18F-FDG PET/CT对皮肌炎抗MDA5抗体及预后的预测价值

目的:分析抗黑色素瘤分化相关基因5(MDA5)抗体阳性皮肌炎患者的肌肉FDG代谢、肿瘤发生率以及肺间质性改变在¹⁸F-FDG PET/CT的影像特征及其鉴别抗MDA5抗体阳性皮肌炎的价值。 方法:回顾性分析2016年6月至2019年7月在上海交通大学医学院附属仁济医院接受¹⁸F-FDG PET/CT检查的75例(34例抗MDA5抗体阳性,41例抗MDA5抗体阴性)皮肌炎患者男21例、女54例,年龄(52.3±14.3)岁]和30名健康对照者男10名、女20名,年龄(53.5±11.8)岁]的影像和临床资料,测定并计算肌肉SUV max及肌肉SUV max平均值(mSUV max);统计皮肌炎患者合并肿瘤性病变的情况;测定皮肌炎合并间质性肺炎患者肺炎病灶的SUV max。采用两独立样本 t检验、单因素方差分析、SNK检验和 χ²检验分析数据;行ROC曲线分析肌肉mSUV max鉴别抗MDA5抗体阳性皮肌炎的诊断效能。 结果:健康对照者、抗MDA5抗体阳性和抗MDA5抗体阴性皮肌炎患者的肌肉mSUV max分别为0.39±0.05、0.66±0.21和0.87±0.29( F=39.93, P<0.001);皮肌炎患者的肌肉mSUV max均高于健康对照者( q值:6.76、12.63,均 P<0.001);抗MDA5抗体阴性患者高于抗MDA5抗体阳性患者( q=5.79, P<0.001)。ROC AUC为0.74,当肌肉mSUV max取最佳阈值0.75时,在皮肌炎中鉴别出抗MDA5抗体阳性的准确性为74.7%(56/75)。抗MDA5抗体阴性患者中,恶性肿瘤6例(14.6%,6/41);抗MDA5抗体阳性患者中,无恶性肿瘤病例(0/34;χ²=5.41, P=0.020)。抗MDA5抗体阴性伴发间质性肺炎11例(26.8%, 11/41),抗MDA5抗体阳性伴发间质性肺炎33例(97.1%, 33/34;χ²=37.81, P<0.001);抗MDA5抗体阳性患者肺炎FDG代谢高于抗MDA5抗体阴性患者(SUV max:3.65±1.83和2.38±1.27;t=2.13, P=0.039)。 结论:抗MDA5抗体阳性皮肌炎患者的肌肉FDG代谢高于健康对照者,但低于抗MDA5抗体阴性患者。抗MDA5抗体阳性患者肿瘤性病变发生率低于抗MDA5抗体阴性患者。抗MDA5抗体阳性患者发生间质性肺炎的比例和严重程度均高于阴性患者。¹⁸F-FDG PET/CT对于鉴别抗MDA5抗体阳性皮肌炎具有一定价值。

Predictive value of18F-FDG PET/CT for anti-MDA5 antibody and prognosis of dermatomyositis

Objective To assess the imaging characteristics of muscle FDG metabolism,tumor incidence,and pulmonary interstitial changes in patients with anti-melanoma differentiation-associated gene 5(MDA5)antibody positivity in¹⁸F-FDG PET/CT imaging,and the value of¹⁸F-FDG PET/CT in differentiating anti-MDA5 antibody positive dermatomyositis.Methods From June 2016 to July 2019,the PET/CT images of 75 patients with dermatomyositis(21 males,54 females,age(52.3±14.3)years;34 anti-MDA5 antibody positive and 41 anti-MDA5 antibody negative)and 30 healthy controls(10 males,20 females;age(53.5±11.8)years)were retrospectively analyzed in Renji Hospital,School of Medicine,Shanghai Jiao Tong University.The SUVmax of muscle was measured and the mean of SUVmax(mSUVmax)was calculated.Statistics of patients with dermatomyositis complicated with neoplastic lesions and the SUVmax of pneumonia lesions in patients with dermatomyositis complicated with interstitial pneumonia was determined.Independent sample t test,one-way analysis of variance,Student-Newman-Keuls(SNK)test andχ² test were used to analyze data.The ROC curve analysis was used to analyze the diagnostic efficacy of mSUVmax for the differential diagnosis of anti-MDA5 antibody positive dermatomyositis.Results The muscle mSUVmax of the control group,anti-MDA5 antibody positive and negative groups were 0.39±0.05,0.66±0.21 and 0.87±0.29(F=39.93,P<0.001),respectively.The muscle mSUVmax of dermatomyositis patients was increased compared with healthy controls(q values:6.76,12.63,both P<0.001),and the muscle mSUVmax of anti-MDA5 antibody negative was higher than positive(q=5.79,P<0.001).The AUC was 0.74,and the cut-off value of muscle mSUVmax was 0.75 with the accuracy of 74.7%(56/75).Of 41 patients with negative anti-MDA5 antibody,there were 6(14.6%)had malignant tumor,while there was no malignant tumor in patients with positive anti-MDA5 antibody(0/34;χ²=5.41,P=0.020).There were 11 patients(26.8%,11/41)with anti-MDA5 antibody negative dermatomyositis complicated with interstitial pneumonia and 33 patients(97.1%,33/34)with anti-MDA5 antibody positive dermatomyositis complicated with interstitial pneumonia(χ²=37.81,P<0.001).FDG metabolism in anti-MDA5 antibody positive patients was higher than that in anti-MDA5 antibody negative patients(lesion SUVmax:3.65±1.83 and 2.38±1.27;t=2.13,P=0.039).Conclusions The muscle FDG metabolism of anti-MDA5 antibody positive dermatomyositis patients is higher than that of healthy controls,but lower than that of anti-MDA5 antibody negative patients.The incidence of neoplastic lesions in patients with positive anti-MDA5 antibody is lower than that in patients with negative anti-MDA5 antibody.The proportion and severity of interstitial pneumonia are higher in patients with positive anti-MDA5 antibody than in those with negative anti-MDA5 antibody.18F-FDG PET/CT has certain value on identifying anti-MDA5 antibody positive dermatomyositis.