抗NXP2抗体阳性皮肌炎患者的系统性钙质沉着病例

翻译者：高洁，西京医院临床免疫科

42岁的妇女因腹痛和口腔不适而进入急诊科。该患者8年前被确诊皮肌炎，抗NXP-2抗体阳性。在过去的3年中，尽管使用强的松联合几种免疫抑制药物（甲氨蝶呤、环孢素、利妥昔单抗和γ-球蛋白）以及抗再吸收疗法，皮肤钙质沉着症仍然发展（图1A，箭头）并恶化。

由于临床怀疑肠梗阻，进行了腹部CT扫描，显示小肠扩张和腹膜钙质病变（图1B和C，箭头）。剖腹探查见无明显梗阻点，活检显示脂肪坏死和营养不良钙化。由于手术和组织学发现，笔者怀疑患者此次发病为皮肌炎有关的肠道侵犯。患者临床状况改善，静脉注射250mg甲基强的松龙连续3天，同时每两周静脉注射0.5g环磷酰胺。

抗NXP2抗体最近已被鉴定与成人皮肌炎伴严重皮肤钙化有关。此外，这种抗体在青少年皮肌炎中出现，并且可与腹部症状有关，可有多种表现：肠道血管炎、溃疡、出血、吞咽困难等。治疗无规范。虽然在青少年皮肌炎中有成功使用γ-球蛋白的案例，但该患者对这种疗法表现出难治性。为此，我们选择糖皮质激素和环磷酰胺进行积极的免疫抑制治疗。治疗后的临床改善证实了该患者肠道疾病发病机制中炎症成分参与的假设。

参考文献：

SystemicCalcinosis in NXP2-Dermatomyositis

42-year-old woman went to the emergencydepartment due to abdominal pain and oral intolerance. She had been diagnosedwith dermatomyositis 8 years ago, with a positive anti- NXP2 antibody. Duringthe previous 3 years, calcinosis cutis developed (Fig. 1A, arrows) and worseneddespite the use of prednisone combined with several immunosuppressive drugs(methotrexate, cyclosporine, rituximab, and gamma-globulin)and anti-resorptivetherapy.

Due to clinical suspicion of intestinalobstruction, an abdominal CT-scan was performed, showing small bowel dilation,and calcium lesions in the peritoneum (Fig. 1B and C, arrows). Surgery teamperformed laparotomy with no evident point of obstruction, and biopsies takenshowed fat necrosis and dystrophic calcification. Because of surgical andhistological findings, we suspected intestinal involvement related todermatomyositis. The patient’s clinical statusimproved with intravenous pulsesof 250 mg of methylprednisolone three consecutive days combined with pulseintravenous of 0.5 g cyclophosphamide fortnightly, to maintain the response.

Anti-NXP2 antibodies have recently beencharacterized and are associated with dermatomyositis in adults with a clinicalcourse with severe cutaneous calcification. Also, this antibody appears in juvenile dermatomyositis, and it isassociated with abdominal involvement with several manifestations: intestinalvasculitis, ulcers, bleeding, dysphagia, etc.Treatment is not well established.Although successful gamma-globulins were used in juvenile dermatomyositis, ourpatienthad shownrefractoriness to this therapy. For this reason, we chose aggressiveimmunosup- pressive therapy with corticosteroids and cyclophosphamide. Clinicalimprovement reinforces the hypothesis of an inflammatory component in thepathogenesis of the intestinal process.