Effect of in vivo lymphocyte-depleting strategies on development of lymphoproliferative disorders in children post allogeneic bone marrow transplantation.

T cell depletion (TCD) of marrow is a proven method of graft-versus-host disease (GVHD) prophylaxis in allogeneic bone marrow transplantation (BMT). Nonetheless, TCD is associated with an increased risk of developing post transplant lymphoproliferative disorder (PTLD). Between 1986 and 1998, 241 pediatric patients at the University of Iowa underwent BMT using ex vivo TCD of marrow from mismatched related or matched unrelated donors. Additional GVHD prophylaxis included antithymocyte globulin (ATG) or anti lymphocyte globulin (ALG) post transplant (in vivo TCD). A total of 30 cases of PTLD were identified based upon a combination of clinical, histological, and immunological features. Nearly all cases occurred within 3 months post BMT. A statistically significant increase in PTLD incidence was noted for patients treated with ATG vs ALG (33 vs 9%). While grade I-II acute GVHD was more common in patients receiving ATG vs ALG, no difference in grade III-IV GVHD or overall survival was noted between the two groups. Assessment of immune recovery at various times post BMT revealed significantly fewer T cells in the ATG-treated group, suggesting the deleterious effect of ATG may be due to excessive depletion of donor-derived Epstein-Barr virus-specific cytotoxic T cells. Thus, caution should be exercised in the use of anti-T-cell antibody therapy for additional GVHD prophylaxis in the setting of TCD BMT.

Successful allogeneic hematopoietic stem cell transplantation (HSCT) for Shwachman-Diamond syndrome.

Shwachman-Diamond syndrome (SDS) is a rare genetic disorder characterized by pancreatic insufficiency, short stature, skeletal abnormalities and bone marrow dysfunction. Patients with SDS have varying degrees of marrow aplasia, which can be severe or progress to leukemic transformation. While allogeneic hematopoietic stem cell transplantation (HSCT) can be curative for the hematologic disturbances of SDS, a recent review of the literature reveals few survivors. Poor outcome with HSCT is often related to excessive cardiac and other organ toxicity from transplant preparative therapy. We describe two young children with SDS who developed aplastic anemia and subsequently underwent successful allografting using a non-cardiotoxic conditioning regimen. Case 1 received marrow from an HLA-identical sibling while case 2 received partially matched umbilical cord blood from an unrelated donor. Both patients are presently alive and well with sustained donor engraftment and excellent hematopoietic function at 36 and 22 months post-HSCT.

Poor outcome in children with refractory/relapsed leukemia undergoing bone marrow transplantation with mismatched family member donors.

The utility of bone marrow transplantation for childhood leukemia in patients unable to achieve a remission prior to transplant is controversial. To address this issue, we analyzed a subset of patients with advanced leukemia entered on prospective transplant trials at our hospital. Fifty-eight patients with ALL or AML (age 1-19) were identified. They had failed standard chemotherapy and were in relapse (22 in 1st, 27 in 2nd, three in 3rd, and three in 4th) or had never achieved an initial remission (three) at the time of transplant. Fifty-two patients received marrow from mismatched family members (haplo or DR-identical), while six received marrow from matched siblings. Most patients received myeloablative therapy consisting of total body irradiation, etoposide, cyclophosphamide, and cytosine arabinoside. Marrow from mismatched donors was T cell depleted. Only one of 52 patients transplanted with a mismatched donor survived long-term while three of six patients transplanted in relapse with a fully matched sibling donor are alive 6-10 years post BMT. The major causes of death were infection (39%) and relapse (28%). Acute GVHD grade III-IV was noted in 7% of patients. A comparable group of patients with leukemia transplanted at our center in remission using similarly mismatched family member donors (haplo or DR-identical) had an event-free survival of 28%. In conclusion, our data suggest that BMT utilizing mismatched family member donors is a poor option for patients in relapse at the time of transplant. New treatment strategies need to be developed to effectively manage these patients.

Ten-year experience of unrelated bone marrow donor transplants in children with malignant and non-malignant conditions.

