Cyclophosphamide-based in vivo T-cell depletion for HLA-haploidentical transplantation in Fanconi anemia

Allogeneic hematopoietic cell transplantation (HCT) is the only known cure for patients with Fanconi anemia (FA) who develop aplasia or leukemia. However, transplant regimens typically contain high-dose alkylators, which are poorly tolerated in FA patients. Furthermore, as many patients lack human leukocyte antigen (HLA)-matched family donors, alternative donors are used, which can increase the risk of both graft rejection and graft-versus-host disease (GVHD). To improve on these three concerns, we developed a multi-institutional clinical trial using a fludarabine (FLU)-based conditioning regimen with limited alkylators/low-dose radiation, HLA-haploidentical marrow, followed by reduced-dose cyclophosphamide (CY) to treat three FA patients with aplasia. All three patients engrafted with 100% donor CD3 chimerism at 1 month. One patient died early from disseminated toxoplasmosis infection. Of the two survivors, one had significant pretransplant co-morbidities and inadequate immunosuppression, and developed severe acute GVHD. The other patient had only mild acute and no chronic GVHD. With a follow-up of 2 and 3 years, respectively, both patients are doing well, are transfusion-independent, and maintain full donor chimerism. The patient with severe GVHD has resolving oral GVHD and good quality of life. We conclude that using low-intensity conditioning, HLA-haploidentical marrow, and reduced-dose CY for in vivo T-cell depletion can correct life-threatening aplasia in FA patients.

Implications of early airflow decline after myeloablative allogeneic stem cell transplantation

The clinical significance of early airflow decline after myeloablative allogeneic hematopoietic SCT is uncertain. We performed a retrospective cohort analysis to determine if airflow decline by day 100 is associated with later development of transplant-related airflow obstruction (AFO) and increased mortality risk. Overall, 750 (40%) patients had airflow decline by day 100. Development of airflow decline by day 100 was associated with an increased risk for AFO at 1 year (relative risk 2.6, 95% confidence interval 2.1-3.1) but not with an increase in mortality risk (hazard ratio (HR) 0.86, P=0.05). However, patients with the fastest rate of decline between day 100 and 1 year (12.5% per year +/-24) had the highest mortality risk (HR 3.2, P<0.001). In conclusion, airflow measurements made on day 100 do not predict the rate of airflow decline between day 100 and 1 year, and therefore are not useful as a single measurement for determining mortality risk associated with development of AFO. Closer monitoring of the rate of airflow decline during the first year may facilitate the timely detection and treatment of early airflow decline and prevent the development of fixed AFO and increased mortality risk after hematopoietic stem cell transplant.

Immunity of patients surviving 20 to 30 years after allogeneic or syngeneic bone marrow transplantation

The duration of immunodeficiency following marrow transplantation is not known. Questionnaires were used to study the infection rates in 72 patients surviving 20 to 30 years after marrow grafting. Furthermore, in 33 of the 72 patients and in 16 donors (siblings who originally donated the marrow) leukocyte subsets were assessed by flow cytometry. T-cell receptor excision circles (TRECs), markers of T cells generated de novo, were quantitated by real-time polymerase chain reaction. Immunoglobulin G(2) (IgG(2)) and antigen-specific IgG levels were determined by enzyme-linked immunosorbent assay. Infections diagnosed more than [corrected] 15 years after transplantation occurred rarely. The average rate was 0.07 infections per patient-year (one infection every 14 years), excluding respiratory tract infections, gastroenteritis, lip sores, and hepatitis C. The counts of circulating monocytes, natural killer cells, B cells, CD4 T cells, and CD8 T cells in the patients were not lower than in the donors. The counts of TREC(+) CD4 T cells in transplant recipients younger than age 18 years (at the time of transplantation) were not different from the counts in their donors. In contrast, the counts of TREC(+) CD4 T cells were lower in transplant recipients age 18 years or older, even in those with no history of clinical extensive chronic graft-versus-host disease, compared with their donors. The levels of total IgG(2) and specific IgG against Haemophilus influenzae and Streptococcus pneumoniae were similar in patients and donors. Overall, the immunity of patients surviving 20 to 30 years after transplantation is normal or near normal. Patients who received transplants in adulthood have a clinically insignificant deficiency of de novo-generated CD4 T cells, suggesting that in these patients the posttransplantation thymic insufficiency may not be fully reversible.

Administration of cyclosporine for 24 months compared with 6 months for prevention of chronic graft-versus-host disease: a prospective randomized clinical trial

This study compared the incidence of clinical extensive chronic graft-versus-host disease (GVHD), transplantation-related mortality, survival, and relapse-free survival among recipients randomly assigned to receive a 24-month or a 6-month course of cyclosporine prophylaxis after transplantation of allogeneic marrow from an HLA-identical sibling or alternative donor. Patients who did not have clinical manifestations of chronic GVHD on day 80 after transplantation were eligible for the study if they previously had acute GVHD or if a skin biopsy showed histologic evidence of chronic GVHD. Clinical extensive chronic GVHD developed in 35 of the 89 patients (39%) in the 24-month group and 37 of the 73 patients (51%) in the 6-month group. The hazard of developing chronic GVHD was not significantly different in the 2 groups (hazard ratio = 0.76; 95% confidence interval, 0.48-1.21; P =.25). In addition, there were no significant differences between the 2 groups in transplantation-related mortality, survival, or disease-free survival.

CD34 cell dose in granulocyte colony-stimulating factor-mobilized peripheral blood mononuclear cell grafts affects engraftment kinetics and development of extensive chronic graft-versus-host disease after human leukocyte antigen-identical sibling transplantation

A retrospective analysis of granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood mononuclear cell (G-PBMC) products harvested from healthy donors indicates significant variability in both the absolute number and relative proportion of CD34, CD3, and CD14 cells obtained. This report examined whether variations in the cellular composition of G-PBMC products correlated with clinical outcomes after myeloablative allogeneic transplantation. The numbers of CD34, CD3, and CD14 cells infused into 181 human leukocyte antigen (HLA)-identical sibling recipients were analyzed with respect to tempo of engraftment, acute graft-versus-host-disease (GVHD), clinical extensive chronic GVHD, overall survival, and disease relapse. Neither acute GVHD, overall survival, nor disease relapse was statistically significantly associated with CD34, CD3, or CD14 cell doses or the CD14 to CD3 ratio. CD3 and CD14 cell doses and CD14 to CD3 ratios did not correlate with the tempo of neutrophil and platelet engraftment. However, increasing CD34 cell numbers were significantly associated with accelerated neutrophil (P =.03) and platelet (P =.01) engraftment. Higher doses of CD34 cells (> 8.0 x 10(6)/kg) were also associated with a significantly increased hazard of clinical extensive chronic GVHD (HR = 2.3, 95% confidence interval [CI] 1.4-3.7, P =.001), but neither CD3 nor CD14 doses were statistically significantly associated with chronic GVHD. It was concluded that CD34 cell dose in G-PBMC grafts appears to affect both the engraftment kinetics and the development of clinical extensive chronic GVHD in HLA-identical sibling recipients but without a demonstrable impact on survival, relapse, and acute GVHD. Given the morbidity associated with extensive chronic GVHD, efforts to further accelerate engraftment in HLA-matched sibling transplants by increasing CD34 cell number in G-PBMC products may be counterproductive.

