Very Severe Aplastic Anemia Research Articles

Interim Results of a Multi-Center Observational Study of Current Treatment Patterns for Patients with Severe Aplastic Anemia (SAA), Very Severe Aplastic Anemia (VSAA) and Transfusion-Dependent Non-Severe Aplastic Anemia (TD-NSAA) in China

BackgroundIn China, the incidence of aplastic anemia (AA) is about 0.74/105, with 0.14/105 of severe aplastic anemia (SAA). Most of these SAA patients are treated in big medical centers or traditional Chinese medicine (TCM) hospitals, which could stand for the current practices in China. Despite the China Aplastic Anemia Consensus, published in 2010, recommended that the immunosuppressive therapy (IST) and hematopoietic stem cell transplantation (HSCT) were the standard treatment for SAA, very severe aplastic anemia (VSAA) and transfusion-dependent non-severe aplastic anemia (TD-NSAA), the current treatment options for patients with these diseases are diverse, including antithymocyte globulin (ATG)/antilymphocyte globulin (ALG) + cyclosporin A (CsA), CSA + androgen, CSA or androgen alone, only supportive care, TCM, etc. This national disease registry study aimed to describe the current clinical practice and treatment patterns for SAA, VSAA and TD-NSAA patients in China and understand their IST patterns as well as the supportive care measures.MethodsIn this prospective, multi-center, observational study, adult or pediatric patients diagnosed as acquired aplastic anemia within 3 months and met the guideline criteria of SAA, VSAA or TD-NSAA were enrolled from October 2012 to April 2014. All enrolled patients will be followed at least for one year. Each subject will be visited every 3 months in the first year and every 6 months from the second year until the patients withdraw the ICF or study close. The main evaluation criteria is the treatment patterns of SAA, VSAA and TD-NSAA which will be specified as: IST (ATG + CsA, CsA + androgen, CsA and others), HSCT, TCM, androgen, supportive care and others. The response of SAA/VSAA and TD-NSAA after each treatment, and serious adverse events, will also be evaluated by the investigators. An interim analysis is planned when all patients have been enrolled (target N=350) and will focus on their baseline characteristics and first treatment choice. This study was sponsored by Sanofi.ResultsA total of 352 patients were enrolled at 29 sites in China (SAA 221 pts; VSAA 84 pts; TD-NSAA 47 pts). The median age was 21 years (range, 0-84) and 65.1% were adults. 51.7% were male and 71.6% had ECOG PS <2. The vast majority of enrolled patients (344/352 pts, 97.7%) had no previous AA-related history. The most common onset symptom at baseline was anemia (92.9%), followed by hemorrhage (72.2%), infection (56.8%) and others (3.4%). TD-NSAA patients had less infections than SAA or VSAA patients (25.5% vs. 57.9%/71.4%). Cytogenetic abnormality were detected in 6.1% of the 245 patients who received cytogenetic test at baseline. The analysis of the primary endpoint showed 74.1% and 4.3% of the total patients received IST and HSCT at baseline, respectively. Among the patients with IST treatment, the standard ATG + CsA treatment was only applied in 26.4% of them (SAA 25.5%; VSAA 42.4%; TD-NSAA 5.4%). The other IST regimens were CsA + androgen (31.0%), CsA (31.4%) and others (11.1%). Three different brands of ATG/ALG were used in patients with IST: Rabbit ATG (75.0%), ATG-Fresenius (2.1%) and ALG-Porcine (22.9%). TCM therapy were applied in 12.8% of the total patients and were more common in SAA/VSAA patients (15.8% & 10.7%, respectively) than in TD-NSAA patients (2.1%). 2.8% of the patients received androgen therapy alone at baseline. 8 patients (2.3%) had switched their treatment pattern within 3 months before the enrolment because of unsatisfying efficacy (5 pts) or personal reasons (3 pts). Supportive care was applied in 95.7% of the total patients. The supportive care measures included blood transfusion (97.9%), antibiotics (64.1%), hematopoietic growth factors (58.8%), protective isolation (46.6%), iron chelators (0.3%) and others (2.7%). When the study initiated, the first treatment choice for all patients were IST (74.1%), HSCT (3.4%) and others (22.4%). There were no substantial difference of the first treatment pattern among SAA, VSAA and TD-NSAA groups.ConclusionsChinese AA patients received diverse treatments in real life clinical practice. Based on this interim analysis, 74.1% of the SAA, VSAA and TD-NSAA patients in China received IST. But only 26.4% of them received the standard ATG + CsA therapy. TCM therapy still played a role in the treatment, especially for SAA and VSAA patients in China. Final results including efficacy and safety profiles will be reported later. DisclosuresOff Label Use: Anti-thymocyte globulin-Fresenius is used as an immunosuppressive therapy for the treatment of aplastic anemia.