Children who require a marrow transplant may receive such hematopoietic cells from one of many sources. This study reviews the experience of one center with 58 children who received marrow from unrelated donors over a 10-year period. These children had a variety of malignant and non-malignant diseases. During that time period, only three of these children had failed to meet engraftment criteria. All donor marrow specimens were T-lymphocyte-depleted using an antibody/complement methodology. No difference was demonstrated in outcome between donors who were perfectly HLA-DR DNA matched versus those who were only partially matched. The increased size of various marrow donor registries has increased the number of potential donors available for these patients. The lack of a requirement for perfect matching means that there is an ever-increasing number of donors available. No graft-versus-host disease (GvHD) or grade III-IV GvHD was associated with a poorer outcome. Stable, long-term engraftment with minimal morbidity has been demonstrated in these children as evidenced by stability of survival curves by two years after marrow transplant.

Complete heart block in association with graft-versus-host disease.

An infant who received haploidentical BM for severe combined immunodeficiency (SCID) developed acute, reversible complete heart block in association with an exacerbation of GVHD. Respiratory distress and myocardial dysfunction were also seen with this and previous GVHD exacerbations. The patient had not received chemotherapy or radiation prior to BMT. The complete heart block resolved after 1 week of intensive immunosuppression. The association of complete heart block with GVHD is important because the heart block is potentially reversible with prompt, aggressive control of the GVHD.

Successful program to prevent aspergillus infections in children undergoing marrow transplantation: use of nasal amphotericin.

Aspergillus infections in the pediatric bone marrow transplant (BMT) patients are usually fatal. We began the use of a prophylactic nasal spray of amphotericin in 1990. This nasal spray was provided in addition to low-dose intravenous amphotericin. During the time of this study, the number of fatal cases of aspergillus in the pediatric BMT population was reduced significantly from 13.8% to 1.8% (P < 0.0025) thereby suggesting that the use of nasal amphotericin in this population helps to prevent fatal aspergillus infections. The lack of significant side-effects and the ease of administration make this a very helpful preventive measure in the supportive care of pediatric bone marrow transplant patients.

Reconstruction of the immune system after unrelated or partially matched T-cell-depleted bone marrow transplantation in children: functional analyses of lymphocytes and correlation with immunophenotypic recovery following transplantation.

Reconstitution of the immune system following T-cell-depleted bone marrow transplantation (BMT) in children has yet to be fully elucidated. Thus, we prospectively studied the recovery of immune function in 64 children who underwent T-lymphocyte-depleted marrow transplants using either matched family member donors or matched unrelated donors. We measured in vitro posttransplantation proliferative responses to phytohemagglutinin (PHA), concanavalin A, pokeweed mitogen, and Candida albicans antigen and assessed unidirectional allogeneic mixed-lymphocyte culture (MLC) responses at various times. A total of 129 healthy individuals served as normal controls for these assays. Responses to T-cell mitogens normalized within 12 months posttransplantation, while MLC responses normalized by 9 months. The presence of graft-versus-host disease (grade II or greater) and cytomegalovirus infection was associated with delays in immune function recovery. Importantly, immune function recovery correlated temporally with a rise in peripheral lymphocyte count. In contrast, the CD4/CD8 ratio was not predictive of immune recovery. Knowledge of immune function recovery may guide clinicians in devising strategies to minimize the risk of infection post-BMT.

Reconstruction of the immune system after unrelated or partially matched T-cell-depleted bone marrow transplantation in children: immunophenotypic analysis and factors affecting the speed of recovery.

We prospectively studied immune reconstitution in 102 children who underwent T-lymphocyte depleted bone marrow transplants using either closely matched unrelated donors or partially matched familial donors by assaying total lymphocyte counts (TLC), T-cell subsets, B cells, and natural killer cells. TLC, CD3+, and CD4+ T-cell counts remained depressed until 2 to 3 years posttransplant, whereas CD8+ T-cell counts normalized by 18 months, resulting in an inverted CD4:CD8 ratio until 12 months posttransplant. Although the percentage of NK cells was elevated early posttransplant, their absolute numbers remained normal. CD20+ B cells were depressed until 12 to 18 months posttransplant. Factors affecting immunophenotypic recovery were analyzed by nonparametric statistics. Younger patients tended to have higher TLC posttransplant. Higher marrow cell doses were not associated with hastened immunophenotypic recovery. Graft-versus-host disease (GVHD) and/or its treatment significantly delayed the immune reconstitution of CD3+, CD4+, and CD20+ cells. The presence of cytomegalovirus was associated with increased CD8+ counts and a decrease in the percentages of CD4+ and CD20+ cells.

