Degree Of HLA Matching Research Articles

Prognostic Significance of Detection of Minimal Residual Disease by Multiparametric Flow Cytometry Before Allogeneic Stem Cell Transplantation in Patients with Acute Myeloid Leukemia,

Abstract 4116The main prognostic determinant of the outcome of allogeneic stem cell transplantation (allo-SCT) for acute myeloid leukemia (AML) is disease phase at transplant while the relevance of the assessment of minimal residual disease (MRD) at transplant has not been elucidated. Although molecular markers are highly sensitive for the detection of MRD, they are available in only half of AML cases to date. On the other hand, multiparametric flow cytometry (MFC) offers the feasibility of MRD assessment in virtually all patients. We retrospectively studied the influence of pre-transplant MRD status by MFC on the outcomes of patients with AML in relation to other known prognostic factors.From 01/2003 to 12/2010, 102 AML patients (male/female; 58/44), aged 15–64 (median; 42) years, received allo-SCT in our center at first (CR1, N=69) or subsequent (CR≥2, N=33) morphologic complete remission. Donors were HLA-compatible siblings (N=45), matched unrelated (N=34) or alternative (haploidentical relatives or unrelated cord blood; N=6 and 17, respectively). The conditioning regimen was myeloablative in 85 (83.33%), and reduced-intensity in 17 (16.67%) cases. Data on MRD assessment by four- or five-color MFC before transplant were available in 92 patients. MRD was defined as any percentage of cells with an aberrant antigen expression pattern compared to normal or regenerating marrow. Transplant outcomes associated with MRD in univariate and multivariate analysis were overall (OS) and disease-free (DFS) survival, relapse incidence, and non-relapse-related mortality (NRM). Prognostic parameters included in the statistical model were the following: age and gender of recipient or donor, interval from diagnosis to transplant, de novo versus secondary AML, CR1 versus CR≥2 at transplant, cytogenetic risk group (according to Intergroup ECOG/SWOG definition), recipient and donor cytomegalovirus (CMV) serostatus, donor type, conditioning regimen (myeloablative versus reduced-intensity), degree of HLA match, method of graft-versus-host disease (GVHD) prophylaxis, and the modified European Blood and Marrow Transplantation Group (EBMT) risk score (Hemmati et al, 2011).With a median follow-up of 47 (range, 6–98) months, OS and DFS were 54.2% and 51.72%, respectively. The cumulative incidence of relapse was 24.45%, and of NRM 23.82%. Eighteen out of 92 (19.57%) patients had MRD by MFC before allo-SCT. According to univariate analysis, the presence of MRD showed a negative association with OS (29.63% versus 63.17% at 4 years in patients with or without MRD, respectively, P=0.053) and DFS (28.52% in MRD-positive versus 59.74% in MRD-negative cases at 4 years, P=0.025, Figure 1). Presence of MRD correlated with higher incidence of relapse compared to MRD negativity (52.7% versus 15.8%, respectively, P=0.001) (Figure 2), but did not influence NRM. In multivariate analysis (Cox proportional hazards, backward stepwise selection), the parameters that remained independent adverse risk factors in terms of specific outcomes were: a) For OS: age and male gender of patient, alternative donor, unfavorable karyotype, CR≥2, and secondary AML, b) For DFS: presence of MRD (HR=3.2, P=0.009), CR≥2 (ÇR=3.1, P=0.005), reduced-intensity conditioning (HR=2.6, P=0.034), and unfavorable karyotype (HR=2.06, P=0.074), c) For relapse: presence of MRD (ÇR=3.83, P=0.003), and unfavorable karyotype (HR=3.55, P=0.007), and d) For NRM: age of recipient, CR≥2, and alternative donor. [Display omitted] [Display omitted] In conclusion, the presence of MRD by MFC before allo-SCT for AML is associated with a significantly higher risk of relapse and an inferior DFS, despite morphologic complete remission at transplant. Moreover, pre-transplantation MRD status has independent prognostic significance in addition to the disease phase, cytogenetic risk group, and intensity of the conditioning regimen. Prospective studies are warranted to examine if the adverse impact of MRD on the outcomes of allo-SCT can be reversed by immunologic manipulations aiming at augmenting graft-versus-leukemia (GVL) effect. Disclosures:No relevant conflicts of interest to declare.

Does Methotrexate Affect Transplant Outcomes? Transplant Related Mortality (TRM), Engraftment, Graft Vs. Host Disease (GvHD), Overall Survival (OS) and Event Free Survival (EFS) in 142 Consecutive Pediatric Cord Blood Transplants (CBT) At Children's Memorial Hospital (CMH)

