Time to engraftment following allogeneic stem cell transplantation is significantly longer in patients with myelodysplastic syndrome than with acute myeloid leukemia.

Patients with myelodysplastic syndrome (MDS) commonly present with pancytopenia, suggesting that the marrow stroma fails to support the growth of both malignant and normal stem cells. We therefore retrospectively analyzed the duration to engraftment of neutrophils (> or =0.5 x 10(9)/l and > or =1.0 x 10(9)/l) and platelets (> or =20 and > or =50 x 10(9)/l) in 37 MDS patients and 42 patients suffering from primary AML, following allogeneic SCT. A significantly shorter time to engraftment was documented in AML as compared to MDS patients in all four parameters. These results held true even when we subgrouped the patients according to gender, age (50 years being the cutoff age between young and elderly patients), patient-donor relationship, donor match and intensity of conditioning. To the best of our knowledge, this is the first time that such a comparison has been made. We suggest that the longer duration of post transplant pancytopenia that is frequently observed in MDS patients may also influence post transplant outcome.

Allogeneic stem cell transplantation from matched related and unrelated donors in thalassemia major patients using a reduced toxicity fludarabine-based regimen.

The only radical cure for thalassemia major patients today is the replacement of the defective hematopoietic system by allogeneic stem cell transplantation (allo-SCT). The major obstacles for the application of allo-SCT even from matched family members have been the transplant-related morbidity and mortality and graft failure that is usually associated with the recurrence of the thalassemia hematopoiesis. The outcome of allo-SCT from HLA-identical family donors is largely dependent on the age of the recipient as well as on pretransplant parameters reflecting the degree of organ damage from iron overload. In this study we report our experience of allo-SCT from matched related and unrelated donors, using a reduced toxicity conditioning consisting of fludarabine, busulfan or more recently busulfex and antithymocyte globulin, in a cohort of 20 patients with thalassemia major. The regimen-related toxicity was minimal, while the incidence of acute grade II-IV and chronic GVHD was 25 and 25%, respectively. With a median follow-up period of 39 months (range: 5-112 months) the overall survival was 100%, while thalassemia-free survival was 80%. Although the results of our study look promising, larger cohorts of patients and prospective clinical trials are required to confirm the benefits of our approach as a possible better alternative to the existing protocols.

A patient with progressive multiple myeloma treated successfully with arsenic trioxide after allogeneic bone marrow transplantation.

Multiple myeloma (MM) is an incurable progressive disease. Many therapeutic options are available to delay progression, including autologous and allogeneic bone marrow transplantation. At advanced stages, MM is often refractory to treatment. We report a heavily pretreated patient with graft-versus-host disease after bone marrow transplantations, treated at a terminal stage with a modified protocol for arsenic trioxide (ATO). This patient with poor clinical status tolerated the treatment very well. He had a remarkable clinical response and achieved complete remission. The mechanisms of ATO are presented and the potential role of ATO for MM is discussed.

A prospective, double-blind phase II study evaluating the safety and efficacy of a topical histamine gel for the prophylaxis of oral mucositis in patients post hematopoietic stem cell transplantation.

The aim of this study was to evaluate the safety, tolerability and efficacy of a topical gel containing histamine dihydrochloride (HDC) versus a placebo gel in preventing oral mucositis in hematopoietic stem cell transplantation (HSCT) patients. A total of 45 patients post-HSCT were enrolled in a prospective longitudinal, placebo-controlled, double-blind study. Patients were evaluated twice weekly for oral mucositis (OMAS, NCI score), oral pain (VAS), oral function and salivary flow rate. Compliance was assessed using a patient diary. Oral mucositis developed in 85% of the HDC group and 63% of the placebo group. The mean maximal intensity for NCI score was 1.45+/-1 in the HDC group and 1.21+/-1.27 in the placebo group (P=0.37). The mean duration of oral mucositis was 4.7+/-3.6 and 2.33+/-2.23 days in the HDC and placebo groups, respectively (P=0.06). The same trends were measured with OMAS. Visual analogue scale for oral pain and oral function was not significantly different between the two groups. Histamine dihydrochloride was found to be safe. In the search for topical agents for the prevention of mucositis, we found that HDC neither improves nor worsens oral mucositis in HSCT patients. The balance between the pro- and anti-inflammatory effects of HDC should be investigated further in order to acquire a clinically effective topical medication based on its anti-inflammatory properties.

