Recombinant interleukin-2 (rIL-2) after autologous bone marrow transplantation (BMT): a pilot study in 19 patients.

In vivo use of rIL-2 autologous BMT may be the means of reproducing a kind of "adoptive immunotherapy" from grafted cells after allogeneic BMT. This approach may enhance the spontaneous generation of cytotoxic T-cells and NK cells which are presumably involved in this immunotherapy. Potential risks of such an approach would be to increase the usual toxicity of rIL-2 and to jeopardize the hemopoietic reconstitution. To determine the feasibility of this approach we have treated 19 poor prognosis patients with a succession of autologous BMT followed 78 +/- 12 days later by a continuous infusion of rIL-2. Eighteen million international units (IU) per m2 per day of Proleukine (CETUS, Amsterdam, The Netherlands) were administrated over 6 or 12 days. No patient died of the procedure. Clinical toxicity related to rIL-2 was not increased. Hemopoietic toxicity, significant both for platelets and granulocytes, was transient. Immune stimulation was dramatic for lymphocytes and subpopulations (CD3+ and NK cells) and for cytolytic functions (NK and LAK activity). This trial establishes the feasibility of administration of high doses of rIL-2, 2 months after autologous BMT. In this setting a 6 day period of continuous infusion of 18 million per m2 per day of Proleukine appears to be a regularly tolerable dosage conducting to a major immune activation and invites further studies to determine the clinical impact of such an approach.     

The choice of allogeneic or autologous hematopoietic transplantation for NHL

NHL constitutes the sixth most common malignancy diagnosed in the USA every year, accounting for approximately 24,400 deaths. Although a subset of patients can be cured with chemotherapy or radiation therapy, the outlook is generally poor for patients with refractory or recurrent disease. High-dose therapy supported by both autologous and allogeneic transplantation has been widely studied in this group of patients. Autologous transplantation may be considered standard therapy for patients with diffuse large-cell NHL in chemotherapy-sensitive relapse. Selected categories of patients with other histologic subtypes may also benefit from this strategy. Allogeneic transplantation using high-dose myeloablative conditioning regimen is an effective, yet hazardous approach. A GvL effect leads to a lower rate of disease recurrence than occurs with autologous transplants, but this benefit is offset by higher risk of treatment related mortality. The recent use of less toxic non-myeloablative conditioning regimens for allogeneic transplantation has reduced the risk of transplant-related mortality, allowing this approach even in older or medically infirm patients. Nonablative allogeneic transplants are a promising strategy, particularly for patients with indolent lymphoid malignancies.     

Post-bone marrow transplant patient management

Increasingly, bone marrow transplant (BMT) is the treatment of choice for certain hematologic diseases. BMT is, however, a risky procedure with many potentially serious complications. Some complications are the result of the conditioning regimen, a stage of transplantation that includes large doses of chemotherapy and/or radiation therapy. Conditioning-induced neutropenia and thrombocytopenia often result in infection, bleeding, and mucositis. Veno-occlusive disease (VOD), a chemotherapy-induced hepatotoxicity, can cause a mild to severe form of liver disease. Other complications are directly attributable to the engrafted new marrow. Graft-versus-host disease, a rejection process initiated by immunocompetent donor T lymphocytes, is a complication frequently observed in allogeneic BMT. Approximately 14-28 days after the day of transplant, signs of engraftment begin to appear. When specific discharge criteria are met, the BMT patient is discharged from the hospital. Specific follow-up medical care is ongoing for about one year after BMT.     

Graft-versus-host disease following interleukin-2/lymphokine-activated killer (LAK) cell immunotherapy in a patient with acute myelogenous leukaemia in second complete remission: autologous LAK cells following allogeneic bone marrow transplantation are donor-derived

A 48-year-old man was treated by allogeneic bone marrow transplantation (BMT) in first remission of M4 acute myelogenous leukaemia (AML). He experienced no graft-versus-host disease (GVHD) and 7 months later he relapsed. Following further chemotherapy, he entered a second complete remission; however, he refused a further allogeneic or autologous BMT but agreed to immunotherapy with interleukin-2 and autologous lymphokine-activated killer (LAK) cells. He tolerated this treatment well but went on to develop grade II skin GVHD. Polymerase chain reaction studies of DNA microsatellites of the autologous LAK cells showed that they were of donor origin. The patient remained well for 9 months until, immediately following the introduction of prednisolone for his persistent GVHD, he relapsed. He declined further active treatment and died 5 months later. The case shows that IL-2/LAK cells can be safely given to patients who have experienced no GVHD following allo-BMT and are likely to be effective through an ongoing graft-versus-leukaemia effect.     