Abstract 3028 Objective:Methotrexate (MTX) is widely used as prophylactic for GvHD. We retrospectively evaluated all CBT, to determine if there is any correlation between transplant outcomes and short course MTX prophylaxis. Patients & Method:Between January 1995 and January 2011, 142 CBT were performed at CMH for the treatment of malignant or non-malignant conditions on IRB approved protocols. Cord blood units were processed as described by Rubenstein et al. GvHD prophylaxis was either Methotrexate (MTX) with anti-thymocyte globulin (ATG) and cyclosporine A (CSA) in 91patients; or non MTX regimens with/without ATG and CSA, in 51 patients. Statistical analysis for group and sub groups were done using Fisher’s exact and log-rank tests, column statistics and unpaired t test. Significance was determined at the p-value of 0.05. Median ± SEM were also calculated and all have a confidence interval at 95%. There were 64 female and 78 male recipients; with 76 female and 65 male CBT units. Median age and weight at transplant were 3.7 yrs (0.1 – 20.6) and 20.1 kg (3.0- 73). Degree of HLA matching was 6/6 (n= 15), 5/6 (n= 35), 4/6 (n= 83), 3/6 (n= 8). 8 cord blood units were from related donors (MR), 134 were from unrelated donors (MUD). 58 patients (41%) had ABO mismatch. HLA matching, ABO group and donor sex was not available for 1 patient-donor pair. The median cell dose was 0.90 × 108/kg TNC, 0.79 × 108/kg MNC and 1.14x 106/kg CD34+ cells, (0.09– 4.27; 0.08– 3.84; 0.02– 8.7 respectively). Malignant diagnoses (n= 95) (ALL (n= 47), AML (n= 29), MDS (n= 8), other (n= 11)); non-malignant (n= 47) (x-linked diseases (n= 21), Anemias (n= 9), Hemophagocytosis (n= 6), Osteopetrosis (n= 5), other (n= 6)). 130 patients (92%) received ablative regimens of fTBI + VP, Cy, TT or Bu, Cy + VP or TT, Cy + FLUD; 12 patients (8%) received non-ablative regimens of VP, Cy, or FLUD + Bu, Cy. Results:An ANC of >500 cells/μL was achieved in 78% of patients at 23 days (14– 60); 75% achieved PLT count of >20, 000 at 43 days (14– 105); and 65% achieved >95% donor cell chimerism at median of 28 days (13– 169). 32 patients (22.5%) died within day +100 from TRM. 17 patients (18%) had relapse at median of 153 days (34– 720). Acute GvHD was seen in 45.8% patients and 5.6% developed chronic GvHD. EFS at 1, 3 and 5 yr was 52%, 50% and 50% respectively, with 1, 3 and 5 yr OS of 63%, 60% and 60%. 62 patients are survivors. Median follow up was for 3 yrs (0.1- 16.4 yr). Outcomes for the MTX and non-MTX groups were as in Table 1.Table 1Whole group, n= 142MTX, n= 91Non-MTX, n= 51p-valueMalignancy (n, %)95, (66.9%)74, (81.3%)21, (41.2%)<0.0001Non-malignancy (n, %)47, (33.1%)17, (18.7%)30, (58.8%)fTBI regimen (n, %)95, (66.9%)72, (79.1%)23, (45.1%)<0.0001Non-TBI regimen (n, %)47, (33.1%)19, (20.9%)28, (54.9%)ANC >500 (n, %)99, (78%)69, (75.8%)30, (58.8%)0.73Median Days to ANC >5002325200.008ANC >500 at 30 & 45 days49%, 76%52%, 78%52%, 70%PLT >20,000 (n, %)93, (75%)65, (71.4%)28, (54.9%)0.52Median Days to PLT >20,0004344420.41PLT >20,000 at 30, 45 & 100 days16%, 45%, 88%16%, 44%, 91%15%, 47%, 79%Chimerism (n, %)92, (64.8%)63, (69.2%)29, (56.9%)0.23Median Days to chimerism2830250.26TRM (n, %)32, (22.5%)19, (20.9%)13, (25.5%)0.55Relapse (malignant group only) (n, %,median days)17/95, (18%), 153 days12/74, (16.2%), 214 days5/21, (23.8%), 57 days0.51EFS (n, % No events); (1yr, 3yr, 5yr %)69, (49%); (52%, 50%, 50%)46, (51%); (54%, 54%, 54%)23, (45%); (51%, 46%, 46%)0.27OS (n, % alive); (1yr, 3yr, 5yr %)83, (58%); (63%, 60%, 60%)52, (57%); (62%, 58%, 58%)31, (61%); (63%, 63%, 63%)0.91Acute GvHD (n, %)65, (45.8%)46, (50.5%)19, (37.3%)0.16Chronic GvHD (n, %)8, (5.6%)6, (6.6%)2, (3.9%)0.71 Conclusion:In this cohort the number of patients with malignant disorders who received fTBI regimen was statistically significantly higher in the MTX group. Patients in the MTX group took longer to ANC engraftment. There was no other statistical significance between the MTX and non-MTX groups with respect to TRM, Engraftment, GvHD, OS or EFS. In conclusion, short course MTX prophylaxis does not influence transplant outcomes in pediatric CBT for malignant or non-malignant conditions. Disclosures:No relevant conflicts of interest to declare.

Mismatches in Ethnicity Between Donor and Recipient Affects Overall Survival In Umbilical Cord Blood Transplantation,

Abstract 4159Limited data is available on the role of ethnicity on outcomes after umbilical cord blood transplants (UCBT). This study retrospectively analyses the role of donor and recipient ethnicity on clinical outcomes after UCBT. All patients (pts) had UCBT at the Texas Transplant Institute in San Antonio where Hispanics make up a large proportion of pts undergoing UCBT. Pts had UCBT between 2001 and 2010. CIBMTR and hospital records supplied the data and included 260 pts who were: White (76), Hispanic (141), Black (19) and Asian (6). Blacks and Asians were excluded from analysis due to small numbers. Characteristics of Whites and Hispanics are described in table. Age, cell dose, myeloablative and non-myeloablative conditioning regimens, and single (s) and double (d) UCBTs were similar between the two ethnicities. More Whites (88%) had UCBT for malignant disease than Hispanics (68%) (p<0.001).Incidence of graft-versus-host disease (GVHD) was similar between Whites (acute GVHD grades II-IV: 44%, grades III-IV: 15%, limited chronic GVHD: 9% and extensive chronic GVHD: 11%) and Hispanics (acute GVHD grades II-IV: 34%, grades III-IV: 22%, limited chronic GVHD: 28% and extensive chronic GVHD: 15%) and regardless of whether they had malignant or non-malignant disease, standard (CR1, CR2 and CML-CP) or high (all others) risk hematologic malignant disease, s or d UCBT, and age. Disease and non-disease related mortalities (DRM and NDRM) were similar between Whites (DRM: 20% and NDRM: 23%) and Hispanics (DRM: 16% and NDRM: 24%) and regardless of whether they had malignant or non-malignant disease, high or standard-risk malignant disease, s or d UCBT, and age.Overall survival (OS) was similar between Hispanics (73.7 months) and Whites (70.2 months) and regardless of whether they had malignant or non-malignant disease, high or standard-risk malignant disease, s or d UCBT, and age. Hispanics had a longer OS (88.7 months) than Whites (68.5 months) when each received an ethnically matched s UCB product (p=0.030) and a shorter OS (43.3 months) than Whites (OS=not evaluable (NE), all patients alive) when each received an ethnically mismatched s UCB product (p=0.004). Hispanics with an ethnically mismatched s UCB product and malignant disease had a shorter OS (47.4 months) than Whites (NE, all patients alive) (p=0.016). Whites and Hispanics with ethnically matched and mismatched s UCB products had similar numbers of patients with malignant and high-risk malignant disease. Only 6 of the 163 Whites and Hispanics who had s UCBT were adults (≥18 years).Improvement in OS in Hispanics with ethnically matched s UCB products was related to an increase in OS from NDRM while worse OS in Hispanics with ethnically mismatched s UCB products was related to decreases in OS from both DRM and NDRM. There was a trend to longer OS among all pts with ethnically matched (82.3 months) versus mismatched (68.5 months) s UCB products (p=0.154). OS was shorter among all Hispanics with mismatched (43.3 months) versus matched (88.7 months) s UCB products (p=0.001). Cell dose, degree of HLA-matching, and percent with malignant and non-malignant disease were similar for all pts and between Whites and Hispanics with ethnically matched and mismatched s UCB products.In conclusion, ethnic mismatches between donor and recipient appear to affect survival in pediatric s UCBT. The effect of ethnic mismatches was more pronounced in Hispanics than Whites.Table:CHARACTERISTICS AND OUTCOMESWhiteHispanicNumber of patients76141Median age at transplant, years (range)9.0 (0.1–79.2)8.0 (0.1–61.7)Age category, years<1861 (82%)116 (82%)≥1813 (17%)21 (15%)Median weight, kg (range)25 (4–111)26.3 (4–160)Recipient sexmale43 (57%)90 (65%)female31 (41%)50 (35%)Transplant typesingle57 (76%)107 (76%)double18 (24%)34 (24%)Recipient CMV statuspositive24 (32%)61 (43%)negative27 (36%)41 (29%)*Malignant disease66 (88%)96 (68%)Donor/Recipient ethnicity match, s UCBmatched39 (70%)57 (53%)mismatched10 (18%)28 (26%)HLA-matching, s UCBT6/614 (25%)9 (8%)5/628 (56%)50 (47%)4/613 (23%)44 (41%)Median cell dose x 10'37 TNC/kg (range)5.7 (1.5–28.5)5.6 (1.5–45.5)Median days ANC >500/μL21 (10–50)20 (10–100)Median days platelets >20K/μL51 (24–165)47 (21–167)Median days platelets >50K/μL60 (29–137)49 (24–224)Overall survival, months70.273.7Median follow-up, months (range)28 (.25–121)25 (.25–69)*p-value < 0.05 Disclosures:Shaughnessy:Otsuka: Honoraria, Speakers Bureau; Millenium: Honoraria, Speakers Bureau; Genzyme: Honoraria, Speakers Bureau.