Nonmyeloablative stem cell transplantation using lymphoablative rather than myeloablative conditioning in the prefludarabine era by ATG and limiting doses of cyclophosphamide.

The feasibility of using lymphoablative rather than myeloablative conditioning for durable engraftment of allogeneic stem cells and subsequent cell therapy with donor lymphocytes was pioneered in the prefludarabine era in patients with resistant lymphoma and metastatic solid tumors. Between July 1995 and August 1996, 15 patients, five males and 10 females, median age 50 (range 20-57) years, were enrolled in a protocol that consisted of different doses of cyclophosphamide (Cy), 50 mg/kg/day for 1, 2, 3 or 4 consecutive days in parallel with a fixed dose of rabbit antithymocyte globulin (ATG) (Fresenius) 10 mg/kg/day for 4 consecutive days. All patients, except one treated with a single dose of Cy, achieved full tri-lineage engraftment and no late graft failure was observed. Only three patients suffered from grade III-IV graft-versus-host disease (GVHD). Three patients out of the 15 survived long term (follow-up >93 to >96 months). We concluded that lymphoablative conditioning with ATG and intermediate-to-high-dose Cy is well tolerated and can result in durable engraftment with acceptable GVHD in heavily pretreated patients with advanced malignancies. Hence, induction of tolerance to donor alloantigens by lymphoablative conditioning while avoiding myeloablative chemotherapy or radiation therapy may serve as a platform for subsequent cell therapy with donor lymphocytes.

Rapid response to alefacept given to patients with steroid resistant or steroid dependent acute graft-versus-host disease: a preliminary report.

We evaluated the effect of alefacept (Amevive), a novel dimeric fusion protein, in steroid resistant/dependent acute graft-versus-host-disease (aGVHD). Seven patients were treated in eight aGVHD episodes. GVHD grade at treatment initiation and at peak ranged 2-4 (median 2.5) and 2-4 (median 4), respectively. System involvement at GVHD peak included skin (n=7), gastrointestinal tract (n=5) and liver (n=3). All patients responded. However, one patient with skin GVHD and two with gastrointestinal GVHD featuring an early initial response (IR) exacerbated and CR was not achieved. Skin GVHD responded rapidly with a median of 1 day to IR and 7 days to CR. Intestinal response was slower with median 7.5 days to IR. Of the four patients that achieved IR, CR was achieved in only one (40 days to CR). None of the patients had significant hepatic GVHD before treatment so no hepatic effect of alefacept could be determined. No immediate alefacept-related side effects were observed. Late side effects included infections (aspergillus sinusitis, pneumonia, bacteremia, pharyngeal thrush), pancytopenia and hemorrhagic cystitis. Three patients had CMV reactivation while on alefacept. We conclude that alefacept may have a beneficial effect in controlling aGVHD. Further investigations in larger cohorts of patients and controlled studies are warranted.

Eosinophils activation in post-autologous bone marrow transplanted patients treated with subcutaneous interleukin-2 and interferon-alpha 2A immunotherapy.

We evaluated eosinophils morphology, physical properties and antileukemic activity in autologous bone marrow transplanted (ABMT) patients treated with subcutaneous recombinant interleukin 2 (rIL-2) and recombinant human interferon alpha 2a (IFN alpha) given as outpatient immunotherapy. All patients receiving rIL-2/IFN alpha therapy developed peripheral blood eosinophilia of 20-40% peaking at 2-4 weeks of therapy. While on rIL-2/IFN alpha therapy the eosinophils became hypodense and hypersegmented. The antibody dependent cell-mediated cytotoxic activity (ADCC) of the eosinophils against the human B-cell lymphoma cell line (Raji) was depressed post-ABMT. Prolonged (28 days) in vivo rIL-2/IFN alpha immunotherapy enhanced ADCC activity of the eosinophils and brought them to normal levels. Similarly, rIL-2/IFN alpha immunotherapy enhanced the depressed cytotoxic activity of neutrophils post-ABMT to normal levels. Thus, eosinophils and neutrophils from rIL-2/IFN alpha-treated ABMT recipients may be targeted toward tumor cells by antibody, and express tumoricidal activity. No effect of rIL-2/IFN alpha was observed on monocyte-dependent ADCC activity which remained normal post-ABMT. We conclude that in addition to their effect on lymphocytes, cytokine-mediated immunotherapy consisting of subcutaneous low doses of riL-2 and IFN alpha may mediate their therapeutic effects in cancer therapy by increasing the number of eosinophils and enhancing the antitumor activity of eosinophils and neutrophils, provided that tumor-specific or tumor-associated antibodies are present.