Usefulness of Y-body study on bone marrow smears to demonstrate the origin of fibroblast stromal cells in allogeneic bone marrow transplantation

The value of Y-body study for assessment of stromal cell engraftment was analyzed in 25 patients submitted to allogeneic bone marrow transplantation (BMT) (sex-matched in 12 cases and sex-mismatched in 13). The study was performed weekly on bone marrow smears until day +35, and the results were compared with those obtained in a control group of 20 patients submitted to autologous BMT (12 males and 8 females). Engraftment of haemopoietic cells was documented in all cases. The results of Y-body study on the recipients' fibroblast cells showed a pattern identical to that observed prior to BMT, independent of donor's sex. On the other hand, there were no differences between allogeneic and autologous BMT recipients in regard to percentage of Y-body positive cells. These results indicate that in allogeneic BMT there is no engraftment of the fibroblastic component of bone marrow stroma.     

Status of allogeneic bone marrow transplantation in childhood in the GDR

Of 25 HLA-identical, MLC negative transplants 10 patients had acute lymphoblastic leukaemia (ALL), 8 acute nonlymphoblastic leukaemia (ANLL), 3 severe aplastic anaemia, 2 malignant histiocytosis, 1 patients neuroblastoma and 1 Fanconi anaemia. 3 HLA nonidentical, MLC positive transplants were performed, two children had malignant infantile osteopetrosis and 1 child had a severe combined immunodeficiency disease. Patients with ALL and ANLL received cyclophosphamide and single dose total body irradiation. 3 patients received fractionated TBI. The results for the allogeneic group overall indicate that the actuarial disease free survival rate is 0.62. 16 of 25 patients are in continuous complete remission (CCR) periods of 3-78 months posttransplant. All three transplanted children with severe aplastic anaemia alive disease-free for periods of 21-81 months. 10 patients with ALL were transplanted (2 in first remission for high risk ALL, 8 in second remission). 7 of 10 patients are alive and disease-free (CCR rate 0.67). 8 patients underwent BMT for ANNL while in first remission in 7 patients and in third partial remission in 1 patient. 4 of 8 patients are alive and disease-free for periods of 25-56 months (CCR rate 0.50). 1 patient with neuroblastoma stage IV survives 24 months, 1 child with Fanconi anemia died on day +25 of GVHD and septicaemia. 1 of the 2 patients transplanted for malignant histiocytosis relapsed 3 months posttransplant, 1 patient is alive and disease-free 5 months posttransplant. In none of the HLA-nonidentical and MLC positive transplantations T-cell depleted marrow engrafted.     

Treatment of neuroblastoma with [131I]metaiodobenzylguanidine: long-term results in 25 patients.

From 1984 to 1990 we have treated altogether 25 children with [131I]metaiodobenzylguanidine (131I-MIBG) for a refractory, relapsed or metastasized neuroblastoma. Three children had stage III and 22 children had stage IV of the disease; at diagnosis their ages were between 4 months and 10 years. Children with stage III disease had at diagnosis a median age of 3.0 years and at treatment 3.8 years. After first-line chemotherapy 2 children had achieved a complete remission (CR), while in 1 child the tumor did not respond (NR) to the initial treatment. At the time of 131I-MIBG treatment 2 children had relapsed and in the other one no further response was achievable. The children were treated by a 13.5 +/- 12.9 mCi/kg BW per course with a mean total dose of 280.7 +/- 243.9 mCi. One child achieved CR by 131I-MIBG alone, while in 2 cases no measurable success was observed. All 3 children were treated additionally by surgery, chemotherapy and bone marrow transplantation (BMT). Two children have died but one is alive and in CR. The 22 children with stage IV disease were treated in two different study groups. In group A, 14 children were studied for side-effects and response to 131I-MIBG. All children were pretreated with standard chemotherapy. Five were treated in relapse, 5 in progression and 3 at a refractory state of the disease; only 1 child was in complete remission when being treated with 131I-MIBG. Group A patients were treated with a mean of 2.4 courses, with 10.3 mCi/kg BW for each course.(ABSTRACT TRUNCATED AT 250 WORDS)     

Immune ablation and stem-cell therapy in autoimmune disease. Experimental basis for autologous stem-cell transplantation