The Saudi Experience in Fludarabine-Based Conditioning Regimens in Patients with Fanconi Anemia Undergoing Stem Cell Transplantation: Excellent Outcome in Recipients of Matched Related Stem Cells but Not in Recipients of Unrelated Cord Blood Stem Cells

Low-dose cyclophosphamide (CY) is now considered the backbone of many of the conditioning regimens used in patients with Fanconi anemia undergoing allogeneic stem cell transplantation (SCT). To reduce the risk of rejection and improve results, CY is usually used in combination with other agents/modalities, such as antithymocyte globulin (ATG), busulfan, radiation, and, more recently, fludarabine (Flu). In this study, we used a uniform Flu-based conditioning regimen (ie, CY, Flu, ATG) in 26 pediatric patients with Fanconi anemia undergoing SCT. The median patient age at the time of SCT was 7.8 years, and the stem cell source was an HLA-matched related donor in 19 patients and partially HLA-matched unrelated cord blood in 7 patients. The CY, Flu, ATG regimen was well tolerated overall, with a remarkably low incidence of graft-versus-host disease and hemorrhagic cystitis. All 19 patients in the matched related donor group engrafted and were alive and transfusion-independent at a median follow-up time of 19 months, compared with only 2 of 7 patients in the unrelated cord blood group. We conclude that the combination of CY, Flu, and ATG in the doses used in this study is well tolerated, and that the proclaimed positive effect of adding Flu to the conditioning regimens of patients with Fanconi anemia undergoing SCT is most pronounced in recipients of HLA-matched related transplants. Its value in unrelated cord blood transplantation probably depends on other factors, such as the degree of HLA matching and the cell dose.

Modification of Human Embryonic Stem Cell-Derived Dendritic Cells with mRNA for Efficient Antigen Presentation and Enhanced Potency

Dendritic cell (DC)-based vaccines are designed to exploit the intrinsic capacity of these highly effective antigen presenting cells to prime and boost antigen-specific T-cell immune responses. Successful development of DC-based vaccines will be dependent on the ability to utilize and harness the full potential of these potent immune stimulatory cells. Recent advances to generate DCs derived from human embryonic stem cells (hESCs) that are suitable for clinical use represent an alternative strategy from conventional approaches of using patient-specific DCs. Although the differentiation of hESC-derived DCs in serum-free defined conditions has been established, the stimulatory potential of these hESC-derived DCs have not been fully evaluated. hESC-derived DCs were differentiated in serum-free defined culture conditions. The delivery of antigen into hESC-derived DCs was investigated using mRNA transfection and replication-deficient adenoviral vector transduction. hESC-derived DCs modified with antigen were evaluated for their capacity to stimulate antigen-specific T-cell responses with known HLA matching. Since IL-12 is a key cytokine that drives T-cell function, further enhancement of DC potency was evaluated by transfecting mRNA encoding the IL-12p70 protein into hESC-derived DCs. The transfection of mRNA into hESC-derived DCs was effective for heterologous protein expression. The efficiency of adenoviral vector transduction into hESC-derived DCs was poor. These mRNA-transfected DCs were capable of stimulating human telomerase reverse transcriptase antigen-specific T cells composed of varying degrees of HLA matching. In addition, we observed the transfection of mRNA encoding IL-12p70 enhanced the T-cell stimulation potency of hESC-derived DCs. These data provide support for the development and modification of hESC-derived DCs with mRNA as a potential strategy for the induction of T-cell-mediated immunity.

