FDA批准**锌转运体8自身抗体（ZnT8Ab）Elisa试剂盒——帮助诊断1型糖尿病

美国食品和药物管理局（FDA）8月20日批准了首个锌转运体8自身抗体（ZnT8Ab）酶联免疫吸附法（Elisa）检测试剂盒，可用于帮助确定患者患有1型糖尿病，而不是其他类型的糖尿病。该款ZnT8Ab Elisa试剂盒由美国爱达荷州的自身免疫检测专家Kronus公司研发。当与其他检测方法及患者临床资料配合使用时，ZnT8Ab Elisa试剂盒可能会帮助某些1型糖尿病患者得到及时的诊断和治疗。

1型糖尿病是儿童和青少年中最常见的糖尿病类型，但在某些情况下，成人也可能患1型糖尿病。1型糖尿病患者，因其免疫系统攻击并破坏产生胰岛素的胰腺β细胞，导致体内胰岛素生成很少或没有。胰岛素（insulin）是一种激素，能够将来源于食物的葡萄糖转化为机体所需的能量。1型糖尿病患者需要注射胰岛素来调节血糖水平，因为恰当的调节对于降低长期并发症风险至关重要，包括失明、肾功能衰竭和心血管疾病。

许多1型糖尿病患者的免疫系统会产生锌转运体8自身抗体（ZnT8Ab），但其他类型糖尿病（2型糖尿病和妊娠期糖尿病）患者体内不产生ZnT8Ab。该款ZnT8Ab Elisa试剂盒能够检测出患者血液中存在的ZnT8Ab。1型糖尿病的及早治疗对于防止胰腺β细胞的进一步恶化至关重要。ZnT8Ab试剂盒可帮助患者得到及时的诊断，并帮助更早的启动正确治疗。

Kronus公司的ZnT8Ab Elisa试剂盒通过全面上市前（de novo premarket）审查途径审查，该监管途径用于一些与已上市设备无实质等效性的低-中风险医疗器械的审查。

FDA审查了一项涉及569份血样的临床研究的数据，其中323份来自确诊1型糖尿病的血样，ZnT8Ab Elisa试剂盒检出ZnT8Ab的阳性率为65%；其余246份来自确诊为其他类型糖尿病、自身免疫性疾病及其他临床疾病的血样，ZnT8Ab Elisa试剂盒检出ZnT8Ab的假阳性率低于2%。

FDA指出，ZnT8Ab检测结果阴性，并不能排除1型糖尿病。该款试剂盒不应用于监测疾病的阶段或对治疗的反应。

关于锌转运体8（ZnT8）及其自身抗体（ZnT8Ab）：

锌是胰岛素储存和分泌机制中的一个重要组分，β细胞需要有效且特异的转运体来累积足够量的锌。锌转运体8（ZnT8）是新近发现的一种1型糖尿病自身抗原，具有高度β细胞特异性，通过影响锌离子浓度而在胰岛素合成和分泌中发挥重要作用。ZnT8自身抗体对自身免疫性糖尿病（尤其对其他自身抗体阴性者）有着重要的诊断与预测价值。ZnT8基因（SLC30A8基因）多态性影响ZnT8自身抗体的特异性。（生物谷Bioon.com）

英文原文：FDA allows marketing of first ZnT8Ab autoantibody test to help diagnose type 1 diabetes

Today, the U.S. Food and Drug Administration allowed marketing of the first zinc transporter 8 autoantibody (ZnT8Ab) test that can help determine if a person has type 1 diabetes and not another type of diabetes. When used with other tests and patient clinical information, the test may help some people with type 1 diabetes receive timely diagnosis and treatment for their disease.

Type 1 diabetes is the most common type of diabetes diagnosed in children and adolescents, but in some instances it may also develop in adults. People with the disease produce little or no insulin because their immune system attacks and destroys the cells in the pancreas that produce insulin, a hormone that converts sugars (glucose) in food to the energy the bodyneeds. People with type 1 diabetes mustinject insulinto regulate their blood glucose because proper regulation is critical to lower their risk of long-term complications such as blindness, kidney failure and cardiovascular disease.

The immune system of many people with type 1 diabetes produces ZnT8Ab, but patients with other types of diabetes (type 2 and gestational) do not. The KRONUS Zinc Transporter 8 Autoantibody (ZnT8Ab) ELISA Assay detects the presence of the ZnT8 autoantibody in a patient’s blood.

“Early treatment of type 1 diabetes is important in helping to prevent further deterioration of insulin producing cells,” said Alberto Gutierrez, Ph.D., director of the Office of In Vitro Diagnostics and Radiological Health in the Center for Devices and Radiological Health at the FDA. “This test can help patients get a timely diagnosis and help start the right treatment sooner.”

The KRONUS ZnT8Ab ELISA Assay was reviewed through the de novo premarket review pathway, a regulatory pathway for some low- to moderate-risk medical devices that are not substantially equivalent to an already legally marketed device.

The agency reviewed data from a clinical study of 569 blood samples -- 323 from patients with diagnosed type 1 diabetes and 246 samples from patients diagnosed with other kinds of diabetes, other autoimmune diseases, and other clinical conditions. The test was able to detect the ZnT8 autoantibody in 65 percent of the samples from patients with diagnosed type 1 diabetes and incorrectly gave a positive result in less than two percent of the samples from patients diagnosed with other disease.

A negative result from the test does not rule out a diagnosis of type 1 diabetes. The test should not be used to monitor the stage of disease or the response to treatment.

KRONUS Zinc Transporter 8 Autoantibody (ZnT8Ab) ELISA Assay is manufactured by KRONUS Market Development Associates, Inc. in Star, Idaho.