Unmanipulated haploidentical bone marrow transplantation and post-transplant cyclophosphamide for hematologic malignanices following a myeloablative conditioning: an update.

This is a report of 148 patients with hematologic malignancies who received an unmanipulated haploidentical bone marrow transplant (BMT), followed by post-transplant high-dose cyclophosphamide (PT-CY). All patients received a myeloablative conditioning consisting of thiotepa, busulfan, fludarabine (n=92) or TBI, fludarabine (n=56). The median age was 47 years (17-74); 47 patients were in first remission (CR1), 37 in second remission (CR2) and 64 had an active disease; all patients were first grafts. The diagnosis was acute leukemia (n=75), myelodisplastic syndrome (n=24), myelofibrosis (n=16), high-grade lymphoma (n=15) and others (n=18). GVHD prophylaxis consisted in PT-CY on days +3 and +5, cyclosporine (from day 0), and mycophenolate (from day +1). The median day for neutrophil engraftment was day +18 (13-32). The cumulative incidence of grades II-IV acute GVHD was 24%, and of grades III-IV GVHD 10%. The incidence of moderate-severe chronic GVHD was 12%. With a median follow-up for the surviving patients of 313 days (100-1162), the cumulative incidence of transplant-related mortality (TRM) is 13%, and the relapse-related death is 23%. The actuarial 22 months overall survival is 77% for CR1 patients, 49% for CR2 patients and 38% for patients grafted in relapse (P<0.001). Major causes of death were relapse (22%), GVHD (2%) and infections (6%). We confirm our initial results, suggesting that a myeloablative conditioning regimen followed by unmanipulated haploidentical BMT with PT-CY, results in a low risk of acute and chronic GVHD and encouraging rates of TRM and overall survival, also for patients with active disease at the time of transplant.

DLI after haploidentical BMT with post-transplant CY.

Forty-two patients relapsing after an unmanipulated haploidentical BM transplant and post-transplant CY (PT-CY), were given 108 DLI, with median interval from transplant of 266 days (range, 67-1372). DLI were given at escalating doses, expressed as CD3+ cells/kg, without GVHD prophylaxis, and ranged from 1 × 10(3) to 1 × 10(7) cells/kg (median 5 × 10(5) cells/kg). The average number of DLI per patient was 2.6 (range, 1-6). The diagnosis was leukemias (n=32) grafted with a myeloablative regimen and Hodgkin's disease (n=10), grafted with a nonmyeloablative regimen. Leukemic patients with molecular relapse (n=20), received DLI alone (n=17) or in association with azacytidine (n=3); leukemic patients with hematologic relapse (n=12) received chemotherapy followed by DLI (n=11) or DLI alone (n=1); Hodgkin patients received DLI following 1-3 courses of chemotherapy. In these three groups the incidence of acute GVHD II-III was 15%, 17% and 10%; response rate was 45%, 33% and 70%; 2-year actuarial survival was 43%, 19% and 80% respectively. This study confirms that escalating doses of DLI can be given in the haploidentical setting with PT-CY, with a relatively low risk of acute GVHD. Response rates and survival are dependent on the underlying disease.

Outcome of patients activating an unrelated donor search: the impact of transplant with reduced intensity conditioning in a large cohort of consecutive high-risk patients.

An unrelated donor (UD) search was submitted to the Italian Bone Marrow Donor Registry between February 2002 and December 2004, for 326 consecutive patients with hematological malignancies, eligible for a reduced intensity conditioning (RIC) UD transplant. Only two regimens were allowed: melphalan, alemtuzumab, fludarabine and total body irradiation of 200 cGy (regimen A) and thiotepa, cyclophosphamide, anti-thymocyte globulin (regimen B). The outcome of patients receiving an UD transplant (n=121) was compared with patients who did not find a donor (n=205), in a time dependent analysis, correcting for time to transplant. The median follow up from activation of donor search was 6.1 years. UD transplant was associated with a significantly better survival in patients with acute leukemia and non-Hodgkin's lymphoma (NHL) whereas only a favorable trend was documented for Hodgkin's disease. No survival benefit was registered for chronic leukemias. The outcome of the two different conditioning regimens was comparable, in terms of survival, transplant-related mortality and graft versus host disease. In conclusion, finding an UD and undergoing a RIC transplant significantly improves survival of patients with acute leukemia and NHL. The advantage is less clear for HD and chronic leukemias. The role of different conditioning regimens remains to be elucidated by prospective clinical trials.

