探头式共聚焦激光显微内镜量化指标诊断幽门螺杆菌相关萎缩性胃炎的临床研究

A clinical study of quantifying index of probe‑based confocal laser endomicroscopy for diagnosis of Helicobacter pylori‑associated chronic atrophic gastritis

摘要:

目的 量化探头式共聚焦激光显微内镜（probe‑based confocal laser endomicroscopy，pCLE）诊断幽门螺杆菌相关萎缩性胃炎（H.pylori‑associated chronic atrophic gastritis，HpCAG）的诊断指标，并评价诊断效能。方法 研究分为2个阶段：第1阶段前瞻性纳入2021年11月至2022年9月在包头医学院第二附属医院行胃镜检查及内镜下活检并行13C呼气试验的患者作为研究对象，离线视频采用Image J图像分析软件测量pCLE视野中的毛细血管直径（capillary diameter，CD）、细胞间距（cells spacing，CS）、腺体间距（gland spacing，GS）、腺体面积（gland area，GA）这4个指标，通过分析受试者工作特征（receiver operating characteristic，ROC）曲线下面积，建立pCLE下量化指标诊断HpCAG的标准；第2阶段回顾性纳入2021年10月至2022年10月间在包头医学院第二附属医院行pCLE检查及13C呼气试验的病例，剔除与第1阶段数据重合的病例，试验采用单盲法，内镜医师和病理医师对彼此的诊断结果不知情，pCLE的诊断根据第1阶段获得的标准进行，统计分析pCLE诊断与组织病理学+13C呼气试验结果的一致性。结果 第1阶段招募到35例患者共计191块标本入组，根据内镜活检病理结果及13C呼气试验结果将患者及胃黏膜标本分为4组，即幽门螺杆菌（Helicobacter pylori，HP）阳性萎缩性胃炎组（n=59）、HP阳性非萎缩性胃炎组（n=52）、HP阴性萎缩性胃炎组（n=40）、HP阴性非萎缩性胃炎组（n=40）。ROC曲线分析结果显示：在HP阳性患者中，GS区分慢性萎缩性胃炎与非萎缩性胃炎胃黏膜的最佳临界值为29.68 μm，在4个参数中ROC曲线下面积最大；在HP阴性患者中，GS区分慢性萎缩性胃炎与非萎缩性胃炎胃黏膜的最佳临界值为23.57 μm，在4个参数中ROC曲线下面积最大；在非萎缩性胃炎患者中，GS区分HP阳性与HP阴性胃黏膜的最佳临界值为20.57 μm，在4个参数中ROC曲线下面积最大；在慢性萎缩性胃炎患者中，CD、CS、GS、GA区分HP阳性与HP阴性胃黏膜的最佳临界值分别为13.23 μm、1.38 μm、34.03 μm、6 066.5 μm2，ROC曲线下面积分别为0.608、0.888、0.849、0.900。最终选择GS区分HpCAG与非HpCAG胃黏膜，最佳临界值为31.71 μm，但考虑到难以通过图像下方的标尺测量31.71 μm的距离，故将临界值改为30 μm，因此将GS>30 μm作为pCLE下HpCAG的诊断标准，此时诊断的敏感度和特异度分别为91.5%和76.0%。第2阶段观察了80例患者的224块标本：pCLE（GS>30 μm）诊断HpCAG的敏感度、特异度、阳性预测值、阴性预测值和准确率分别为96.5%（164/170）、88.9%（48/54）、96.5%（164/170）、88.9%（48/54）和94.6%（212/224），与组织病理学+13C呼气试验的诊断一致性极好（Kappa=0.854）。结论 pCLE下可以实现胃黏膜微观结构的定量监测，量化后的指标有助于提高HpCAG诊断的准确率。

Abstract:

Objective To quantify the diagnostic index of probe‑based confocal laser endomicroscopy (pCLE) for diagnosing Helicobacter pylori (HP)‑associated chronic atrophic gastritis (HpCAG), and to evaluate the efficacy of the quantified diagnostic index for HpCAG. Methods The study was divided into two stages. The first stage prospectively included patients undergoing gastroscopy, endoscopic biopsy and 13C breath test from November 2021 to September 2022 at the Second Affiliated Hospital of Baotou Medical College. The capillary diameter (CD), cells spacing (CS), gland spacing (GS), and gland area (GA) in the pCLE field of offline video was measured with Image J. The diagnostic criteria of HpCAG by quantitative indicators under pCLE was established by analyzing the area under the receiver operating characteristic (ROC) curve (AUC). In the second stage, the cases with pCLE examination and 13C breath test at the Second Affiliated Hospital of Baotou Medical College from October 2021 to October 2022 were included. The cases that overlapped with the first stage were excluded. The trial was single‑blind, with endoscopists and pathologists blind to each other''s diagnoses. The diagnosis of pCLE was conducted according to the criteria obtained in the first stage, and the consistency between pCLE diagnosis and the results of histopathology and 13C breath test was analyzed. Results The first stage enrolled 191 specimens from 35 patients. According to the pathological results of endoscopic biopsy and 13C breath test results, patients and gastric mucosa samples were divided into 4 groups, HP‑positive CAG group (n=59), HP‑positive non‑CAG group (n=52), HP‑negative CAG group (n=40), and HP‑negative non‑CAG group (n=40). ROC curve analysis results showed that in HP‑positive patients, the optimal critical value of GS to distinguish between CAG and non‑CAG gastric mucosa was 29.68 μm, and the AUC was the largest among the 4 parameters. In HP‑negative patients, the optimal critical value of GS for distinguishing gastric mucosa from CAG and non‑CAG was 23.57 μm, and the AUC was the largest among the 4 parameters. In patients with non‑CAG, the optimal critical value for GS to distinguish HP‑positive and HP‑negative gastric mucosa was 20.57 μm, and the AUC was the largest among the 4 parameters. In patients with CAG, the optimal critical values of CD, CS, GS and GA to distinguish between HP‑positive and HP‑negative gastric mucosa were 13.23 μm, 1.38 μm, 34.03 μm and 6 066.5 μm2, respectively, and the AUC were 0.608, 0.888, 0.849 and 0.900, respectively. Finally, GS was selected to distinguish between HpCAG and non‑HpCAG gastric mucosa, and the optimal critical value was 31.71 μm. However, considering that it was difficult to measure the distance of 31.71 μm by the ruler below the image, the critical value was changed to 30 μm, so GS>30 μm was used as the diagnostic criteria for HpCAG in pCLE, and the diagnostic sensitivity and the specificity were 91.5% and 76.0%, respectively. In the second phase 224 specimens from 80 patients were observed. The sensitivity, the specificity, the positive predictive value, the negative predictive value and accuracy of pCLE (GS>30 μm) in the diagnosis of HpCAG were 96.5% (164/170), 88.9% (48/54), 96.5% (164/170), 88.9% (48/54) and 94.6% (212/224), respectively, with excellent diagnostic agreement with histopathology and 13C breath test (Kappa=0.854). Conclusion The quantitative monitoring of gastric mucosal microstructure can be achieved under pCLE, and the quantifying indicators are helpful to improve the accuracy of HpCAG diagnosis.