Treatment of rats suffering from florid chronic progressive systemic arthritis or from chronic remitting/relapsing encephalomyelitis with autologous bone marrow transplantation (BMT) is highly effective. This finding was unexpected as the genotype of the bone marrow largely determines the susceptibility of both spontaneous and induced autoimmune diseases in rodents. The success of autologous stem-cell transplantation depends on the completeness of eradication of the effectors of autoimmune disease, in other words activated and memory T lymphocytes. The reviewed experimental data, when translated to the clinic, indicate that the patients should be subjected to a conditioning regimen that induces maximal lymphoablation and that the autologous transplant has to be T-cell depleted.     

Immune ablation and stem-cell therapy in autoimmune disease: Experimental basis for autologous stem-cell transplantation

Treatment of rats suffering from florid chronic progressive systemic arthritis or from chronic remitting/relapsing encephalomyelitis with autologous bone marrow transplantation (BMT) is highly effective. This finding was unexpected as the genotype of the bone marrow largely determines the susceptibility of both spontaneous and induced autoimmune diseases in rodents. The success of autologous stem-cell transplantation depends on the completeness of eradication of the effectors of autoimmune disease, in other words activated and memory T lymphocytes. The reviewed experimental data, when translated to the clinic, indicate that the patients should be subjected to a conditioning regimen that induces maximal lymphoablation and that the autologous transplant has to be T-cell depleted.     

Non-myeloablative stem cell transplantation and donor lymphocyte infusion for the treatment of cancer and life-threatening non-malignant disorders

Allogeneic bone marrow or blood stem call transplantation (BMT) represents an important therapeutic tool for the treatment of otherwise incurable malignant and non-malignant diseases. Until recently, autologous and allogeneic bone marrow and mobilized blood stem cell transplantations were used primarily to replace malignant, genetically abnormal or deficient immunohematopoietic compartments, and therefore highly toxic myeloablative regimens were considered to be mandatory for the effective eradication of all undesirable host-derived hematopoietic elements. Our preclinical and ongoing clinical studies have indicated that much more effective eradication of the host immunohematopoietic system cells can be achieved by adoptive allogeneic cell therapy with donor lymphocyte infusion following BMT. Thus, eradication of blood cancer cells, especially in patients with chronic myeloid leukemia and, less frequently, in patients with other hematologic malignancies, can frequently be accomplished despite the complete resistance of such tumor cells to maximally tolerated doses of chemoradiotherapy. Our cumulative experience has suggested that graft-vs.-leukemia (GVL) effects might be a useful tool for the eradication of otherwise resistant tumor cells of host origin. Based on the cumulative clinical experience and experimental data in animal models of human diseases, it appears that the induction of host-vs.-graft tolerance as an initial step may allow the durable engraftment of donor immunocompetent lymphocytes, which may be used for the induction of effective biologic warfare against host-type immunohematopoietic cells that need to be replaced, including malignant, genetically abnormal or self-reactive cells. Based on the aforementioned rationale, we speculated that the therapeutic benefit of BMT may be improved by using safer conditioning as part of the transplant procedure, with the goal being to induce host-vs.-graft tolerance to enable subsequent induction of GVL, possibly graft-vs.-tumor or even graft-vs.-autoimmunity effects, rather than attempting to eliminate host cells with hazardous myeloablative chemoradiotherapy. This hypothesis suggested that effective BMT procedures could be accomplished without lethal conditioning of the host, using new well-tolerated non-myeloablative regimens, thus possibly minimizing immediate and late side-effects related to the myeloablative procedures until recently considered to be mandatory for the conditioning of BMT recipients. Recent clinical data presented in this review suggest that effective BMT procedures may be accomplished with well-tolerated non-myeloablative stem cell transplantation (NST) regimens, with no major toxicity. Thus, new NST approaches may offer the feasibility of safer BMT procedures for a large spectrum of clinical indications in children and elderly individuals, without lower or upper age limits, while minimizing procedure-related toxicity and mortality. Taken together, our data suggest that high-dose chemotherapy and radiation therapy may be successfully replaced by a more effective biologic tool, alloreactive donor lymphocytes, thus setting the stage for innovative therapeutic procedures for safer and more effective treatment of patients in need of BMT.     

