***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: A matched cohort study was design ed to test the efficacy of polyclonal rabbit antiserum specific for human T cells ( Thymoglobulin ) , administered in vivo on days 1–5 ( 2 mg/kg/day ) before T cell-replete unrelated donor marrow transplantation .  Thymoglobulin was given to 52 leukemic patients at Huddinge Hospital . Control patients matched for diagnosis , disease stage , age and treated with a similar regimen , apart from the omission of Thymoglobulin , were selected in Seattle during the same period ( n = 104 ) . All received conditioning with cyclophosphamide and TBI . In the study group all patients received 10 Gy single dose TBI , while the controls were given 12–14.4 Gy fractionated TBI . GVHD prophylaxis was cyclosporine and methotrexate . Patients were treated for grade I acute GVHD in the study group , and for grade II GVHD in the control group . Multivariable analyses were adjusted for patient and donor age and CMV serology , HLA matching , donor gender and marrow cell dose . Non-relapse mortality was lower in the study patients ( hazard ratio = 0.30 , 95 % CI 0.12–0.75 , P value = 0.005 ) . The 5-year cumulative incidence of non-relapse mortality was 19 % in the study cohort , and 35 % in the control cohort . Overall mortality was also lower in study patients ( hazard ratio 0.51 , 95 % CI 0.27–0.97 , Pvalue = 0.03 ) . No significant difference in the risk of relapse was seen ( P = 0.63 ) . This suggests that Thymoglobulin during conditioning may reduce non-relapse mortality after unrelated donor marrow transplantation . Bone Marrow Transplantation ( 2002 ) 29 , 391–397 . BACKGROUND Graft-versus-host disease ( GVHD ) is a major cause of morbidity and mortality after allogeneic haematopoietic cell transplantation from unrelated donors .  Anti-T-cell globulins ( ATGs ) might lower the incidence of GVHD . We did a prospect i ve , r and omised , multicentre , open-label , phase 3 trial to compare st and ard GVHD prophylaxis with ciclosporin and methotrexate with or without anti-Jurkat ATG-Fresenius ( ATG-F ) . METHODS Between May 26 , 2003 , and Feb 8 , 2007 , 202 patients with haematological malignancies were central ly r and omly assigned using computer-generated centre-stratified block r and omisation between treatment groups receiving ciclosporin and methotrexate with or without additional ATG-F. One patient in the ATG-F group did not undergo transplantation , thus 201 patients who underwent transplantation with peripheral blood ( n=164 ; 82 % ) or bone marrow ( n=37 ; 18 % ) grafts from unrelated donors after myeloablative conditioning were included in the full analysis set , and were analysed according to their r and omly assigned treatment ( ATG-F n=103 , control n=98 ) . The primary endpoint was severe acute GVHD ( aGVHD ) grade III-IV or death within 100 days of transplantation . The trial is registered with the numbers DRKS00000002 and NCT00655343 . FINDINGS The number of patients in the ATG-F group who had severe aGVHD grade III-IV or who died within 100 days of transplantation was 12 and 10 ( 21.4 % , 95 % CI 13.4 - 29.3 ) , respectively , compared with 24 and nine ( 33.7 % , 24.3 - 43.0 ) patients , respectively , in the control group ( adjusted odds ratio 0.59 , 95 % CI 0.30 - 1.17 ; p=0.13 ) . The cumulative incidence of aGVHD grade III-IV was 11.7 % ( 95 % CI 6.8 - 19.8 ) in the ATG-F group versus 24.5 % ( 17.3 - 34.7 ) in the control group ( adjusted hazard ratio [ HR ] 0.50 , 95 % CI 0.25 - 1.01 ; p=0.054 ) , and cumulative incidence of aGVHD grade II-IV was 33.0 % ( n=34 ; 95 % CI 25.1 - 43.5 ) in the ATG-F group versus 51.0 % ( n=50 ; 95 % CI 42.0 - 61.9 ) in the control group ( adjusted HR 0.56 , 0.36 - 0.87 ; p=0.011 ) . The 2-year cumulative incidence of extensive chronic GVHD was 12.2 % ( n=11 ; 95 % CI 7.0 - 21.3 ) versus 42.6 % ( n=34 ; 95 % CI 33.0 - 55.0 ; adjusted HR 0.22 , 0.11 - 0.43 ; p<0.0001 ) . There were no differences between treatment groups with regard to relapse , non-relapse mortality , overall survival , and mortality from infectious causes . INTERPRETATION The addition of ATG-F to GVHD prophylaxis with ciclosporin and methotrexate result ed in decreased incidence of acute and chronic GVHD without an increase in relapse or non-relapse mortality , and without compromising overall survival . The use of ATG-F is safe for patients who are going to receive a haematopoietic cell transplantation from matched unrelated donors . FUNDING Fresenius Biotech Summary : Matched unrelated donor transplants have an increased risk of severe graft-versus-host disease and transplant-related mortality ( TRM ) .  