Immediate major dynamic changes in the T- and NK-cell subset composition after cardiac transplantation

Early kinetics of lymphocyte subsets involved in tolerance and rejection following heart transplantation (HTx) are barely defined. Here, we aimed to delineate the early alloimmune response immediately after HTx. Therefore, blood samples from 23 heart-transplanted patients were collected before (pre-), immediately (T0), 24 hours (T24), and 3 weeks (3 wks) after HTx. Immunophenotyping was performed using flow cytometry. A significant increase was detected for terminally differentiated (TEMRA) CD4⁺ or CD8⁺ T cells and CD56^dimCD16⁺ NK cells immediately after HTx linked to a decrease in naïve CD8⁺ and CM CD4⁺ T as well as CD56^brightCD16⁻ NK cells, returning to baseline levels at T24. More detailed analyses revealed increased CD69⁺CD25⁻ and diminished CD69⁻CD25⁻CD4⁺ or CD8⁺ T-cell proportions at T0 associated with decreasing S1PR1 expression. Passenger T and NK cells were found at low frequencies only in several patients at T0 and did not correlate with lymphocyte alterations. Collectively, these results suggest an immediate, transient shift toward memory T and NK cells following HTx. Opposite migratory properties of naïve versus memory T and NK cells occurring in the early phase after HTx could underlie these observations and may impinge on the development of allo-specific immune responses.     

Decrease of blood type antigenicity over the long-term after ABO-incompatible kidney transplantation

Background

Few studies have investigated the changes in the antigenicities of the transplanted organs after transplantation.

Methods

We examined, by immunohistochemical assay, the changes in expression of the blood-type antigens on the transplanted kidneys over the long-term after ABO-incompatible kidney transplantation with A- or B-antigen incompatibility (blood type A to B and B to A). The subjects were six patients, including one case with graft loss, who had received ABO-incompatible kidney allografts more than ten years previously. As normal controls, four cases of ABO-compatible transplantation during the same period, including two recipient/donor pairs each with blood group A1 and blood group B were enrolled.

Results

Expression of the blood-type A or B antigens decreased gradually to 91.8% during the first three months after transplantation, 85.8% during the first five years, 64.1% during the first ten years, and 57.6% over ten years after transplantation on average in ABO-incompatible transplant recipients. In one patient with graft loss due to severe antibody-mediated rejection, the donor's type B blood-type antigens on the transplanted graft had changed but partially to the recipient's blood-type A antigen by 2582 days after the transplantation, suggestive of the occurrence of blood-type chimerism on the endothelium. In ABO-compatible transplant recipients, such changes in expression were not observed. The average percentage of blood-type antigen-positive vessels at more than ten years after the renal transplantation was 99.8%.

Conclusions

Decrease in the expression of the donor's blood-type antigen on the endothelium of the graft has been considered as one of the mechanisms underlying the accommodation occurring over the long-term after ABO-incompatible kidney transplantation. On the other hand, establishment of antigenic chimerism on the graft endothelium could be one of the hallmarks of the immunological reaction associated with antibody-mediated rejection.     

Engraftment kinetics and hematopoietic chimerism after reduced-intensity conditioning with fludarabine and treosulfan before allogeneic stem cell transplantation

Reduced-intensity conditioning with fludarabine and treosulfan before allogeneic stem cell transplantation (SCT) was introduced several years ago. Although its feasibility has recently been proven, only limited data are available on myelotoxicity, engraftment kinetics, and the significance of hematopoietic chimerism using this novel conditioning regimen. To clarify these open questions, we analyzed 27 patients with various hematological diseases, who received allogeneic SCT preceded by fludarabine/treosulfan conditioning. Further assessment endpoints included graft-vs-host disease (GvHD), mortality, and overall survival (OS). Allogeneic SCT was followed by neutropenia (absolute neutrophil count ≤ 0.5 × 10⁹/l) and thrombocytopenia (platelets ≤ 20 × 10⁹/l) in all patients. All patients showed stable neutrophil engraftment, and all except one had stable platelet engraftment. Grades II–IV acute GvHD was found in 48% of patients, whereas 52% developed chronic GvHD. The treatment-related mortality on day +100, 1 year after SCT, and at the last follow-up was 11, 26, and 33%, respectively. We found complete chimerism rates of 46, 57, and 72% on days +28, +56, and at the last follow-up or before death, respectively. The underlying malignancy tended to relapse more frequently in patients with mixed chimerism than in those with complete chimerism on day +28 as well as on day +56 (not significant). Additionally, no significant association was found between hematopoietic chimerism and donor type, GvHD, or OS, respectively. We conclude that reduced-intensity conditioning with fludarabine and treosulfan before allogeneic SCT is myeloablative, provides stable engraftment, and leads to complete chimerism in the majority of patients. Part of the abstract has been presented at the annual meeting of DGHO 2006 (Leipzig, Germany).     

