Clinical evidence of a graft-versus-lymphoma effect against relapsed diffuse large B-cell lymphoma after allogeneic hematopoietic stem-cell transplantation

BACKGROUND

A graft-versus-lymphoma effect against diffuse large B-cell lymphoma (DLBCL) is inferred by sustained relapse-free survival after allogeneic stem-cell transplantation; however, there are limited data on a direct graft-versus-lymphoma effect against DLBCL following immunotherapeutic intervention by either withdrawal of immunosuppression or donor lymphocyte infusion (DLI).

MATERIALS AND METHODS

An analysis was carried out to determine whether a direct graft-versus-lymphoma effect exists against DLBCL. The analysis was restricted to patients with DLBCL, who were either not in complete remission at day +100 after allogeneic stem-cell transplantation or subsequently relapsed beyond this time point.

RESULTS

Fifteen patients were identified as either not in complete remission (n = 13) at their day +100 evaluation or subsequently relapsed (n = 2) and were assessed for subsequent responses after withdrawal of immunosuppression or DLI. Eleven patients were treated with either withdrawal of immunosuppression (n = 10) or a DLI (n = 1) alone; four patients received chemotherapy with DLI to reduce tumor bulk. Nine (60%) patients subsequently responded (complete = 8, partial = 1). Six responses occurred after withdrawal of immunosuppression alone. Six patients are alive (range 42-83+ months) in complete remission without further treatment.

CONCLUSION

The demonstration of sustained complete remission following immunotherapeutic intervention provides direct evidence of a graft-versus-lymphoma effect against DLBCL.

Correlations among vitality, physical competence, lipid profile and measures of inflammation in transplant survivors with chronic graft versus host disease

7108

Background: Chronic graft vs. host disease (cGVHD) is a multi-system disorder and a late complication of cancer therapy experienced by more than 50% of survivors after allogeneic hematopoietic stem cell transplantation. An improved understanding of the underlying biology and its relation to clinical symptoms may guide the development of better treatments for cGVHD. Methods: In a prospective, cross-sectional natural history protocol we examined the associations among organ/system dysfunction, measures of physical performance and health status with clinical measures of inflammation and fat metabolism. Variables included: 1. a composite severity score (CAS) rated by clinician-specialists (skin, eyes, mouth, gastrointestinal/liver, hematological, gynecological, pulmonary function evaluations); 2.functional measures [2 minute walk time (WT), grip strength (GS), SF-36 physical component summary score (PCS), vitality (VT) subscale, maximal activity score (MAS) of the Human Activity Profile]; 3.Laboratory tests (glucose, LDH, hemoglobin, ferritin, platelets, lymphocytes, pre-albumin, cholesterol, lipoproteins (HDL, LDL), triglycerides (TG), beta-2microglobulin (B2), and CRP. Results: 43 pts (mean age 47 yrs) with prior hematologic malignancy participated (mean 3 yrs post transplant). An average of 3.5 organ systems were affected, 77% were on systemic treatment for cGVHD, and 67% had prior acute GVHD. The mean body mass index (BMI) was 25, TG 255, cholesterol 222, LDL 132. They were moderately disabled by self-report (MAS), had slower than normal WT (540 ft/min), lower than normal GS (63 pounds), PCS (36) and VT (46) than a healthy population. Using a backward selection model with a significance of 0.1, low lung diffusing capacity (p<.001) and low PCS (p=0.01) correlated with high CAS. VT correlated negatively with LDH, platelets, B2 and LDL (all p<0.01). Low GS correlated with high LDH and B2 (p=0.01). Conclusions: Reported physical function and vitality in cGVHD patients are associated with abnormal lipid profiles and markers of inflammation. Establishment of such profiles is a critical step in the development of testable and validated outcome measures and for evaluation of new therapies in cGVHD.

No significant financial relationships to disclose.

Effects of rhIL-7 administration in humans on in vivo expansion of naïve, memory and effector subsets of CD4+ & CD8+ T-cells

