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Biomedical subjects

I Khouri

Publications and source records attributed to I Khouri.

At least 37 records · Page 2Linked to original sources
PubMed2000

Allogeneic stem cell transplantation with fludarabine-based, less intensive conditioning regimens as adoptive immunotherapy in advanced Hodgkin's disease.

Six patients with advanced Hodgkin's disease in which multiple conventional treatments (median prior chemotherapy regimens: seven), radiation therapy, and a prior autologous stem cell transplantation (SCT) had failed underwent allogeneic SCT following a fludarabine-based conditioning regimen. Median age was 29 years (22-30). Median time to progression after autologous SCT was 6 months (4-21). Disease status at transplant was refractory relapse (n = 3) and sensitive relapse (n = 3). Cell source was filgrastim-mobilized peripheral blood stem cells from an HLA-identical sibling (n = 4) or matched unrelated donor marrow (n = 2). Conditioning regimens were fludarabine-cyclophosphamide-antithymocyte globulin (n = 4), fludarabine-melphalan (n = 1) and fludarabine-cytarabine-idarubicin (n = 1). Myeloid recovery was prompt, with an absolute neutrophil count > or =500/microl on day 12 (11-15). Median platelet recovery to > or =20000/microl was on day 9 (0-60). Chimerism studies on day 30 indicated 100% donor-derived hematopoiesis in 4/5 evaluable patients (4/4 non-progressors). All responders (3/3) have ongoing 100% donor-derived chimerism. Acute graft-versus-host disease (GVHD) was diagnosed in 4/6 evaluable patients. Chronic GVHD was present in 2/4 evaluable patients. There were no regimen-related deaths. Overall day 100 transplant-related mortality was 2/6 (33%). Three patients have expired and three are alive and progression-free with a median follow-up of 9 months (6-26) post transplant. We conclude that allogeneic stem cell transplantation with fludarabine-based preparative regimens is feasible in these high-risk, heavily pretreated HD patients.

Adult↗
PubMed2000

Early detection of relapse by hypermetaphase fluorescence in situ hybridization after allogeneic bone marrow transplantation for chronic myeloid leukemia.

PURPOSE: Standard G-band cytogenetic analysis (CG) provides information on approximately 25 metaphases for monitoring the presence of Philadelphia chromosome positive (Ph+) cells in chronic myelogenous leukemia (CML) patients, making the detection of a low frequency of Ph+ cells problematic. The purpose of this study was to improve the detection of a low frequency of Ph+ cells. PATIENTS AND METHODS: We combined fluorescence in situ hybridization (FISH) with long-term colcemid exposure, capturing several hundred metaphases in bone marrow cultures (hypermetaphase FISH [HMF]). Using probes that identify Ph+ cells, HMF was compared with CG analysis in the follow-up evaluations of 51 patients with CML at various time points after allogeneic bone marrow transplant (BMT). RESULTS: Thirty-five patients never showed the presence of Ph+ cells by either method. In four patients, high frequencies of Ph+ cells were detected by both methods. In the remaining 12 patients, Ph+ cells were detected by HMF at time points after BMT when they were not detected by CG. In seven of the 12 patients, low but statistically significant frequencies of Ph+ cells (0.37% to 5.20%) were detected 3 months or later after BMT, and when no intervention was initiated, all seven patients later relapsed. Based on those data, an eighth patient with mixed chimerism and a similar HMF-detected Ph+ frequency (1.8% at 27 months after BMT) was reinfused with donor lymphocytes and achieved remission with 0% Ph+ cells studied by HMF (up to 50 months after BMT). Ph+ cells detected by HMF but not by CG less than 3 months after BMT disappeared on later examination in two of four patients. After detection of Ph+ cells by HMF only, the median time to cytogenetic progression (detection of Ph+ cells by CG) was 101 days. CONCLUSION: The results demonstrate the ability of HMF to detect low but clinically relevant levels of leukemic cells not detected by CG in transplant patients. The data indicate that HMF can detect low levels of Ph+ cells before standard cytogenetics at a time that may be useful in monitoring disease status and planning clinical interventions.

Bone Marrow Transplantation↗
PubMed1999

Risk factors for acute graft-versus-host disease after allogeneic blood stem cell transplantation.