Immunotherapy of minimal residual disease in conjunction with autologous and allogeneic bone marrow transplantation (BMT).

Recent investigations in animal models of human lymphoid and myeloid leukemia suggest that induction of immune-mediated antitumor effects is feasible at the stage of minimal residual disease (MRD) using allogeneic immunocompetent lymphocytes following initial reconstitution with T cell depletion and/or activation of reconstituting syngeneic or allogeneic immune cells by recombinant interleukin-2 (rIL2). Pilot clinical trials in patients with leukemias and lymphomas at high risk to relapse following autologous bone marrow transplantation (BMT) suggest that beneficial antitumor effects may be achieved at the stage of MRD by home immunotherapy as soon as hematopoietic reconstitution occurs using rIL2 (Cetus) and alpha interferon (Roferon A) (Hoffmann LaRoche). Although results obtained from our open trial seem encouraging, prospective randomized trials and longer observation periods are needed in order to confirm immune-mediated antitumor effects in conjunction with autologous BMT in patients with malignant hematological disorders at high risk to relapse. Likewise, it seems that amplification of anti-leukemia effects following allogeneic BMT is feasible by post-transplant infusion of donor's peripheral blood lymphocytes for prevention and/or treatment of relapse.

Adoptive immunotherapy with haploidentical allogeneic peripheral blood lymphocytes following autologous bone marrow transplantation.

Patients who undergo autologous bone marrow transplantation for acute leukemia are at high risk for relapse. We have evaluated the feasibility of administering cell-mediated immunotherapy with family-related haploidentical lymphocytes following autologous bone marrow transplantation in order to evoke a graft-vs-leukemia effect in the autologous setting.Twenty-six patients aged 1.5-48 years were enrolled in this study. Eighteen suffered from acute myeloid leukemia, seven from acute lymphoblastic leukemia, and one from myelodysplastic syndrome. Eleven patients were transplanted in first remission, six in second remission, one in fourth remission, and eight in relapse. Conditioning consisted of Busulfan/Cyclophosphamide or Busulfan/Thiotepa/Cyclophosphamide. Nineteen patients (Group A) were treated with gradual increments of haploidentical donor T cells, starting on day +1, with an additional course of T cells plus intravenous recombinant human interleukin-2 one month later if no signs of graft-vs-host disease developed in the interim. Seven patients (Group B) were treated with high-dose haploidentical T cells on day +1 in conjunction with intravenous recombinant human interleukin-2. Donor cells were detected in the peripheral blood of both groups 12-48 hours post-cell-mediated immunotherapy, peaking at 48 hours. Three patients in Group A developed transient Grade I graft-vs-host disease. One patient in Group B developed Grade I, and three Grade IV, graft-vs-host disease. Group A patients engrafted normally, but the Group B patients with Grade IV graft-vs-host disease showed no signs of engraftment. Our results show that it is feasible to induce graft-vs-host disease in the autologous stem cell transplantation setting. However, the high-dose regimen of haploidentical T cells in conjunction with interleukin-2 results in severe toxicity and nonengraftment.

Enhancement of GVL effect with rhIL-2 following BMT in a murine model for acute myeloid leukemia in SJL/J mice.