Prostaglandin E1 bladder instillations to control severe hemorrhagic cystitis.

Severe hemorrhagic cystitis developed in 6 children after marrow transplantation, 3 of whom had a viral etiology. All 6 patients received instillations of prostaglandin E1 directly into the bladder and 5 of the 6 had complete resolution of hematuria. This finding contrasts with our previous experience with severe hemorrhagic cystitis, particularly the type due to a viral infection, persisting in the face of numerous bladder manipulations. We encourage the use of this nontoxic treatment to gain further information regarding its effect on the bladder epithelium. The mechanism of action remains completely unknown.

Bone marrow transplantation improves survival for acute lymphoblastic leukemia in relapse: a preliminary report.

Acute lymphoblastic leukemia of childhood is the most common malignant disease in children greater than 1 year of age. Chemotherapy has improved the survival of children with this disorder. More than 95% of children will achieve a remission with chemotherapy. However, 30% of children with acute lymphoblastic leukemia who achieved a remission will have a relapse sometime after successful remission-inducing chemotherapy. Although a second remission can be induced in most of these children, in 10-40% a remission cannot be induced or they relapse shortly thereafter and develop refractory leukemia. We present in this preliminary report the early results of therapy for refractory leukemia with an intensive preparative regimen for bone marrow transplantation including etoposide, cytosine arabinoside, cyclophosphamide, and fractionated total body irradiation. Transplantation was done in twenty-three patients with refractory leukemia. Projected survival at 917 days after transplantation in these patients is 43.4% +/- 11%. The survival of these patients so far is similar to the survival of children with acute lymphoblastic leukemia transplanted in second remission. All patients treated with this regimen who had transplantation in relapse were free of leukemia 27 days after transplantation. The results of this preliminary report suggest that an intensive preparative regimen can improve the outlook of refractory leukemia and may rescue some patients who otherwise would have died of their disease.

Alpha-interferon therapy for lymphoproliferative disorders developing in two children following bone marrow transplants.

Two children developed lymphoproliferative processes following marrow transplantation. One of the two lymphoproliferative processes was documented to be Epstein-Barr virus (EBV)-associated. Both children received an extended course of alpha-interferon and gammaglobulin and responded with the disappearance of the lymphoproliferative process. Side effects from the alpha-interferon were minimal. Previous experience with EBV-associated lymphoproliferative processes following marrow transplantation have been usually fatal. This report further substantiates that alpha-interferon has a role in the treatment of EBV-associated lymphoproliferative processes following marrow transplantation.

Effects of acute atrial fibrillation on the vasodilator reserve of the canine atrium.

Acute atrial fibrillation appreciably alters atrial physiology by increasing atrial blood flow and atrial oxygen consumption. To determine the effects of atrial fibrillation on atrial vasodilator reserve atrial fibrillation was produced in dogs by electrical atrial stimulation. Reactive hyperaemic responses were measured using Doppler crystals fixed to the sinus node artery and to an adjacent right ventricular branch artery during sinus rhythm, after 20 minutes of atrial fibrillation, and after systemic administration of chromonar (a potent coronary dilator) during atrial fibrillation. During sinus rhythm the peak to resting blood flow velocity ratio after a 20 s occlusion of the sinus node artery was 3.2(1) (mean(SEM)). A 20 s occlusion of a right ventricular branch artery during sinus rhythm resulted in a significantly larger response (5.9(0.7). The repayment to debt area ratio in response to a 20 s occlusion was 1.1(0.2) for the sinus node artery but 3.9(1.0) for a right ventricular branch. During atrial fibrillation the peak to resting velocity ratio was substantially decreased in the sinus node artery (2.3(0.6)) but was not significantly changed in the right ventricular branch (4.4(0.6)). Atrial fibrillation plus chromonar abolished reactive hyperaemia in both the sinus node artery and the right ventricular branch vessel. Right atrial blood flow (microspheres) increased from 45(4) in sinus rhythm to 106(19) ml X min-1 X 100 g-1 in atrial fibrillation and to 208(22) ml X min-1 X 100 g-1 after chromonar administration during atrial fibrillation. Thus the quantitative characteristics of coronary reactive hyperaemia in the right atrium were substantially different from those in the right ventricle.(ABSTRACT TRUNCATED AT 250 WORDS)