Rabbit antithymocyte globulin as first-line therapy for severe aplastic anemia

Rabbit antithymocyte globulin (rATG) was proven effective as salvage therapy for refractory aplastic anemia (AA), or for relapse after initial therapy with horse ATG (hATG). Several clinical trials were performed to assess the efficiency of rATG as a first-line therapy for AA patients; however, their results were variable. The aim of the present study was to assess hematologic response and survival in severe AA (SAA) and very severe AA (VSAA) patients treated with rATG and cyclosporin A (CsA) in our center. The factors involved in these outcomes were also explored. A total of 292 patients with newly diagnosed, acquired SAA or VSAA received a combination of rATG and CsA as first-line therapy, and the results were retrospectively assessed. The median age was 18 years (range = 2-73 years). The early death rate was 5.5%, and the total response rates were 49.0% (143 responders), 60.3% (176 responders), 65.8% (192 responders), and 68.5% (200 responders) at 3, 6, 9, and 12 months, respectively, after immunosuppressive therapy. In multivariate analysis, initial response to granulocyte colony-stimulating factor (G-CSF) was the predictive factor for response to therapy at 12 months. Median follow-up of surviving patients was 34 months (range = 0-117 months). Five-year overall survival was 83.2%, and the 5-year, event-free survival was 67.2%. Independent prognostic factors for overall survival were neutrophil count and achievement of any response following rATG therapy. Our results indicate that rATG/CsA is a safe and effective first-line treatment for SAA/VSAA.

Comparison of rabbit antithymocyte globulin and Jurkat cell-reactive anti-t lymphocyte globulin as a first-line treatment for children with aplastic anemia

The purpose of this study was to investigate the effects of rabbit antihuman thymocyte globulin (R-ATG) and Jurkat cell-reactive anti-T lymphocyte globulin (ATG-F) in the treatment of childhood aplastic anemia (AA) and compare their efficacy and side effects. A total of 53 children with AA were analyzed in the present study, including 32 cases of severe AA, 10 cases of very severe AA and 11 cases of transfusion-dependent nonsevere AA. While receiving immunosuppressive therapy (IST), 29 and 24 patients, all of whom received long-term oral supplement with cyclosporin A (CSA), androgen, and traditional Chinese medicines, were treated with R-ATG and ATG-F, respectively. If necessary, the patients were also given supportive care such as component transfusion and/or infection control. Absolute counts of peripheral blood lymphocyte at various time points were dynamically measured after ATG therapy. According to the International AA Treatment and Effect standards, we found that there were no statistically significant differences in the response rate (70.83% vs. 68.97%, p > 0.05) and the overall survive rate (83.33% vs. 82.76%, p > 0.05) between the ATG-F and R-ATG groups. In addition, no obvious differences were observed between these two groups in the response time, efficacy in severe AA and very severe AA, or the incidence rates of ATG-related adverse reactions. After ATG treatment, the extent of peripheral blood lymphocyte reduction and duration in peripheral blood were similar between the ATG-F and R-ATG groups. The results of this study showed that ATG-F and R-ATG had similar efficacy and adverse reactions in the first-line treatment of childhood AA, despite being derived from different immunogens.