A murine model for acute myeloid leukemia (mAML) was used to study graft-vs.-leukemia (GVL) effects on residual leukemic cells across both major (MHC) and minor histocompatibility antigens (mHA) barriers. In addition, the therapeutic effect of recombinant human interleukin-2 (rhIL-2)-administered postsyngeneic and allogeneic bone marrow transplantation (BMT) was examined. SJL/J mice inoculated with mAML cells were exposed later to total body irradiation (TBI) and transplanted with bone marrow cells (BMC) mixed with spleen cells derived from normal syngeneic (SJL/J), congenic (B10.S), or allogeneic (C57BL/6) donor mice. One-half of the mice in each group received low dose rhIL-2 for 3 days starting 1 day post-BMT. Spleen cells from treated recipients were transferred to secondary naive SJL/J mice for in vivo detection of residual tumor cells. At a tumor load of 10(5) cells per animal, none of the mice rescued with SJL/J or B10.S cells was cured since 100% of secondary recipients developed leukemia. Concomitant treatment of recipients of B10.S cells with rhIL-2 induced GVL effects since none of the secondary recipients developed leukemia after 2 years. All adoptive recipients of mice rescued with C57BL/6 cells remained free of leukemia after 2 years whether or not rhIL-2 was injected. The potency of the GVL effects observed across mHA and MHC were tumor-cell dose dependent since fewer animals inoculated with 10(6) mAML cells were cured. Only marginal GVL effects were noticed following syngeneic BMT and rhIL-2. Our results sustain the importance of the GVL effects in the treatment of myeloid leukemia and demonstrate that immunotherapy with rhIL-2 following BMT can enhance the therapeutic effect induced by the allograft.

Allogeneic cell-mediated immunotherapy for eradication of minimal residual disease: comparison of T-cell and IL-2 activated killer (LAK) cell-mediated adoptive immunotherapy in murine models.

In the course of allogeneic bone marrow transplantation (BMT), avoiding graft-versus-host disease (GVHD) while retaining the antileukemic effects of the T cells remains a major challenge. T-cell depletion (TCD) reduces the incidence of GVHD but increases the relapse rate after allogeneic BMT. We attempted to develop a regimen that would retain or increase the graft-versus-leukemia effect induced by donor T cells while preventing GVHD. Immunosuppressed mice were given immunocompetent donor cells, i.e., fresh lymphocytes or lymphokine-activated killer (LAK) cells differing from the host in major (MHC) or minor (MiHC) histocompatibility antigens. Engraftment of donor cells was documented by polymerase chain reaction analysis. Administration of MHC- and MiHC-incompatible allogeneic LAK cells, especially in conjunction with recombinant interleukin-2 (rIL-2), increased disease manifestations and mortality associated with GVHD. On the other hand, irradiated LAK cells or TCD-LAK cells prevented GVHD in both mice models studied. Phenotypic analysis of LAK cells demonstrated that CD8(+)-equivalent (Lyt-2) T cells are of significance in aggravation of GVHD. The in vitro cytotoxic capacity of LAK cells against MHC-nonrestricted target cells was not reduced by either irradiation or TCD. These results provide the background for designing improved protocols for immunotherapy of residual disease after BMT. In addition, the data imply that antitumor effects may be retained by irradiated rIL-2-activated allogeneic cells without causing GVHD. Whereas unmodified allogeneic LAK cells can induce more effective graft-versus-leukemia effects at the cost of GVHD, irradiated allogeneic donor LAK cells might play some role in eradication of minimal residual disease following autologous or allogeneic BMT without causing GVHD.

Allogeneic cell therapy for relapsed leukemia after bone marrow transplantation with donor peripheral blood lymphocytes.

Allogeneic bone marrow transplantation (BMT) is the treatment of choice for hematologic malignancies resistant to conventional chemotherapy and for patients who are at high risk for relapse. Until recently, no cure could be offered to patients relapsing following allogeneic BMT. We present our long-term observations of the first patient with remission reinduced by allogeneic cell therapy (allo-CT) using donor peripheral blood lymphocytes (PBL). In addition, we review the cumulative international experience with allo-CT used to treat 163 patients, 105 with CML and 58 with other hematologic diseases, who relapsed following allogeneic BMT. The first patient treated by allo-CT was diagnosed with acute resistant pre-B lymphoblastic leukemia (ALL) in extensive third hematologic and extramedullary relapse shortly after BMT. He was given infusions of donor (sister) PBL in multiple increments. Subsequently, he developed mild, reversible graft-vs-host disease (GVHD) in parallel with regression of all hematologic and cytogenetic disease manifestations. More than 8 years after allo-CT, he is disease-free with Karnofsky score 100% and no evidence of residual male cells by PCR. International data show that relapse after BMT was successfully reversed by donor PBL treatment in 97 of 158 evaluable patients; 72/100 (72%) with chronic myeloid leukemia (CML) and 25/58 (44.8%) with other malignant hematologic diseases including acute leukemia, lymphoma, and myelodysplastic syndrome. T cell depletion (TCD) for prevention of GVHD was performed for 60/105 (57%) patients with CML and 31/58 (53.4%) patients with other hematologic malignancies. Complete response after allo-CT was obtained in recipients of both TCD-BMT and unmodified BMT. GVHD due to allo-CT developed in 86/158 (54.4%) of the patients, 63/100 (63.0%) with CML and 23/58 (39.6%) with other hematologic diseases. alpha-interferon (IFN-alpha) was given to 67.9% of patients with CML and 28.1% of patients with other diseases. The cumulative experience shows that allo-CT can successfully reverse chemoradiotherapy-resistant relapse of acute leukemia and even more effectively of chronic leukemia independently of alpha-interferon therapy. Although GVHD was frequent among responders, accompanied occasionally by transient or irreversible marrow aplasia, remissions were also obtained in patients with no GVHD. Allo-CT should therefore be considered as treatment of choice for overt relapse or de novo minimal residual disease post-BMT. Administration of donor peripheral blood lymphocytes in graded increments at an early stage of relapse may be the best approach for combining optimal timing at the stage of minimal disease while controlling and minimizing the risk of GVHD on an individual basis.

