Experiencia de una década en niños sometidos a esplenectomía en el Hospital Nacional de Niños / Experience on children's splenectomy: a ten year single center retrospective study

Resumen Objetivo: describir las características clínicas y la evolución de los pacientes sometidos a esplenectomía en el Hospital Nacional de Niños, de enero de 1996 a diciembre del 2006. Métodos: este es un estudio descriptivo retrospectivo que analiza un periodo de 10 años, de pacientes sometidos a esplenectomías en el Hospital Nacional se Niños. Se realizó una revisión de 107 expedientes con el diagnóstico en cuestión. De estos expedientes se obtuvieron: datos clínicos, epidemiológicos, indicaciones para el procedimiento y su respectiva evolución, complicaciones y mortalidad asociada. Se analiza además el seguimiento de las recomendaciones con respecto a profilaxis antibiótica y vacunación. Resultados: se analizó una muestra total de 107 casos. Entre los resultados se encontró que la edad promedio de intervención fue de 6,4 años. Los diagnósticos más comunes fueron hemoglobinopatías (59,8 %), púrpura trombocitopénica idiopática (16,8 %) y osteopetrosis maligna (8,4 %). Entre las indicaciones para esplenectomías predominaron el tratamiento de enfermedad de base (39,9%), hiperesplenismo (26,2 %) y ausencia de respuesta al tratamiento médico (22,4 %). El procedimiento quirúrgico más común fue la laparotomía en el 87,9 % de los casos. La complicación quirúrgica inmediata más frecuente fue la hemorragia persistente (3,7 %), mientras que la complicación quirúrgica tardía más común fue la sepsis (16,8 %). La respuesta terapéutica en la mayoría de los pacientes fue completa (66,7 %). Hubo 5 pacientes fallecidos, de los cuales en dos se relacionó su mortalidad con sepsis. La edad promedio al momento de fallecimiento fue de 6,7 años. Conclusiones: la esplenectomía es una alternativa para el tratamiento de las enfermedades médicas, tras la cual se evidenció una respuesta satisfactoria en la mayoría de los casos del estudio.

Abstract Aim: to describe clinical characteristics and evolution of patients who underwent splenectomy in Costa Rica's National Children's Hospital during January 1996 through December 2006. Methods: This is a chart review study in a 10 year period including children who underwent splenectomy. A hundred and seven charts of children with ages between 0 and 18 years old were reviewed to obtain their clinical presentation, characteristics, indications for splenectomy, follow up, complications and mortality. Also the antibiotic prophylaxis and immunization schedule was analyzed based on international recommendations. Results: A total of 107 patients were included. Results showed that the mean age at which splenectomy was performed was 6.4 years. Most of the patients had their splenectomy due to hemoglobinophaties (59.8%), followed by immune thrombocytopenic purpura (16.8%) and malignant osteopetrosis (8.4%). The most common indications for splenectomy were treatment of the disease (39.9%), hyperesplenism (26.2%) and lack of responde to medical treatment (22.4%). Laparotomy was the most performed surgery (87.9%). Mainly sepsis and hemorrhage were found as complications due to procedure. Overall, complete response to surgical treatment was observed (66.7%). Five patients died during follow up. Conclusions: Splenectomy is an alternative for treating medical disease with predominantly good outcomes observed in our study.

Successful matched sibling donor marrow transplantation following reduced intensity conditioning in children with hemoglobinopathies.

Fifty-two children with symptomatic sickle cell disease sickle cell disease (SCD) (N = 43) or transfusion-dependent thalassemia (N = 9) received matched sibling donor marrow (46), marrow and cord product (5), or cord blood (1) allografts following reduced intensity conditioning (RIC) with alemtuzumab, fludarabine, and melphalan between March 2003 and May 2014*. The Kaplan-Meier probabilities of overall and event-free survival at a median of 3.42 (range, 0.75-11.83) years were 94.2% and 92.3% for the group, 93% and 90.7% for SCD, and 100% and 100% for thalassemia, respectively. Treatment-related mortality (all related to graft versus host disease, GVHD) was noted in three (5.7%) recipients, all 17-18 years of age. Acute and chronic GVHD was noted in 23% and 13%, respectively, with 81% of recipients off immunosuppression by 1 year. Graft rejection was limited to the single umbilical cord blood recipient who had prompt autologous hematopoietic recovery. Fourteen (27%) had mixed chimerism at 1 year and beyond; all had discontinued immunosuppression between 4 and 12 months from transplant with no subsequent consequence on GVHD or rejection. Infectious complications included predominantly bacteremia (48% were staphylococcus) and CMV reactivation (43%) necessitating preemptive therapy. Lymphocyte recovery beyond 6 months was associated with subsidence of infectious complications. All patients who engrafted were transfusion independent; no strokes or pulmonary complications of SCD were noted, and pain symptoms subsided within 6 months posttransplant. These findings support using RIC for patients with hemoglobinopathy undergoing matched sibling marrow transplantation (*www.Clinical Trials.gov: NCT00920972, NCT01050855, NCT02435901).

