Department of Endocrinology, Diabetes and Metabolic Diseases "Mladen Sekso", University Hospital Center "Sestre Milosrdnice", University of Zagreb School of Medicine, Zagreb,
University of Zagreb School of Medicine, Zagreb, Croatia.
Neuroendocrinology. 2018;107(3):284-291. doi: 10.1159/000492934. Epub 2018 Aug 16.
Serum chromogranin A (CgA) is routinely used as a biomarker in patients with neuroendocrine neoplasms (NENs). Several conditions and comorbidities may be associated with falsely elevated CgA, often leading to extensive diagnostic evaluation, which may be costly and harmful. The aim of this study was to analyze the effectiveness of the acute octreotide suppression test (AOST) in differentiating falsely elevated serum CgA.
Our prospective study enrolled 45 patients from two different patient cohorts: (1) 29 patients with suspicion or presence of NENs (extensive workup and subsequent biopsy confirmed 16 NENs); (2) 16 consecutive patients admitted via the Emergency Department without NENs (non-NENs). AOST was performed after an overnight fast. Baseline CgA was measured, after which 0.25 mg of octreotide was administered subcutaneously. CgA was measured 3 and 6 h after administration.
Baseline CgA levels were similar in NENs and non-NENs. At the end of the AOST, CgA decreased by a median of 83.3% (41.0-127.4) in non-NENs and 13.8% (0.0-43.6) in NENs (p < 0.001). In patients with increased baseline CgA, a decrease in CgA at the 6th hour of < 51.3% had 90.0% sensitivity and 88.9% specificity in detecting NENs. In patients with normal baseline serum CgA, a decrease in CgA at the 3rd hour of < 17.6% had 83.3% sensitivity and 81.8% specificity in detecting patients with NENs. The diagnostic accuracy of the AOST in the entire study population was 86.7%.
AOST is a promising tool to increase the diagnostic accuracy of serum CgA.
血清嗜铬粒蛋白 A（CgA）通常被用作神经内分泌肿瘤（NEN）患者的生物标志物。一些情况和合并症可能与 CgA 的假性升高有关，这通常会导致广泛的诊断评估，这可能是昂贵和有害的。本研究的目的是分析急性奥曲肽抑制试验（AOST）在区分血清 CgA 假性升高方面的效果。
我们前瞻性地招募了来自两个不同患者队列的 45 名患者：（1）29 名怀疑或存在 NEN 的患者（广泛的检查和随后的活检证实了 16 例 NEN）；（2）16 名连续通过急诊部入院的无 NEN 的患者（非 NEN 患者）。在禁食过夜后进行 AOST。测量 CgA 的基线值，然后皮下给予 0.25mg 奥曲肽。给药后 3 小时和 6 小时测量 CgA。
NEN 和非 NEN 患者的 CgA 基线水平相似。在 AOST 结束时，非 NEN 患者的 CgA 中位数降低了 83.3%（41.0-127.4），而 NEN 患者降低了 13.8%（0.0-43.6）（p<0.001）。在基线 CgA 升高的患者中，6 小时时 CgA 的下降<51.3%在检测 NEN 时具有 90.0%的敏感性和 88.9%的特异性。在基线血清 CgA 正常的患者中，3 小时时 CgA 的下降<17.6%在检测 NEN 患者时具有 83.3%的敏感性和 81.8%的特异性。AOST 在整个研究人群中的诊断准确性为 86.7%。
AOST 是提高血清 CgA 诊断准确性的有前途的工具。