Soluble interleukin-6 receptors in hematology patients undergoing bone marrow transplantation.

Soluble interleukin-6 receptor (sIL-6R) has previously been shown to potentiate the activity of interleukin (IL)-6, which may display antitumor activity. We evaluated sIL-6R and IL-6 levels in the sera of 24 patients following transplantation (allogeneic, n=17; autologous, n=7). Five patients developed acute graft-versus-host disease (AGVHD), three had early graft rejection, and three had an early relapse following bone marrow transplantation (BMT). Soluble IL-6R levels were evaluated at day - 10, day 0, day of engraftment, and during BMT-related complications, using IL-6R-specific monoclonal antibodies (mAb) and double-sandwich ELISA. In normal controls, sIL-6R and IL-6 levels were 20+/-3 ng/ml and 0.01+/-0.005 ng/ml, respectively. Soluble IL-6R levels increased in direct correlation with engraftment in the uneventful allogeneic transplants (17.7+/-2.1 ng/ml at day 0 to 49.7+/-2.6 ng/ml at day of engraftment, n=6, P<0.05) as well as in the autologous transplants (26.8+/-2.82 at day 0 to 66.4+/-12.9 at day of engraftment, n=5, P=0.01). In contrast, IL-6 levels declined with time during the conditioning period and showed only a modest elevation following BMT. Increased levels of sIL-6R and IL-6 were found in the patients who developed AGVHD (23.8+/-4.2 and 0+/-0 ng/ml at day 0 to 79+/-6.9 and 0.26+/-0.04 ng/ml, respectively, at time of AGVHD, n=5, P=0.01). No correlation was found between the severity of AGVHD and sIL-6R levels. In the three patients with early relapse, sIL-6R levels increased from 30+/-0 ng/ml at day 0 to 90 ng/ml (P=0.05) and IL-6 levels increased from 0 to 0.16+/-0 ng/ml, respectively. The mean elevation of sIL-6R in the patients with early relapse and AGVHD was significantly higher than the mean elevation in the patients with the relatively smooth engraftment (P<0.05). Contrary to these findings, in the three patients with graft rejection, sIL-6R levels decreased while IL-6 was found to be elevated. Basic disease, conditioning regimen, type of transplant, GVHD propylaxis, and T cell depletion had no effect on sIL-6R or IL-6 levels. In summary, sIL-6R levels positively correlated with engraftment. Both sIL-6R and IL-6 levels were found to be significantly elevated in patients who developed AGVHD or early relapse following BMT. Therefore, the sIL-6R level may be used as a tool for assessing engraftment and transplant-related complications following BMT.

Amplification of immunological functions by subcutaneous injection of intermediate-high dose interleukin-2 for 2 years after autologous stem cell transplantation in children with stage IV neuroblastoma.