The significance of bcr-abl molecular detection in chronic myeloid leukemia patients "late," 18 months or more after transplantation

The bcr-abl chimeric messenger RNA is frequently detected in chronic myeloid leukemia (CML) patients after bone marrow transplantation. It was previously reported that the relapse risk of bcr-abl detection 6 to 12 months after transplantation was greater than 40%. This risk decreased as the time between transplantation and detection increased. To further define the relapse risk associated with bcr-abl molecular detection in "late" CML survivors, 379 consecutive CML patients alive at 18 months after transplantation or later were studied. Ninety of 379 patients (24%) had at least one positive bcr-abl test 18 months after transplantation or later; 13 of 90 bcr-abl-positive patients (14%) and 3 of 289 bcr-abl-negative patients (1.0%) relapsed. The median time from bcr-abl detection to relapse was 916 days (range, 251-2654 days). The hazard ratio of relapse associated with bcr-abl detection was 19.2 (P <.0001). The stage of disease, chronic graft-versus-host disease, and the donor type did not alter the association between bcr-abl and relapse. Quantification of bcr-abl was performed on 344 samples from 85 bcr-abl-positive patients by means of a real-time quantitative reverse transcriptase-polymerase chain reaction assay. The median bcr-abl change of patients who relapsed was significantly greater than those that remained in remission (P =.002). The median bcr-abl level at relapse was 40 443 bcr-abl copies per microg RNA (range, 960-299 552). Of 73 bcr-abl-positive patients who failed to relapse, 69% had only one positive test at a median of 24 copies bcr-abl per microg RNA. The detection of bcr-abl is common following transplantation. The prognostic significance of a qualitative bcr-abl can be refined by quantitative assays and thus may target patients who would benefit from early intervention.

Relapse after allogeneic bone marrow transplantation for refractory anemia is increased by shielding lungs and liver during total body irradiation

Patients with the refractory anemia (RA) subtype of myelodysplastic syndrome who undergo allogeneic bone marrow transplantation (BMT) have a low risk of relapse, but they have a high risk of nonrelapse mortality when prepared with conventional preparative regimens. To try to reduce nonrelapse mortality, we treated 14 RA patients with a modified approach to total body irradiation (TBI) followed by cyclophosphamide (CY) and HLA-identical sibling BMT. Median patient age was 44 years (range, 28 to 65 years). Patients received TBI with shielding of the right lobe of the liver and both lungs followed by electron beam boosts to shielded ribs. Total radiation exposure in nonshielded areas was 12 Gy (n = 10), 10 Gy (n = 3), or 6 Gy (n = 1). After TBI, patients received CY at 120 mg/kg over 2 days, followed by transplantation of unmanipulated bone marrow. All patients initially achieved engraftment with donor cells, although 2 patients had subsequent reemergence of host hematopoiesis without evidence of disease relapse. Five patients died of transplantation-related causes between 22 and 1262 days post-BMT. Four patients relapsed between 157 and 1096 days post-BMT. These 14 patients were compared with 46 historical controls with RA who received conventional CY/TBI or busulfan/CY preparative regimens. Patients in the experimental group had a similar nonrelapse mortality rate compared with the historical control group (29% versus 37%, respectively; P = .8), but a higher relapse rate (34% versus 2%, P = .0004) and a lower disease-free survival (38% versus 61%, P = .16). We conclude that this modified TBI approach is associated with an unacceptably high risk of relapse for patients with RA undergoing BMT.

Immune reconstitution after allogeneic marrow transplantation compared with blood stem cell transplantation

Allogeneic peripheral blood stem cell grafts contain about 10 times more T and B cells than marrow grafts. Because these cells may survive in transplant recipients for a long time, recipients of blood stem cells may be less immunocompromised than recipients of marrow. Immune reconstitution was studied in 115 patients randomly assigned to receive either allogeneic marrow or filgrastim-mobilized blood stem cell transplantation. Between day 30 and 365 after transplantation, counts of most lymphocyte subsets were higher in the blood stem cell recipients. The difference was most striking for CD4 T cells (about 4-fold higher counts for CD45RA(high) CD4 T cells and about 2-fold higher counts for CD45RA(low/-)CD4 T cells; P <.05). On assessment using phytohemagglutinin and herpesvirus antigen-stimulated proliferation, T cells in the 2 groups of patients appeared equally functional. Median serum IgG levels were similar in the 2 groups. The rate of definite infections after engraftment was 1.7-fold higher in marrow recipients (P =.001). The rate of severe (inpatient treatment required) definite infections after engraftment was 2.4-fold higher in marrow recipients (P =.002). The difference in the rates of definite infections was greatest for fungal infections, intermediate for bacterial infections, and lowest for viral infections. Death associated with a fungal or bacterial infection occurred between day 30 and day 365 after transplantation in 9 marrow recipients and no blood stem cell recipients (P =.008). In conclusion, blood stem cell recipients have higher lymphocyte-subset counts and this appears to result in fewer infections. (Blood. 2001;97:3380-3389)

Hematopoietic cell transplantation in older patients with hematologic malignancies: replacing high-dose cytotoxic therapy with graft-versus-tumor effects

Toxicities have limited the use of allogeneic hematopoietic cell transplantation (HCT) to younger, medically fit patients. In a canine HCT model, a combination of postgrafting mycophenolate mofetil (MMF) and cyclosporine (CSP) allowed stable allogeneic engraftment after minimally toxic conditioning with low-dose (200 cGy) total-body irradiation (TBI). These findings, together with the known antitumor effects of donor leukocyte infusions (DLIs), led to the design of this trial. Forty-five patients (median age 56 years) with hematologic malignancies, HLA-identical sibling donors, and relative contraindications to conventional HCT were treated. Immunosuppression involved TBI of 200 cGy before and CSP/MMF after HCT. DLIs were given after HCT for persistent malignancy, mixed chimerism, or both. Regimen toxicities and myelosuppression were mild, allowing 53% of eligible patients to have entirely outpatient transplantations. Nonfatal graft rejection occurred in 20% of patients. Grades II to III acute graft-versus-host disease (GVHD) occurred in 47% of patients with sustained engraftment. With median follow-up of 417 days, survival was 66.7%, nonrelapse mortality 6.7%, and relapse mortality 26.7%. Fifty-three percent of patients with sustained engraftment were in complete remission, including 8 with molecular remissions. This novel allografting approach, based on the use of postgrafting immunosuppression to control graft rejection and GVHD, has dramatically reduced the acute toxicities of allografting. HCT with the induction of potent graft-versus-tumor effects can be performed in previously ineligible patients, largely in an outpatient setting. Future protocol modifications should reduce rejection and GVHD, thereby facilitating studies of allogeneic immunotherapy for a variety of malignancies. (Blood. 2001;97:3390-3400)

