were 17.1%,36.8%,48.2%at 3 months (P＜0.001); and 24.3%,46.2%,61.2%at 6 months (P＜0.001), respectively. The patients with higher pre-treatment ARC level had a significantly higher response rates than those with lower ones at 3 (49.6% VS 20.8%, P<0.001) and 6 months (59.5% VS 30.8%, P＜0.001). There was a better response in the patients with long disease duration (>60 days), compared with shorter disease duration (<60 days) at 3 and 6 months (P=0.05 and 0.03, respectively). The response rate of the patients older than 40 years was inferior than the younger ones at 3 and 6 month (P=0.001 and 0.001, respectively). Multivariate analysis further demonstrated that younger age of <40 years old, pre-treatment ARC> 17.1×103/μL and higher initial ANC remained to be statistically significant favorable factors for achieving response at 6 months.62/261 (23.75%) patients died within the median interval of 4.5 (0.2-46) months after CSA&LMS regimen. The estimated 5-year overall survival were 33.8%(95% CI,20.6% to 47%) and 80.5%(95% CI,69.7% to 91.3%) for VSAA and moderate SAA, respectively (P＜0.001). To date,9 (3.45%) patients relapsed at a median interval of 24.0 months (range,9-42 months) after initial response.6 patients (2.30%) evolved to clonal disorders, including 2 overt paroxysmal nocturnal hemoglobinuria (PNH),3 myelodysplastic syndrome (MDS) and 1 acute myeloid leukemia (AML).Conclusions:The novel CSA&LMS-based regimen might represent a promising immuno-suppressive strategy for moderate SAA, especially for those who can’t access to the first-line treatments as ATG and BMT in the developing counties.Objective:To determine gene frequencies of human leukocyte antigen (HLA)-A/B/C/DR/DQ alleles in Chinese patients with severe aplastic anemia (SAA), and investigate association of HLA alleles with susceptibility and severity of the disease and response to immunosuppressive therapy.Methods:The DNA of SAA patients was extracted and high-resolution genotyping of HLA-A/B/C/DR/DP/DQ alleles was conducted using polymerase chain reaction-sequence based typing technique (PCR-SBT). For ethnically matched controls,600 healthy BM donors were chosen randomly from the China Marrow Donor Program (CMDP). Pearson’s χ2 analysis and two-sided Fisher’s exact test were used for the comparison of HLA genotype differences between SAA patients and control, moderate SAA (mSAA) and very severe AA (VSAA), also responsors and non-responsors, to clarify the association of HLA class Ⅰ and Ⅱ allele polymorphisms with disposition, severity and therapeutic effect of SAA patients in Chinese population. The values of χ2, odds ratios (ORs) and 95% confidence intervals (95%CI) were determined using SPSS 17.0 statistical software.Results:1. In all the allelles dientified from the patients and control, A*1101, A*2402, A*0201, B*4001, C*0102, C*0304, DRBl*0901, DRB1*1501, DQB1*0301, DQB1*0303, DQB1*0601 have the most high frequencies.2. Analysis of gene frequencies of HLA alleles exhibits significant increases of HLA-A*02:01, A*02:06, B*13:01, DRB1*07:0, DRB1*09:01, DRB1*15:01, and DQB 1*06:02 alleles in the group of patients with SAA as compared to those in the control group (all P< 0.05). Moreover, the gene frequency of A*02:07, A* 11:01 and B*40:01was significantly lower in the SAA patients than those in the contro(P= 0.001, 0.002,0.005, respectively).3. Comparison among different severity of SAA groups showed significantly increased frequencies of DRB1*15:01 (P= 0.027) and DQB1*06:02 (P= 0.013), but obviously lower frequencies of B*46:01 (P= 0.023) and DRB 1*09:01 (P= 0.020) in mVSAA patients than in VSAA patients.4. In all the patients, the allelic frequencies of B*46:01, DRB1*09:01, DQB1*03:03 in the responsors were significantly lowers than the non-responsors(P=0.0162,0.03,0.037, respectively). In the patients who used CSA only, there was a significant deference of C*01:02 frequency between the responsors and non-responsors (P=0.016). No significant diffrences of HLA alleles were found between responsors and non-responsors in the ATG/ALG+CSA treated patients.Conclusions:A*1101, A*2402, A*0201, BM001, C*0102, C*0304, DRB1*0901, DRB1*1501, DQB 1*0301, DQB 1*0303, DQB 1*0601 have the most high frequencies in our subjects which can represent the Chinese people. HLA-A*0201 and DQB 1*0602 may be susceptibility genes for AA, and HLA-A*1101 could be a protect gene from AA. No significant association was found between HLA and severity of AA, as well as response to IST.