In vivo B-cell depletion with rituximab for alternative donor hemopoietic SCT.

We retrospectively analyzed 55 patients given a fixed dose of rituximab (200 mg) on day+5 after an alternative donor transplant, to prevent EBV DNA-emia; 68 alternative transplants who did not receive prophylactic rituximab served as controls. The two groups were comparable for donor type, and all patients received anti-thymocyte globulin in the conditioning regimen. Rituximab patients had a significantly lower rate of EBV DNA-emia 56 vs 85% (P=0.0004), a lower number of maximum median EBV copies (91 vs 1321/10(5) cells, P=0.003) and a significantly lower risk of exceeding 1000 EBV copies per 10(5)cells (14 vs 49%, P=0.0001). Leukocyte and lymphocyte counts were lower on day +50 and+100 in rituximab patients, whereas Ig levels were comparable. The cumulative incidence of grade II-IV acute GvHD was significantly reduced in rituximab patients (20 vs 38%, P=0.02). Chronic GvHD was comparable. There was a trend for a survival advantage for patients receiving rituximab (46 vs 40%, P=0.1), mainly because of lower transplant mortality (25 vs 37%, P=0.1). Despite the drawback of a retrospective study, these data suggest that a fixed dose of rituximab on day +5 reduces the risk of a high EBV load, and also reduces acute GvHD.

Risk factors for enterococcal bacteremia in allogeneic hematopoietic stem cell transplant recipients.

Bacteremia is a well known cause of morbidity and mortality in hematopoietic stem cell transplant (HSCT) recipients and enterococci are among the most frequently isolated pathogens. The aim of this study was to identify risk factors for enterococcal bacteremia during the first 30 days after allogeneic HSCT. A retrospective case-control study was performed; for each case, 3 controls were randomly selected among 306 patients transplanted during the study period (January 1, 2004 to December 31, 2007). Odds ratios (OR) with 95% confidence intervals (CI) were calculated for variables influencing the risk for bacteremia. Overall, 33 patients developed enterococcal bacteremia, within a median of 9 days after HSCT (range, 2-24). The cumulative incidence was 10.8%. Multivariate analysis identified the following variables as risk factors for enterococcal bacteremia: donor and transplant type (greater risk for mismatched related or cord blood) (OR=8.98, 95% CI, 1.65-48.99 and OR=7.52, 95% CI, 1.56-36.31, respectively, P=0.047); severe (grades 3-4) mucositis (OR=9.04, 95% CI, 1.97-41.52, P=0.018); pharyngeal enterococcal colonization (OR=4.48, 95% CI, 1.11-18.03, P=0.035); and previous empirical therapy with cephalosporins (OR=4.16, 95% CI, 0.93-18.66 for 1-7 days of therapy, and OR=7.31, 95% CI, 1.78-30.12 for 8-23 days, P=0.018). Higher Karnofsky score (≥50) and previous empirical therapy with glycopeptides were associated with a decreased risk (OR=0.25, 95% CI, 0.06-0.97, P=0.045 and OR=0.11, 95% CI, 0.02-0.59, P=0.010, respectively). The crude mortality at 7 and 30 days was 12% (4/33) and 24% (8/33), respectively. Enterococcal bacteremia is frequent after allogeneic HSCT. The factors associated with this infection are type of transplant, pharyngeal colonization, severe mucositis, and use of cephalosporins. Good general conditions and the use of vancomycin were associated with lower risk of enterococcal bacteremia.

Pre-emptive treatment of acute GVHD: a randomized multicenter trial of rabbit anti-thymocyte globulin, given on day+7 after alternative donor transplants.