Quantitative angiographic morphology of coronary stenoses leading to myocardial infarction or unstable angina.

Identification of a characteristic morphology of a coronary stenosis likely to result in myocardial infarction would facilitate the prospective evaluation of infarct prevention strategies and identification of high-risk patients. We postulated that coronary lesions associated with recent myocardial infarction or unstable angina would have an angiographic morphology suggesting disruption of an atherosclerotic plaque and would appear morphologically different from lesions associated with chronic stable angina. To test this hypothesis, quantitative coronary angiography (Brown-Dodge method) was performed in 15 patients 4 to 30 days after myocardial infarction, in 10 patients with the abrupt onset of unstable angina and single-vessel coronary disease, and in 15 patients with chronic stable angina without prior myocardial infarction. Serial arterial diameters (20 to 40) within each lesion were determined and the degree of luminal irregularity was quantitated by calculation of an "ulceration" index. The majority of all lesions analyzed resulted in severe luminal stenosis (mean 78% area stenosis, all groups). Despite small differences in mean lesion severity among groups, overlap in the degree of luminal compromise prevented precise classification of lesions associated with myocardial infarction or unstable angina based on percent stenosis or minimum luminal cross-sectional area. The mean ulceration index of lesions in patients with unstable angina and in the infarct-related vessel in those with acute myocardial infarction was 0.62 +/- 0.05 (+/- SEM) and 0.61 +/- 0.03, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Transluminal, subselective measurement of coronary artery blood flow velocity and vasodilator reserve in man.

Assessment of coronary blood flow and the vasodilator reserve capacity of individual coronary arteries in the catheterization laboratory has been hampered by methodologic limitations. We have developed and validated a small Doppler catheter that can subselectively measure phasic coronary blood flow velocity (CBFV). In seven anesthetized calves, CBFV was varied from 0.1 to 5.7 times control CBFV. Changes in mean CBFV measured intraluminally by catheter in the left anterior descending and left circumflex arteries were similar to those measured simultaneously with an epicardial Doppler probe on the surface of the same vessel (n = 85, r = .95, slope = 1.04) and to changes in coronary sinus flow (n = 69, r = .97, slope = 1.06) measured with timed venous collections. Identical maximal coronary reactive hyperemic responses with the catheter present and absent in the artery being studied demonstrated that coronary obstruction by the catheter was minimal. Safety studies in six additional calves demonstrated that the catheter caused small changes in coronary endothelial permeability. Histologic studies revealed no endothelial denudation or thrombus formation. Stable phasic recordings of coronary blood flow velocity have been obtained in 58 of 70 patients studied. One of the 70 patients studied had abrupt coronary occlusion probably related to catheter-induced vasospasm. In 10 normal patients, intracoronary meglumine diatrizoate increased CBFV to 3.5 times that at rest (range 2.8 to 5.0). CBFV rose 5.0-fold after an intravenous infusion of dipyridamole (range 3.8 to 7.0). In each patient, dipyridamole produced greater vasodilation than meglumine diatrizoate. The time- and dose-response characteristics to dipyridamole infusion were heterogeneous, underscoring the advantage of continuous on-line measurement of CBFV in the measurement of vasodilator reserve. This method of measuring CBFV and assessing vasodilator reserve in the catheterization laboratory should facilitate studies of the coronary circulation in man.