Cyclophosphamide and antithymocyte globulin to condition patients with aplastic anemia for allogeneic marrow transplantations: the experience in four centers

This report summarizes the experience with a conditioning regimen of cyclophosphamide and antithymocyte globulin in patients with severe aplastic anemia given HLA-matched related marrow grafts at 4 transplantation centers. Enrolled were 94 consecutive patients, of whom 87 had received multiple transfusions and 38 had failed immunosuppressive therapy. Their ages ranged from 2 to 59 years. After transplantation, 89 patients received a methotrexate/cyclosporine regimen for graft-versus-host disease (GVHD) prevention. Cyclosporine with or without prednisone was given in 4 patients, and no immunosuppression was given in 1 patient. Ninety-six percent of patients had sustained grafts, whereas 4% rejected grafts between 2 and 7 months after transplantation. Of the 4 rejecting patients, 3 are alive with successful second engraftments. Acute grade II GVHD was seen in 21% of patients, grade III in 7%, and grade IV in 1% of patients. Chronic GVHD was seen in 32% of patients, most of whom responded completely to immunosuppressive therapy. With a median follow-up of 6.0 years (range, 0.5-11.6 years), the survival rate was 88%. No unusual long-term side effects have been seen with the regimen. We conclude that the cyclophosphamide/antithymocyte globulin regimen combined with methotrexate/cyclosporine after transplantation is well tolerated and effective in heavily pretreated patients with aplastic anemia.

Granulocyte colony-stimulating factor given to donors before apheresis does not prevent aplasia in patients treated with donor leukocyte infusion for recurrent chronic myeloid leukemia after bone marrow transplantation

We conducted 2 sequential studies of donor leukocyte infusion (DLI) in 26 patients with chronic myeloid leukemia in hematologic relapse after unmodified allogeneic bone marrow transplantation. In the first study, cells for DLI were collected from 13 donors who were not treated with granulocyte colony-stimulating factor (G-CSF) (group 1). In the second study, cells were collected from 13 donors who received G-CSF before apheresis (group 2) in an attempt to avoid aplasia after DLI. Patients in group 2 received 550-fold more CD34+ cells than those in group 1. We found no significant difference in the incidence (31% versus 22%), onset time (41 vs. 48 days), or duration (15 vs. 14 days) of cytopenia after DLI in the 2 groups. G-CSF given to donors before collection of cells did not prevent aplasia. These findings support the hypothesis that the pathogenesis of aplasia after DLI is not restricted to the destruction of recipient hematopoietic cells but also involves failure of donor hematopoiesis by undefined mechanisms.

Transplantation of bone marrow as compared with peripheral-blood cells from HLA-identical relatives in patients with hematologic cancers

BACKGROUND

In recipients of allogeneic hematopoietic-cell transplants, peripheral-blood cells mobilized with the use of filgrastim (recombinant granulocyte colony-stimulating factor) engraft more rapidly than bone marrow. However, the relative effects of these techniques on the rates of acute and chronic graft-versus-host disease, overall survival, and disease-free survival have not been determined in randomized studies.

METHODS

Between March 1996 and July 1999, 172 patients (12 to 55 years of age) with hematologic cancer were randomly assigned to receive either bone marrow or filgrastim-mobilized peripheral-blood cells from HLA-identical relatives for hematopoietic rescue after the treatment of hematologic cancer with high doses of chemotherapy, with or without radiation.

RESULTS

The recovery of both neutrophils and platelets was faster with peripheral-blood cells than with marrow (P<0.001 for both comparisons). The cumulative incidence of grade II, III, or IV acute graft-versus-host disease at 100 days was 64 percent with peripheral-blood cells and 57 percent with marrow (hazard ratio, 1.21; 95 percent confidence interval, 0.81 to 1.81; P=0.35). The cumulative incidence of chronic graft-versus-host disease was 46 percent with peripheral-blood cells and 35 percent with marrow (hazard ratio, 1.16; 95 percent confidence interval, 0.71 to 1.90; P=0.54). The estimated overall probability of survival at two years was 66 percent with peripheral-blood cells and 54 percent with marrow (hazard ratio for death, 0.62; 95 percent confidence interval, 0.38 to 1.02; P=0.06). The rate of disease-free survival at two years was 65 percent with peripheral-blood cells and 45 percent with marrow (hazard ratio for relapse or death, 0.60; 95 percent confidence interval, 0.38 to 0.95; P=0.03).

CONCLUSIONS

In patients given high-dose chemotherapy, with or without radiation, for the treatment of hematologic cancer, allogeneic peripheral-blood cells used for hematopoietic rescue restore blood counts faster than allogeneic bone marrow, without increasing the risk of graft-versus-host disease.

Chronic graft-versus-host disease of the liver: presentation as an acute hepatitis

Chronic graft-versus-host disease (GVHD) of the liver usually presents as an indolent cholestatic disease in patients with skin, mouth, and eye involvement. We observed 14 patients in whom chronic GVHD of the liver presented with marked elevations of serum aminotransferases, clinically resembling acute viral hepatitis. Onset of liver dysfunction was at 294 days (range, 74-747 days) after allogeneic hematopoietic cell transplantation and coincided with a recent cessation or taper of immunosuppressive drugs. Median peak serum alanine transaminase (ALT) was 1,640 U/L (698-2,565 U/L), and median bilirubin was 12.3 mg/dL (0.9-55.9 mg/dL). All biopsies showed characteristic features of GVHD with damaged and degenerative small bile ducts. Other features included a marked lobular hepatitis, moderate to marked amounts of hepatocyte unrest, sinusoidal inflammation with perivenular necroinflammatory foci, and many acidophilic bodies scattered throughout the lobule. When high-dose immunosuppressive therapy was instituted soon after presentation, progressive improvement and eventual normalization of liver enzymes and bilirubin levels were observed. However, in cases in which the diagnosis was not made and therapy was delayed, a progressive cholestatic picture emerged with histologic evidence of loss of small bile ducts and portal fibrosis. We conclude that a distinct syndrome of chronic liver GVHD presenting as an acute hepatitis can be recognized in a patient at risk who is receiving no, or minimal, immunosuppressive medications. Liver biopsy is necessary to exclude viral causes of liver dysfunction and to confirm characteristic abnormalities of small bile ducts. Institution of high-dose immunosuppression can prevent progressive bile duct destruction and effect resolution of jaundice if given early.