Bone marrow transplantation in childhood leukaemia--experience and strategies in the Federal Republic of Germany

BMT has gained its place in the treatment of childhood leukaemia. Nevertheless, there are still many questions open. In acute lymphoblastic leukaemia children should normally be grafted in 2nd remission (CR). Some high risk cases, however, should probably be grafted in 1st CR. It is not clear whether children with late relapses benefit more from BMT than from renewed chemotherapy. Children with a relapse during maintenance therapy, however, have a better survival rate with BMT. In acute nonlymphoblastic leukaemia certain high risk patients should be grafted in 1st CR but it has still to be shown that BMT is superior to chemotherapy in such cases. It is not clear whether children with a relapse following intensive chemotherapy (such as the BFM-protocols) will benefit from BMT at all. In chronic myelocytic leukaemia, BMT in chronic phase should be performed. Thus, for the first time cure has become possible for this disease. Waiting for acceleration or even the occurrence of a blast crisis decreases the chance of survival after BMT dramatically. Since complications of BMT such as graft-versus-host reaction or severe infections are less frequent in children, relapses remain the main problem after BMT in childhood leukaemia.     

Graft versus neuroblastoma reaction is efficiently elicited by allogeneic bone marrow transplantation through cytolytic activity in the absence of GVHD

Continuous efforts are dedicated to develop immunotherapeutic approaches to neuroblastoma (NB), a tumor that relapses at high rates following high-dose conventional cytotoxic therapy and autologous bone marrow cell (BMC) reconstitution. This study presents a series of transplant experiments aiming to evaluate the efficacy of allogeneic BMC transplantation. Neuro-2a cells were found to express low levels of class I major histocompatibility complex (MHC) antigens. While radiation and syngeneic bone marrow transplantation (BMT) reduced tumor growth (P < 0.001), allogeneic BMT further impaired subcutaneous development of Neuro-2a cells (P < 0.001). Allogeneic donor-derived T cells displayed direct cytotoxic activity against Neuro-2a in vitro, a mechanism of immune-mediated suppression of tumor growth. The proliferation of lymphocytes from congenic mice bearing subcutaneous tumors was inhibited by tumor lysate, suggesting that a soluble factor suppresses cytotoxic activity of syngeneic lymphocytes. However, the growth of Neuro-2a cells was impaired when implanted into chimeric mice at various times after syngeneic and allogeneic BMT. F1 (donor-host) splenocytes were infused attempting to foster immune reconstitution, however they engrafted transiently and had no effect on tumor growth. Taken together, these data indicate: (1) Neuro-2a cells express MHC antigens and immunogenic tumor associated antigens. (2) Allogeneic BMT is a significantly better platform to develop graft versus tumor (GVT) immunotherapy to NB as compared to syngeneic (autologous) immuno-hematopoietic reconstitution. (3) An effective GVT reaction in tumor bearing mice is primed by MHC disparity and targets tumor associated antigens.     

Improved survival following HLA-incompatible bone marrow transplantation. Munich Cooperative Group of Bone Marrow Transplantation

In most centers allogeneic bone marrow transplantation is restricted to patients with HLA-identical siblings as donors. We have transplanted 16 patients with marrow of donors other than HLA-identical siblings. Seven patients were grafted in the years 1978 until 1984. Six died of transplant complications and one of recurrent leukemia. More recently 9 patients were transplanted following an improved immunosuppressive conditioning treatment derived from experimental studies in dogs. Four are alive and in continuous remission between more than 2 months and 2 years. 5 patients died, 3 from fungal infections, one from recurrent leukaemia and one early from endothelial leakage syndrome. Our results indicate that intensified immunosuppressive conditioning may improve the results of marrow transplantation from HLA-haploidentical donors.     

Immune recovery following bone marrow transplantation

83 patients undergoing allogeneic or autologous BMT because of haematologic malignancies have been studied before and after transplantation at different intervals. The determinations consisted of lymphocyte counts, E-rosetting, lymphoblastic response, evaluation of serum immunoglobulin levels, skin testing, and in a smaller part of the patients surface marker studies using monoclonal antibodies of the BL-series. At first after BMT the lymphocyte and T cell counts went to normal between 4-18 weeks post transplant, about 4 weeks earlier in autologous than in allogeneic BMT. T suppressor cells showed an early increase compared to T helper cells which normalized much slower about 6 months after BMT. Lymphoblastic responses, however, tended to normal not before the second half of the first year both in autologous and allogeneic transplantation. Skin test reactivity became normal during the 2nd and 3rd year posttransplant, which was more complete in autologous than in allogeneic BMT. The IgG and IgM levels were depressed for half a year and IgA levels for 2 years. The most striking aspect was the multiphase course of lymphoblastic response in every individual patient. We suggest this to be the expression of sequential differentiation of donor lymphocytes.     