Shedding a new light on the HLA matching

Shedding a new light on the HLA matching

The Outcome of the Combination of Tacrolimus, Sirolimus, and ATG for GvHD Prophylaxis on Allogeneic Stem Cell Transplantation From Matched Unrelated Donors

AbstractAbstract 2345 Background:Graft-vs-Host Disease (GvHD) remains a significant complication of allogeneic stem cell transplantation from matched unrelated donors (MUD). Compared to MTX-based regimen, Tacrolimus/Sirolimus was found to decrease the incidence of acute GvHD (Keil et al, Biol Blood Marrow Transplant. 2009;16(2):S319, and Cutler et al, Blood. 2007;109:3108–14), whereas, the incorporation of Antithymocyte globulin (ATG) into MTX-based regimen decreases the incidence of chronic GvHD (Bacigalupo et al, Biol Blood Marrow Transplant. 2002;8(12):656–61). There are no reports of the outcome of the combination of Tacrolimus/Sirolimus and ATG. We compared the results of MUD using tacrolimus and sirolimus (day-3 to day +180) combined with ATG (2.5 mg/kg day −3,−2, and −1) (TSA) prophylaxis in consecutive patients treated at our institution from September 2006 to March 2009, with those using MTX-based prophylaxis without ATG in consecutive patients treated from January 2000 to August 2006. The primary endpoints were incidence of acute and chronic GvHD, lethal infectious complications, relapse, and survival. Result:Between 1/2000 and 3/2009, 71 MUD stem cell transplants were performed. 27 patients received TSA regimen as GvHD prophylaxis and 44 patients received traditional MTX-based prophylaxis without ATG. More patients in the TSA group received PBSC compared to the MTX group (63% vs. 36%; P=0.029), otherwise both groups were matched for age, sex, underline malignancies, disease risk per ASBMT criteria, degree of HLA-match, CMV serology, and conditioning regimens. The cumulative incidence of Grade II-IV classic acute GvHD at day +100 was significantly lower in the TSA group compared to control group (11.7% vs. 41.6%; Gray's test P =0.008). However, the cumulative incidence of aGvHD at day +365 was not statistically significant between both groups (33.1% vs. 44.4%; Gray's test P=0.154); this was due to an increase rate of delayed-onset aGvHD in TSA group (18.5%) compared to MTX group (2.3%). The rate of limited cGvHD was 7.1% vs. 30% in the TSA group and MTX group, respectively (Fisher's P= 0.12). 23% of patients surviving beyond day +100 in MTX group developed extensive/overlap cGvHD, whereas, there were no cases in the TSA group. The rate of CMV infection in patients not receiving corticosteroid treatment for GVHD was higher in the TSA group, although not statistically significant (36.8% vs. 16%, P=0.27). The rate of invasive fungal infections was similar (10.7% vs. 11.8%). The cumulative incidence of relapse at 2 years was 38.5% vs. 22.8% in the TSA and MTX groups, respectively (Gray's test P=0.18). Non-relapse mortality at 2 years was similar in both groups (42% vs. 48%; Grays's test P=0.8). Day +100 mortality was 14.4% and 27.3% in TSA and MTX group respectively. The median survivals were 251 days (95% CI, 170–332) vs. 349 days (95% CI, 236–462) for TSA and MTX groups, respectively. The 1- and 2-year overall survival were 42.3% and 31.7% for TSA group vs. 47.7% and 34.1% for MTX group, respectively (P=0.704). While the mortality rate from bacterial sepsis were equivalent, more patients in the TSA group who were not receiving corticosteroid treatment for aGvHD died from viral and fungal infection (14.3% vs. 0% at 12 months, Fisher's P=0.014). Summary:This is the first report of the combination of TSA for GvHD prophylaxis in MUD transplants. This regimen resulted in a significant decrease in classic aGvHD as previously reported for combination of Tacrolimus/Sirolimus, and decrease in incidence of cGvHD as reported previously in the studies incorporated ATG in MTX-based regimens. Hence, this did not translate into benefit in overall survival due to an increased rate of relapse and lethal viral and fungal infections with TSA regimen. Our study does not demonstrate an appreciable benefit for the addition of ATG, at the dose used, to sirolimus and tacrolimus for GvHD prophylaxis. Further studies directed at optimizing the dose of ATG to lower the rate of lethal infections may result in an overall benefit. Disclosures:No relevant conflicts of interest to declare.

Allogeneic Stem Cell Transplantation From Unrelated One-Antigen HLA-Mismatched Donor, Increases Acute II-IV Gvhd Incidence without Interfering with Other Post-Transplant Complications

AbstractAbstract 2378Allogeneic stem cell transplantation (allo-SCT) offers potential curative treatment of for a wide range of otherwise fatal hematological diseases. However, only one third of patients have an HLA-identical sibling donor. We have previously reported that in patients with standard risk malignancy, transplantation from unrelated HLA-allellically matched donors (10/10) led to outcomes similar to those from HLA-identical sibling donors (Yakoub-Agha et al, JCO 2006). Indeed, with the increase in the number of single-child families, stem cell grafts from unrelated donors are being increasingly used and more than 30% of patients eligible for allo-CST, are still lacking a well-matched donor. In the attempt to investigate the impact of unrelated one-antigen HLA-mismatched graft, we report a single center retrospective study on 209 patients who underwent allo-CST from identical HLA-sibling donor (n=123), unrelated HLA-matched donor (10/10) (n=73) and unrelated one-antigen-HLA-mismatched donor (9/10) (n=13) over the last 5 years. In order to homogenize our cohort, patients with CML, aplastic anemia or lymphoproliferative disorder were excluded from the study. Therefore, underlying diseases were AML (n=104), ALL (n=54), myelodysplastic syndrome (n=30), and myeloproliferative syndrome (n=21). Of the 117 (56%) males patients, 49 (23%) received graft from female donor (classical sex-mismatch). Medians age of recipients and donors at transplantation were 45.2 years (4.4-65.5) and 40.8 years (2.0-67.5), respectively. Patients received conditioning regimens using either myeloablative (n=149) including 81 who received High-dose TBI (12Gy) or nonmyeloablative (n=60) including 48 who received low-dose TBI (2Gy). Antithymoglobulin was given to 25 pts. Bone marrow was the main source of stem cells (n=150; 72%). Results:with the median of follow-up of 37.9 months, 78 patients died including 25 from TRM. Relapse was recorded in 70 patients. Seventy-two patients experienced acute GVHD (aGVHD) including 47 with II-IV grades and 30 with III-IV grades. In multivariate analyses, donor type (unrelated regardless the degree of HLA-matching vs related) and conditioning (nonmyeloablative vs myeloablative) were the most important risk factors negatively influencing the overall survival [p=.002; HR=2.038 and p=.016; HR=1.81, respectively) and event-free survival (p=.005; HR=1.783 and p=.015; HR=1.728, respectively). As expected, the only factor that influenced the risk of relapse was the conditioning type (nonmyeloablative vs myeloablative) (p=.048; HR=1.699) while donor type was found to influence TRM (p=.030; HR=2.428). Graft from unrelated one-antigen HLA-mismatched donor (9/10) was the foremost risk factor for acute grade II-IV GVHD (p=.019; HR=2.663; [95%CI: 1.178–6.019]).In conclusion, except for acute II-IV GHVD, allo-CST from unrelated one-antigen HLA-mismatched donor (9/10), seemed to led to outcomes similar to those from HLA-identical unrelated donor (10/10) and may be considered as an alternative option for patients without a full-matched donor. Prospective studies are warranted, however, to confirm our data in larger cohort of patients. Disclosures:No relevant conflicts of interest to declare.