We evaluated demographic characteristics and graft composition as risk factors for acute graft-versus-host disease (GVHD) in 160 adult recipients of HLA-identical allogeneic blood stem cell transplants. The patients received a median nucleated cell dose of 7.9 x 10(8)/kg and median C34(+) cell dose of 5.6 x 10(6)/kg. GVHD prophylaxis consisted of cyclosporine (CSA) and steroids, tacrolimus (FK506) and steroids, or FK506 and methotrexate. Grades 2 to 4 GVHD occurred in 31% (95% CI, 23% to 39%), and grades 3 to 4 GVHD in 14% (95% CI, 8% to 20%). In univariate analyses, GVHD prophylaxis with CSA and high CD34(+) cell doses were significant risk factors for grades 2 to 4 GVHD, but diagnosis, age, use of total body irradiation, donor sex, female donor for male recipient, donor parity, donor alloimmunization, viral serology, nucleated cell dose, CD3(+) cell dose, and CD56(+) cell dose did not alter the incidence of GVHD significantly. With a CD34(+) cell dose less than 8 x 10(6) CD34(+) cells/kg, the risk of grades 2 to 4 GVHD was significantly higher for those who received CSA (39%, 95% CI, 21% to 47%) in comparison with those on FK506 (18%, 95% CI, 10% to 26%) (P =.03), but GVHD prophylaxis regimen had less impact with a higher CD34(+) cell dose (overall grades 2 to 4 GVHD rate 52%, 95% CI, 37% to 67%). GVHD prophylaxis and CD34(+) cell dose are independent risk factors for acute GVHD after allogeneic blood stem cell transplantation.

Adolescent↗
PubMed1999

Allogeneic hematopoietic transplantation as adoptive immunotherapy. Induction of graft-versus-malignancy as primary therapy.

An immune-mediated graft-versus-malignancy effect is important to prevent relapse after allogeneic bone marrow transplant for a range of hematologic malignancies and potentially some solid tumors. Graft-versus-leukemia (GVL) effects as seen in response to donor lymphocyte infusions have been most prominent against indolent malignancies including chronic myelogenous leukemia, chronic lymphocytic leukemia, and low-grade lymphoma. Acute myelogenous leukemia and multiple myeloma may also respond. An alternative strategy for allogeneic transplantation is to avoid the toxicity of high-dose chemoradiotherapy and use a relatively nontoxic, nonablative preparative regimen to achieve engraftment, allowing subsequent infusion of additional donor lymphocytes to mediate GVL. Fludarabine-based nonablative chemotherapy agents, using standard dose combinations, produce moderate myelosuppression but are sufficiently immunosuppressive to allow engraftment of an allogeneic hematopoietic transplant and generation of graft-versus-malignancy effects.

Antigens, Neoplasm↗
PubMed1999

Graft-vs.-malignancy with allogeneic blood stem cell transplantation: a potential primary treatment modality.

The high-dose chemotherapy and radiation typically used as the preparative regimen for bone marrow transplantation produces considerable morbidity and mortality. An alternative strategy is to utilize a low-dose, non-myeloablative, preparative regimen designed not to eradicate the malignancy, but to provide sufficient immunosuppression to achieve engraftment of an allogeneic hematopoietic graft and allow subsequent development of a graft-vs.-malignancy effect. We studied this approach in patients who were ineligible for standard myeloablative preparative regimens because of advanced age or comorbidities and demonstrated that purine analog (fludarabine or 2-CDA) containing non-myeloablative chemotherapy allows engraftment of HLA-compatible hematopoietic progenitor cells, and extended remissions were observed in approximately half of chemosensitive patients with recurrent AML or CML. Patients with CLL or lymphoma have been effectively treated using a non-myeloablative regimen of fludarabine/cyclophosphamide of fludarabine, cytarabine, cisplatin. This chemotherapy is known to be non-myeloablative and mixed chimerism was anticipated. All patients with engraftment have responded and 67% have achieved complete remission. Maximal responses are slow to develop and occur gradually over a period of several months to one year. Long-term efficacy must still be determined and controlled trials are necessary comparing this approach with alternative therapies as well as standard transplantation regimens.

Child↗
PubMed1999

Thiotepa, busulfan and cyclophosphamide as a preparative regimen for allogeneic transplantation for advanced chronic myelogenous leukemia.