Somatic Mutations Implicated In Myeloid Malignancies Are Frequent In Idiopathic Aplastic Anaemia and Its Relevance To Disease Classification and Treatment- a Comprehensive Analysis Of 150 Patients

▪ BackgroundAcquired aplastic anemia (AA) is an immune mediated disease, characterized by severe quantitative defects in stem cell number leading to a hypocellular marrow and peripheral blood cytopenias. A major complication of AA following immunosuppressive therapy (IST) is the emergence of clonal hemopoiesis, manifesting as paroxysmal nocturnal hemoglobinuria (PNH), myelodysplastic syndrome (MDS) and acute myeloid leukaemia. The nature of genetic defects in such cases evolving to clonal hemopoiesis has not been addressed hitherto. It is likely that the hematopoietic stress leads to telomere attrition, chromosomal instability and susceptibility to acquire mutations in genes several years after the initial diagnosis. We postulated the existence of mutations leading to clonal haemopoiesis in a subset of AA and thereby helping in early prediction. MethodsWe undertook a massively parallel targeted sequencing of 832 genes implicated in regulating hematopoiesis initially in a cohort of 57 patients with acquired AA. We also performed single nucleotide polymorphism-array karyotyping, telomere measurement, PNH flow cytometry and correlated it with clinical characteristics. A second cohort of 93 patients was sequenced at a greater depth for ASXL1 and DNMT3A. ResultsThe median age of AA patients was 44 years (range 17-87 years). The diagnosis was non severe AA (NSAA) 64, severe AA (SAA) 52, very severe AA (VSAA) 27 and pure red cell aplasia (PRCA)/amegakaryocytic thrombocytopenia 7. PNH-type cells and cytogenetic aberrations were seen in 52% and 9% of patients respectively. IST was administered in 72% of patients with 55% receiving ATG containing regimens. Allogeneic hematopoietic stem cell transplant was performed in 25% (n=37). Clonal evolution to MDS/AML was observed in 12% of patients.Somatic mutations in genes usually implicated in myeloid malignancies were detected in 15% (22/150) of AA. No particular sub-group of AA patients had a predilection to harbour somatic mutations, although a slightly higher incidence was noted in SAA and NSAA, compared to VSAA (22% vs. 14%, p=0.1).Thirty-five (23%) AA patients had either morphological (n=18) and/or molecular (n=22) evidence of evolution to MDS. Of the 18 patients with morphological evolution to MDS, ASXL1 and TET2 mutations were observed in 5 patients. ASXL1 (n=11) mutations were the most common somatic variation and correlated with older age, evolution to MDS and the presence of monosomy 7. Although there was no predilection for a particular ‘hot spot', all mutations occurred in exon 12 and were uniformly heterozygous. DNMT3A (n=7) and BCOR(n=2) were the other frequent mutations. The median allele burden of somatic mutations was 30%. AA with somatic mutations were older (51 vs. 38 years, p<0.07), had a longer disease duration (44 vs. 9 months, p< 0.06), shorter telomere lengths (median T/S length, 1.3 vs. 0.8, p<0.008) and were less likely to achieve complete remission to IST (10% vs. 34%) compared to those without mutations. ConclusionUp to 25% of AA patients have morphological or molecular evidence of clonal evolution with a fifth of AA patients harboring mutations in genes implicated in myeloid malignancies, with both diagnostic and therapeutic implications. Disclosures:No relevant conflicts of interest to declare.

Predicting early response to immunosuppressive therapy in severe aplastic anemia by soluble transferrin receptor assay

To evaluate the value of serum soluble transferrin receptor (sTfR) concentration in predicting early response to immunosuppressive therapy (IST) in severe aplastic anemia (SAA). Clinical data and hematologic responses of 140 SAA patients treated with rabbit antithymocyte globulin (rATG) combination with cyclosporine in our hospital were retrospectively analyzed. Correlation of pre-IST baseline of sTfR and IST responses was statistically analyzed and receiver operating characteristic (ROC) curve was used to estimate the sensitivity and specificity of sTfR in prediction of early responses. Serum concentration of sTfR in very SAA (VSAA) patients were significantly lower than SAA and transfusion dependent non-SAA cases (P=0.001). The responders, especially at 3 months, had significantly higher pre- IST baseline of sTfR [median, 0.89 (range, 0.21-2.42) mg/L] than that [median, 0.58 (range, 0.13-1.88) mg/L] of non-responders (P=0.005). The cutoff level of 0.91 mg/L and 0.88 mg/L for predicting responses at 3 and 6 months were established based on the ROC curve, with the degree of accuracy of 65.0% and 60.7% respectively. Multivariate analysis showed that pre-IST baseline of sTfR was the independent factor of predicting response at 3 months (P=0.007) and at 6 months (P=0.021). As a indicator of bone marrow failure severity, sTfR could predict early response to IST therapy in aplastic anemia.