Polyclonal hematopoiesis with variable telomere shortening in human long-term allogeneic marrow graft recipients

Donor-derived hematopoiesis was assessed in 17 patients who received allogeneic marrow grafts from HLA-matched siblings between 1971 and 1980. Complete blood counts were normal or near normal in all patients except one. Chimerism analyses, using either dual-color XY-chromosome fluorescence in situ hybridization (FISH) or analysis of variable number tandem repeat loci, indicated that 15 out of 16 patients had greater than 97% donor-derived hematopoiesis, whereas 1 patient had indeterminate chimerism. All 12 recipients of grafts from female donors exhibited polyclonal hematopoiesis by X-linked clonal analysis with the use of molecular probes. Of the 17 recipients, 9 exhibited a less than 1.0-kilobase shortening of granulocyte telomere length compared with their respective donors, according to terminal restriction fragment analysis or flow-FISH with a fluorescein-labeled peptide nucleic acid probe. These data suggest that under standard transplantation conditions, the stem cell proliferative potential is not compromised during hematopoietic reconstitution. (Blood. 2000;96:3991-3994)

Thalidomide for treatment of patients with chronic graft-versus-host disease

In a randomized, placebo-controlled, double-blind trial, thalidomide or placebo together with glucocorticoids and either cyclosporine or tacrolimus was administered as initial therapy for clinical extensive chronic graft-versus-host disease (cGVHD). All patients had thrombocytopenia or cGVHD that evolved directly from acute GVHD as an indicator of a poor prognosis. The study drug (thalidomide or placebo) was administered initially at a dose of 200 mg orally per day, followed by a gradual increase to 800 mg/d if side effects were tolerable. Treatment with the study drug was discontinued before resolution of cGVHD in 23 (92%) of the 25 patients who received thalidomide and in 17 (65%) of the 26 patients who received placebo (P =.02). Neutropenia and neurologic symptoms were the most frequent reasons for early discontinuation of treatment with thalidomide. The duration of treatment with thalidomide was too short to assess its efficacy in controlling cGVHD. (Blood. 2000;96:3995-3996)

Low B-cell and monocyte counts on day 80 are associated with high infection rates between days 100 and 365 after allogeneic marrow transplantation

To ascertain which mononuclear cell subset deficiency plays a role in the marrow transplant recipient's susceptibility to infections, mononuclear cell subset counts were prospectively determined in 108 patients on day 80. Infections occurring between day 100 and 365 were recorded by an investigator blinded to the subset counts. In univariate analyses, the counts of the following subsets showed a significant inverse correlation with infection rates: total B cells, IgD(+) B cells, IgD(-) B cells, total CD4 T cells, CD28(+) CD4 T cells, CD28(-) CD4 T cells, CD45RA(low/-) CD4 T cells and monocytes. In multivariate analyses, the counts of the following subsets remained significantly inversely correlated with the infection rates: total B cells (P =.0004) and monocytes (P =.009). CD28(-) CD8 T-cell counts showed no correlation with infection rates. In conclusion, the susceptibility of patients to infections late posttransplant may be due in part to the slow reconstitution of B cells and monocytes.

Prolonged fluconazole prophylaxis is associated with persistent protection against candidiasis-related death in allogeneic marrow transplant recipients: long-term follow-up of a randomized, placebo-controlled trial

Two randomized, placebo-controlled trials previously showed that fluconazole (400 mg/d) administered prophylactically decreases the incidence of candidiasis in blood and marrow transplant (BMT) recipients. However, there exists conflicting data regarding the optimal duration of fluconazole administration, specifically whether prophylaxis through acute graft-versus-host disease (GVHD) results in improved survival in allograft recipients. Reported here are the results of long-term follow-up and a detailed analysis of invasive candidiasis and candidiasis-related death in 300 patients who received fluconazole (400 mg/d) or placebo for 75 days after BMT at the Fred Hutchinson Cancer Research Center. Patients in both treatment arms were compared for survival, causes of death, and the incidence of invasive fungal infections early (less than 110 days) and late (more than 110 days) after BMT. After 8 years of follow-up, survival is significantly better in fluconazole recipients compared with placebo recipients (68 of 152 vs 41 of 148, P =.0001). The overall incidence of invasive candidiasis was increased in patients who received placebo compared with fluconazole (30 of 148 vs 4 of 152, P <.001). More patients who received placebo died with candidiasis early (13 of 148 vs 1 of 152, P =.001) and late (8 of 96 vs 1 of 121, P =.0068) after BMT. The incidence of severe GVHD involving the gut was higher in patients who did not receive fluconazole (20 of 143 vs 8 of 145, P =.02), and fewer patients who received fluconazole died with this complication. Thus, administration of fluconazole (400 mg/d) for 75 days after BMT appears to be associated with decreased gut GVHD, a persistent protection against disseminated candidal infections and candidiasis-related death, resulting in an overall survival benefit in allogeneic BMT recipients.

Treatment of relapsed leukemia after unrelated donor marrow transplantation with unrelated donor leukocyte infusions

The efficacy and toxicity of donor leukocyte infusions (DLI) after unrelated donor bone marrow transplantation (BMT) is largely unknown. We identified 58 recipients of unrelated DLI (UDLI) for the treatment of relapsed disease from the National Marrow Donor Program database. A retrospective analysis was performed to determine response, toxicity, and survival after UDLI and to identify factors associated with successful therapy. UDLI was administered for relapsed chronic myelogenous leukemia (CML) (n = 25), acute myelogenous leukemia (AML) (n = 23), acute lymphoblastic leukemia (ALL) (n = 7), and other diseases (n = 3). Eight patients were in complete remission (CR) before UDLI, and 50 were evaluable for response. Forty-two percent (95% confidence interval [CI], 28%-56%) achieved CR, including 11 of 24 (46%; 95% CI, 26%-66%) with CML, 8 of 19 (42%; 95% CI, 20%-64%) with AML, and 2 of 4 (50%; 95% CI, 1%-99%) with ALL. The estimated probability of disease-free survival (DFS) at 1 year after CR was 65% (95% CI, 50%-79%) for CML, 23% (95% CI, 9%-38%) for AML, and 30% (95% CI, 6%-54%) for ALL. Acute graft-versus-host disease (GVHD) complicated UDLI in 37% of patients (grade II-IV, 25%). A total of 13 of 32 evaluable patients (41%) developed chronic GVHD. There was no association between cell dose administered and either response or toxicity. In a multivariable analysis, only a longer interval from BMT to relapse and BMT to UDLI was associated with improved survival and DFS, respectively. UDLI is an acceptable alternative to other treatment options for relapse after unrelated donor BMT. (Blood. 2000;95:1214-1221)