Resultados del trasplante de progenitores hematopoyéticos en hemoglobinopatías: talasemia maior y enfermedad drepanocítica / Results of hematopoietic stem cell transplantation in hemoglobinopathies: Thalassemia major and sickle cell disease

Introducción: La prevalencia de las hemoglobinopatías en nuestro medio ha aumentado como consecuencia de los flujos migratorios. La talasemia mayor cursa con anemia hemolítica crónica y necesidad de transfusiones regulares desde el año de vida. La enfermedad drepanocítica cursa con anemia, vasculopatía y daño orgánico progresivo. En ambas, la esperanza de vida está disminuida. El trasplante alogénico de progenitores hematopoyéticos es una opción de curación para estos pacientes. Pacientes: Diecisiete pacientes recibieron un trasplante alogénico de progenitores hematopoyéticos: 14 afectados de talasemia maior y 3 de enfermedad drepanocítica. Resultados: Los donantes fueron en los pacientes con talasemia mayor 9 hermanos HLA-idénticos, 2 progenitores con una diferencia antigénica HLA y 3 donantes no emparentados, y en aquellos con enfermedad drepanocítica, 3 hermanos HLA-idénticos. La fuente fue la médula ósea en todos, excepto uno. La media de edad al trasplante de progenitores hematopoyéticos fue de 6 años (intervalo: 1-16) en los niños con talasemia mayor y doce años (intervalo: 8-15) en los niños con enfermedad drepanocítica. Se confirmó injerto medular en todos los pacientes. Dos con talasemia mayor presentaron fallo de injerto secundario, precisando nuevamente soporte transfusional. Trece pacientes presentaron quimerismo completo y 2 quimerismo mixto, todos con normalización de la cifra de hemoglobina y sin requerimiento de transfusiones. Los pacientes con enfermedad drepanocítica no presentaron más episodios vasooclusivos y la funciones pulmonar y cerebral en aquellos pacientes que presentaban afectación en el momento del trasplante se estabilizaron. Tres pacientes con talasemia mayor desarrollaron enfermedad injerto contra huésped crónica y 5, hipogonadismo hipogonadotropo. Conclusiones: Nuestra experiencia confirma que el trasplante alogénico de progenitores hematopoyéticos de hermano HLA idéntico es una buena opción en el tratamiento de la talasemia mayor y la enfermedad drepanocítica. En el caso de la talasemia mayor, el trasplante de donante no emparentado es una opción terapéutica en centros especializados, ya que, a pesar de los buenos resultados presentados, la morbimortalidad de este procedimiento puede ser elevada, frente a la alternativa de un tratamiento médico no curativo pero con expectativas de supervivencia prolongada. En el caso de la enfermedad drepanocítica, el trasplante de donante no emparentado todavía está en fases preliminares de investigación (AU)