BACKGROUND: Immunotherapy given post-autologous stem cell transplantation may eliminate residual tumor cells escaping the conditioning protocol. METHODS: Five children suffering from stage IV neuroblastoma were treated by recombinant interleukin-2 (IL-2) post-autologous peripheral blood stem cell transplantation. The patients' peripheral mononuclear cells were monitored for CD3+ and CD56+ levels, their proliferative response and killing of various cell lines targets. RESULTS: An increase in the level of total lymphocytes, mainly due to expansion of T cells, and enhanced proliferative response to phytohemaglutinin were observed. Elevated cytotoxicity against K562 and neuroblastoma target cells was detected in four patients and against K562 targets in one patient. Toxicity included mild thrombocytopenia, and fever in four patients and mild to moderate encephalopathy which necessitated withdrawing one patient from the protocol. Three of five patients studied are alive today, one of them whose IL-2 was stopped, is in relapse. Two patients have died. CONCLUSIONS: Immunotherapy with s.c. intermediate-high dose IL-2 is feasible and results in expansion of T cells and in stimulation of killing activity against several targets including in some cases, neuroblastoma tumor cells.

IL-2 activated cell-mediated immunotherapy: control of minimal residual disease in malignant disorders by allogeneic lymphocytes and IL-2.

The present experiments were designed to investigate whether it might be possible to combine their therapeutic benefits of autologous BMT and allogeneic BMT following administration of T-lymphocyte depleted marrow allografts with additional immunotherapy following BMT. The tumor model used for investigating graft vs leukemia (GVL) effects was the murine B-cell leukemia (BCL1), a spontaneous, nonimmunogenic, highly lethal leukemia of BALB/c origin. Immunotherapy with high dose recombinant human interleukin-2 (IL2) (10(5) Cetus units x 3/day intraperitoneally (IP) for 5 days) produced significant anti-tumor effects in BCL1-bearing mice. BALB/c mice inoculated with 10(3) BCL1 leukemia cells received were treated on day -1 with cyclophosphamide 100 mg/kg and transplanted with normal syngenic BM cells on day 0. High-dose IL2 (100,000 Cetus Units x 3/day IP x 5 consecutive days) was initiated on day +1, +7, or +21 following BMT. Optimal time for administration of IL2 was noted at 3 weeks post-BMT with 90% of the mice surviving with no evidence of disease greater than 1 year. An experimental model designed to study GVL effects in a state of minimal residual disease following T-cell depleted allogeneic BMT indicated that mice receiving low dose of BCL1 challenge (10(4] were successfully treated by either IL2 (2 x 10(4) Cetus units x 2/day IP x 3 days), allogeneic spleen cells (10(6) on day +1, 10(7) on day +5 and 5 x 10(7) on day +9) alone and certainly following a combination of both.(ABSTRACT TRUNCATED AT 250 WORDS)

Invasive fungal infections in lymphoma patients receiving immunotherapy following autologous bone marrow transplantation (ABMT).

Invasive fungal infections are quite rare (1-5%) following conventional ABMT for malignant lymphoma. Two high-risk lymphoma patients (one non-Hodgkin's lymphoma (NHL) and one Hodgkin's disease) underwent ABMT followed by immunotherapy as part of an experimental therapy given to 12 lymphoma patients aiming to prevent relapse following transplantation. The post-immunotherapy course in both patients was complicated by invasive fungal infections (pulmonary mucormycosis and generalized aspergillosis). The association between invasive fungal infection and immunotherapy following ABMT for malignant lymphoma patients is discussed.

The effect of in vitro T lymphocyte depletion on generation of IL2-activated cytotoxic cells.

The effect of immunocompetent lymphocyte depletion on precursors and effector cells of IL2 activated non-MHC restricted cytotoxic cells (LAK) generated from bone marrow (BM) or peripheral blood was investigated. Lymphocyte depletion was carried out by using Campath-1, a monoclonal rat anti-human lymphocyte antibody recognizing CDW52, that binds human complement and is used routinely in clinical bone marrow transplantation (BMT). The results indicate that LAK precursors derived from BM cells are sensitive to Campath-1 treatment, while a variable degree of sensitivity was demonstrated in LAK precursor cells derived from peripheral blood. In contrast, effector LAK cells generated in vitro were shown to be resistant to treatment with Campath-1 and complement. We hypothesize that if indeed IL2-dependent non-MHC restricted cytotoxic cells play a role in vivo in the immediate post-BMT period, a T lymphocyte depletion procedure such as the Campath-1 may have the capacity to reduce, at least temporarily, the graft-versus leukemia effects mediated by such anti-tumor effector mechanisms.

Immunotherapy of relapsed resistant chronic myelogenous leukemia post allogeneic bone marrow transplantation with alloantigen pulsed donor lymphocytes.