Reduced dose intravenous immunoglobulin does not decrease transplant-related complications in adults given related donor marrow allografts

Graft-vs.-host disease (GVHD) and infection are major complications of allogeneic bone marrow transplantation. Intravenous immunoglobulin (IVIg) given at a dose of 500 mg/kg/wk has been shown to decrease the risk of acute GVHD, interstitial pneumonia, and infection in adults early after allogeneic transplantation. The current study is a controlled trial to determine whether a lower total dose of IVIg given with pretransplant loading reduces the incidence of transplant-related complications. In a randomized trial of 241 patients > or =20 years of age who were given related donor marrow allografts, 121 individuals receiving Ig prophylaxis (500 mg/kg/d loading from day -6 to -1 and then 100 mg/kg every 3 days from day 3 to 90) were compared with 120 control patients who did not receive IVIg. Randomization was stratified by human leucocyte antigen-matching, remission status of malignancy, GVHD prophylaxis, and cytomegalovirus (CMV) serology. The study was powered to detect a reduction in acute GVHD by 18% and a decrease in transplant-related mortality by 17%. Pretransplant IVIg loading and posttransplant maintenance achieved median serum IgG levels >1350 mg/dL, which were approximately twofold greater than the untreated controls (p<0.01). White blood cell and platelet recoveries were similar for the two groups, although control patients required fewer units of platelets per day (2.5 vs. 3.3, p = 0.008). No significant differences in the incidence of CMV infection, interstitial pneumonia, or bacteremia were observed. The incidence of acute GVHD did not differ between the two groups; however, acute GVHD was less frequent among IVIg recipients achieving maximum serum IgG levels >3000 mg/dL (60 vs. 79%). Neither transplant-related mortality nor disease-free survival was significantly altered by Ig prophylaxis. However, the cumulative incidence of relapse of malignancy was higher in IVIg recipients than in controls (31 vs. 18%, p = 0.03). Multivariable regression analysis demonstrated a 1.89 increased relative risk of relapse for individuals given IVIg (p = 0.021). We conclude that pretransplant loading and a shorter course and lower total dose of IVIg prophylaxis did not appear to decrease the risk of acute GVHD or mortality among adults receiving related donor marrow transplants. Note, IVIg administration may be associated with an increased risk of recurrent malignancy, a finding that warrants further investigation.

High rates of Pneumocystis carinii pneumonia in allogeneic blood and marrow transplant recipients receiving dapsone prophylaxis

Chemoprophylaxis for Pneumocystis carinii pneumonia (PCP) is routinely given after allogeneic blood or marrow transplantation. We evaluated the effectiveness of dapsone prophylaxis (50 mg orally twice daily, 3 times per week) compared with twice-weekly trimethoprim-sulfamethoxazole (TMP-SMZ) in preventing PCP after allogeneic blood or marrow transplantation. Patients included all (n=646) who received allogeneic blood or marrow transplants between 1 September 1993 and 31 December 1996 who survived at least 100 days after transplantation. A cohort of 111 dapsone recipients was compared with the remaining 535 who received TMP-SMZ. Ten patients developed PCP; 8 were taking dapsone. PCP incidence in the TMP-SMZ cohort was 0.37% versus 7.2% for dapsone. The relative risk for PCP associated with dapsone use was 18.8 (P<.001) and was not accounted for by age, clinical extensive chronic graft-versus-host disease, donor source, or malignant relapse. Dapsone prophylaxis at this dosage is associated with significantly higher rates of PCP than is TMP-SMZ after allogeneic marrow transplantation. We advise caution in prescribing alternatives to TMP-SMZ prophylaxis in this setting.

A phase I-II clinical trial to evaluate removal of CD4 cells and partial depletion of CD8 cells from donor marrow for HLA-mismatched unrelated recipients

We conducted a phase I-II clinical trial to test the hypothesis that removal of CD4 cells from an HLA-mismatched unrelated marrow graft would substantially reduce the risk of grades III-IV graft-versus-host disease (GVHD) and that retention of a specified number of CD8 cells in the graft would be sufficient to prevent rejection. Patients were eligible for this study when an HLA-A, -B, or -DRB1-matched unrelated donor could not be identified. HLA matching of the donor and recipient was based on typing of HLA-A and -B antigens by serologic methods and by typing of HLA-DRB1 alleles by molecular methods, and donors were selected when disparity was limited to a single HLA-DRB1 allele or a single HLA-A or -B antigen. Twenty-seven patients with hematologic malignancy or aplastic anemia were prepared to receive a transplant with conventional regimens of cyclophosphamide and fractionated total body irradiation, and a standard regimen of methotrexate and cyclosporine was given for GVHD prophylaxis. CD4 cells were removed from the donor marrow, and the numbers of CD8 cells were adjusted systematically in graded steps for successive patients, depending on the occurrence of grades III-IV GVHD or graft failure in previously enrolled patients. Removal of CD4 cells did not cause graft rejection or appreciably decrease the risk of grades III-IV GVHD. Depletion of CD8 cells was associated with an increased risk of rejection with either HLA-DRB1 disparity or with HLA-A or -B disparity. With either type of disparity, the risk of grades III-IV GVHD is likely to be higher than 15% at any dose of CD8 cells associated with less than 5% risk of graft failure. The absence of graft failure associated with CD4 depletion supports the hypothesis that donor CD4 cells are not essential for preventing marrow graft rejection in humans. The correlation between graft failure and the number of CD8 cells in the donor marrow supports the hypothesis that donor CD8 cells help to prevent marrow graft rejection.

Pathophysiology and treatment of graft-versus-host disease

Acute graft-versus-host disease denotes a distinctive syndrome characterized by a triad of dermatitis (rash), hepatitis (jaundice), and gastroenteritis (abdominal pain, diarrhea) developing in the first 100 days after allogeneic hematopoietic cell transplantation. Chronic graft-versus-host disease designates a more diverse syndrome, usually presenting with multiorgan involvement and commonly developing 100 days after hematopoietic cell transplantation. This article discusses the pathophysiology, incidence and predictive factors, clinical manifestations, diagnosis and grading, prevention, and treatment for both types of the disease.