We have previously shown that hemopoietic stem cell transplant (HSCT) recipients can be stratified on day+7 as having low, intermediate or a high risk of transplant-related mortality (TRM). With the aim of reducing TRM and GVHD, intermediate and high-risk patients (n=170) were randomized to receive anti-thymocyte globulin (ATG, thymoglobuline) on day+7 (n=84) or no treatment (n=86) (controls). There was a reduction of TRM from 35% in controls to 29% in ATG patients (P=0.3), of acute GVHD III-IV from 15 to 5% (P=0.02) and of chronic GVHD from 26 to 11% (P=0.03); survival was comparable. The predictive value of the day+7 score on TRM was confirmed for controls (19 vs 42% for intermediate vs high risk, respectively, P=0.03), whereas ATG abrogated this predictive effect (29 vs 29%). ATG reduced GVHD (P=0.006) in high-risk patients, but not in patients with an intermediate risk. In conclusion, we confirm that TRM can be predicted on the basis of day+7 laboratory values, after alternative donor HSCT; in high-, but not intermediate-risk patients, the administration of ATG on day+7 reduces GVHD. These results may represent a platform for risk-adapted post transplant immune modulation.

Changes in lung volumes and airway responsiveness following haematopoietic stem cell transplantation.

Changes in lung volume occur following haematopoietic stem cell transplantation (HSCT); airway hyperresponsiveness was occasionally reported, without mechanistic explanation. The present authors studied 17 patients by standard methacholine (MCh) challenge before and then 3 and 12 months after HSCT (n = 16 and n = 13, respectively). Another 6 patients were challenged before and 3 months after HSCT using a modified challenge to investigate the effect of deep inhalations. No patient developed bronchiolitis obliterans or bronchiolitis obliterans organising pneumonia. At 3 months, forced vital capacity (FVC) was significantly reduced by 0.33+/-0.55 L, forced expiratory volume in one second (FEV(1)) by 0.31+/-0.50 L, total lung capacity (TLC) by 0.39+/-0.37 L and single-breath diffusing capacity of the lung for carbon monoxide (D(L,CO)) by 15+/-12%. At 12 months, TLC decreased by 0.43+/-0.36 L and D(L,CO )by 8+/-8%. With standard challenge, no significant changes in FEV(1) response to MCh were observed after HSCT but FVC decreased significantly less after HSCT compared with prior to HSCT, suggesting less air trapping. With modified challenge, deep inhalations reversed the MCh-induced decrease in partial expiratory flow more after HSCT compared with before HSCT and this correlated with TLC decrements. In conclusion, an increase in airway responsiveness is unlikely after haematopoietic stem cell transplantation, at least in patients without pulmonary complications, and mechanisms opposing airway narrowing may blunt the bronchoconstrictor response.

Extracorporeal photopheresis for the treatment of steroid refractory acute GVHD.

Extracorporeal photopheresis (ECP) was given to 23 patients with steroid-refractory acute GVHD (aGVHD, grade II (n=10), III (n=7) or IV (n=6)). The median duration of ECP was 7 months (1-33) and the median number of ECP cycles in each patient was 10. Twelve patients (52%) had complete responses. Eleven patients (48%) survived and 12 died, 10 of GVHD with or without infections and two of leukaemia relapse. The average grade of GVHD was reduced from 2.8 (on the first day of ECP) to 1.4 (on day +90 from ECP) (P=0.08), and the average dose of i.v. methylprednisolone from 2.17 to 0.2 mg/kg/d (P=0.004). Complete responses were obtained in 70, 42 and 0% of patients, respectively, with grades II, III and IV aGVHD; complete responses in the skin, liver and gut were 66, 27 and 40%. Patients treated within 35 days from onset of aGVHD had higher responses (83 vs 47%; P=0.1). A trend for improved survival was seen in grade III-IV aGVHD treated with ECP as compared to matched controls (38 vs 16%; P 0.08). ECP is a treatment option for patients with steroid refractory aGVHD and should be considered early in the course of the disease.

Improved outcome in young adults with de novo acute myeloid leukemia in first remission, undergoing an allogeneic bone marrow transplant.