Thirty-six adults with chronic myelogenous leukemia (CML) in second or greater chronic phase, accelerated phase, or blast crisis underwent marrow or blood stem cell transplantation from an HLA-matched sibling using high-dose thiotepa, busulfan and cyclophosphamide (TBC) as the preparative regimen. All evaluable patients engrafted and had complete donor chimerism. One patient failed to clear meningeal leukemia, and one patient had one of 30 metaphases positive for the Philadelphia chromosome at 2 months post transplant. The remainder of the patients studied had eradication of CML documented by cytogenetics and/or Southern blot for BCR gene rearrangement, and 13 of 15 patients studied became negative for the BCR gene rearrangement by polymerase chain reaction. Three-year relapse rate is 42% (95% CI, 19-64%). The relapse rate was significantly lower for patients transplanted without blast crisis (9% vs 100%, P < 0.001). Eight (22%, 95% CI, 10-39%) patients had severe or fatal veno-occlusive disease (VOD). Elevated liver enzymes within 1 month prior to transplantation and transplantation using marrow were significantly associated with the occurrence of VOD. Three-year survival is 28% (95% CI, 13-43%). Survival was significantly higher for patients transplanted without blast crisis (45% vs 0%, P = 0.01). TBC is an effective preparative regimen for CML in accelerated phase but not refractory blast crisis, and it should be used with caution in patients with prior hepatopathy who have an increased risk of severe VOD.

Adult↗
PubMed1999

Tacrolimus and minidose methotrexate for prevention of acute graft-versus-host disease after HLA-mismatched marrow or blood stem cell transplantation.

Thirty adults with leukemia or lymphoma transplanted with marrow or blood stem cells from 1-antigen mismatched related donors received tacrolimus and minidose methotrexate to prevent acute graft-versus-host disease (GVHD). The group had a median age of 42 years (range 18-56 years). Twenty-seven patients had advanced disease, and 13 were resistant to conventional therapy. Tacrolimus was administered at 0.03 mg/kg/day i.v. by continuous infusion from day -2, converted to oral at four times the i.v. dose following engraftment, and continued to day 180 post-transplant. Methotrexate 5 mg/m2 was given i.v. on days 1, 3, 6 and 11. Mild nephrotoxicity was common before day 100; 69% of patients had a doubling of creatinine, 56% had a peak creatinine greater than 2 mg/dl, and two patients were dialyzed. Other toxicities prior to day 100 thought to be related to tacrolimus included hypertension (45%), hyperkalemia (17%), hyperglycemia (14%), seizures (13%), headache (3%) and hemolytic uremic syndrome (3%). Grades 2-4 GVHD occurred in 59% (95% CI, 38-70%), and grades 3-4 GVHD in 17% (95% CI, 1-32%). Overall survival at 1 year was 29% (95% CI, 12-45%). We conclude that tacrolimus and minidose methotrexate is active post-transplant immunosuppression for patients with 1-antigen mismatched donors.

Acute Disease↗
PubMed1999

Carmustine, etoposide, cytarabine and melphalan as a preparative regimen for allogeneic transplantation for high-risk malignant lymphoma.

BACKGROUND: The combination of carmustine, etoposide, cytarabine and melphalan (BEAM) is an effective autologous transplantation preparative regimen for lymphoma and has little toxicity, but the feasibility and tolerance of BEAM as a preparative regimen for allogeneic transplantation has not been established. PATIENTS AND METHODS: Thirty adults with primary refractory or recurrent intermediate- or low-grade lymphoma were treated on a prospective phase II study with carmustine 300 mg/m2 i.v. day -6, etoposide 200 mg/m2 i.v. followed by cytarabine 200 mg/m2 i.v. twice daily days -5 to -2, melphalan 140 mg/m2 i.v. day -1, and marrow or blood stem cells from an HLA-identical donor on day 0. Tacrolimus and methotrexate were used to prevent graft-vs.-host disease (GVHD). RESULTS: Median time from transplantation was 20 mos (range 6-32 months). Median maximal regimen-related toxicity grade was 2, and four patients (13%) had a grade 3-4 regimen-related toxicity. Two patients had idiopathic interstitial pneumonitis. One patient had primary graft failure, and a second had autologous reconstitution documented at three months posttransplant. Grades 2-4 acute GVHD occurred in 31%, grades 3-4 in 16%, and chronic GVHD in 54%. Day-100 survival was 70%. Twenty-three patients achieved a complete response. The two-year relapse rate was 23%, survival was 48%, and disease-free survival (DFS) was 42%. CONCLUSIONS: BEAM supports engraftment of allogeneic transplants and is a tolerable preparative regimen for allogeneic transplantation for lymphoma.