Is Acute Fibrinous and Organizing Pneumonia the Expression of Immune Dysregulation?

Acute fibrinous and organizing pneumonia (AFOP) is a recently described histologic pattern of diffuse pulmonary disease. In children, all cases reported to date have been fatal. In this study, we describe the first nonfatal AFOP in a child and review the literature. A 10-year-old boy developed very severe aplastic anemia (VSAA) after being admitted to our hospital with a fulminant hepatic failure of unknown origin. A chest computed tomography scan revealed multiple lung nodules and a biopsy of a pulmonary lesion showed all the signs of AFOP. Infectious workup remained negative. We started immunosuppressive therapy with antithymocyte globulin and cyclosporine to treat VSAA. Subsequent chest computed tomography scans showed a considerable diminution of the lung lesions but the VSAA did not improve until we performed hematopoietic stem cell transplantation 5 months later. Aplastic anemia is associated with a variety of autoimmune syndromes. The sequence of events in our patient suggests that the hepatic failure, AFOP, and the VSAA may all have been part of an autoimmune syndrome. AFOP could be the result of immune dysregulation in this pediatric case with favorable outcome after immunosuppressive therapy and hematopoietic stem cell transplantation.

Aplastic anemia: clinicohaematological features, treatment and outcome analysis.

To determine the clinicohaematological features, treatment and outcome of children diagnosed with aplastic anemia at a single institution. Observational study. The Aga Khan University Hospital, Karachi, from January 1999 till December 2008. Medical records of children aged less than 15 years of age diagnosed with aplastic anemia were reviewed. Clinicohaematological features, treatment and its response to therapy and outcome were recorded. Results were described in percentages. Ninety patients were diagnosed to have aplastic anemia (AA); 65 were male during the study period. Age ranged from 1 to 15 years. Fever in 65 patients (72.2%), pallor in 53 (58.8%), skin bleeding in 49 (54.4%) and epistaxis in 31(34.4%) were the most common and frequent presenting features. Congenital (Fanconi's) anemia was found in 15 (16.6%) and acquired idiopathic in 75 (83.4%) of patients. Very severe aplastic anemia (VSAA) was seen in 29 (32.2%), 26 (28.9%) had severe AA and 17 (18.9%) had moderate AA. Eight patients (8.9%) underwent haematopoietic stem cell transplantation (HSCT), 12 (13.3%) received immunosuppressive therapy (IST) and 70 patients (77.7%) received other and supportive therapy. Five (62.5%) patients showed complete response to HSCT and 3 (37.5%) failed to engraft. IST showed complete response in 3 (25%), partial response in 5 (41.6%) and no response in 4 (33.3%). Twenty two patients (24.4%) expired either due to infection in 16 (72.7%, fungal in 6, bacterial in 10) and intracranial haemorrhage in 6 (27.3%) cases. Majority of cases with AA were acquired and idiopathic in etiology. VSAA and SAA were frequent. Response to HSCT and IST was sub-optimal.

Analysis of the prognostic factors of very severe aplastic anemia treated with Chinese Kidney-invigorating drugs in combination with anti-lymphocyte globulin or anti-thymocyte globulin