We assessed the outcome of 170 patients with AML in first complete remission, aged 1-47 years (median 29), who had undergone an allogeneic BMT before or after 1990 (n=80 and n=90, respectively); all patients were prepared with cyclophosphamide and TBI; the median follow-up for surviving patients was 13 years. The donor was an HLA-identical sibling in 164 patients. Transplant-related mortality (TRM) was 30% before and 7% after 1990 (P<0.001); relapse-related death (RRD) was 26 and 11% (P=0.002); and actuarial 10-year survival was 42 and 79% (P<0.00001). Patients transplanted after 1990 were older, had a shorter interval diagnosis-BMT, had less FAB-M3 cases, received a higher dose of TBI, a higher marrow cell dose and combined (cyclosporine+methotrexate) GVHD prophylaxis. Patients relapsing after transplant had an actuarial survival of 0 vs 31% if grafted before or after 1990 (P=0.01), and their median follow-up exceeds 10 years. In conclusion, the overall survival of first remission AML undergoing an allogeneic BMT has almost doubled in the past two decades, despite older age and fewer M3 cases. Improvement has come not only from changes in transplant procedures, but also from effective rescue of patients relapsing after transplant.

Allogeneic hemopoietic stem cell transplants for patients with relapsed acute leukemia: long-term outcome.

We assessed the long-term outcome of patients with relapsed acute myeloid (n=86) or acute lymphoid leukemia (n=66), undergoing an allogeneic hemopoietic stem cell transplantation in our unit. The median blast count in the marrow was 30%. Conditioning regimen included total body irradiation (TBI) (10-12 Gy) in 115 patients. The donor was a matched donor (n=132) or a family mismatched donor (n=20). Twenty-two patients (15%) survive disease free, with a median follow-up of 14 years: 18 are off medications. The cumulative incidence of transplant related mortality is 40% and the cumulative incidence of relapse related death (RRD) is 45%. In multivariate analysis of survival, favorable predictors were chronic graft-versus-host disease (GvHD) (P=0.0003), donor other than family mismatched (P=0.02), donor age less than 34 years (P=0.02) and blast count less than 30% (P=0.07). Patients with all four favorable predictors had a 54% survival. In multivariate analysis of relapse, protective variables were the use of TBI (P=0.005) and cGvHD (P=0.01). This study confirms that a fraction of relapsed leukemias is cured with an allogeneic transplant: selection of patients with a blast count <30%, identification of young, human leukocyte antigen-matched donors and the use of total body radiation may significantly improve the outcome.

Progenitor cells trapped in marrow filters can reduce GvHD and transplant mortality.

A bone marrow harvest is filtered either in the operating room, in the laboratory or during infusion to the patient. Filters are usually discarded. Little is known of haemopoietic progenitor cells (HPCs) trapped in the filters. The aim of the study was to evaluate HPC content in the filters and to assess the outcome of transplants with filter-discarded or filter-recovered cells. Haemopoietic progenitors were grown from filters of 19 marrow transplants. We then compared the outcome of 39 filter-recovered transplants from HLA-identical siblings (years 2001-2004) with a matched cohort of 43 filter-discarded marrow grafts (years 1997-2000). Filters contained on average 21% long-term culture-initiating cells (LTC-IC) and 15% fibroblasts colony-forming units (CFU-F) of the total progenitor cell content. Filter-discarded transplants had significantly more grade II-IV graft-versus-host disease (GvHD) (42 vs 15%, P=0.008) as compared to filter-recovered transplants, and more transplant-related mortality (TRM) (20 vs 3%, P=0.04). The actuarial survival at 5 years is 69 vs 87%, respectively (P=0.15). This study suggests that a significant proportion of LTC-IC is lost in the filters together with CFU-F. Recovery and add back of progenitors trapped in the filters may reduce GvHD and TRM.

ABO-incompatible bone marrow transplantation: a GITMO survey of current practice in Italy and comparison with the literature.