ATG has been introduced to decrease GvHD and to facilitate engraftment . We conducted a retrospective analysis of 333 patients with chronic myelogenous leukemia , who were treated with Fresenius ATG ( n=145 , average=90 mg/kg bw , range 40–90 mg/kg bw ) or st and ard immunosuppression without ATG ( n=188 ) . Both groups were comparable regarding distribution of age , sex , HLA-matched vs mismatched donors . ATG Fresenius led to a faster leukocyte engraftment , decreased the incidence of acute GvHD and TRM ( P=0.01 and P=0.03 ) and led to a significant better overall survival ( 70 vs 57 % , P=0.03 ) . We concluded that a prospect i ve r and omized study is needed to evaluate the definite role of ATG in hemopoietic stem cell transplantation We studied the feasibility and activity of adding sirolimus to tacrolimus and low-dose methotrexate as graft-versus-host disease ( GVHD ) prophylaxis in recipients of alternative donor transplants . Forty-one patients with hematologic malignancies were conditioned with cyclophosphamide and total body irradiation . Marrow stem cells were from an HLA-A , -B , and -DR compatible , unrelated donor ( n = 26 , 68 % ) , from a 5 of 6 antigen-matched unrelated donor ( n = 8 , 20 % ) , or from a 5 of 6 antigen-matched family member ( n = 5 , 12 % ) . Therapeutic serum levels of sirolimus were attained in most patients . All evaluable patients engrafted . An absolute neutrophil count of 500/microL was achieved on day + 18 ( range , 11 - 32 days ) . Sustained platelet counts of more than 20 000/ microL were attained on day + 29 ( range , 14 - 98 days ) . Grade s 0-I acute GVHD occurred in 75 % of patients . Grade s II , III , and IV acute GVHD occurred in 13 % , 8 % , and 5 % , respectively ( total grade s II-IV GVHD , 26 % ) . Median survival is 366 days ( 95 % CI 185 , not estimable ) and actuarial survival at 1 year is 52 % . Oral sirolimus is tolerable , adequate blood levels are achievable , and there is a low rate of acute GVHD compared with historical data in this high-risk population . This novel agent is worthy of further study in allogeneic transplantation One hundred nine patients with hematologic malignancies , undergoing bone marrow transplants ( BMT ) from unrelated donors , were r and omized 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 r and omized 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 r and omized 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 A hematopoietic cell transplantation regimen was adapted from a pre clinical model that used reduced-intensity conditioning ( RIC ) and protected against graft-versus-host disease ( GVHD ) by skewing residual host T-cell subsets to favor regulatory natural killer T cells . One hundred eleven patients with lymphoid ( 64 ) and myeloid ( 47 ) malignancies received RIC using total lymphoid irradiation ( TLI ) and antithymocyte globulin ( ATG ) followed by the infusion of granulocyte colony-stimulating factor-mobilized grafts . Included were 34 patients at least 60 years of age , 32 patients at high risk of lymphoma relapse after disease recurrence following prior autologous transplantation , and 51 patients at high risk of developing GVHD due to lack of a fully human leukocyte antigen (HLA)-matched related donor .  Durable chimerism was achieved in 97 % of patients . Cumulative probabilities of acute GVHD ( grade s II-IV ) were 2 and 10 % of patients receiving related and unrelated donor grafts . Nonrelapse mortality ( NRM ) at 1 year was less than 4 % . Cumulative incidence of chronic GVHD was 27 % . The 36-month probability of overall and event-free survival was 60 % and 40 % , respectively . Disease status at start of conditioning and the level of chimerism achieved after transplantation significantly impacted clinical outcome . The high incidence of sustained remission among patients with active disease at time of transplantation suggests retained graft-versus-tumor reactions . Active trial registration currently at clinical trials.gov under IDs of NCT00185640 and NCT00186615 We assessed the combination of sirolimus and tacrolimus without methotrexate  after myeloablative allogeneic stem cell transplantation from 53 matched related donors ( MRDs ) and 30 unrelated donors ( URDs ) . All patients received cyclophosphamide and total body irradiation conditioning followed by transplantation of mobilized peripheral blood stem cells . The median time to neutrophil engraftment was 14 days . The median time to platelet engraftment was 12 days . No differences between MRD and URD cohorts was noted . The incidence of grade II-IV and III-IV acute graft-versus-host disease ( GVHD ) were 20.5 % and 4.8 % . The cumulative incidence of chronic GVHD was 59.1 % . There were no differences in acute or chronic GVHD incidence between MRD and URD cohort 
    Output:
    
We conclude prophylactic use of ATG exerts a favorable effect in reducing cGVHD without survival impairment in a long term , although a higher relapse rate is a major threat