Adult↗
PubMed1999

Reinventing bone marrow transplantation: reducing toxicity using nonmyeloablative, preparative regimens and induction of graft-versus-malignancy.

Bone marrow transplantation was initially developed as a means to deliver supralethal doses of chemotherapy and radiation for treatment of malignancies. Myelosuppression is the dose-limiting toxicity for many chemotherapy drugs and whole-body radiation. Many malignancies exhibit a steep dose-response relationship to chemotherapy or radiotherapy. Bone marrow transplantation allows escalation of doses beyond those levels which produce severe bone marrow toxicity. Doses of many agents, particularly alkylating agents and whole body radiation, can be increased three- to fivefold above their conventional maximally tolerated dose. Marrow transplantation was considered a supportive care modality to restore hematopoiesis. It has become clear, however, that the high dose therapy does not eradicate the malignancy in many patients, and that the therapeutic benefit of allogeneic marrow transplantation is largely related to an associated immune-mediated graft-versus-malignancy effect.

Antineoplastic Agents↗
PubMed1999

Intensive dose ifosfamide and etoposide with G-CSF for stem cell mobilization in patients with non-Hodgkin's lymphoma.

We studied 36 patients with non-Hodgkin's lymphoma to evaluate the stem cell yield following recovery from intensive dose ifosfamide and etoposide given as mobilization chemotherapy. We also assessed the toxicity of the regimen and engraftment kinetics. All patients had intermediate grade lymphoma and had either failed to achieve a complete remission to induction chemotherapy or had relapsed. Patients received ifosfamide 10 g/m2 IV total dose given over 72 hours, etoposide 150 mg/m2 IV every 12 hours for 6 doses and G-CSF 10 microg/kg/d. Thirty-four patients went on to receive high-dose chemotherapy with BEAM or with CVP and BEAM. A median of 2 (1-10) apheresis was required to reach the target CD34+ count of >4 x 10(6)/kg. A median of 13.1 CD34+ cells/kg (4.1-148) was obtained. Toxicity was limited to mucositis in 3 patients, transient confusion and transient rise in liver function tests in 3 and 2 patients respectively. The median time to engraftment was 10 days (8-17) for all the patients undergoing high-dose chemotherapy. The regimen of intensive dose ifosfamide and etoposide along with G-CSF is well tolerated and in this group of patients has lead to successful stem cell harvests and sustained engraftment.

Adult↗
PubMed1999

Reinventing bone marrow transplantation. Nonmyeloablative preparative regimens and induction of graft-vs-malignancy effect.

The therapeutic benefit of allogeneic hematopoietic transplantation is due largely to an immune graft-vs-malignancy effect. Most of the evidence for such an effect has come from studies of allogeneic transplantation in leukemia. In patients with susceptible malignancies who relapse following an allogeneic transplant, infusion of donor lymphocytes can induce durable remissions. Use of less toxic, nonmyeloablative preparative regimens permits engraftment and generation of graft-vs-malignancy effects. This strategy permits allogeneic transplantation to be used in older patients and those with comorbidities who cannot tolerate conventional high-dose preparative regimens. The long-term efficacy of nonmyeloablative preparative regimens and induction of graft-vs-malignancy effects remains to be determined. Also, further clinical trials are required to address various unresolved issues and to compare this strategy with standard, myeloablative transplantation regimens.

Bone Marrow Transplantation↗
PubMed1999

Non myeloablative "mini transplants".