Allogeneic cell-mediated immunotherapy with donor lymphocyte infusion (DLI) can successfully reverse chemoradiotherapy-resistant relapse in patients with chronic myeloid leukemia treated by allogeneic bone marrow transplantation (BMT). We describe the first successful attempt in 1992 to treat DLI-resistant relapse in a patient with CML in full hematologic relapse, using immunized donor lymphocytes. Donor lymphocytes were pulsed in vitro with a mixture of irradiated peripheral blood lymphocytes (PBL) obtained from both parents, in order to trigger alloactivation of donor lymphocytes against host alloantigens presented by parental cells, using as stimulating cells maternal PBL expressing the shared maternal haplotype and paternal PBL expressing the shared paternal haplotype of the patient. Full hematologic, cytogenetic and molecular remission was induced for the first time, independently of GVH, and has persisted for more than 9 years. To the best of our knowledge, this report represents the first successful immunotherapy with donor lymphocytes activated against host-type antigens. We suggest that immune donor PBL may be superior to DLI, possibly effective even when all other modalities fail, perhaps even independently of GVHD.

Major salivary gland dysfunction in patients with hematological malignancies receiving interleukin-2-based immunotherapy post-autologous blood stem cell transplantation (ABSCT).

lnterleukin-2 (IL-2) is known to cause xerostomia and skin manifestations similar to graft-versus-host disease (GVHD). We therefore evaluated major salivary gland function in patients with hematological malignancies treated with IL-2 and interferon-alpha (IFN-alpha) after ABSCT. Eleven patients (seven male, four female) of median age 40 (24-47) were evaluated, seven with non-Hodgkin lymphoma (NHL); one with Hodgkin's disease (HD) and three with acute myelogenous leukemia (AML). Parotid and submandibular salivary gland function was assessed before, during and after IL-2/IFN-alpha administration by evaluation of the salivary flow rate and the composition of secreted saliva. Significant reductions in both the resting and stimulated parotid and submandibular salivary flow rates were observed during IL-2/IFN-alpha immunotherapy compared with the pre- and post-therapy values (P < 0.01), while no hyposalivation was observed in the control patients who underwent ABSCT and did not received IL-2. Sialochemical evaluation revealed a significant increase in potassium concentration (24.4+/-0.6 mEq/l to 28.9+/-1.4 mEq/l) and a significant decrease in sodium concentration (6.7+/-2.1 mEq/l to 3.3+/-1.0 mEq/l) (P < 0.05) in the stimulated parotid gland saliva secreted during IL-2/IFN-alpha administration. Salivary protein concentrations were not altered by the IL-2/IFN-alpha immunotherapy. Similar changes were previously observed in mice and humans with chronic GVHD. We conclude that IL-2 immunotherapy induces major salivary gland dysfunction in humans, similar to our previous observations in patients with chronic GVHD, which may indicate similar pathophysiologic mechanisms.

The graft-versus-leukemia (GVL) phenomenon: is GVL separable from GVHD?

Graft-versus-leukemia (GVL) is a major component of the overall beneficial effects of allogeneic bone marrow transplantation (BMT) in the treatment of leukemia. Although several clinical trials have suggested a direct relationship between GVL effects and acute and chronic graft-versus-host disease (GVHD), it is not yet known whether GVL can be separated from GVHD. However, several investigations in murine models of human leukemia indicate that the two may be at least partially separable. Moreover, analysis of clinical data from the International Bone Marrow Transplant Registry suggest that allogeneic BMT may be more advantageous than syngeneic BMT, regardless of the GVHD. Likewise, T lymphocyte depletion is associated with an increased incidence of relapse, independently of GVHD. Recent investigations in murine leukemia suggest that GVL-like effects may be inducible following syngeneic BMT by recombinant cytokines with no overt GVHD. Taken together, current data in experimental animals and man suggest that GVL may be at least partially separable from GVHD. Hence, further understanding of effector and target cells of GVL as well as our ability to induce antitumor effector cells, especially those that are MHC nonrestricted, may lead to new approaches for potentiating anti-tumor effector mechanisms without inducing severe, clinically overt GVHD. Successful attempts in these directions may also lead to improved results following autologous BMT as a result of activation of GVL-like effects by recombinant cytokines that are capable of activating effector cells with anti-leukemic activity in vivo, such as recombinant human IL2, alpha interferon or perhaps a synergistic combination of factors.