Background: The prevalence of hemoglobinopathies in Spain is increasing as a result of immigration. Thalassemia major presents with chronic hemolytic anemia that requires regular red blood cell transfusions within the first year of life. Patients with sickle cell disease suffer from chronic anemia, vasculopathy and progressive damage in almost any organ. There is decreased life expectancy in both conditions. Allogeneic hematopoietic stem cell transplantation represents the only potentially curative option. Patients: Seventeen patients (fourteen thalassemia major, and three sickle cell disease) underwent allogeneic hematopoietic stem cell transplantations. Results: In the thalassemia group, nine donors were HLA-geno-identical siblings, two were partially matched related donors (one HLA allele mismatch), and three unrelated donors. All three patients with sickle cell disease were transplanted from HLA-geno-identical siblings. The source of stem cells was bone marrow in sixteen cases. Median patient age at transplant was six years (range: 1–16) in the thalassemia group, and twelve years (range: 8–15) in the sickle cell disease group. The graft was successful in all patients. Secondary graft rejection was observed in two thalassemia patients rendering them dependent on blood transfusions. Complete chimerism was observed in thirteen patients and, although mixed chimerism occurred in two, with all of them showing normal hemoglobin levels after transplantation and not requiring further transfusion support. Patients affected by sickle cell disease did not present with new vaso-occlusive crises, and stabilization of pulmonary and neurological function was observed. Chronic graft-versus-host disease was detected in three patients affected by thalassemia, and hypogonadotrophic hypogonadism in five patients. Conclusions: We conclude that for thalassemia major and sickle cell disease, allogenic hematopoietic stem cell transplantation from HLA-geno-identical siblings offers a high probability of complication-free survival. Despite good results, morbidity and mortality associated with transplantation from unrelated donors is a risk that might be considered, in contrast to a non-curative medical treatment that offers a long term survival. For thalassemia major groups it could be an option, but not for sickle cell disease, which is still in the investigational phase (AU)

[Results of hematopoietic stem cell transplantation in hemoglobinopathies: thalassemia major and sickle cell disease]. / Resultados del trasplante de progenitores hematopoyéticos en hemoglobinopatías: talasemia maior y enfermedad drepanocítica.

BACKGROUND: The prevalence of hemoglobinopathies in Spain is increasing as a result of immigration. Thalassemia major presents with chronic hemolytic anemia that requires regular red blood cell transfusions within the first year of life. Patients with sickle cell disease suffer from chronic anemia, vasculopathy and progressive damage in almost any organ. There is decreased life expectancy in both conditions. Allogeneic hematopoietic stem cell transplantation represents the only potentially curative option. PATIENTS: Seventeen patients (fourteen thalassemia major, and three sickle cell disease) underwent allogeneic hematopoietic stem cell transplantations. RESULTS: In the thalassemia group, nine donors were HLA-geno-identical siblings, two were partially matched related donors (one HLA allele mismatch), and three unrelated donors. All three patients with sickle cell disease were transplanted from HLA-geno-identical siblings. The source of stem cells was bone marrow in sixteen cases. Median patient age at transplant was six years (range: 1-16) in the thalassemia group, and twelve years (range: 8-15) in the sickle cell disease group. The graft was successful in all patients. Secondary graft rejection was observed in two thalassemia patients rendering them dependent on blood transfusions. Complete chimerism was observed in thirteen patients and, although mixed chimerism occurred in two, with all of them showing normal hemoglobin levels after transplantation and not requiring further transfusion support. Patients affected by sickle cell disease did not present with new vaso-occlusive crises, and stabilization of pulmonary and neurological function was observed. Chronic graft-versus-host disease was detected in three patients affected by thalassemia, and hypogonadotrophic hypogonadism in five patients. CONCLUSIONS: We conclude that for thalassemia major and sickle cell disease, allogenic hematopoietic stem cell transplantation from HLA-geno-identical siblings offers a high probability of complication-free survival. Despite good results, morbidity and mortality associated with transplantation from unrelated donors is a risk that might be considered, in contrast to a non-curative medical treatment that offers a long term survival. For thalassemia major groups it could be an option, but not for sickle cell disease, which is still in the investigational phase.

Hematopoietic stem cell transplantation for hemoglobinopathies: current practice and emerging trends.

Despite improvements in the management of thalassemia major and sickle cell disease, treatment complications are frequent and life expectancy remains diminished for these patients. Hematopoietic stem cell transplantation (HSCT) is the only curative option currently available. Existing results for HSCT in patients with hemoglobinopathy are excellent and still improving. New conditioning regimens are being used to reduce treatment-related toxicity and new donor pools accessed to increase the number of patients who can undergo HSCT.

Glutathione S-transferase T1-null seems to be associated with graft failure in hematopoietic SCT.