2504

Background: IL-7 has a critical and non-redundant role in T-cell lymphopoiesis and peripheral T-cell homeostasis. IL-7 administration may prove clinically valuable in conditions of disease induced (HIV) or iatrogenic T-cell depletion and for modulation of vaccine immune responses. In the first phase I study in humans, recombinant human interleukin-7 (“CYT 99–007”, Cytheris Inc., Rockville, MD) was administered subcutaneously every other day for two weeks in adults with refractory malignancies at 3, 10, 30 and 60 μg/kg/dose. Biologic activity, defined as a 50% increase over baseline of peripheral blood CD3+ T-cells, was seen at and above the 10μg/kg/dose in all patients. The kinetics of proliferation and expansion of peripheral blood T-cell subsets were analyzed. Methods: Multicolor flow cytometry was performed at baseline, 1, 2 and 3 weeks. Among CD4+ cells, the most naïve were defined as CD45RA+ /CD31+. Among CD4+ & CD8+ cells, the main naïve, memory and effector populations were defined respectively as CD45RA+/CD27+, CD45RA-/CD27+ and CD45RA-/CD27-. Within each subset, the number of cells in cycle was defined by Ki67 staining. Results: Following IL-7 therapy, there was marked proliferation of all T-cells subsets, peaking at week 1, most striking for the naive subsets with 30–70% of circulating cells induced to cycle. Proliferation rates were halved by week 2 despite continuation of treatment, coincident with the observed down-regulation of the IL-7 receptor. Cycling returned to baseline by week 3. Significant proliferation was also induced in effector and memory CD4+ and CD8+ T-cells but to a lesser magnitude, resulting in a greater net expansion of the naïve subsets, still ongoing one week after the end of treatment. Conclusions: IL-7 administration induces marked expansion of naïve, memory and effector CD4+ & CD8+ T-cells in humans. Consistent with the known down-regulation of the IL-7 receptor upon IL-7 exposure, proliferation rates decrease during the second week of treatment. rhIL-7 induced T-cell expansion may prove clinically valuable in adoptive immunotherapy as an adjunct to tumor vaccination and / or immunorestorative agent.

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Targeted immune depletion prior to reduced-intensity allogeneic stem cell transplantation results in rapid and complete donor chimerism with low treatment-related mortality

6540

Background: Significant variation in host immune status may influence outcomes after reduced-intensity (RI) allogeneic stem cell transplantation (alloSCT). We have investigated a strategy of targeted immune depletion (TID) with conventional chemotherapy to deplete host T cells and achieve a minimal disease state prior to RI alloSCT. The aim of TID is to rapidly establish complete donor chimerism after RI alloSCT in order to potentiate a graft-versus-tumor (GVT) effect. In a prospective phase II trial (NIH 03-C-0077), we evaluated the effect of TID on donor chimerism, acute graft-versus-host disease (GVHD), and clinical outcome. Methods: Thirty-one patients (pts) with relapsed and refractory hematologic malignancies (NHL = 16; HL = 4; CLL/PLL = 4; MDS/AML = 3; other = 4) were enrolled. Median age was 57 years (range: 31–71). All pts received EPOCH-F (etoposide, prednisone, vincristine, cyclophosphamide, adriamycin, fludarabine) ± rituximab (R) as TID to deplete host CD4+ cells <100/μL. All pts then received a RI conditioning regimen consisting of fludarabine and cyclophosphamide followed by a T-cell replete allograft from HLA-matched siblings. GVHD prophylaxis consisted of cyclosporine plus short-course mini-methotrexate. Results: EPOCH-F(R) achieved the target host T-cell level in 74% of pts. All 31 pts engrafted after RI alloSCT. Complete donor chimerism (> 95%) was observed in 74% and 81% of pts at day +14 and +28 post-transplant, respectively. The incidence of grade II-III acute GVHD was 42% with no cases of grade IV acute GVHD. The median potential follow-up from transplant is 25 months. Actuarial treatment-related mortality at 1 and 2 years was 3% and 8%, respectively. Event-free survival probabilities at 1 and 2 years post-transplant are 65% and 49%, respectively. Ten pts are alive and event-free >24 months post-transplant. The overall survival probabilities at 1 and 2 years are 84% and 64%, respectively. Conclusions: TID prior to RI alloSCT results in rapid, complete donor engraftment and may potentiate GVT effects. This treatment strategy was associated with very low TRM and favorable outcomes in an older patient population with advanced hematologic malignancies.

No significant financial relationships to disclose.

Legionnaires' disease after bone marrow transplantation

Four patients developed legionnaires' disease after bone marrow transplantation. Two cases occurred early after transplant and were considered as part of a hospital epidemic due to contamination of water supply. The other two cases were considered to be sporadic because they occurred 3-4 weeks after hospital discharge. The outcome was good in two patients. In the third patient, recurrent disease was probably due to acquired resistance to macrolides, and complete cure was achieved after treatment with pefloxacin and rifampicin. The fourth patient died of overwhelming infection despite early treatment with erythromycin and pefloxacin. During the same period we treated 14 patients with pefloxacin for prevention of bacterial infection, of whom none developed Legionella pneumophila infection, while three of the patients reported here were in a group of 11 patients who received only oral non-absorbable antibiotics for gut decontamination. The fourth patient in this report was receiving no antibiotics. Thus pefloxacin seems to be effective as prophylaxis against L. pneumophila infection. When the hospital water supply was heated to 60 degrees C and chlorinated, the nosocomial cases in the hospital completely disappeared.