Hepatitis C virus infection and bone marrow transplantation: a cohort study with 10-year follow-up

Before the introduction of routine blood donor screening in 1991, marrow transplant recipients were at significant transfusion-associated risk for infection with hepatitis C virus (HCV). We followed a cohort of 355 patients undergoing transplant in Seattle during 1987 to 1988 to determine (1) the impact of pretransplant HCV infection on the occurrence and severity of venocclusive disease (VOD); (2) the impact of HCV infection on liver dysfunction, other than VOD, occurring between 21 and 60 days after transplantation; and (3) the natural history of post-transplant HCV liver disease with a 10-year follow-up. HCV-RNA status was determined on serum stored before transplant and at day 100 post-transplant. Sixty-two (17%) patients were HCV-RNA positive before transplant, and 113 (32%) were HCV-RNA positive by day 100 post-transplant (or before death). Severe VOD developed in 22 of 46 (48%) evaluable patients with pretransplant HCV infection and in 150 of 229 (14%) evaluable patients without HCV (P <.0001). In multivariable analysis of risk factors for developing VOD, pretransplant HCV infection associated with elevated serum aspartate transaminase (AST) levels predicted the development of severe VOD (relative risk, 9.6; P =.0001). The presence of HCV with normal AST levels before transplant was not a risk factor for severe VOD. Between 21 and 60 days after transplant, HCV-RNA positive-patients had higher AST levels (median 101 U/L), but similar alkaline phosphatase and total bilirubin levels compared with HCV-negative patients, suggesting that cholestatic liver disease (particularly graft-versus-host disease [GVHD]) was not related to HCV infection. An acute flare of hepatitis (AST >10 times the upper limit of normal) developed at a mean of 136 +/- 58 days in 31% of HCV-positive patients; no patients developed fulminant hepatitis. Between 5 and 10 years after transplant, 57% of HCV-positive and 6% of HCV-negative patients had mild to moderate elevations of AST (P <. 0001), but HCV infection was not associated with excess mortality between 3 and 10 years after bone marrow transplantation. In summary, HCV infection with elevated AST levels is a significant risk factor for severe VOD after marrow transplant. However, the decision to proceed to transplantation in HCV-positive patients must balance the absolute risk of death from VOD against the risks of the underlying disease. In long-term survivors, HCV infection is not associated with excess mortality over 10 years of follow-up.

The development of chronic graft-versus-host disease: an analysis of screening studies and the impact of corticosteroid use at 100 days after transplantation

The value of routine chronic graft-versus-host disease (GVHD) screening studies performed between 70 and 120 days after allogeneic marrow transplantation was retrospectively evaluated among 241 patients. All patients received methotrexate and cyclosporine for GVHD prophylaxis and survived without relapse more than 4 months after transplant. Ninety-one patients (38%) developed clinical extensive chronic GVHD requiring systemic therapy. Data on patients who developed clinical extensive chronic GVHD were compared with those on patients without chronic GVHD to determine which of the following screening tests predicted the subsequent development of clinical extensive chronic GVHD: skin biopsy, oral exam, lip biopsy, Schirmer's test, serum alkaline phosphatase, aspartate transaminase, immunoglobulin level and platelet count. In a univariable analysis, a positive oral examination and a low platelet count were predictive of chronic extensive GVHD development. In a multivariable analysis which adjusted for the contribution of other chronic GVHD risk factors, such as age and a history of acute GVHD none of the screening tests were predictive of chronic GVHD development. The risk factors in this multivariable analysis which had the strongest association with the development of chronic GVHD was a history of acute GVHD and use of corticosteroids at day 100 (RR = 3.9, P = 0.001). The use of corticosteroids for acute GVHD at day 100 had a predictive effect on chronic GVHD development independent of the grade of acute GVHD (RR = 2.1, P = 0.004). Based on these study results, the use of chronic GVHD screening tests may not be of value in predicting who will develop this complication. Patients on corticosteroids at day 100 should be considered for clinical trials to determine the efficacy of new immunosuppressive agents in preventing chronic GVHD.

Unrelated and HLA-nonidentical related donor marrow transplantation for thalassemia and leukemia. A combined report from the Seattle Marrow Transplant Team and the International Bone Marrow Transplant Registry

Allogeneic marrow transplantation is curative therapy for thalassemia, but fewer than 30% of patients have an HLA-identical sibling marrow donor. Selection of alternative donors of hematopoietic stem cells (unrelated individuals or HLA-nonidentical family members) has been aided by establishment of world-wide donor registries now exceeding 3.6 million volunteers and by DNA-based HLA typing to more closely match potential donors. Coupled with improved methods to control graft-versus-host disease and prevent fungal and cytomegalovirus infection, remarkable progress has been made in alternative donor transplantation. For patients 50 years of age or younger, with recently diagnosed chronic myelogenous leukemia (CML) in chronic phase, 1- and 5-year survivals after HLA-A, B, DRB1 identical unrelated marrow transplantation in Seattle are 82% and 74%, respectively. These results are essentially identical to outcome in similar patients given HLA-matched sibling allografts. However, the world-wide number of alternative donor transplants for thalassemia remains limited to date: 4 unrelated and 60 HLA-nonidentical related transplants have been reported to the IBMTR since 1969 with actuarial overall survival of 75%. Using the paradigm of CML, it is likely that access to curative therapy of thalassemia will improve with optimal HLA typing and donor selection early in the course of disease.

Long-term outcome after marrow transplantation for severe aplastic anemia

We reviewed the records and reevaluated 212 patients with aplastic anemia transplanted at the Fred Hutchinson Cancer Research Center (FHCRC) between 1970 and 1993 who survived >/=2 years and who have been followed for up to 26 years. Parameters analyzed included hematopoietic function, chronic graft-versus-host disease (GVHD), skin disease, cataracts, lung disease, skeletal problems, posttransplant malignancy, depression, pregnancy/fatherhood, and the return to work or school, as well as patient self-assessment of physical and psychosocial health, social interactions, memory and concentration, and overall severity of symptoms. Survival probabilities at 20 years were 89% for patients without (n = 125) and 69% for patients with chronic GVHD (n = 86) (the status was uncertain in 1 surviving patient). All patients had normal hematopoietic parameters. Skin problems occurred in 14%, cataracts in 12%, lung disease in 24%, and bone and joint problems in 18% of patients. Eleven patients (12%) developed a solid tumor malignancy and 19% of patients experienced depression. Chronic GVHD was the dominant risk factor for late complications. Seventeen patients died at 2.5 to 20.4 years posttransplant; 13 of these had chronic GVHD and related complications. At 2 years, 83% of patients had returned to school or work; the proportion increased to 90% by 20 years. At least half of the patients preserved or regained the ability to become pregnant or father children. Patients rated their quality of life as excellent and symptoms as minimal or mild. In conclusion, marrow transplantation in patients with aplastic anemia established long-term normal hematopoiesis. No new hematologic disorders occurred. The major cause of morbidity and mortality was chronic GVHD. However, the majority of patients who survived beyond 2 years returned to a fully functional life.