Outcome of Chinese children with unrelated donor hematopoietic stem cell transplantation

To evaluate the prognostic factors and outcomes in Chinese children undergoing unrelated donor hematopoietic stem cell transplantation (UDT). Retrospective analysis of clinical data from 53 consecutive children who received UDT from November 2002 to December 2007 in our center. The median recipient age was 8.4 years (range 1.5-21). With a median follow-up of 36 months (range 18-80), the probability of 3-year overall survival (OS) was 71.5%. Treatment-related mortality (TRM) was 19.0%, and 9.5% died after post-transplant leukemia relapse. Incidence of grades I-II, III-IV acute and chronic graft versus host disease (GVHD) was 63%, 29%, and 46%. There was significant difference in OS between patients older or younger than 10 years (50.0% vs. 84.8%, P = 0.003), patients with different underlying diseases (ALL, AML, CML, and non-malignant disease: 36.4%, 80.0%, 61.5%, and 100%, P = 0.001) and patients receiving either HLA 0-1 versus 2-3 loci high-resolution mismatched UDT (83.3% vs. 53.3%, P = 0.034). The OS was not affected by the stem cell source (peripheral stem cell 70.3%, bone marrow 87.5% vs. cord blood 62.5%, P = 0.542) or the severity of acute GVHD (grade 0-II 77.8% vs. grade III-IV 60.0%, P = 0.140). The important prognostic factors for OS after UDT were the degree of HLA match, the age of patient and the type of underlying disease. Patients < 10-year with non-malignant disease receiving 0-1 locus high-resolution mismatched UDT had the most favorable outcomes.

Multiple unit umbilical cord blood transplantation with total body irradiation, etoposide and antithymocyte globulin for adult haematological malignancy patients

Multiple unit umbilical cord blood transplantation with total body irradiation, etoposide and antithymocyte globulin for adult haematological malignancy patients

Long-term outcomes of HLA-matched sibling compared with mismatched related and unrelated donor hematopoietic stem cell transplantation for chronic phase chronic myelogenous leukemia: a single institution experience in China

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains the only curative therapy for chronic myelogenous leukemia (CML). In this study, the long-term outcomes of HLA-matched sibling donor (MSD) with mismatched related donor (MRD) and unrelated donor (URD) transplantation for CML in the first chronic phase (CML-CP1) using different graft vs. host disease (GVHD) prophylaxis regimens according to donor source and the degree of HLA matching were compared. The data of 91 patients with CML-CP1 were analyzed with respect to GVHD, overall survival (OS), and transplant-related mortality (TRM). The incidence of grade II-IV acute GVHD was 25.5% in the MSD and 40.5% in the MRD/URD group (P = 0.133). The 1-year cumulative incidence of chronic GVHD was not different between the MSD and the MRD/URD groups, while extensive chronic GVHD was different between the two groups (31.9% vs. 10.8%, P = 0.023). The 5-year cumulative relapse rate was not different between the MSD and the MRD/URD groups, while TRM was different between the two groups (6.6% vs. 26.3%, P = 0.010). The 5-year cumulative OS was 90.9%, 71.5%, and 85.4% in the MSD, the MRD/URD, and the HLA allele-matched URD transplantation, respectively (MSD vs. MRD/URD, P = 0.013; MSD vs. HLA allele-matched URD, P = 0.437). In conclusion, survival in HLA allele-matched URD is equivalent to MSD, but in MRD and mismatched URD is inferior to MSD in patients with CML-CP1 undergoing allo-HSCT using different GVHD prophylaxis regimens according to donor source and degree of HLA matching. Patients undergoing MRD/URD transplantation have an equal quality of life as patients undergoing MSD transplantation.

Leukemia Lineage-Specific Chimerism Analysis and Molecular Monitoring Improve Outcome of Donor Lymphocyte Infusions

A retrospective analysis was performed of 118 patients with hematologic malignancies who received donor lymphocyte infusions (DLIs) after allogeneic stem cell transplantation (ASCT). Treatment was either given because of hematologic relapse (n = 44), molecular/cytogenetic relapse (n = 52), or other causes (n = 22). Molecular relapse was in most cases based on leukemia lineage-specific chimerism analysis. Patients with acute leukemia and myelodysplastic syndrome showed a 3-year survival of 42% if DLI treatment was given because ofmolecular relapse, compared to 16% in hematologic relapse (P < .006). In multivariate analysis, there was a correlation between response to DLI and nonhematologic relapse (risk ratio [RR] 3.36, P = .001), chronic graft-versus-host disease (cGVHD) (RR = 1.51, P = .005), and late relapse (RR = 2.06, P = .017). The overall incidences of acute GVHD (aGVHD) grades I-II and grades III-IV aGVHD were 33% and 8.5%, respectively. Probability of cGVHD was 33%. The development of aGVHD or cGVHD did not significantly influence the response of DLI in patients with molecular/cytogenetic relapse. However, the development of cGVHD was significantly associated with a better response in patients with hematologic relapse because only 4 of 29 patients without cGVHD responded compared to 7 of 12 with cGVHD (P = .007). The development of cGVHD increased significantly if DLI was given >12 months after ASCT (46% versus 27%, P = .04). In contrast, time between ASCT and start of DLI treatment had no significant influence on the risk of developing aGVHD. To conclude, monitoring of leukemia lineage-specific chimerism is of utmost importance for DLI response after ASCT.

