ABSTRACT
Objective To investigate the expression of follicular helper T (Tfh) cell subsets in peripheral blood of patients with liver transplantation (LT) and relevance to the prognosis. Methods Eleven liver transplant patients with stable liver function were enrolled in this study. The frequencies of Tfh subsets were examined by flow cytometry. The frequencies and the level of alanine aminotransferase (ALT), aspartate transaminase (AST) and total bilirubin (TBIL) were monitored dynamically within one month after LT. Results The frequency of CD4+CXCR5+CXCR3–CCR6– Tfh2 subset in peripheral blood increased significantly after LT as compared with those before transplantation (P<0.05). In addition, the frequency of CD4+CXCR5+CXCR3–CCR6+ Tfh17 subset in peripheral blood showed a trend of increase. The frequency of CD4+CXCR5+CXCR3+CCR6– Tfh1 subset, however, showed a downtrend, but no statistical difference was found. Conclusion The subsets of Tfh2 and Tfh17 may be involved in the regulation of alloimmune response and play a role in maintaining liver function stability in liver transplant patients.
ABSTRACT
Uma das maiores controvérsias relacionadas ao uso de osso alógeno relaciona-se à possível sensibilização imunogênica do paciente receptor. Isso, teoricamente, poderia causar rejeição, incorporação óssea lenta, osteólise, erosões ósseas, degeneração articular, infecção e fratura. Existem na literatura alguns trabalhos demonstrando indícios de sensibilização imunológica frente ao uso dos enxertos ósseos alógenos frescos congelados, com sensibilização da molécula HLA doador-específico. No entanto, há carência de trabalhos científicos que avaliem as possibilidades de sensibilização em humanos após transplante ósseo para fins de reconstrução, para posicionamento de implante dentário. Nosso grupo demonstrou em um trabalho recente a sensibilização para HLA em 33,3% dos pacientes receptores de transplante ósseo córtico-medular, porém, não existiu repercussão significativa da sensibilização na incorporação do enxerto, já que em todos os indivíduos da pesquisa os enxertos apresentaram boa incorporação e remodelação. Apesar da ausência de influência da sensibilização por HLA na incorporação dos enxertos ósseos, deve-se ponderar que uma parcela significativa dos pacientes (33,3%) foi sensibilizada, o que poderia acentuar a rejeição a futuros transplantes, como de fígado ou coração, portadores dos mesmos antígenos HLA (second-set rejection). Faz-se necessário o aprofundamento das investigações científicas sobre a possibilidade de sensibilização dos pacientes receptores de transplante ósseo para fins de reabilitação dentária por meio de implantes.
There is much controversy regarding the use of allogeneic bone in relation to the risk of immunogenic sensitization of the host. This could increase the chances of graft rejection, slow bone incorporation, osteolysis, bony erosions, joint degeneration, infection and fracture. Some studies have shown evidence of immunological sensitization, when using fresh frozen allogeneic bone grafts, against the donor-specific HLA molecule. However, there are only a few studies assessing the risk of sensitization in humans after bone grafting for bone reconstruction prior to dental implant placement. Our group has recently demonstrated a 33.3% rate of HLA sensitization in patients receiving a corticancellous bone graft, however, with no significant effect on graft incorporation, since all subjects in the study showed adequate incorporation and bone remodeling. Despite there being no influence of HLA sensitization in bone graft incorporation, it should be highlighted that a significant portion of patients (33.3%) was sensitized, which could jeopardize future transplants, such as liver or heart, from donors with the same HLA type (second-set rejection). Further investigation is necessary on the sensitization risk among patients receiving bone transplant for the purpose of dental rehabilitation using implants.
Subject(s)
Humans , Bone Transplantation , Dental Implantation , Transplantation ImmunologyABSTRACT
Objective To determine the expression characteristics of peripheral blood follicular helper T cells (Tfh) and their molecules during pre- and post-transplantation period in liver transplant patients to explore the role of Tfh in alloreactive response after liver transplantation. Methods Twenty liver transplant (LT) patients and 20 healthy individuals as control were enrolled in this study. Thirteen LT patients with stable liver function were included for cross-sectional study. Another seven LT patients with complete clinical data were included for follow-up study. The frequencies of Tfh cells were examined by flow cytometry. For the seven patients, Tfh cells and level of alanine aminotransferase (ALT) were monitored dynamically for one month after LT. Results The frequencies of CD4+CXCR5+Tfh and CD4+CXCR5+PD-1+ cells in peripheral blood increased significantly after liver transplantation as compared with those before liver transplantation (P<0.05). In addition, the frequencies of CD4+CXCR5+ICOS+ cells showed a rising trend, but no statistical difference. In early follow-up period it was found that the frequencies of CD4+CXCR5+ Tfh obviously increased after liver transplantation in patients with stable liver function, and reached the peak value after one week and then decreased. The AL level also decreased when reaching peak 10 days after surgery. Interestingly, the frequencies of CD4+CXCR5+ Tfh in one patient with acute rejection after liver transplantation showed the same trend with ALT levels changes. Furthermore, the frequencies of CD4+CXCR5+Tfh, CD4+CXCR5+PD-1+ and CD4+CXCR5+ICOS+ cells in stable liver function group were higher than those in the healthy control group (P<0.05). Conclusion The CD4+CXCR5+Tfh cells in peripheral blood will be upregulated in liver transplant patients, which indicates that the Tfh maybe involved in liver alloreactive response.