Syngeneic or autologous graft-versus-host disease

Graft-versus-host disease (GVHD) until recently was supposed to occur only when immunocompetent T lymphocytes are infused into immunoincompetent allogeneic hosts that possess histocompatibility antigens not possessed by the donor that could act as targets for cell-mediated cytotoxicity. A syndrome clinically and histologically identical to mild allogeneic GVHD occurs infrequently, following syngeneic or autologous bone marrow transplantation (BMT). This syndrome called syngeneic or autologous GVHD can be regularly produced with Cyclosporine (CsA) in animals undergoing syngeneic or autologous BMT. Animals with this syndrome develop T cells that are autocytotoxic to Ia antigen-bearing cells. The presence of an irradiated thymus and CsA administration is necessary to produce this disease. Operationally, this disease results from a disturbance of balance between a normally present autoregulatory cell and an autocytotoxic T cell. The study of mechanisms involved in the generation of this disease will add to our fundamental understanding of the cellular regulation of autocytotoxic T cell-medicated reactions and diseases. Most recently, we have been able to induce this disease in man with the aim of investigating its therapeutic effect in autologous BMT in patients with Ia-bearing tumors.     

Somatic cell mutation in pediatric patients undergoing allogeneic bone marrow transplantation

In order to examine whether bone marrow transplantation (BMT) has genotoxic effects in vivo, mutant frequencies (Mfs) at the hypoxanthine-guanine phosphoribosyl transferase (Hprt) locus were evaluated. Thirty-seven pediatric patients who had received allogeneic BMT for various hematologic or immunologic disorders were enrolled. Nine out of the 37 patients (24.3%) were found to have Hprt-Mfs exceeding the 99% confidence limits calculated from observation of healthy controls. Among factors including gender, primary disease of the patient, donor-recipient histocompatibility relationship, age of donor, and total body irradiation as conditioning regimen, none was associated with an increased Hprt-Mf. In three patients who had chimerism in their peripheral blood after BMT, Hprt mutant clones turned out to be of donor- or recipient-origin. Mfs at the T-cell receptor (TCR) locus were examined in 28 patients. Four patients (14.3%) were found to have increased TCR-Mfs. However, there were not any patients who showed elevation of both Hprt-and TCR-Mfs. These data, taken together, suggest that BMT may cause genotoxicity in vivo in some patients.     

Use of radioimmunotherapy in stem cell transplantation and posttransplantation: focus on yttrium 90 ibritumomab tiuxetan

Although autologous stem cell transplantation (ASCT) produces prolonged disease-free survival in many patients with non-Hodgkin's lymphoma (NHL), relapse remains the most common cause of treatment failure. Because of the potential benefit of adding targeted irradiation to conditioning regimens, clinical trials are testing the safety and efficacy of combining radioimmunotherapy with yttrium 90 ibritumomab tiuxetan or iodine 131 tositumomab and chemotherapy, either as replacement for total body irradiation or in addition to standard high-dose chemotherapy (HDC) regimens. Current strategies include using standard or escalated doses of radioimmunoconjugates with HDC before ASCT in patients with relapsed or refractory B-cell NHL. We reviewed the safety and efficacy of (90)Y ibritumomab tiuxetan as part of the conditioning regimen before ASCT. Preliminary data from phase 1 and 2 trials show that (90)Y ibritumomab tiuxetan may be safely added to HDC preparative regimens for high-risk B-cell NHL. Additionally, comparisons of outcomes with radioimmunotherapy and ASCT with historical controls suggest that it may be more effective than conventional regimens. Results of (90)Y ibritumomab tiuxetan alone posttransplantation in select patients who have relapsed after HDC and ASCT are also encouraging. Studies of (90)Y ibritumomab tiuxetan in the setting of allogeneic stem cell transplantation appear promising as well.     

