ANALYSIS OF FINE-NEEDLE ASPIRATION BIOPSIES BY FLOW CYTOMETRY IN LIVING-RELATED PEDIATRIC LIVER TRANSPLANT PATIENTS

前言：肝移植的效果有了很大改善。然而，急性排斥反应仍然是一个主要问题。细针吸取活检(FNAB)是诊断急性排斥反应的一种非常安全和有帮助的方法，其诊断率与有经验的中心的核心肝活检相似。本研究的目的是用FNAb样本定量评价移植肝的免疫学状态，并与外周血淋巴细胞(PBL)进行比较。方法：对10例活体儿童同种异体肝移植物进行FNAb监测，每隔2~3d监测一次，每隔2~3天怀疑发生排斥反应。结果：轻、中度排斥反应时，CD4CD25、CD8CD25和CD4DR的表达均略有升高(3~6%)。但在排斥反应发生前1~3天，FNAB组CD8DR阳性细胞数显著高于PBL组(p&lt；0.05)。严重排斥反应时，不仅CD4DR、CD8DR阳性细胞数增加，CD4CD25、CD8CD25阳性细胞数也增加(20-30%)，FNAB组尤为明显。这些发现与生化实验室参数有很好的相关性，移植物中活化的淋巴细胞(CD4CD25、CD4DR、CD8CD25、CD8DR阳性细胞)的增加早于血清值升高提示肝功能损害的2-5天。此外，在非免疫性移植肝损伤(如动脉血栓形成或胆汁渗漏)过程中，无明显的系列变化。结论：FNAb标本的流式细胞术研究可以作为预测移植肝免疫激活(即急性排斥反应)的可靠方法。

Introduction: The outcome of liver transplants has improved. However, acute rejection is nevertheless a major problem. Fine-needle aspiration biopsy (FNAB) is a very safe and helpful procedure for the diagnosis of acute rejection, achieving a similar diagnostic yield as core liver biopsy in experienced centers. The purpose of this study is to evaluate an immunological state of allografts quantitatively using FNAB samples in comparison with peripheral blood lymphocytes (PBL) by flow cytometric analysis.Methods: Ten living-related liver allografts for children were monitored with FNAB at 2-3 day intervals and whenever rejection crisis was suspected. Lymphoid cell subpopulations from PBL and aspiration biopsies of allografts by flow cytometry were analyzed.Results: The expression of CD4CD25, CD8CD25 and CD4DR increased slightly (3-6%) in case of mild to moderate rejection in both samples. However, 1 to 3 days prior to rejection, CD8DR positive cells increased significantly in FNAB samples compared to that in PBL (p<0,05). In severe rejection episodes, not only CD4DR, CD8DR but CD4CD25, CD8CD25 positive cells also increased (20-30%) especially in FNAB samples. These findings correlated well with biochemical laboratory parameters, and the increase of activated lymphocytes (CD4CD25, CD4DR, CD8CD25, CD8DR positive cells) in the grafts could be observed already 2-5 days earlier than elevated serum values indicated liver dysfunction. Furthermore, there was no significant serial change during non-immunological graft damages (I.e. arterial thrombosis or bile leakage).Conclusion: Flow cytometry study of FNAB samples could be a reliable method to prospect immunological activation in liver allografts (I.e. acute rejection episodes).