The efficacy of graft-vs.-leukemia induction to treat relapses after allogeneic progenitor cell transplant in a variety of hematologic malignancies suggest that it may be possible to use the graft versus leukemia as primary therapy for these malignancies without the need of myeloablative therapy. This type of strategy should be explored initially in patients considered ineligible for conventional myeloablative therapies either because of age or concurrent medical conditions. GVHD remains a major obstacle that needs to be overcome. Although a potentially lower level of inflammatory cytokines may be present after non-myeloablative therapies, fatal GVHD still occurs. Methods to diminish GVHD after allogeneic transplant include selective T-cell depletion (39-43) and transduction of donor T-cells with Herpes simplex virus thymidine kinase which renders these cells sensitive to ganciclovir treatment (see chapter 16). We and others have demonstrated that nonablative chemotherapy using fludarabine combinations is sufficiently immunosuppressive to allow engraftment of allogeneic blood progenitor cells. Patients could then receive graded doses of donor lymphocytes without rejection, to mediate GVL. Ideally, this therapy could be titrated to levels of residual malignant cells using sensitive detection techniques. This novel approach to therapy would reduce the toxicity of the transplant procedure, allow it to be administered more safely to debilitated patients and possibly extend the use of transplantation to older patients who are not presently eligible for BMT procedures. Other possible indications include treatment of non-malignant disorders and induction of tolerance for solid organ transplantation.

Graft vs Host Disease↗
PubMed1998

Allogeneic marrow transplantation for myeloproliferative disorders other than chronic myelogenous leukemia: review of forty cases.

The role of allogeneic marrow transplantation as treatment of myeloproliferative disorders other than chronic myelogenous leukemia is not yet determined. At our center, 1 patient with primary myelofibrosis, 1 with mastocytosis, and 4 with myeloid metaplasia have been transplanted using HLA-identical sibling donors. All patients engrafted with full donor chimerism, and morphologic and cytogenetic manifestations of disease in the marrow resolved posttransplant. Three patients died; two with relapse and one from infection. The other three patients are alive in remission at 24+, 28+, and 32+ months posttransplant. Including these cases, a total of 40 patients transplanted for myeloproliferative disorders have been reported. The most common indications for transplantation were cytopenias, increasing blasts in marrow or blood, uncontrolled counts on conventional therapy, poor prognosis cytogenetics, organ dysfunction, and consolidation after induction therapy for blast transformation. Using the outcome data published for these patients, the actuarial estimate of 3-year survival is 55% (95% C.I., 44-76%) with a median reported follow-up of survivors of 21 months (range, 4-158 months). For patients with myeloproliferative disorders and evidence of accelerated disease, HLA-identical marrow transplantation is well tolerated and can result in an extended disease-free survival.

Adult↗
PubMed1998

High-dose chemotherapy for relapsed and refractory diffuse large B-cell lymphoma: mediastinal localization predicts for a favorable outcome.

PURPOSE: This study was performed to evaluate the outcome of high-dose chemotherapy and autologous transplantation in patients with diffuse B-cell large-cell lymphoma, and, specifically, to evaluate the impact of primary mediastinal localization on the outcome of high-dose chemotherapy. PATIENTS AND METHODS: A retrospective review was performed of all patients with diffuse large B-cell lymphoma who underwent autologous marrow or peripheral-blood stem-cell transplantation at our institution between January 1 986 and December 1995. RESULTS: Ninety patients were identified, of whom 31 (34%) had a primary mediastinal B-cell large-cell lymphoma (PML). Cumulative probabilities of disease-free survival, overall survival, and disease progression are 40% (95% confidence interval [CI], 29 to 51), 42% (95% CI, 31 to 53), and 52% (95% CI, 40 to 64), respectively. By univariate analysis, low lactate dehydrogenase (LDH) level and low Ann Arbor stage at transplant were associated with improved survival and disease-free survival. There was a trend for improved disease-free survival and survival for patients with PML. Multivariate stepwise Cox regression analysis showed that LDH level, Ann Arbor stage, and primary mediastinal localization were independent favorable prognostic factors for disease-free survival and survival. LDH level and Ann Arbor stage were also predictive for the risk of disease progression. CONCLUSION: Our results indicate that patients with PML may display an increased susceptibility to high-dose chemotherapy compared with other types of B-cell large-cell lymphoma. These findings, if confirmed, may have implications for the initial management of patients with PML.

Adolescent↗
PubMed1997

Engraftment of allogeneic hematopoietic progenitor cells with purine analog-containing chemotherapy: harnessing graft-versus-leukemia without myeloablative therapy.