Donor‐specific transfusions

Date written: June 2007Final submission: October 2008

Outcome Of Chinese Children With Unrelated Donor Hematopoietic Stem Cell Transplantation: A Single Center Experience

Outcome Of Chinese Children With Unrelated Donor Hematopoietic Stem Cell Transplantation: A Single Center Experience

Platelet transfusion refractoriness in highly immunized beta thalassemia children undergoing stem cell transplantation

Immune-mediated refractoriness to platelet transfusion is a major problem in patients undergoing HSCT. In a cohort of 50 pediatric patients affected by beta thalassemia coming from Middle East countries, we experienced a high incidence of refractoriness because of anti-HLA antibodies during post-HSCT aplasia. In a risk factors analysis, factors predicting a negative transfusion outcome were presence of spleen and the number of anti-HLA antibodies. We adopted a policy to select platelet donors by avoiding HLA antigens against which the patient had specific antibodies. Transfusion of dedicated units resulted in 26% refractoriness compared to 74% to random units (p < 0.0001). When dedicated transfusions were used, the presence of spleen did not influence transfusion outcome. Analyzing transfusion outcome depending on the degree of HLA match and ABO compatibility, 76% successful transfusions were obtained with HLA-matched- ABO compatible followed by 67% in HLA-1mismatch- ABO compatible or HLA-matched- ABO incompatible and by 46% in HLA-1mismatch- ABO incompatible. In conclusion, we provide evidence that the selection of platelet donors according to patient characteristics, anti-HLA antibodies and ABO matching, is successful in reducing platelet refractoriness in heavily alloimmunized thalassemia patients undergoing transplantation.

Unrelated cord blood transplantation in pediatric patients: a report from Saudi Arabia

In unrelated cord blood (UCB) transplantation, survival has been shown to correlate with the degree of HLA matching. Thus, to extend transplant access to different ethnic backgrounds, many western UCB transplantation banks now encourage donation from non-Caucasians. Until recently, Saudi Arabia did not have a national UCB bank. In this study we report our experience in UCB transplantation in children using units procured from western cord blood banks. A total of 97 children underwent unrelated UCB transplantation at King Faisal Specialist Hospital and Research Center (KFSHRC), of which 95 were of Arab ethnicity. A total of 30 patients had malignant disorders, 25 patients had non-malignant hematological disorders and 42 patients had inborn errors. Conditioning was according to disease, with six patients receiving reduced-intensity regimens. In all, 46 patients received one-Ag-mismatched units and 51 received two-Ag-mismatched units. Engraftment occurred in 93% of patients, the 100-TRM was 15%, acute GVHD developed in 20% of patients and chronic GVHD occurred in 9% of patients. The 5-year OS and EFS estimates were 52 and 43%, respectively. The search for UCB transplantation units for Saudi patients in western banks yielded reasonably compatible units for our patients; the results are consistent with published data. Our data are encouraging for UCB transplant programs in countries in which there are no national UCB transplantation banks.

Selection of Donors with Favorable KIR B Genotypes for Unrelated Hematopoietic Cell Transplantation Results in Superior Relapse Protection and Better Relapse-Free Survival for Patients with AML.

Abstract 665Unrelated donor (URD) transplants from donors with KIR group B/x genotypes (vs. A/A) confer a significant relapse-free survival (RFS) benefit for patients with acute myeloid leukemia (AML) (RR: 0.70 [95% CI: 0.55-0.88]; P = .002; Blood 2009; 113[3]). This new analysis was designed to investigate the beneficial effect of KIR B donors and to develop a donor selection strategy to improve clinical outcomes after hematopoietic cell transplantation (HCT) for leukemia. Based on an analysis of 27 unique KIR haplotype sequences we identified common centromeric and telomeric gene content motifs. KIR A haplotypes contain a Cen-A motif (defined by the presence of the inhibitory KIR gene 2DL3) and a Tel-A motif (defined by the presence of the activating gene 2DS4). The B haplotypes were defined as containing Cen-B (presence of 2DS2 and/or 2DL2) and/or Tel-B (presence of 2DS1), with further subdivisions possible at the allelic level. Thus, based on gene content alone, donor KIR genotypes can be classified as homogyzous A/A or defined by the type (Cen-B or Tel-B) or number (0, 1, 2 or ≥3; B domain content score) of B domains. Multivariate models were used to evaluate the effect of donor KIR genotypes on clinical outcomes after URD transplants facilitated by the National Marrow Donor Program for AML (n=1086) and acute lymphoblastic leukemia (ALL: n=334) between 1988 and 2006. The improved RFS associated with donor KIR B genotypes (Cen-A/B, Cen-B/B, Tel-A/B or Tel-B/B) vs. KIR A genotypes (Cen-A/A or Tel-A/A) in AML was most evident in the 115 donors (10.6%) who were homogyzous for the Cen-B motif (RR 0.72 [95% CI 0.55-0.94]; p=0.014). Likewise, Cen-B/B donors conferred significant protection against relapse (RR 0.34 [95% CI 0.2-0.57]; p < 0.0001); with absolute relapse rates of only 10% (Cen-B/B) vs. ∼31% (A/A). Similarly, multivariate models demonstrated that compared to KIR A/A donors, donors with higher KIR B domain content scores resulted in improved RFS (2B motifs: (RR 0.78 [95% CI 0.63-0.95]; p=0.013; n=244) or ≥3 B motifs: (RR 0.76 [95% CI 0.57-1.02]; p=0.07; n=84) and less relapse (2B motifs: (RR 0.54 [95% CI 0.39-0.74]; p=0.0001) or ≥3 B motifs: (RR 0.45 [95% CI 0.27-0.74]; p=0.0017). Donor KIR genotype had no effect on rates of graft vs. host disease or treatment related mortality. Importantly, the use of KIR B donors of any type was not associated with any improvement in clinical outcomes for patients with ALL. These data suggest that AML blasts may be particularly sensitive to killing by NK cells and raises the possibility that activating genes present in the donor KIR B haplotypes may uniquely recognize ligands on AML blasts. The KIR B genotype effects were not affected by the degree of HLA matching. Therefore, these data support the consideration of KIR genotyping with HLA typing into the unrelated donor search criteria for patients with AML. To capture the benefit of Cen-B and/or higher B domain content scores we propose that the ∼30% of donors who have ≥2 B domains (includes all Cen-B/B donors) be given preference over donors with 0 or 1 KIR B domains. In this large retrospective dataset, assignment by that rule resulted in significant improvements in RFS (RR 0.80 [95% CI 0.68-0.94]; p=0.0063) and relapse (RR 0.53 [95% CI 0.41-0.69]; p<0.0001). A prospective trial to test this strategy is planned. Disclosures:No relevant conflicts of interest to declare.