Hematopoietic SCT (HSCT) from HLA-matched donors is sometimes complicated by GVHD or graft rejection, because of mismatched mHA. This study presents data suggesting the involvement of glutathione S-transferase theta-1 (GSTT1), a phase II detoxifying enzyme encoded by GSTT1, in Ab-mediated rejection of HSCT in children with congenital hemoglobinopathies (CHs). Mismatch of GSTT1, which often features a deletion polymorphism variant, can have major consequences in solid organ transplantation outcome. In liver transplantation, it has been shown to lead to de novo hepatitis, whereas in kidney transplantation, chronic allograft rejection has been documented. In this study on 18 children with CH who underwent HSCT, five cases of graft rejection occurred, all in GSTT1-null patients, four of which featured anti-GSTT1 antibodies. The data suggest that when GSTT1-null patients are transplanted with a GSTT1-positive graft, rejection due to an Ab-mediated immune response against GSTT1 displayed on transplanted stem cells may take place. Thus, it seems that detection of anti-GSTT1 antibodies in patients with a GSTT1-null genotype before transplantation may be predictive of graft rejection in the event of a GSTT1-positive donor.

High incidence of severe cyclosporine neurotoxicity in children affected by haemoglobinopaties undergoing myeloablative haematopoietic stem cell transplantation: early diagnosis and prompt intervention ameliorates neurological outcome.

BACKGROUND: Neurotoxicity is a recognized complication of cyclosporine A (CSA) treatment. The incidence of severe CSA-related neurological complications following hematopoietic stem cell transplantation (HSCT) is 4-11%. METHODS: We describe 6 cases of CSA related neurotoxicity out of 67 matched related HSCT performed in paediatric Middle East patients affected by haemoglobinopaties (5 beta thalassemia major, 1 sickle cell disease-SCD). Conditioning regimen consisted of iv busulphan, cyclophosphamide and graft-versus-host-disease (GvHD) prophylaxis with CSA, methylprednisolone, methotrexate and ATG. RESULTS: All 6 patients presented prodromes such as arterial hypertension, headache, visual disturbances and vomiting, one to two days before overt CSA neurotoxicity. CSA neurotoxicity consisted of generalized seizures, signs of endocranial hypertension and visual disturbances at a median day of onset of 11 days after HSCT (range +1 to +40). Brain magnetic resonance imaging (MRI) performed in all subjects showed reversible leukoencephalopathy predominantly in the posterior regions of the brain (PRES) in 5/6 patients. EEG performed in 5/6 patients was always abnormal. Neurotoxicity was not explainable by high CSA blood levels, as all patients had CSA in the therapeutic range with a median of 178 ng/ml (range 69-250). CSA was promptly stopped and switched to tacrolimus with disappearance of clinical and radiological findings. All patients are symptoms-free at a median follow up of 882 days (range 60-1065). CONCLUSIONS: Our experience suggests that paediatric patients with haemoglobinopaties have a high incidence of CSA related neurological events with no correlation between serum CSA levels and neurotoxicity. Prognosis is good following CSA removal. Specific prodromes such as arterial hypertension, headache or visual disturbances occurring in the early post-transplant period should be carefully evaluated with electrophysiological and MRI-based imaging in order to intervene promptly and avoid irreversible sequels.

Transplant outcomes in bone marrow failure syndromes and hemoglobinopathies.

Allogeneic hematopoietic stem cell transplantation (HSCT) is the only potential cure for most bone marrow (BM) failure syndromes and hemoglobinopathies. Over the past decade, umbilical cord blood (UCB) has been used more frequently as a stem cell source in patients who lack a suitable BM donor. Although graft failure remains a significant problem, UCB transplantation (UCBT) using the optimal conditioning regimen can be a salvage treatment for patients without a suitable BM donor and warrants evaluation in further prospective studies.

Related cord blood banking for haematopoietic stem cell transplantation.

The aims of this single centre study were to assess the feasibility of related cord blood collecting, the appropriateness of storage and the final suitability for transplantation. Since September 1994, 63 families were enrolled in this study. Families were eligible if they were caring for a patient with a disorder treatable by haematopoietic stem cell transplantation and were experiencing a pregnancy. A total of 72 cord blood units were collected and stored for 64 patients (both siblings and parents). We focussed on human leucocyte antigen (HLA) compatibility and cell content as critical requirements to unit's suitability for transplantation. HLA-typing was carried out for 34 donor-recipient couples and most units (72%) mismatched with the related patients. About 60% of collections had a minimum cell dose considered acceptable for transplantation. Only 21% of units had both compatibility degree and cell content suitable for transplantation. When applicable, information on the compatibility degree between the foetus and the patient should be obtained during pregnancy. Appropriateness of related cord blood banking for parents should be further investigated and cost-effective guidelines policies should be provided. Finally, as banking of related cord blood units is an important resource then, this public service should be supported and enhanced.