Use of alpha-2a-interferon to treat cytogenetic relapse of chronic myeloid leukemia after marrow transplantation

Fourteen patients with cytogenetic relapse of chronic myeloid leukemia (CML) after transplantation with unmanipulated bone marrow were treated with alpha-2a-interferon. There were eight men and six women, median age, 33 years. Twelve patients received marrow from a related allogeneic donor and two received marrow from a syngeneic donor. The median percentage of Ph-positive metaphases at the time of starting interferon was 55% (10% to 87%). Daily interferon was started at a dose of 1 to 3 x 10(6) U/M2/d, depending on initial blood counts and was adjusted as tolerated to maintain the white blood count in the range of 2,000 to 3,000/microL and the platelet count greater than 60,000/microL. After a stable cytogenetic remission was achieved, the interferon dose was decreased to a maintenance level. Twelve patients achieved a complete cytogenetic remission on at least one occasion. Median time to achieve a complete cytogenetic remission was 7.5 months (range, 1.5 to 12). Eight patients remain in cytogenetic remission for 10+ to 54+ months from the time of first documented remission. After complete cytogenetic remission was established, nine patients were tested for the presence of the mRNA transcript of the bcr/abl fusion gene by polymerase chain reaction (PCR) testing. Four patients were PCR-negative on at least one occasion: two patients were PCR-negative on a single occasion; one patient had serial tests, which were PCR-negative; and one patient had serial PCR-negative peripheral blood tests with a single PCR-positive bone marrow obtained concurrently with a negative peripheral blood test. Median follow-up time for all patients is 44 months (range, 20 to 64). Interferon was generally well tolerated; only one responding patient was unable to continue interferon because of toxicity. Interferon induces durable cytogenetic remissions in a significant proportion (57%) of patients with cytogenetic relapse following bone marrow transplantation (BMT) without causing life-threatening toxicities.

Methotrexate and cyclosporine for graft-vs.-host disease prevention: what length of therapy with cyclosporine?

One hundred three patients with leukemia, aplastic anemia, or myelodysplastic syndrome were treated by marrow transplantation from genotypically HLA-identical siblings (n = 92) or HLA haploidentical family members differing for one HLA antigen on the nonshared haplotype (n = 11). To prevent graft-vs.-host disease (GVHD), they were administered postgrafting immunosuppression with a short course of intermittent methotrexate with daily cyclosporine for no more than 11 days. Customarily, we have given cyclosporine for 180 days after transplant. In the current study, we asked whether cyclosporine could be stopped earlier without affecting the risk of chronic GVHD. By day 60, patients who never had acute GVHD, or whose acute GVHD had resolved, were randomized to have cyclosporine stopped (n = 52) or continued for the usual 180 days (n = 51). Results were analyzed with a median follow-up of 9.3 years after transplant, and showed that patients in whom cyclosporine was discontinued on day 60 had a significantly more rapid onset (p = 0.001), but not a significantly higher overall incidence of chronic GVHD than those in whom the drug was stopped on day 180 (43 vs. 54%; p = 0.26). Transplant-related mortality was comparable among patients without preceding acute GVHD, regardless of when cyclosporine was discontinued (11% for both study arms). However, transplant-related mortality appeared to increase among patients with preceding acute GVHD in whom cyclosporine was stopped by day 60 (38 vs. 17%). Results suggest that cyclosporine can safely be discontinued early in patients who never had evidence of acute GVHD, while those with preceding acute GVHD would benefit from a longer course of the drug. Because of the relatively small sample sizes, these results would best be treated as promising preliminary findings that should be confirmed in larger randomized studies.

Nocardiosis after bone marrow transplantation: a retrospective study

To evaluate the spectrum of nocardiosis after marrow transplantation, we reviewed the medical records of 27 patients with nocardiosis who were treated at three centers, and we reviewed the findings of three cases reported in the literature. Nocardial involvement was defined as invasive nocardiosis (n = 25), colonization (n = 4), or contamination (n = 1). The median time to the diagnosis of nocardiosis after marrow transplantation was 210 days. Nocardia asteroides complex accounted for 96% of isolates. All 25 invasive infections occurred in allogeneic marrow recipients. Ten (40%) of 25 patients with invasive nocardiosis were receiving double-strength oral trimethoprimsulfamethoxazole twice weekly as prophylaxis for Pneumocystis carinii pneumonia. Treatment regimens for nocardiosis included sulfonamides; synergistic agents were also often added. The overall survival rate at 6 years was 34%; survival from the infection itself was 84%. Two of four nocardiosis-related deaths also involved other pathogens. The incidence of nocardiosis among allogeneic marrow recipients averaged 0.3% over 25 years. We conclude that nocardiosis is a rare infection that occurs later after marrow transplantation than other infections and that is marginally associated with increased mortality among long-term survivors of allogeneic marrow transplantation.

Allogeneic marrow transplantation for aplastic anaemia associated with dyskeratosis congenita

Eight patients with aplastic anaemia associated with dyskeratosis congenita received allogeneic marrow grafts from either HLA-identical siblings (six patients) or HLA-matched unrelated donors (two patients). Patients who received marrow from HLA-identical siblings were conditioned with cyclophosphamide (140-200 mg/kg), with or without antithymocyte globulin. Patients who received unrelated donor marrow were conditioned with cyclophosphamide (120 mg/kg) and total body irradiation (1200 cGy). The six patients who survived for >2 weeks following transplant all had haematological evidence of engraftment, and all three patients who survived for at least a year following transplant recovered normal haematological function. Three patients died with respiratory failure and pulmonary fibrosis at 70 d. 8 years and 20 years posttransplant; three patients died during the neutropenic period of invasive fungal infections; one patient died on day 44 of refractory acute graft-versus-host disease; and one patient remains alive 463 d following transplant. The surviving patient recently underwent surgical resection of a Dukes' stage C rectal carcinoma diagnosed 14 months posttransplant. The aplastic anaemia associated with dyskeratosis congenita can be successfully treated by allogeneic bone marrow transplantation; however, this approach does not reverse the other systemic manifestations of the syndrome. The pathogenesis of the intestinal lung disease observed in dyskeratosis congenita patients following marrow transplantation is not understood.

