NIH-Defined Graft-Versus-Host Disease in Patients with Acute Lymphoblastic Leukemia: Natural History, Prognostic Impact and Effect of Donor Lymphocyte Infusions
Authors: Terwey Theis H. , Le Duc Tanja M. , Hemmati Philipp G. , Vuong Lam G. , Martus Peter , le Coutre Philipp D. , Dörken Bernd , Arnold Renate 
Published: October 2019

Abstract
Abstract 4547

Introduction:
The 2005 NIH consensus criteria (NCC) for acute and chronic graft-versus-host disease (aGVHD, cGVHD) are the gold standard for classifying GVHD in trials but they are not routinely used in the clinic, in part due to uncertainty about their prognostic value. To address this limitation we analyzed NIH-defined GVHD in 147 consecutive acute lymphoblastic leukemia (ALL) patients who received a first myeloablative transplant at our center between 1995 and 2009.

Methods:
Median age was 31 years (range: 17–56). Disease status was CR1 (50%), CR>1 (22%) or no CR (28%). Myeloablative conditioning consisted of 12 Gy TBI ± etoposide ± cyclophosphamide. Donors were HLA-matched related (42%), -matched unrelated (46%) or -mismatched (12%) and peripheral blood stem cells (74%) or bone marrow (26%) were given. GVHD-prophylaxis consisted of CSA/MTX (72%), CSA/prednisolone (19%) or other CSA-based regimens (9%). ATG was given in HLA-mismatched transplants (12%) and since 2005 also in matched unrelated transplants (11%), according to GMALL study protocols. Preemptive donor lymphocyte infusions (DLI) were a treatment option in case of mixed chimerism or minimal residual disease.

Results:
Median follow-up was 60 months (8–185). Projected overall survival (OS) at 1, 2 and 5 years was 64%, 56% and 49%. 5-year cumulative incidence of relapse was 33% and of non-relapse mortality (NRM) 25% (7% infections, 9% aGVHD, 7% cGVHD, 2% other). Median time until onset of classic aGVHD was 20 days (5–95). Cumulative incidence of classic aGVHD was 41% for grade I/II and 29% for grade III/IV. Among patients with classic aGVHD, skin, liver or gut involvement was seen in 94%, 32% and 34%. Late aGVHD was observed in 12% at a median of 100 days (range 100–240). Among late aGVHD cases 82% were subclassified as persistent or recurrent classic aGVHD. Median time until onset of chronic GVHD was 115 days (14–294) measured from transplant or DLI with a cumulative incidence for mild, moderate and severe forms of 13%, 15% and 25%. Mouth, skin, eyes, liver, joints and fascia, gut, lung and other organs were involved in 91%, 70%, 61%, 48%, 27%, 19%, 10% and 6% of cGVHD cases. cGVHD was subclassified as classic cGVHD and overlap syndrome in 40% and 60% of cases. 62% had progressive or quiescent type of onset. In multivariate Cox regression analysis with GVHD as time-dependant covariate (table 1) classic aGVHD grade III/IV was associated with inferior OS due to higher NRM. Comparable effects were seen for late aGVHD. In contrast, moderate and severe cGVHD were associated with superior OS due to lower relapse incidence. Classic and overlap cGVHD had no differential prognostic impact. 34 patients without GVHD after cessation of immunosuppression received preemptive DLI. In this subgroup cumulative incidence of classic aGVHD, late aGVHD or cGVHD was 62%, 6% and 62%. Organ involvement was comparable to non-DLI associated GVHD. In a time-dependant multivariate analysis, patients who developed NIH-defined cGVHD after DLI had improved OS (HR 0.21, 95%CI: 0.054–0.81, P=0.023) due to lower relapse incidence (HR 0.26, 95%CI: 0.043–0.91, P=0.048) compared to patients without cGVHD after DLI.

Conclusions:
This is the first study on the natural history and prognostic impact of NIH-defined GVHD in ALL patients. We found that severe classic aGVHD leads to higher NRM and inferior OS with similar effects seen for late aGVHD. cGVHD had a positive impact on OS and relapse rate, both after transplant and after preemptive DLI, indicating a potent graft-versus-leukemia effect. Although our cohort contains some heterogeneity we believe that this data supports the use of the NCC as diagnostic and prognostic tool in ALL patients.
Multivariate Cox regression analysis for OS, relapse and NRM with GVHD as time-dependant covariate. Only results for GVHD are shown.

Disclosures:
No relevant conflicts of interest to declare.