Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
Hum Pathol. 2018 Feb;72:71-79. doi: 10.1016/j.humpath.2017.11.001. Epub 2017 Nov 11.
In the past, the diagnosis and typing of amyloidosis often required an invasive biopsy of an internal organ, such as the heart or kidneys. Abdominal fat pad excisional biopsy (FPEB) offers a less invasive approach, but the sensitivity of this technique has been unclear. To determine the sensitivity of FPEB for immunoglobulin light chain (AL) and transthyretin (ATTR) amyloidosis, we performed a retrospective clinicopathologic analysis of 97 patients who had undergone FPEB, of which 16 were positive for amyloid. The most significant pretest feature predicting a positive FPEB was a serum free light chain κ/λ ratio less than .5, and in this group of patients the probability of a positive biopsy was dependent on the size of the biopsy (P=.004). In FPEBs, the amyloid was present in multiple distinct patterns: pericellular, septal, medium-sized vessel, small vessel, and nodular. For patients with AL amyloidosis for which direct typing was attempted using the FPEB tissue, the amyloid was successfully typed in the FPEB in 90% of cases. The overall sensitivity of FPEB was 79% for AL amyloidosis and 12% for ATTR amyloidosis (P=.0003). In patients with AL amyloidosis, the sensitivity of FPEB was dependent on biopsy size, with small biopsies (≤700 mm) having a sensitivity of ~50%, and large biopsies (>700 mm) having a sensitivity of ~100%. This study demonstrates that FPEB has high sensitivity for AL amyloidosis, and can be routinely used to type the amyloid. However, FPEB has low sensitivity for ATTR amyloidosis in our patient population.
过去，淀粉样变性的诊断和分型通常需要对心脏或肾脏等内脏器官进行有创性活检。腹壁脂肪垫切取活检（FPEB）提供了一种侵入性较小的方法，但该技术的敏感性尚不清楚。为了确定 FPEB 对免疫球蛋白轻链（AL）和转甲状腺素蛋白（ATTR）淀粉样变性的敏感性，我们对 97 例接受 FPEB 的患者进行了回顾性临床病理分析，其中 16 例为淀粉样变阳性。预测 FPEB 阳性的最重要的术前特征是血清游离轻链 κ/λ 比值小于 0.5，在这群患者中，活检阳性的概率取决于活检的大小（P=0.004）。在 FPEB 中，淀粉样蛋白以多种不同的模式存在：细胞周围、间隔、中等大小血管、小血管和结节状。对于尝试使用 FPEB 组织直接对 AL 淀粉样变性进行分型的患者，在 90%的 FPEB 中成功对淀粉样蛋白进行了分型。FPEB 对 AL 淀粉样变性的总体敏感性为 79%，对 ATTR 淀粉样变性的敏感性为 12%（P=0.0003）。在 AL 淀粉样变性患者中，FPEB 的敏感性取决于活检的大小，小活检（≤700mm）的敏感性约为 50%，大活检（>700mm）的敏感性约为 100%。本研究表明，FPEB 对 AL 淀粉样变性具有较高的敏感性，可常规用于淀粉样蛋白的分型。然而，在我们的患者群体中，FPEB 对 ATTR 淀粉样变性的敏感性较低。