Frequency of CD4+CD25hiFOXP3+ Regulatory T Cells Has Diagnostic and Prognostic Value as a Biomarker for Acute Graft-Versus-Host Disease.

Abstract 514JMM and XQ contributed equally to this work.Regulatory T cells (Treg) play an important role in the maintenance of tolerance after bone marrow transplantation (BMT) in experimental models. However, the relationship between Treg and acute graft-versus-host disease (GVHD) in allogeneic BMT recipients is not well established. We conducted a prospective analysis of Treg frequency in 215 BMT patients (125 allogeneic, 90 autologous) at the University of Michigan. Fresh peripheral blood samples were acquired prior to therapy within 24 hours of GVHD onset and at equivalent time points in patients without GVHD. Treg frequency was measured in triplicate by three color cytometry analysis to determine the frequency of CD4+CD25hiFOXP3+ cells within total lymphocytes. There were no significant differences between patients with and without GVHD for median age, nonmalignant disease, conditioning intensity, and median day of sample acquisition. Recipients of grafts from donors who were not family members or who were not HLA-matched were overrepresented in the GVHD group. Autologous BMT patients (N=90) and allogeneic BMT patients without GVHD (N=65) had the same mean Treg frequency (1.09% ± 0.10 vs. 1.09% ± 0.11, p = 0.54), showing that the use of calcineurin inhibitors did not affect Treg frequency. Patients with GVHD (N=60) had 40% fewer Treg (0.66% ± 0.07, p < 0.001) than those without GVHD. Frequencies of Tregs decreased in a linear fashion with each increasing grade of GVHD at onset, and were significantly reduced in patients with ≥ grade II compared to patients without GVHD (p < 0.001) (Figure 1). The calculated Receiver Operating Characteristic (ROC) curve for Treg frequency as an independent biomarker of GVHD was 0.69 (95%CI, 0.55-0.83). Treg frequency also correlated with the eventual maximum overall grade of GVHD (p < 0.001), suggesting a prognostic value for this measurement. Therefore, we evaluated whether Treg frequency would correlate with non relapse mortality (NRM) in the 60 patients with GVHD. Patients with low Treg frequency (<0.5%, N=30) had a significantly greater NRM (41% vs. 8%, p = 0.03) than patients with high Treg frequency (≥0.5%, N=30), which resulted in an inferior survival at two years (38% vs. 63%, p = 0.03) (Table 1). Acute GVHD accounted for the majority of NRM in the low Treg frequency group. Relapse mortality was similar between groups (p = 0.9) (Table 1). This difference in survival remained significant after adjusting for other important prognostic factors such as age, degree of HLA-match, and conditioning intensity (p = 0.05). In this set of sixty patients, frequency of CD4+CD25hiFOXP3+ Tregs at onset of GVHD correlates with GVHD severity, eventual maximum grade and NRM. Treg frequency thus has important diagnostic and prognostic value as biomarker for acute GVHD. [Display omitted] Table 1Clinical outcomes according to CD4+CD25hiFOXP3+ frequency at GVHD onset.OutcomeTreg Frequency ≥ 0.5 %Treg Frequency <0.5%p valuen=30n=301 year Non-Relapse Mortality8% (95% CI, 2-27)41% (95% CI, 23-61)0.032 year Relapse Mortality25% (95% CI, 15-40)20% (95% CI, 11-35)0.92 year Overall Survival63% (95% CI, 43-91)38% (95% CI, 23-63)0.03 Disclosures:No relevant conflicts of interest to declare.

Standard Gvhd Prophylaxis Augmented with TNF-Inhibition in Alternative Donor HCT: Lower TNFR1 Levels Correlate with Better Outcomes.

Abstract 43We have previously shown that TNF Receptor 1 (TNFR1) levels early after myeloablative hematopoietic cell transplant (HCT), especially following unrelated donor (URD) HCT, predict later graft-versus-host disease (GVHD), non-relapse mortality (NRM), and overall survival (OS). Given this data we hypothesized that augmenting standard GVHD prophylaxis with the TNF-inhibitor etanercept would protect against GVHD and NRM while improving survival. We therefore conducted an IRB-approved Phase II trial at two centers to determine whether prophylactic TNF blockade with etanercept decreases the rates of acute GVHD and day 100 NRM seen after high-risk allogeneic matched (n=68, 71%) or single antigen mismatched URD (n=25, 26%) or single antigen mismatched related donor (RD) (n=3, 3%) HCT. Follow-up data are available for 96/100 patients (pts) enrolled between 2005 and 2009. HLA matching used high-resolution DNA-based techniques for HLA-A, B, C, and DR. Patients received tacrolimus, methotrexate (5 mg/m2 on days 1, 3, 6, 11) and etanercept (0.4 mg/kg, max 25 mg) twice weekly from the start of conditioning to day 56. All pts received myeloablative regimens; either TBI/cyclophosphamide (TBI, n=29), fludarabine and 12.8 mg/kg IV busulfan (FluBu4, n=31) or other myeloablative chemotherapy regimens, either BCNU/etoposide/cyclophosphamide or busulfan/cyclophosphamide (BCNU/Busulfan, n=36). The median age of the pts was 45y (range 2-61y).To determine whether the administration of etanercept effectively reduced post-transplant TNFR1 levels we compared day 7 post-transplant TNFR1 levels in the 96 study pts to 132 control pts who received standard GVHD prophylaxis of tacrolimus/methotrexate and were matched for age, conditioning regimen, degree of HLA-match, and disease status. The median day 7 TNFR1 levels in study pts was 2518 pg/ml, significantly lower than the median day 7 level of 3529 pg/ml in control pts (p<0.001), thus confirming that etanercept administration is associated with lower TNFR1 levels early post-transplant. Similar statistically significant results were seen with mean TNFR1 levels. We then tested whether day 7 TNFR1 levels were associated with outcomes in etanercept treated pts. For each doubling of TNFR1 levels, there was an increased risk for NRM (HR 2.0, p<0.001) and death (HR 1.5, p<0.06); the association with NRM remained significant after adjusting for age, gender, risk group, and donor (p=0.002). Interestingly, as shown in the Table, we observed that the effect of etanercept on day 7 TNFR1 levels differed statistically according to the myeloablative conditioning regimen administered (p<0.001). Patients who received FluBu4 had the lowest median day 7 TNFR1 levels and also experienced the best outcomes with low rates of grade 2-4 GVHD after high-risk HCT (39%, p=0.04), no deaths in the first 100 days (p<0.001), and outstanding 2 year survival rates (70%, p=0.03), compared to other study pts.PATIENT OUTCOMES BY CONDITIONING REGIMENSample SizeMedian Day 7 TNFR1 Levels (pg/mL)Mean Day 7 TNFR1 Levels (pg/mL)Day 100 Grade 2-4 GVHDDay 100 Grade 3-4 GVHDDay 100 NRM2 yr NRM2 yr OSOVERALL962518305353%23%16%34%55%FluBu4311735189739%11%0%12%70%BCNU/Busulfan362552300961%25%14%31%58%TBI293907422662%32%34%55%38%We have evidence that etanercept effectively lowers TNFR1 levels at day 7 post-transplant, a time point associated with GVHD and HCT outcomes. However, the degree of TNFR1 level reduction appears to depend in part on the conditioning regimen. The median day 7 TNFR1 levels were statistically different across conditioning regimens, and those with low TNFR1 levels have improved outcomes (FluBu4>BCNU/Busulfan>TBI). In fact, for the FluBu4 pts in particular, preliminary data suggest superior outcomes, including low rates of GVHD and remarkably high 2 year OS for high-risk transplant pts, without use of thymoglobulin. After highly intense conditioning regimens, such as TBI-based, TNFR1 levels remained high despite TNF reduction with etanercept and outcomes are similar to those expected with standard GVHD prophylaxis. With the less toxic, but still myeloablative FluBu4 conditioning regimen, however, the addition of etanercept appeared to lower TNFR1 levels to levels that were protective against NRM. Thus, the effectiveness of etanercept may depend on the conditioning regimen, warranting a randomized trial to explore this interaction further. Disclosures:Off Label Use: Etanercept - for GVHD prophylaxis.

