1月10日,，刊登在PNAS雜志上的一項研究"Indirect evidence that maternal microchimerism in cord blood mediates a graft-versus-leukemia effect in cord blood transplantation"說,，用共同的父本血標記去匹配臍帶血的受體和捐獻者可能減少某些類型的白血病的復發(fā)率。
科研人員一直無法解釋為什么臍帶血——臍帶血被認為在免疫上是不成熟的——被證明在攻擊沒有親緣關(guān)系的受體的白血病細胞方面有效,。Jon J. van Rood及其同事研究了來自紐約血液中心國家臍帶血項目的信息,，并報告說臍帶血中母親的免疫力可能阻止了白血病的復發(fā)。
在懷孕期間,，女性常常變得對胎兒從父親那里遺傳的父本抗原具有免疫,，制造出了進入胎兒血液循環(huán)的免疫系統(tǒng)細胞。這組作者提出了一種假說,，即臍帶血中的這些“敏化的”母親細胞可能識別沒有親緣關(guān)系的移植受體的同樣的遺傳父本抗原（IPA）并且引發(fā)針對白血病細胞的強大的免疫應(yīng)答,。
這組科研人員觀察到，與沒有擁有和捐獻者的血標記相同的受試者相比,，患急性骨髓和淋巴白血病的受試者在接受了來自與捐助者的遺傳父本抗原（IPA）匹配的臍帶血之后白血病的復發(fā)率較低,。這組作者說，這些發(fā)現(xiàn)可能有助于未來的癌癥監(jiān)測研究,，而且可能整合到目前移植中心使用的用于幫助匹配臍帶血捐獻者和受體的搜索算法中,。（生物谷Bioon.com）
doi:10.1073/pnas.1119541109
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PMID:
Indirect evidence that maternal microchimerism in cord blood mediates a graft-versus-leukemia effect in cord blood transplantation
Jon J. van Rooda,1, Andromachi Scaradavoub, and Cladd E. Stevensb,2
During pregnancy women can develop B- and T-cell immunity against the inherited paternal antigens (IPAs) of the fetus, such as HLA, peptides of minor histocompatibilty antigens, and possibly onco-fetal antigens. The biological and pathological role of these pregnancy-induced immunological events is only understood in part. However, anti-IPA immunity in the mother persists for many decades after delivery and may reduce relapse in offspring with leukemia after HLA-haploidentical transplantation of maternal hematopoietic stem cells (HSC). We hypothesized that maternal anti-IPA immune elements cross the placenta and might confer a potent graft-versus-leukemia effect when cord blood (CB) is used in unrelated HSC transplantation. In a retrospective study of single-unit CB recipients with all grafts provided by the New York Blood Center, we show that patients with acute myeloid or lymphoblastic leukemia (n = 845) who shared one or more HLA-A, -B, or -DRB1 antigens with their CB donor's IPAs had a significant decrease in leukemic relapse posttransplantation [hazard ratio (HR) = 0.38, P < 0.001] compared with those that did not. Remarkably, relapse reduction in patients receiving CB with one HLA mismatch (HR = 0.15, P < 0.001) was not associated with an increased risk of severe acute graft-versus-host disease (HR = 1.43, P = 0.730). Our findings may explain the unexpected low relapse rate after CB transplantation, open new avenues in the study of leukemic relapse after HSC transplantation (possibly of malignancies in general), and have practical implications for CB unit selection.