ABO incompatibility is not considered a contraindication for allogeneic haematopoietic stem cell transplantation (HSCT) despite its association with several immunohaematological complications. At present, there is no general agreement concerning the best methods to reduce these problems. To survey current practice related to ABO-incompatible HSCT in Italy, a questionnaire was sent to all GITMO centres. Specific questions were addressed for management in pretransplant, peritransplant and post transplant phases. A comparison was made with the experience reported in the literature. In all, 74% of GITMO centres answered the questionnaire. A high degree of heterogeneity concerning the pretransplant tests, methods to overcome infusion of ABO-incompatible marrow and post transplant transfusion policy and monitoring was evident. For many of these aspects the literature does not contain unanimous guidelines. The considerable degree of heterogeneity that reflects, at least partially, the lack of consensus in the literature demonstrates that ABO incompatibility is still an open issue in the setting of HSCT and that further studies are needed for a more rationale approach and for the production of evidence-based guidelines.

A revised day +7 predictive score for transplant-related mortality: serum cholinesterase, total protein, blood urea nitrogen, gamma glutamyl transferase, donor type and cell dose.

We have previously described a scoring system for patients undergoing hemopoietic stem cell transplantation (HSCT) based on day +7 blood urea nitrogen (BUN) and serum bilirubin levels. We have revised that scoring system using a formal multivariate approach based on a training phase (305 patients) and a validation phase (217 patients). Day +7 BUN, serum cholinesterase (CHE), total proteins (TP), gamma glutamyl transferase (gammaGT), donor type and cell dose at transplant were included in the new score. The score distribution identified three groups of patients in the training set (<25, 25-75, >75 percentile of the score) which were classified as low, intermediate and high risk. Their actuarial risk of transplant-related mortality (TRM) at 6 years was, respectively, 12, 38 and 60%. In the validation set the 6 year actuarial TRM was, respectively, 15, 40 and 69%. High risk patients had more graft-versus-host disease (GvHD) (P <0.0001) and lower platelet counts (P <0.0001). This study confirms that GvHD and TRM can be predicted on day +7 after HSCT: pre-emptive GvHD therapy may be one option for high-risk patients and is being tested in a prospective randomized trial. The score for single patients can be calculated on the web site http://213.26.110.20/lrm/day_seven_score.html.

Impact of marrow unrelated donor search duration on outcome of children with acute lymphoblastic leukemia in second remission.

We analyzed the outcome of 167 consecutive children with second CR acute lymphoblastic leukemia (ALL), for whom an unrelated donor (UD) search was activated between 1989 and 1998 at a median time of 2 months after relapse. A suitable donor was identified for 70 patients at 1 year and 6.5 months before and after 1995 from search activation, respectively; a further leukemia relapse occurred during the search in 94 children at a median of 4 months after search activation, 36 of whom underwent UD (14) or other types of transplant (22), beyond second CR, while 58 died of progressive disease. Of 73 patients not experiencing a second relapse, 64 underwent UD (46) or other types of transplant (18), while nine proceeded with chemotherapy, and only four of them survived. The 3-year disease-free survival (DFS) from second CR for the 167 patients is 15.1%, whereas 3-year DFS after transplant for the 60 UD and 40 alternative donor transplanted children is 31.6 and 25.4%, respectively. In conclusion, a further relapse is the main factor adversely affecting outcome of children with second CR ALL. Thus, for these patients, the search should be activated early after relapse and either a UD or an alternative transplant should be performed as early as possible.

Factors predicting response and graft-versus-host disease after donor lymphocyte infusions: a study on 593 infusions.

In the present study, we analyze factors predicting graft-versus-host disease (GvHD) and response after donor lymphocyte infusions (DLI). A total of 100 patients received 593 DLI between June 1990 and December 2000 in a bulk dose (n=14) or in escalating dose infusions (n=86). Patients were analyzed after stratification for type of relapse: (1). molecular relapse (n=6), (2). cytogenetic relapse (n=20), (3). chronic phase of chronic myeloid leukemia (CML) or complete remission of other disease post chemotherapy (n=24), (4). CML in accelerated/blastic phase (n=14), (5). resistant disease not responding to chemotherapy (n=36). The proportion of responders to DLI in these five groups was 100, 90, 75, 36 and 0% (P<0.0001). Factors predicting response by multivariate analysis were type of relapse (P<0.0001), post-DLI GvHD (P=0.005), pancytopenia (P=0.008), and a diagnosis of CML (P=0.04). Acute GvHD (grades II-IV) occurred in 21 patients (21%), and correlated in multivariate analysis with pancytopenia and less than four DLI. Other predictors of GvHD were the number of CD3+cells/infusion and serum levels of gamma-glutamyl transferase (gammaGT). The actuarial probability of treatment-related mortality was 9% for HLA identical siblings and 44% for alternative donor transplants (P=0.006). Response to DLI is predicted by tumor burden and is associated with GvHD and pancytopenia.