To explore the prognostic factors for very severe aplastic anemia (VSAA) patients treated mainly with Chinese Kidney (Shen)-invigorating drugs (CKID) combined with anti-lymphocyte globulin (ALG) or anti-thymocyte globulin (ATG). Twenty-seven VSAA patients were treated with CSID+ALG/ATG therapy in conjunction with cyclosporine A, androgen, hemopoietic growth factor, etc. The relationship of the effectiveness and some factors (age of patients, course of illness, blood and bone marrow figures, etc.) were analyzed. In the 25 evaluated VSAA patients who had been followed up for over 1 year, 9 patients (36.0%) were basically cured, 5 (20.0%) remitted, 6 (24.0%) were markedly improved, and 5 (20.0%) were treated in vain, with the total effective rate of treatment being 80.0% (20/25). Better clinical therapeutic effects were shown in patients newly diagnosed with VSAA, of male sex (P=0.037), >20 years old (P=0.045), with an illness course [Symbol: see text] month (P=0.048), with peripheral neutrophil count >0.1 × 10(9)/L (P=0.023), and with reticulocyte count >10 × 10(9)/L (P=0.002). Platelet count (P=0.620) and bone marrow lymphocyte percentage (P=0.736) showed no correlation with the therapeutic effectiveness. Multi-factor analysis by the Kaplan-Meier procedure on the factors influencing survival showed that rather longer survival times occurred in patients > 20 years old, with peripheral neutrophil count [Symbol: see text] 0.1 × 10(9)/L, reticulocyte count [Symbol: see text]10 × 10(9)/L, and platelet count > 10 × 10(9)/L (all P=0.0001). Bone marrow lymphocyte percentage and the initiation time of ALG/ATG application (from onset of the illness) showed no significant influence on patients' survival time (P=0.085 and P=0.935, respectively). CSKD+ALG/ATG therapy for treatment of VSAA could enhance the current clinical therapeutic effects and elevate patients' survival rate. Conditions including male sex, age >20 years, illness course [Symbol: see text]1 month, neutrophil count >0.1 × 10(9)/L, and reticulocyte count >10 × 10(9)/L are the likely effective indices for predicting favorable therapeutic effectiveness in newly diagnosed VSAA patients.

Functional Characterization of CD4+ T-Cells in Aplastic Anemia (AA)

