血清IgG4和CA199联合检测在自身免疫性胰腺炎和胰腺癌鉴别诊断中的意义

目的研究血清IgG4在中国人自身免疫性胰腺炎（AIP）中的诊断价值．并探讨联合检测血清糖类抗原199（CA199）在AIP和胰腺癌鉴别诊断中的作用。方法750例慢性胰腺炎患者和30例胰腺癌患者血样采白2009年8月至2010年7月消化科门诊或住院患者；30名正常健康人血样取自血站和体检部。血清IgG4浓度采用速率散射比浊法测定，血清CA199浓度采用电化学免疫发光法测定。各组间血清IgCA和CA199浓度变化的差异采用非参数统计分析。结果750例慢性胰腺炎患者血清中有28例血清IgG4浓度高于正常参考值上限（〉2．0g／L），其中11例（1．4％）患者经影像学和胰腺穿刺活检病理检查等确诊为AIP，其IgG4浓度中位数为11．10（4．12～37．20）g／L；胰腺癌患者IgG4浓度为0．51（0．06～1．12）g/L，正常对照组IgG4浓度为0．56（0．18～1．50）g／L。AIP患者组血清中的IgG4浓度明显高于正常参考值上限，且明显高于胰腺癌患者和正常对照组（P〈0．0001）。胰腺癌组血清IgG4水平均低于正常参考值上限，与正常对照组比较差异无统计学意义。所有确诊A1P患者血清CA199浓度7例患者轻、中度升高，余低于正常参考值上限（〈37U／L），浓度中位数为41．48（0．60～136．40）U／L；然而胰腺癌组血清CA199浓度中位数为533．60（4．25～1000）U／L，明显高于AIP患者组（P〈0．01）。结论血清IgG4明显升高，用于辅助诊断AIP具有较高的特异性和敏感性，提示将IgG4水平纳入AIP的诊断标准对中国人也适用；在AIP和胰腺癌难以鉴别时，同时检测血清IgG4和CA199有助于临床对AIP和胰腺癌的鉴别诊断。

Significance on the combination determination of serum IgG4 and CA199 in differential diagnosis between autoimmune pancreatitis and pancreatic cancer

Objective To investigate the diagnostic value of the serum IgG4 in autoimmune pancreatitis （AIP） in Chinese people and the differential diagnosis value of the combination determination of serum IgG4 and carbohydrate antigen 199（CA199） between AIP and pancreatic cancer. Methods A total of 750 patients with chronic pancreatitis and 30 patients with pancreatic cancer were enrolled from patients and inpatients of digestion department during August 2009 to July 2010. The 30 healthy blood samples were collected from the blood bank and health examination department. Serum lgG4 was determined by rate nephelometry assay, and serum CA199 was detected by electrochemilumineseence assay. Non-parametric statistical analysis was performed to analyze the concentration differences of serum IgG4 and CA199 in each group. Results In serum samples from 750 patients with chronic pancreatitis, 28 cases had IgG4 levels exceeding the upper limit of normal reference（ 〉 2.0 g/L） , among which II cases （ 1. 4% ） were finally identified as AIP according to imaging and pathological examination. The median concentration of IgG4 was ll. l0 （4. 12-37. 20）g/L. The median concentrations of serunl IgG4 in patients with pancreatic cancer and healthy control group were 0.51 （0.06-1. 12 ） g/L and 0.56 （0. 18-1.50 ） g/L, respectively. Serum IgG4 concentrations in AIP patients exceeding the upper limit of normal reference were significantly higher than those in patients with pancreatic cancer and healthy control group （P 〈 0. 000 1 ）. All serum IgG4 concentrations in patients with pancreatic cancer were lower than the upper limit of normal reference and had no statistical significance with the healthy control group. Serum CA199 in 7 out 11 of AIP patients were higher, while the other 4 patients were lower than the upper limit of normal reference （ 〈 37 U/L）. The median concentration was 41.48 （0.60-136.40）U/L. Serum CA199 in patients with pancreatic cancer was significantly higher than that in AIP patients with a median concentration of 533.60 （4.25-1 000 ） U/L （P 〈 0.01 ）. Conclusions High specificity and sensitivity of serum IgG4 obvious increasing in AIP diagnosis is further confirmed in Chinese people. The combination determination of serum IgG4 and CA199 contributes to the differential diagnosis of AIP and pancreatic cancer.