Low-dose fractionated total body irradiation (TBI) adversely affects prognosis of patients with leukemia receiving an HLA-matched allogeneic bone marrow transplant from an unrelated donor (UD-BMT).

The optimal total body irradiation (TBI) regimen for unrelated donor bone marrow transplant (UD-BMT) is unknown. In the present study we analyze the outcomes of two different TBI regimens used in our center for patients with leukemia undergoing an UD-BMT. Between January 1994 and August 2001, 99 consecutive UD-BMT patients entered this comparative study. The conditioning regimen consisted of cyclophosphamide, 120 mg/kg followed by TBI on days -3, -2 and -1. Forty-six patients received TBI 12 Gy (2 Gy, twice a day) in six fractions (HF-TBI) and 53 patients received TBI 9.90 Gy (3.30 Gy per day) fractionated over 3 days (F-TBI). End-points were transplanted-related mortality (TRM), leukemia relapse rate (LRR) and overall survival (OS). At median follow-up of 22 months (58 months for HF-TBI and 17 for F-TBI, respectively), 60 patients were alive (32 in HF-TBI sub-group and 28 in F-TBI one). The actuarial 5-year TRM was 31% for HF-TBI and 41% for F-TBI (P = 0.1), whereas the 5-year LRR was 13% for HF-TBI and 31% for F-TBI (P = 0.04). The actuarial 5-year OS was 68% for patients treated with HF-TBI and 51% for those treated with F-TBI (P = 0.02). At multivariate analysis F-TBI schedule emerged as an adverse predictor for OS (P = 0.04) and LRR (P = 0.03). These data indicate that a lower total dose of TBI appears significantly less effective in leukemia eradication and associated with worse overall survival when compared with a higher dose of radiation.

Prophylactic antithymocyte globulin reduces the risk of chronic graft-versus-host disease in alternative-donor bone marrow transplants.

We studied the impact of preparative regimens with or without antithymocyte globulin (ATG) on chronic GVHD in 160 patients undergoing marrow transplants from unrelated donors (n = 127) or partially mismatched related donors (n = 33). A conditioning regimen that included rabbit ATG, 7.5 to 15 mg/kg (Thymoglobuline; Sangstat, Lyon, France), was given to 102 patients, whereas a conditioning regimen without ATG was given to 58 patients. The median patient age was 34 years for the ATG group and 29 years for the non-ATG group (P = .002); otherwise the 2 groups were matched for disease phase, diagnosis, donor age, interval from diagnosis to transplantation, and number of cells infused at the time of transplant. Median follow-up for surviving patients was 4.5 years (range, l.5-9 years). The conditioning regimen was cyclophosphamide (CY) and total body irradiation (TBI) in 95 patients and CY-thiotepa in 65 patients; the source of stem cells was bone marrow for all patients. Acute GVHD grades II-IV and grades III-IV were reduced in patients receiving ATG compared to patients not receiving ATG (51% versus 74%, P = .004 and 14% versus 28%, P = .03, respectively). There were significantly fewer patients with chronic GVHD in the ATG group than in the non-ATG group at 6 months (14% versus 30%, P = .03), 1 year (7% versus 41%, P = .0001), 2 years (16% versus 36%, P = .02), and 4 years (5% versus 34%, P = .002) and beyond 4 years (0% in 19 patients at risk versus 29% in 24 patients at risk, P = .01). More patients in the ATG group than in the non-ATG group had a performance status (Karnowski score) greater than 90 at last follow-up (93% versus 56%, P = .01) and had discontinued cyclosporin treatment 2 years posttransplant (28% versus 3%, P = .003). Survival rates were comparable in the ATG and non-ATG groups for patients who received TBI (56% versus 59%, P = .7) and those who received thiotepa (33% versus 18%, P = .3). Transplant mortality and relapse rates were also comparable in the 2 groups for these patients. We conclude that pretransplant ATG administration reduces the risk of acute and chronic GVHD, improves quality of life, and increases the likelihood that discontinuation of immunosuppressive therapy will be possible.