The immune-mediated graft-versus-leukemia effect is important to prevent relapse after allogeneic progenitor cell transplantation. This process requires engraftment of donor immuno-competent cells. The objective of this study was to assess the feasibility of achieving engraftment of allogeneic peripheral blood or bone marrow progenitor cell after purine analog containing nonmyeloablative chemotherapy. Patients with advanced leukemia or myelodysplastic syndromes (MDS) who were not candidates for a conventional myeloablative therapy because of older age or organ dysfunction were eligible. All patients had an HLA-identical or one-antigen-mismatched related donor. Fifteen patients were treated (13 with acute myeloid leukemia and 2 with MDS). The median age was 59 years (range, 27 to 71 years). Twelve patients were either refractory to therapy or beyond first relapse. Eight patients received fludarabine at 30 mg/m2/d for 4 days with idarubicin at 12 mg/m2/d for 3 days and ara-c at 2 g/m2/d for 4 days (n = 7) or melphalan at 140 mg/m2/d (n = 1). Seven patients received 2-chloro-deoxyadenosine at 12 mg/m2/d for 5 days and ara-C 1 at g/m2/d for 5 days. Thirteen patients received allogeneic peripheral blood stem cells and 1 received bone marrow after chemotherapy. Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine and methyl-prednisolone. Treatment was generally well tolerated, with only 1 death from multiorgan failure before receiving stem cells. Thirteen patients achieved a neutrophil count of greater than 0.5 x 10(9)/L a median of 10 days postinfusion (range, 8 to 17 days). Ten patients achieved platelet counts of 20 x 10(9)/L a median of 13 days after progenitor cell infusion (range, 7 to 78 days). Eight patients achieved complete remissions (bone marrow blasts were < 5% with neutrophil recovery and platelet transfusion independence) that lasted a median of 60 days posttransplantation (range, 34 to 170+ days). Acute GVHD grade > or = 2 occurred in 3 patients. Chimerism analysis of bone marrow cells in 6 of 8 patients achieving remission showed > or = 90% donor cells between 14 and 30 days postinfusion, and 3 of 4 patients remaining in remission between 60 and 90 days continued to have > or = 80% donor cells. We conclude that purine analog-containing nonmyeloablative regimens allow engraftment of HLA-compatible hematopoietic progenitor cells. This approach permits us to explore the graft-versus-leukemia effect without the toxicity of myeloablative therapy and warrants further study in patients with leukemia who are ineligible for conventional transplantation with myeloablative regimens either because of age or concurrent medical conditions.

Acute Disease↗
PubMed1997

Allogeneic blood stem cell transplantation in advanced hematologic cancers.

Allogeneic bone marrow transplantation for advanced hematologic cancer is associated with a high risk of early treatment-related morbidity and mortality. To determine the short-term benefits of allogeneic blood stem cell transplants when compared to bone marrow transplants, we reviewed outcomes of 74 adults with advanced hematologic cancer transplanted from HLA-matched related donors after conditioning with thiotepa, busulfan and cyclophosphamide. There were three cohorts: group 1 received bone marrow transplants with cyclosporine (CsA) and methotrexate (MTX) for GVHD prophylaxis; group 2 received bone marrow transplants with CsA and methylprednisolone (MP); and group 3 received blood stem cells with CsA and MP. All patients received filgrastim post-transplant. Median times (range) to neutrophils > or = 0.5 x 10(9)/l were 17 (8-30), 9 (8-16) and 10 (8-13) days post-transplant, and to platelets > or = 20 x 10(9)/l were 28 (14-100+), 19 (13-100+) and 14 (9-86) days post-transplant for groups 1, 2 and 3, respectively (P < 0.05 only for group 1 vs group 3 for both outcomes). Blood stem cell recipients had the least regimen-related toxicity, fewest early deaths and earliest discharge. There was no significant difference in acute GVHD between the three groups. One hundred and eighty-day survivals (95% CI) were 53% (35-72%), 32% (10-53%), and 68% (49-87%) for groups 1, 2 and 3, respectively (P < 0.05 only for group 2 vs group 3). For allogeneic transplantation, use of blood stem cell grafts has substantial advantages over marrow grafts.

Adolescent↗