异基因造血干细胞移植后的嵌合状态分析

目的研究异基因外周血造血干细胞移植（allo-PBSCT）后T淋巴细胞和粒细胞嵌合状态与疾病复发、移植物被排斥和移植物抗宿主病（GVHD）等的关系.方法21例HLA完全相合allo-PBSCT患者,流式细胞仪分选出外周血粒细胞、T淋巴细胞,分别进行短串联重复片段（STR）-PCR扩增.结果移植后7 d时17/21例患者T淋巴细胞的植入程度高于粒细胞,供者嵌合比例（DC）分别为60%（15%～76%）和0%（0%～40%）.除去移植后28 d复发且T淋巴细胞一直为混合嵌合（MC）1例,其余20例T淋巴细胞达到完全嵌合（CDC）的中位时间是21（14～102）d,粒细胞为14 d.T淋巴细胞比粒细胞更早植入,但达到CDC的时间较粒细胞晚.7例在疾病复发或移植物被排斥时,T淋巴细胞比粒细胞更早出现DC的下降,其中4例患者仅表现为T淋巴细胞出现DC的下降,而全骨髓细胞和粒细胞仍为CDC或无明显下降,骨髓象检查未见异常.而在减量、停用免疫抑制剂或供者淋巴细胞输注后,治疗有效的4例患者T淋巴细胞逐渐由MC变为CDC,并有3例在转变过程中出现急性GVHD.结论allo-PBSCT后进行白细胞亚群,尤其是T淋巴细胞的嵌合状态检测可以比全血或全骨髓样本更早发现供者细胞的植入、疾病复发或移植物被排斥,及时采取相应的免疫干预措施,提高移植成功率.     

Donor-derived bone marrow transfusion produces mixed chimerism and promotes a Th2 shift in Th1/Th2 balance in rat heterotopic small bowel transplantation

Background and aim

In this study, we investigated immunomodulatory effects of donor-derived bone marrow transfusion in rat heterotopic small bowel transplantation.

Methods

Rat heterotopic segmental small bowel transplantation models (male Brown Norway to female Lewis) were established. The recipients were randomly divided into control group (pute small bowel transplantation), tacrolimus group (small bowel transplantation plus oral tacrolimus) and small bowel transplantation plus oral tacrolimus and intraportal infusion of donor-derived bone marrow cells group. We investigated the survival time, graft pathologic injuries and rejection grade by haematoxylin–eosin staining, serum IL-2 and IL-10 detection by enzyme labelled immunosorbent assay after small bowel transplantation. The recipients mixed chimerism were observed by detecting sex-determining region of Y chromosome gene in blood, liver, spleen and intestine by using real-time polymerase chain reaction and fluorescence in situ hybridization.

Results

Bone marrow cells group showed a superior survival than the other groups, accompanied by milder pathologic injuries and lower rejection grade, decreasing serum IL-2 and increasing serum IL-10. The recipient chimerism rate in blood, liver, spleen and intestine in bone marrow cells group was significantly higher than the other groups.

Conclusion

Transfusion of donor-derived bone marrow cells via portal vein induces mixed chimerism in rats after small bowel transplantation, which may promote a Th2 shift in Th1/Th2 balance and facilitate the induction of immune tolerance.     

Organ Transplantation in Taiwan

Abstract: We performed the first successful kidney transplantation in Taiwan on May 27, 1968. Since then, kidney, heart, lung, pancreas, liver, and heart-kidney transplantations have been increasingly successful in restoring lives of otherwise dying patients with organ failure. The first successful kidney, liver, and heart transplantations in Asia were achieved in Taiwan in 1968, 1984, and 1987, respectively. Individual organ transplantation, organ transplant recipient survival, graft survival, and problems and pitfalls encountered in the care of organ transplantation recipients are analyzed. Using polymerase chain reaction amplification with sequence-specific primers, donor-specific DNA was detected in the peripheral blood of the patient who survived the longest (26 years) in this series. Interestingly enough, recently, we had a patient undergoing cadaveric renal transplantation in whom chi-merism was detected in her lymph nodes and skin only 3 years after transplantation. Organ procurement in Taiwan is the greatest problem, and we have been exerting our maximal effort to establish a transplantation coordination team to create a central network and to educate, procure, preserve, distribute, and increase the availability of organs and tissues for transplantation.     