Antithymocyte globulin for graft-versus-host disease prophylaxis in transplants from unrelated donors: 2 randomized studies from Gruppo Italiano Trapianti Midollo Osseo (GITMO).

One hundred nine patients with hematologic malignancies, undergoing bone marrow transplants (BMT) from unrelated donors, were randomized in 2 consecutive trials to receive or not to receive antithymocyte globulin (ATG) in the conditioning regimen, as follows: (A) 54 patients (median age, 28 years; 39% with advanced disease) were randomized to no ATG (n = 25) versus 7.5 mg/kg rabbit ATG (Thymoglobulin; Sangstat, Lyon, France) (n = 29); (B) 55 patients (median age, 31 years, 71% with advanced disease) were randomized to no ATG (n = 28) versus 15 mg/kg rabbit ATG (n = 27). Grade III-IV graft-versus-host disease (GVHD) was diagnosed in 36% versus 41% (P =.8) in the first and in 50% versus 11% (P =.001) in the second trial. Transplant-related mortality (TRM), relapse, and actuarial 3-year survival rates were comparable in both trials. In fact, despite the reduction of GVHD in the second trial, a higher risk for lethal infections (30% vs 7%; P =.02) was seen in the arm given 15 mg/kg ATG. Extensive chronic GVHD developed overall more frequently in patients given no ATG (62% vs 39%; P =.04), as confirmed by multivariate analysis (P =.03). Time to 50 x 10(9)/L platelets was comparable in the first trial (21 vs 24 days; P =.3) and delayed in the ATG arm in the second trial (23 vs 38 days; P =.02). These trials suggest that (1) 15 mg/kg ATG before BMT significantly reduces the risk for grade III-IV acute GVHD, (2) this does not translate to a reduction in TRM because of the increased risk for infections, and (3) though survival is unchanged, extensive chronic GVHD is significantly reduced in patients receiving ATG.

Bone marrow transplantation from unrelated donors: the impact of mismatches with substitutions at position 116 of the human leukocyte antigen class I heavy chain.

The hypothesis was tested that amino acid substitutions in specific positions within human leukocyte antigen class I heavy chain would have different impacts on transplant-related mortality (TRM) in patients receiving transplanted bone marrow from unrelated donors. One hundred patients and their unrelated donors were typed by sequence-based typing for the human leukocyte antigen (HLA)-A, -B, and -C loci. All pairs were matched for DRB1, DRB3, DRB4, DRB5, DQA1, and DQB1 loci. Forty pairs were also matched at class I, and 60 pairs had one or more mismatches at class I loci. It was found that substitutions at positions 116 and 114 of class I heavy chain significantly increased the risk for TRM in univariate and bivariate Cox analyses. Conversely, no association between number of multiple mismatches or number of amino acid substitutions and TRM was seen when positions 116 and 114 were adjusted for. Variables predictive of TRM in multivariate Cox analysis were number of cells infused, diagnosis (chronic myeloid leukemia [CML] or non-CML), and amino acid substitution at position 116 or 152. The only variable predictive of severe acute graft-versus-host disease (GVHD) in multivariate Cox analysis was substitution at position 116. Actuarial risk for acute GVHD grade III-IV, TRM, and relapse in pairs with substitutions at position 116 (n = 37) compared to other pairs (n = 63) was, respectively, 36% versus 14% (P =.01), 59% versus 28% (P =.001), and 25% versus 31% (P =.4). In conclusion these data suggest that substitutions at position 116 of class I heavy chain increase the risk for acute GVHD and TRM in patients who receive transplanted bone marrow from unrelated donors.