Abstract 1340We have examined the role of CD4+ T-cells in the pathogenesis of AA in 63 patients, 48 of whom were analyzed at diagnosis and 15 following immunosuppressive therapy (IST). Absolute numbers of CD4+ regulatory T cells (Tregs, defined as CD3+CD4+CD25highCD27+Foxp3+) were lower in pre-treatment AA patients compared to 10 healthy donors (HDs) (5.5 × 106 v 1.4 × 107)(p=0.01). In patients with severe (SAA) and very severe AA (VSAA), the absolute number and frequency of Tregs were lower than non-severe AA (NSAA) (4.4 × 106/L v 1 × 107/L)(p=0.01) and HDs (4.4 × 106/L v 3 × 107/L) (p<0.001). Absolute numbers of Th1 and Th2 cells in all pre-treatment patients were higher compared to HDs (6.4 × 107/L v 1.8 × 107/L)(p=0.03) for Th1 and (2.6 × 107/L v 2.4 × 106/L)(p=0.006) Th2 cells. Although mean percentages of AA Th17 cells were higher than in HDs (1.5% v 0.15%)(p=0.04), differences in absolute numbers were not significant. Absolute numbers of Th2 and Th17 cells were increased in SAA (1.3 × 107/L v 7.4 × 106/L for Th2)(p=0.01) compared to NSAA (5.7 × 106/L v 2.15 × 106/L for Th17)(p=0.02). Ratios of Th1/Tregs (p=0.003), Th2/Tregs (p=0.02), and Th17/Tregs (p=0.001) were higher in SAA and VSAA compared to NSAA. Percentage of both activated (CD4+CD45RA−CD25highFoxp3high) and resting (CD4+CD45RA+ CD25highFoxp3low) Tregs was decreased in AA patients, compared to HDs (p=0.004 and p=0.01), whereas cytokine secreting Tregs (CD4+CD45RA−CD25high Foxp3low) were increased in AA (p<0.003). Sorted Tregs from AA patients did not suppress cytokine secretion by autologous or HD T effectors (Te) cells in 1:1 co-cultures, whereas IL-2 and IFN-γ secretion by AA Te (CD4+CD25lowCD127high) was suppressible by allogeneic Tregs from HDs, confirming Tregs dysfunction. AA Tregs did not inhibit either CD154 or CD69 expression on Te cells. Tregs from AA patients secreted significantly more IFN-γ, TNF-α and IL-17 (p=0.02, p=0.02 and p=0.01, respectively) after 4 hours stimulation with PMA/Ionomycine compared to HDs. Expression levels of FoxP3, ROR□c and T-bet in AA Tregs was normal. IFN-γ secreting cells (Th1) were enriched using enrichment kit then further enriched by FACS sorting. CDR3 region products of TCR Vβ-chain were amplified using Vβ specific forward and Cβ reverse primers. CDR3 PCR products from AA patients and HDs were subjected 454 sequencing (Roche GS FLX titanium). Sequencing was performed to yield an average ‘depth' in excess of 1000 clonally reads (1000x) for each sample specific CDR3 PCR amp icon. Reads were processed using Roche Amp icon Variant Analyzer software (AVA). Diversity of TCR receptors (measured by spectratyping and confirmed by high throughput deep sequencing) in AA Th1 cells was lower than HDs (p=0.037), as shown by the percentage and number of consensus clusters in total sequence reads. Interestingly, percentages of the most dominant CDR3 clones, revealed by high throughput sequencing, were higher in AA compared to HDs, regardless of spectratyping pattern. Global gene expression of Tregs was compared in 3 pre-IST AA patients and 5 HDs. A unique gene signature consisting of 86 genes that were significant was identified. There were 8 down regulated genes (fold change) in the pre-treatment group; PIN4 (−4.1), OR2T12 (−3.3), AMAC1 (−2.73), PERP (−2.69), UTS2 (−2.27), RNF139 (−2.13), COMMD9 (−2.09) and LOC100128356 (−2.01). The top 10 of 78 up-regulated genes in the pre-treatment group were HBB (19.5), PSME2 (13.8), CSDA (13.07), FAM127A (7.78), EXOSC1 (7.73), BPGM (7.43), CYSLTR1 (7.17), CHPT1 (6.96) and PLAC8 (6.71). qPCR analysis for CSDA, HBB, PSMiE2, PERP, PIN4, and UTS2 confirmed a similar trend to the microarray results. Interestingly absolute number of Tregs, and Th2/Treg ratio were higher in 10 IST responsive patients compared to 5 non-responsive patients (p=0.005 and 0.02, respectively).We show that expansion of Th1, Th2, Th17, and decreased/skewed Tregs immunophenotype and function are a consistent and defining feature of SAA and VSAA. Clonal expansion of Th1 cells is likely to be antigen driven and the presence of dysfunctional Tregs aggravates this autoimmune response.Increases of Tregs, and Th2/Treg ratios following IST predicts a favourable response to this treatment. Disclosures:No relevant conflicts of interest to declare.

Long-Term Outcome of Immunosuppressive Therapy with Rabbit Antithymocyte Globulin (rATG) for Childhood Severe Aplastic Anemia for 15 Years