Early Immune Recovery Predicts Overall and Disease-Free Survival After Allogeneic Hematopoietic Stem Cell Transplantation.

Abstract 2222Poster Board II-199 Background:Immune recovery is an important determinant of outcome after allogeneic hematopoietic stem cell transplantation (alloHSCT). Previous studies have demonstrated that early recovery of absolute lymphocyte count (ALC) predicts overall (OS) and disease free survival (DFS) in conventional and partially T-cell depleted (TCD) alloHSCT. Recipients of conventional and especially TCD alloHSCT can have prolonged recovery of their immune systems, which may extend beyond one year. We have previously shown that the rate of CD4+ T cell recovery after TCD alloHSCT correlates with the risk of opportunistic infections. However, the impact of lymphocyte subset recovery on relapse and long-term survival following alloHSCT remains an important unknown. Methods:We conducted a retrospective study on 353 consecutive patients (median age 39, range 2-68) who received a fully TCD alloHSCT at MSKCC between January 1997 and December 2005. We excluded patients transplanted after 2005, because they received KGF for which pre-clinical data suggest an effect on immune recovery. Diseases included ALL (85), AML (146), CML (43), MDS (31), NHL (47), and undifferentiated leukemia (1). We excluded patients who died or did not have stable engraftment by 30 days. Immune recovery data, including ALC through day 90 and lymphocyte subsets through one year were grouped by quartile of cohort (table). The primary endpoints were OS and DFS. The score statistic from the Cox proportional hazards model defined the association of these endpoints with the values of ALC, CD4+ and CD8+ T cells, and NK cells. Subsequent to individual score tests, the Cox model determined the values associated with survival endpoints, in addition to prognostic clinical factors. Because markers were measured post-HSCT, a landmark analysis explored their prognostic significance. The landmark times were 1, 2, 3, 6, 9, and 12 months post-HSCT. Additional factors in the Cox model were: patient sex, age, number of remissions, stem cell source, and donor-recipient HLA match. The Kruskal-Wallis test evaluated if the diagnoses were associated with lymphocyte recovery.Variable1MinLower QuartileMedianUpper QuartileMaxALC 3000.30.50.811.6ALC 6000.40.81.26.7ALC 9000.50.71.217.9NK 3001683485252393NK 6002203034662229NK 90201722704271569CD4 61751362091771CD4 1201462484091574CD8 60521322873643CD8 12212625149436921ALC in K/mcL; NK/CD4/CD8 in cell/mcL Results:In univariate analysis, high ALC at day 30 (ALC 30, p < 0.001) and day 60 (ALC 60, p = 0.015) were associated with improved OS. High ALC 30 was also associated with improved DFS (p = 0.005). Multivariate analysis demonstrated that high ALC 30 was independently associated with improved OS (p = 0.011). NK cell count at day 60 was associated with improved OS and DFS by univariate (p = 0.014, 0.010) and multivariate (p = 0.007, 0.002) analysis. Similarly, CD4+ T-cell count at 6 and 12 months predicted survival. By univariate analysis, CD4+ T-cell count at 6 and 12 months predicted OS (p = 0.007, p < 0.001) and DFS (p= 0.032, 0.002). This relationship remained with multivariate analysis. CD4+ T-cell count at 6 and 12 months independently predicted OS (p = 0.013, 0.007) and DFS (p = 0.059, 0.043). There was no association of CD8+ T cell count with OS or DFS. Other predictors of improved survival included younger age, higher degree of HLA match, peripheral blood as stem-cell source, and transplant in 1st remission. Diagnosis did not differentiate clinical outcomes except for CML patients, who had decreased DFS (but not OS) secondary to increased relapse with TCD. Finally, diagnosis was not associated with post transplant immune recovery. Discussion:We demonstrate that several measures of immune recovery, including time points as early as day 30, are important predictors of OS and DFS after fully TCD alloHSCT. Our finding that ALC 30 predicts OS in the TCD setting is consistent with prior studies in the conventional and partially TCD settings. We further demonstrate that reconstitution of NK cells and, later, CD4+ T cells predicts survival and relapse in the TCD setting. Finally, we show there is no relationship between diagnosis and immune recovery. It is likely that these findings will also apply to conventional alloHSCT given the concordance of our ALC 30 outcomes. These results may help identify patients most likely to benefit from interventions to enhance post-alloHSCT immune reconstitution. Disclosures:Castro-Malaspina:Alexion: Consultancy, Honoraria.