Suppressed alloreactivity and mixed chimerism in rats with accepted cardiac allografts by intrathymic injection of donor bone marrow cells

Intrathymic injection of donor bone marrow cells (ITBMCs) at the time of transplantation and treatment with antilymphocyte serum (ALS) permitted the indefinite survival of Brown Norway (BN, RT1ⁿ) rat heart grafts in 6 out of 8 Lewis (LEW, RT1^l) rat recipients. LEW recipients with long-surviving BN heart grafts (LSGs) also accepted additional BN heart grafts without further immunosuppression, though they rejected Piebald Virol Glaxo (PVG, RT1^c) rat heart grafts in the usual fashion. In the in vitro study, the proliferative response of the lymphocytes from LEW recipients with LSGs remained suppressed when they were stimulated by BN spleen cells, but not when stimulated by PVG cells. Bone marrow cells (BMCs) from LEW rats with LSGs showed strong, nonspecific, suppressive effects on the proliferative response in the mixed lymphocyte culture reaction, suggesting that one of the possible explanations for tolerance might be the involvement of a suppressor mechanism. Received: 7 August 1996 Received after revision: 12 February 1997 Accepted: 17 February 1997     

异种骨髓移植中移植物抗宿主病的实验研究

目的 :探讨克服异种骨髓移植间强烈的移植物抗宿主病的方法。方法 :实验分两步 :第一步 ,SD大鼠亚致死剂量 5 .5Gy全身照射后 ,4h内经尾静脉输入正常BALB/c小鼠骨髓细胞 8× 10 7。 2d后予腹腔注射Cy15 0mg/kg。诱导形成嵌合体大鼠 ,使其对BALB/c小鼠产生特异性免疫耐受。第二步 ,BALB/c小鼠接受致死剂量 9.0Gy全身照射 ,随机三分组。照射后 4h内经尾静脉注射骨髓进行移植。A组输注正常SD大鼠的骨髓细胞 4× 10 7;B组输注正常SD大鼠的骨髓细胞 4× 10 7和脾细胞 2× 10 7;C组输注嵌合体SD大鼠的骨髓细胞 4× 10 7和脾细胞 2× 10 7;比较GVHD发生情况。结果 :A组有 2只小鼠死于感染和放射损伤 ,所有对象均未观察到明显GVHD表现。B组平均存活时间为 (9.0± 1.3)d ,且死前均出现不同程度的典型GVHD表现 ,如皮毛脏乱、消瘦、弓背体位、腹泻 ,甚至血便等 ;肝实质内有灶性淋巴细胞及多形细胞浸润 ,并可见局灶性坏死 ;肠绒毛部分或大部分脱落 ,粘膜坏死、有大量炎性细胞浸润 ,符合GVHD病理改变。而C组除 2只小鼠分别于 18d、31d死亡外 ,余均存活超过 6 0d ,与B组有显著差异 ,且死亡率最低。结论 :有受者嵌合体的供者 ,在进行异种骨髓移植后有助于克服异种移植物抗宿主病。     

Study of hematopoietic chimerism following allogeneic peripheral blood stem cell transplantation using PCR amplification of short tandem repeats

 Allogeneic peripheral blood progenitor cell transplantation (PBPCT) is increasingly being used to treat hematologic malignancies. However, the capacity of PBPC to maintain long-term hematopoiesis remains controversial. To add further information to this issue we studied the chimeric status in 12 patients receiving G-CSF-mobilized PBPC from HLA-identical sibling donors. All patients were conditioned with cyclophosphamide and total body irradiation. In six cases the apheresis product was partially T-cell depleted by counterflow centrifugation (n=2) or the immunoadsorption biotin-avidin method (n=4). The follow-up was longer than 6 months in five patients, with a maximum of 420 days. Molecular analysis of the engraftment was done using PCR amplification of short tandem repeats. Apparent complete donor chimerism was detected in all patients between 28 and 420 days after engraftment. This study indicates that full short-term engraftment is achieved in patients receiving allogeneic G-CSF-mobilized PBPC from healthy donors and suggests that this might also be true for long-term engraftment. Received: 5 December 1995 / Accepted: 22 January 1996