Abstract 1346Immunosuppressive therapy (IST) with horse antilymphocyte globulin (ALG) and cyclosporin (CSA) has been reported to achieve a 60∼70% response rate in children with severe aplastic anemia (SAA). Rabbit antithymocyte globulin (rATG) has greater immunosuppressive potency than ALG (Blood 2007;109:3219), and may be effective when implemented in the IST of children with SAA. However, several reports with rATG in IST for SAA showed lower response and survival than with ALG. We analyzed retrospectively the long-term outcome of childhood aplastic anemia (AA) with CSA and rATG (2.5mg/kg/day for 5 days).We retrospectively reviewed the medical records of 112 children newly diagnosed with SAA between 1991 and 2005, who initially did not have an HLA-matched donor, and received IST with ALG or rATG for 5 days and CSA (5mg/kg) for 6 months. Some patients received oxymetholone after IST. Fifty eight children were treated with rATG and cyclosporine (CSA) only.Median age at diagnosis was 9.2 years-old (0.8 ∼15.3), and 30 boys (51.7%) were included in this study. Eleven children (18.9%) were diagnosed with very SAA (VSAA). In most patients (84.5%), the etiology of SAA was not identified. Median time between diagnosis and start of IST was 11 days (1 ∼ 260). The response rates were 36.2% at 4 weeks, 50.0% at 3 months, 48.3% at 6 months, 55.4% at 9 months, and 55.6% at 12 months post-IST. The response rate showed an increasing trend up till 9 months post-IST. The overall relapse rate observed was 31.4% (median time 22.4 months, range: 1.3 ∼ 101.8). Important adverse events included serum sickness (43.1%), and elevated liver enzyme (5.2%). Seven children with no response or relapse received 2nd IST with ALG or rATG. Fifteen children with no response (n=11) or relapse (n=4) were transplanted with an HLA- matched donor after median of 1.4 years (0.4 ∼ 9.2) post-IST. The overall survival (OS) and failure free survival (FFS) rates were 79.8% and 41.6% in IST with rATG and CSA. Prognostic factors for OS were severity (P=0.046, HR: 2.59, 95%CI: 1.02∼6.59) and relapse (P=0.03, HR: 7.24, 95% CI: 1.21∼43.46) in multivariate analysis, although absolute neutrophil counts, corrected reticulocyte count, time between diagnosis and IST, response at 4 weeks, 3 months, 9 months, and 12 months were also significant in univariate study. Important prognostic factor for FFS was response at 9 months (P<0.001, HR: 8.59, 95% CI: 3.78∼ 19.51) in multivariate study, although response at 4 weeks, 6 months, 12 months were also important in univariate analysis.In this study, the response rate observed 12 months after IST with rATG and CSA was 55.6%, and OS or FFS rates were comparable to historical results obtained with ALG. We concluded that IST with rATG (2.5mg/kg/day for 5 days) may be an effective therapeutic strategy for childhood SAA, with delayed response assessment when compared to IST with ALG. Results of IST with rATG with modified doses are important for further evaluation of therapeutic potential of rATG in pediatric SAA. Disclosures:No relevant conflicts of interest to declare.

Treatment of childhood aplastic anemia with antithymocyte globulin, management of side effects and long-term follow-up

To evaluate the efficacy of antithymocyte globulin (ATG) based immunosuppression therapy for childhood aplastic anemia, to reduce the adverse effects and to observe the long-term outcome. Thirty-five children with aplastic anemia (AA) were enrolled in this study. Six of the cases had very severe AA (VSAA), 11 had severe AA (SAA)-I, 8 had SAA-II and 10 had moderate AA (MAA). All these patients were treated with ATG plus Cyclosporin A (CSA). The following measures were taken during the ATG therapy: infection of the patients had been controlled before ATG treatment. Comprehensive anti-allergic measures were implemented. Close attention was paid to the hemorrhage related with platelet reduction caused by ATG and severe infection of the patients. Shortly after the ATG usage, all the patients had a significant decrease of absolute peripheral lymphoblast count by more than 60 percent. With a mean follow-up time of 28 months, the total effective rate was 77.14% (27/35), significant response rate was 57.14%(20/35). There was no significant difference among VSAA, SAA and MAA groups in the response rate. Adverse reactions included the following: (1) 48.6% (17/35) patients presented mild anaphylactoid reaction during the first day of ATG treatment; (2) 42.9%(15/35) cases presented serum sickness 5 - 11 days after the last dose of ATG with a mean duration of 3.6 days, all the patients were cured effectively with methylprednisolone; (3) 25.7% (9/35) patient's peripheral blood platelet count was reduced, might be caused by ATG, to below 10 × 10(9)/L, but no patient had severe hemorrhagic complication after platelet transfusion was performed; (4) 22.9%(8/35)of patients got infection within a month after ATG therapy, including 3 cases with clinical septicemia, all the 3 cases recovered after antibiotics treatment. There was no ATG treatment-related death in this series. ATG is a very effective therapy for children with SAA and MAA. Comprehensive measures are needed to prevent and handle the side effects to avoid treatment-related death. Long-term supportive therapy and proper follow up contribute to the favourable outcomes of the patients.