CMV infections in bone marrow transplanted patients--evaluation of prophylaxis with Cytotect (CMV hyperimmuneglobulin)

Cytomegalovirus (CMV) infection is a frequent and clinically important infection following bone marrow transplantation. Candidates for this study were patients admitted for transplantation: 22 patients received bone marrow from a HLA-identical, MCR-nonreactive sibling, in 9 patients an autologous BMT was performed. The anti-CMV IgG (Cytotect) was administered at a dosage of 1 ml/kg on days -7, 13, 33, 53, 73 and 93 after BMT. 5 patients in the very beginning of our BMT program did not receive Cytotect. Patients were given random blood products from the bloodbank not tested for CMV positivity. Active CMV infection or seroconversion in our patients was defined as a rise in IgG titer against the late antigen of fourfold or more or an IgM increase. In the allogeneic BMT group the pretransplant serological status was in 6 cases negative in recipients and donor, in 7 patients positive in recipients and negative in donors, and in 4 patients positive in recipients and donors. Of the 6 patients seronegative in recipients and donors, 3 developed active infection and of the 7 patients pretransplant positive with seronegative donors 3 developed active infection and 4 latent infections during the period from 2 to 100 days following grafting. 1 patient out of the group transplanted in third partial remission of AML developed interstitial pneumonia and died on day +30.4 of the 4 cases with seropositivity of recipients and donors developed active CMV infection. Of 9 patients with autologous transplantation 6 patients were pretransplant seropositive. 3 of these 6 developed active infection and 2 latent infection 30 to 180 days after grafting.(ABSTRACT TRUNCATED AT 250 WORDS)     

Outcome of [131I]metaiodobenzylguanidine therapy of neuroblastoma: seven years after.

Beginning in 1984 and based on a total of 40 treatments with [131I]metaiodobenzylguanidine (131I-MIBG) in most cases with a follow-up of 5 years or more, it seems to be worthwhile reevaluating our clinical data and draw some final conclusions: We treated 12 children with a neuroblastoma (NB) IV and 3 with a NB III. In no case 131I-MIBG was the primary therapy. The great majority suffered from recurrence. The mean treatment interval after chemotherapy was 6 months (range 0-54). We calculated a median cumulative tumor dose of 77 Gy (range 0-259) in patients with stage III and 30 Gy (range 4-267) in stage IV NB. The tumor half-life time of 131I-MIBG does not significantly differ between stage III (3 days) and IV (2-5 days). Although the median tumor dose of stage III NB exceeded that of stage IV, we found in NB IV a significant tumor remission in 7 out of 12 cases. On the other hand, a slight reduction of tumor size was seen in only 1 case of stage III NB. This indicates a lower radiation sensitivity of stage III NB. Despite this fact, the two patients with stage III NB who presented a sufficient 131I-MIBG-tumor uptake turned to become operable after 131I-MIBG. Stage IV patients improved, too, even if most of them suffered from recurrence with a very poor prognosis: 3 patients of stage IV lived longer than 48-60 month or are still alive. However, no one of this group remitted completely.(ABSTRACT TRUNCATED AT 250 WORDS)     

Surfactant protein A is a required mediator of keratinocyte growth factor after experimental marrow transplantation

We reported an association between the ability of recombinant human keratinocyte growth factor (rHuKGF) to upregulate the expression of surfactant protein A (SP-A) and to downregulate pulmonary inflammation that occurs after allogeneic bone marrow transplantation (BMT). To establish a causal relationship, rHuKGF (5 mg/kg) was administered subcutaneously for three consecutive days before irradiation to SP-A-sufficient and -deficient [SP-A(+/+) and SP-A(-/-), respectively] mice given inflammation-inducing allogeneic spleen T cells at the time of BMT. In contrast with SP-A(+/+) mice, rHuKGF failed to suppress the high levels of TNF-alpha, IFN-gamma, and nitric oxide contained in bronchoalveolar lavage fluids collected on day 7 after BMT from SP-A(-/-) mice. Early post-BMT weight loss was attenuated by rHuKGF in both SP-A(+/+) and SP-A(-/-) recipients. In the absence of supportive respiratory care, however, SP-A deficiency eventually abolished the ability of rHuKGF to prevent weight loss and to improve survival monitored for 1 mo after allogeneic BMT. In further experiments, the addition of cyclophosphamide (which is known to cause severe injury to the alveolar epithelium in donor T cell-recipient mice) to the conditioning regimen prevented rHuKGF-induced upregulation of SP-A and suppression of lung inflammation in both SP-A(+/+) and SP-A(-/-) mice. We conclude that endogenous baseline SP-A levels and optimal upregulation of SP-A are required for the anti-inflammatory protective effects of KGF after allogeneic transplantation.