Hematopoietic stem cell gene transfer for the treatment of hemoglobin disorders.

Hematopoietic stem cell (HSC)-targeted gene transfer is an attractive approach for the treatment of a number of hematopoietic disorders caused by single gene defects. Indeed, in a series of gene transfer trials for two different primary immunodeficiencies beginning early in this decade, outstanding success has been achieved. Despite generally low levels of engrafted, genetically modified HSCs, these trials were successful because of the marked selective advantage of gene-corrected lymphoid precursors that allowed reconstitution of the immune system. Unlike the immunodeficiencies, this robust level of in vivo selection is not available to hematopoietic repopulating cells or early progenitor cells following gene transfer of a therapeutic globin gene in the setting of beta-thalassemia and sickle cell disease. Both preclinical and clinical transplant studies involving bone marrow chimeras suggest that 20% or higher levels of engraftment of genetically modified HSCs will be needed for clinical success in the most severe of these disorders. Encouragingly, gene transfer levels in this range have recently been reported in a lentiviral vector gene transfer clinical trial for children with adrenoleukodystrophy. A clinical gene transfer trial for beta-thalassemia has begun in France, and one patient with transfusion-dependent HbE/beta-thalassemia has demonstrated a therapeutic effect after transplantation with autologous CD34(+) cells genetically modified with a beta-globin lentiviral vector. Here, the development and recent progress of gene therapy for the hemoglobin disorders is reviewed.

Umbilical cord blood transplantation: pros, cons and beyond.

Large body of clinical and scientific data has been generated since the first cord blood transplantation (CBT) was performed in 1989. Superior immune plasticity of CB grafts, that allows for less stringent HLA matching, is especially valuable in the face of a persistently growing need for unrelated donor (UD) transplants. Limited cell dose remains the main setback of CBT, particularly in adult population. New strategies, such as transplantation with two cord blood units or using non-myeloablative conditioning, have remarkably expanded the availability of CB transplants in adults with hematological malignancies. Clinical trials with in vitro expanded CB-derived stem cells are under way. Currently cord blood is considered a second best choice after matched bone marrow. However, results of recent international studies indicate that in particular clinical settings, such as in children with leukemia, CB may become a frontline hematopoietic stem cell (HSC) source for transplantation. Recent advances in understanding the unique biology of cord blood will further expand indications for its use in different settings, including those beyond hematopoietic stem cells transplantation (HSCT).

Ventajas de la esplenectomía en hemoglobinopatía infantil / Splenectomy advantages in infantile hemoglobinopathy

Se realiza un estudio retrospectivo, descriptivo y longitudinal donde se revisan 10 expedientes clínicos correspondientes a pacientes con afecciones hematológicas, a los cuales se les había realizado la esplenectomía parcial como parte de su tratamiento, en los archivos del Hospital Pediátrico Docente ¨Pedro Agustín Pérez” de Guantánamo, durante el período de tiempo comprendido desde el 1ro. de enero de 2000 hasta el 30 de junio de 2003. Se exponen los resultados en cuadros estadísticos, haciendo énfasis en los aspectos quirúrgicos. Se resalta la importancia del Levine, las transfusiones sanguíneas cuando son necesarias y los análisis complementarios, como el hemograma completo, glicemia, grupo y Rh, coagulograma completo, conteo de plaquetas y conteo de reticulocitos, en la preparación preoperatoria de los pacientes. Se efectúan comparaciones con estudios nacionales y extranjeros. En la presente serie se significan lasenfermedades hematológicas de base que presentaron los pacientes estudiados, la morbilidad, la mortalidad y la evolución postoperatoria, así como los beneficios del tratamiento quirúrgico. Se formulan conclusiones y recomendaciones al respecto.(AU)

Tratamiento laparoscópico del quiste esplénico primario / Laparoscopic treatment of primary splenic cyst

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Reappraisal of in utero stem cell transplantation based on long-term results.

