RESUMEN
Chronic graft-versus-host disease (cGVHD) is a severe and frequent complication of allogenic bone marrow transplantation which is often treated with extracorporeal photochemotherapy (ECP) with a positive clinical outcome in patients resistant to conventional protocols. The mechanism of action of ECP has not been fully elucidated, although several authors have reported that it is able to induce apoptosis. Using samples obtained from ten cGVHD patients, we sought to determine whether lymphocytes treated with ECP underwent apoptosis and, above all, the mechanisms involved. Lymphocytes at four stages were isolated: immediately before ECP, from the last buffy coat collected, after UV irradiation prior to reinfusion, and the day after ECP. When cultured for 48 h, lymphocytes treated with ECP underwent accelerated apoptosis (tested as annexin V binding cells and as intracellular histone-associated DNA fragments) in comparison with lymphocytes from the other samples. This enhanced programmed cell death could not be prevented by IL-2. Immediately after isolation, there was no difference in Bcl-2 or bax expression among the four different samples, or in Fas and FasL mRNA. However, when cultured, lymphocytes treated with ECP showed a rapid downregulation of Bcl-2, an upregulation of bax with an increased bax/Bcl-2 ratio, a decrease in bcl-2 mRNA and an increase in Fas. No changes were detectable in lymphocytes from the other samples. IL-2 and TNF-alpha production was not significantly different among lymphocytes from the four samples. In conclusion, in patients affected by cGVHD, ECP induced apoptosis of lymphocytes with the involvement of both the Fas/FasL system and the Bcl-2 protein family.
Asunto(s)
Trasplante de Médula Ósea/efectos adversos , Enfermedad Injerto contra Huésped/terapia , Linfocitos/citología , Glicoproteínas de Membrana/metabolismo , Fotoféresis , Receptor fas/metabolismo , Adulto , Apoptosis/efectos de los fármacos , Apoptosis/inmunología , Células Cultivadas , Enfermedad Crónica , Regulación hacia Abajo/efectos de los fármacos , Proteína Ligando Fas , Femenino , Expresión Génica/efectos de los fármacos , Enfermedad Injerto contra Huésped/inmunología , Enfermedad Injerto contra Huésped/metabolismo , Humanos , Interleucina-2/metabolismo , Linfocitos/metabolismo , Masculino , Glicoproteínas de Membrana/genética , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Regulación hacia Arriba/efectos de los fármacos , Proteína X Asociada a bcl-2RESUMEN
Duplications leading to functional disomy of chromosome Xq28, including MECP2 as the critical dosage-sensitive gene, are associated with a distinct clinical phenotype in males, characterized by severe mental retardation, infantile hypotonia, progressive neurologic impairment, recurrent infections, bladder dysfunction, and absent speech. Female patients with Xq duplications including MECP2 are rare. Only recently submicroscopic duplications of this region on Xq28 have been recognized in four females, and a triplication in a fifth, all in combination with random X-chromosome inactivation (XCI). Based on this small series, it was concluded that in females with MECP2 duplication and random XCI, the typical symptoms of affected boys are not present. We present clinical and molecular data on a series of five females with an Xq28 duplication including the MECP2 gene, both isolated and as the result of a translocation, and compare them with the previously reported cases of small duplications in females. The collected data indicate that the associated phenotype in females is distinct from males with similar duplications, but the clinical effects may be as severe as seen in males.
Asunto(s)
Anomalías Múltiples/diagnóstico , Duplicación Cromosómica , Cromosomas Humanos X/genética , Discapacidad Intelectual/genética , Proteína 2 de Unión a Metil-CpG/genética , Fenotipo , Anomalías Múltiples/genética , Niño , Bandeo Cromosómico , Femenino , Estudios de Asociación Genética , Humanos , Linaje , Inactivación del Cromosoma XRESUMEN
BACKGROUND: Chronic graft-versus-host disease (cGVHD) is a major complication of allogeneic bone marrow transplantation. Extracorporeal photopheresis (ECP) has recently been introduced as an alternative treatment for cases of cGVHD refractory to conventional immunosuppressive treatment, but its mechanism of action is not yet clear. OBJECTIVES: To investigate in seven patients with cGVHD the effects of ECP on resistance of monocytes to apoptosis and on monocyte cytokine production. METHODS: We designed an in vitro model that could mimic the potential in vivo effect of reinfusion of peripheral blood mononuclear cells treated by ECP. The model was based on coculture of ECP-treated lymphocytes with untreated monocytes from the same patient. RESULTS: ECP did not accelerate spontaneous apoptosis of monocytes. However, ECP-treated monocytes produced increased amounts of interleukin (IL)-12. In contrast, IL-12 production by monocytes did not increase in cocultures, but IL-10 production was upregulated. CONCLUSIONS: These results suggest that reinfusion of large numbers of autologous apoptotic lymphocytes is significant for the therapeutic outcome of ECP through upregulation of IL-10, which is an immunosuppressive cytokine.