Marrow transplantation for Fanconi anaemia: conditioning with reduced doses of cyclophosphamide without radiation

Nine patients with Fanconi anaemia (FA) were conditioned for HLA-identical sibling bone marrow transplant (BMT) with reduced dose of cyclophosphamide (Cy) without radiation or antithymocyte globulin (ATG). The total dose of Cy was 140 mg/kg (n = 2) or 120 mg/kg (n = 7). The median patient age was 8 years (range 4-19). Graft-versus-host disease (GVHD) prophylaxis was with methotrexate and cyclosporine (n = 8) or cyclosporine alone (n = 1). All patients had sustained engraftment and two developed grade>/= II acute GVHD. Cy toxicity included grade >/= 2 mucositis seen in all evaluable patients and haemorrhagic cystitis in two patients. The Kaplan-Meler survival estimate is 89% with a median follow-up of 285 d (range 56-528). For the purpose of comparison, this report also reviews and updates long-term follow-up data on 32 previously reported FA patients conditioned with 140-200 mg Cy/kg without radiation. The lowest dose of Cy (without radiation or ATG) after which HLA-identical sibling marrow transplant can be successfully performed in FA patients has yet to be determined, but it appears that uniform and sustained engraftment can be achieved with a Cy dose of as low as 120 mg/kg.

Immunological recovery after bone marrow transplantation for severe aplastic anaemia: a Brazilian experience

Twenty-nine patients with severe aplastic anaemia (SAA) were submitted to bone marrow transplantation (BMT) and their immunological recovery analysed. Total lymphocyte counts, estimation of B lymphocytes, T lymphocytes and their subsets, natural-killer (NK) activity were performed. Cells with the CD8+ phenotype and NK activity were the first signs of immunological recovery, whereas the CD4+ subset recovered later in patients who suffered from acute graft versus host disease (GvHD) and infections. Acute and chronic GvHD, cirrhosis, rejection and HIV viral infection contributed to the persistence of the profound immunodeficiency status observed after BMT. Our results did not differ greatly from the others and confirmed that BMT may be performed in underdeveloped countries despite the difficulties it might pose.

Spontaneous factor VIII inhibitor occurring in association with chronic graft-versus-host disease

The development of spontaneously acquired Factor VIII inhibitors is rare and may lead to serious hemorrhagic sequelae. We report here the case of a patient who acquired a Factor VIII inhibitor two years after an allogeneic bone marrow transplant for CML. This occurred in association with a flare of chronic graft versus host disease (GVDH). He responded to corticosteroid therapy. A review of autoimmune phenomena associated with chronic GVDH and the treatment of Factor VIII inhibitors is discussed.

Marrow transplantation for Fanconi anemia with or without leukemic transformation: an update of the Seattle experience

Between March 1973 and August 1990, 17 patients with Fanconi anemia (FA) underwent bone marrow transplantation in Seattle. Marrow donors were HLA identical siblings (n = 14), phenotypically HLA identical parents (n = 2) and a one antigen mismatched parent (n = 1). Patients with no evidence of leukemic transformation (n = 12) were conditioned with 140-200 mg/kg cyclophosphamide (CY). Of five patients with leukemic transformation, four received CY (120 mg/kg) plus 12 Gy fractionated total body irradiation and one patient received busulfan (14 mg/kg) and CY (100 mg/kg). All patients engrafted; however, one patient whose sibling donor's cells showed variable results when assayed for chromosome instability required two additional marrow infusions. Toxicity associated with the conditioning regimen included severe oral mucositis (n = 14), hemorrhagic cystitis (n = 11) and diffuse erythroderma (n = 3). Seven of the 12 patients without leukemic transformation are surviving 1-17 years (median = 5 years) after transplant, with an estimated survival probability at 5 years of 65% (95% CI 0.31; 0.85). Two patients developed squamous cell carcinoma of the tongue greater than 10 years post-transplant. One of these patients died at 10.3 years as a result of the malignant process, and the other is disease free more than 12 years post-transplant. Of the five patients with leukemic transformation, one is alive at 8 years. These data demonstrate that marrow transplantation can offer long-term survival for patients with FA, engraftment can be achieved with reduced doses of CY in FA patients, and less toxic preparative regimens are needed for FA patients who have developed leukemic transformation.

Previous donor pregnancy as a risk factor for acute graft-versus-host disease in patients with aplastic anaemia treated by allogeneic marrow transplantation

To determine if previous donor pregnancies influence the development of acute graft-versus-host disease (GVHD) we evaluated data from 136 patients with aplastic anaemia greater than 15 years of age and given marrow grafts from HLA-identical sibling donors. Of the 136 marrow donors, 30 were parous females (previous history of pregnancy), 30 were nulliparous females (no history of pregnancy or abortions), and 76 were males. The cumulative incidence of grade II-IV GVHD was 57%, 21% and 46% for patients with parous, nulliparous and male donors, respectively. A multivariate analysis of the data confirmed that the risk of grade II-IV acute GVHD was significantly increased among patients receiving marrow from parous females as compared to those from nulliparous females (relative risk = 2.5, P = 0.02). There was no statistically significant difference in the incidence of acute GVHD, however, between patients with parous donors and male donors (relative risk = 1.3, P = 0.26). Male patients given grafts from parous donors showed a higher incidence of acute GVHD (63%) than female patients (45%), though this difference was not statistically significant. The 5-year probability of survival was 47% for patients with parous donors, 68% for patients with nulliparous donors and 70% for those with male donors. We confirm that prior donor pregnancy represents an important factor in selecting marrow donors or designing clinical protocols for GVHD prophylaxis.

Long-term transplantation of canine keratinocytes made resistant to G418 through retrovirus-mediated gene transfer

We studied cultured canine keratinocytes to determine whether they could serve as targets for retrovirus-mediated gene transfer and whether infected cells could persist after transplantation into dogs, a large random-bred model for gene transfer studies. Canine keratinocytes obtained from skin biopsy samples were cultured in vitro with lethally irradiated NIH 3T3 cells used as a feeder layer. The keratinocyte colonies consisted of squamous epithelium with numerous desmosomes, tonofilaments, and keratohyalin granules. In addition, the cells were strongly reactive with monoclonal antibodies to cytokeratin intermediate filament proteins. For the infection studies, we grew the keratinocytes on a feeder layer of lethally irradiated PA317 retrovirus packaging cells, which produced a helper-free amphotropic retroviral vector containing the neomycin phosphotransferase (neo) gene. After cocultivation, 34% (range, 10-76%) of the keratinocytes were found to be resistant to the neomycin analogue G418. Infected keratinocytes were then transplanted into the dog of origin; 1% (range, less than 0.1-3%) of the keratinocytes obtained 27-130 days after transplantation from skin biopsy samples gave rise to G418-resistant colonies. We conclude that canine keratinocytes cultured in vitro can be infected efficiently with a neo gene-containing retroviral vector, and they show persistent G418 resistance for at least 130 days after transplantation into the skin donor.