The therapeutic field of in utero transplantation of stem cells, into human fetuses, has developed since 1988 with the hope of improved probability of engraftment and tolerance, due to immune immaturity of the host. Fifteen years later, it is possible to evaluate the results that we and others have obtained in the treatment of several fetal diseases. Seven fetal patients have been treated in Lyon: In 2 cases, pregnancy termination was induced by the in utero injection; in the 5 other cases, engraftment was obtained and repeatedly documented with presence of donor HLA antigens and/or Y chromosome in recipients. In the 2 patients with combined immunodeficiency disease, a sustained reconstitution of immunity was obtained as a result of the transplant but other complications occurred thereafter. In patients with thalassemia major, Niemann-Pick disease or hemophilia, a very partial and very transitory benefit was only obtained. Approximately 33 other patients with immunodeficiencies, hemoglobinopathies or inborn errors of metabolism have been treated worldwide, over the last 13 years, with a comparable method, using parental or fetal stem cells transplanted in utero. Successful treatment has usually been recorded in immunodeficiencies, and insufficient results have been obtained in the other cases. This form of treatment can therefore be recommended after prenatal diagnosis of combined immunodeficiency but additional research is required to improve the degree of engraftment, the lack of resistance of the host and the 'space' available for hematopoiesis in the other conditions.

Stem cell therapy in utero.

In utero stem cell transplantation represents a new and still experimental therapeutic strategy for diseases related to the hematopoietic system, i.e. hemoglobinopathies, immunodeficiency diseases and metabolic disorders. To date, a total of 21 cases of transplantations using stem cells either of fetal liver or adult bone marrow origin have been reported in the literature. Success has been limited--with the exception of one case of beta-thalassemia--to four cases with immunodeficiency diseases. In this review the broad therapeutic implications as well as potentials and limitations of this technique are summarized. Furthermore, ethical considerations based on the use of fetal cells are pointed out and a prospective view concerning experimental and clinical future perspectives including the possibility for gene therapy is presented.

Neuroanestesia y Drepanocitosis: reporte de dos casos y revisión de la literatura / Neuroanesthesia and sickle cell disease: case report and literature review

Los autores describen dos casos de pacientes con anemia drepanocítica quienes presentaron hemorragia subaracnoidea por ruptura de aneurisma intracraneal, y fueron llevados a cirugía para su clipaje. Ambos tuvieron una evolución intra y postoperatoria satisfactoria. Se hizo una revisión bibliográfica acerca del manejo médico y anestésico perioperatorio a propósito de esta rara asociación de patologías. El control multidisciplinario de variables tales como hemoglobina, hemoglobina S, hidratación oxigenación, equilibrio ácido base y temperatura entre otras, garantizará la exitosa recuperación de estos pacientes

Fetal hematopoietic stem cell transplantation.

In utero hematopoietic stem cell transplantation (IUHSCTx) is a promising approach for the treatment of a potentially large number of fetuses affected by congenital hematologic disorders. With technical and molecular advances in prenatal diagnosis, the majority of these diseases can now be diagnosed early in gestation, allowing consideration of prenatal treatment. In addition, technical advances in fetal imaging and intervention make it possible to perform the transplants with relatively minimal risk. It, therefore, stands to reason that there is increasing interest in performing in utero hematopoietic stem cell transplantation at many fetal treatment centers. Although the approach remains experimentally promising, expansion of clinical application will depend on improved understanding of the biological barriers to engraftment in the fetus as well as the development of effective clinical strategies based on the hematopoietic biology of individual disorders. This article presents the current status of this emerging therapeutic approach.

[AS heterozygote hemoglobinopathy and coronary risk]. / Hémoglobinopathie hétérozygote AS et risque coronaire.

There have been several reports of vaso-occlusive events and sudden death in subjects with sickle cell trait. However, the precise mechanism underlying these episodes remains unclear. The clinical observations have been supported by in vitro studies in which haemoglobin AS (Hb AS) red cells showed abnormalities of their filterability, probably related to gelling or polymerisation of the Hb AS. These in vitro studies and reports in the literature of sickle-cell hearts led the authors to investigate the possible association between AS subject and coronary risk. The results of coronary angiography in 9 patients with Hb AS, paired with respect to the usual cardiovascular risk factors, were compared with those of 18 AA subjects. The number of patients who underwent coronary bypass surgery for three-vessel disease was much greater in the AS subjects. However, the difference was not statistically significant. This tendency of AS subjects to develop thrombosis and coronary artery disease requires further study with larger numbers of patients.