The Use of Anti-Human T Lymphocyte Porcine Immunoglobulin and Cyclosporine A to Treat Patients with Acquired Severe Aplastic Anemia

Objective: To evaluate the treatment efficacy and tolerance of anti-human T lymphocyte porcine immunoglobulin (p-ALG) plus cyclosporine A (CsA) in acquired severe aplastic anemia (SAA). Method: Forty-eight SAA patients [31 males and 17 females; 17 with very SAA (VSAA)] were treated with p-ALG plus CsA and were analyzed retrospectively according to early mortality, response rate and quality, survival rate, toxicity, and complications. They were stratified further by gender, age, disease severity, interval from diagnosis to treatment, and preexisting infections. Result: The median age was 28 years (range 13–64). The interval from diagnosis to treatment was 45 days. The median neutrophil count was 0.178 × 10⁹/l. The overall response was 83.3% (54.2% complete and 29.2% partial) with a 90-day median time (range 23–380), and 10.4% died of infection within 30 days. The 1.5-year survival was 87.5%. vSAA patients had less response, a higher early mortality, and less survival (64.7, 29.4, 51.8%) compared to SAA patients (93.5, 0, and 100%, respectively; p < 0.05). Groups with different age, gender, intervals between diagnosis and treatment, and preexisting infections had the same response. Mild toxicities were observed. Conclusion: p-ALG plus CsA is a reliable and well-tolerated treatment for SAA, and it has the great advantage of a much lower cost compared to horse/rabbit ATG. VSAA was a poor predictive factor for the response rate.

Antithymocyte globulin and cyclosporin in children with acquired aplastic anemia

To assess the responses to ATG and cyclosporin combination in patients of aplastic anemia. Twenty three (17M: 6F) patients of aplastic anemia (11 very severe aplastic anemia (VSAA) and 12 severe aplastic anemia (SAA), were administered antithymocyte globulin and cyclosporin. The median age of patents was 8 years (range 6-12 years). Three patients died within 2 months of therapy. Twenty children (11 SAA and 9 VSAA) were finally analysed. Six months after the start of treatment, 8/20 (40%) patients responded-2 complete (CR) and 6 partial responses (PR). At the end of 1 year; 2 patients maintained CR and seven patients continued PR (overall responders 45%). The response was better in SAA (54.5%) with 2 CR and 4 PR; than in VSAA (33%) with 3 PR . Eleven (55%) children were alive without response. One patient developed AML 13 months later. We conclude that antithymocyte globulin and cyclosporin combination is an effective treatment for aplastic anemia patients who are ineligible for bone marrow transplantation.

Screening for paroxysmal nocturnal hemoglobinuria (PNH) clone in Egyptian children with aplastic anemia.

Aplastic anemia and paroxysmal nocturnal hemoglobinuria (PNH) are clinically related. In addition to their concurrent or sequential appearance in individual patients, PNH and aplastic anemia share several pathophysiologic features. The aim of the present study was to screen for PNH clone in Egyptian aplastic anemia pediatric patients before the initiation of any specific therapy and to evaluate the clinical status of studied patients 3-6 months after initiation of immunosuppressive therapy. We studied 11 pediatric patients with newly diagnosed acquired aplastic anemia and followed them up clinically for 3-6 months after initiation of immunosuppressive therapy. In addition to routine clinical and laboratory evaluation, sucrose lysis test and staining of bone marrow for CD59 were performed in all subjects. All studies cases had severe aplastic anemia (SAA) except one case which had very severe aplastic anemia (VSAA). Sucrose lysis test was negative in all studied cases. Presence of PNH clone (as evident by loss of normal staining of hematopoietic cells for CD59 = CD59 negative cells) was evident in four subjects. All cases with PNH clone were >6 years old and one of them developed splenic vein thrombosis. As regards the laboratory data WBC < or = 2.8 x 10(3)/mm3 and reticulocytes > or = 0.6 per cent were the most frequent factors associated with PNH clone found in all PNH subjects, but only in 28.6 per cent and 14.3 per cent respectively, of non-PNH subjects. Mortality rate was higher in non-PNH subjects (28.5 per cent) compared to 25 per cent of PNH subjects. We conclude that immunohistochemical staining of bone marrow sections is a sensitive tool to detect the emergence of PNH clone in aplastic anemia patients. Thrombotic complications should be anticipated in cases with aplastic anemia having a PNH clone.