Maleki Iradj, Aminafshari Mahmood Reza, Taghvaei Tarang, Hosseini Vahid, Rafiei Alireza, Torabizadeh Zhila, Barzin Maryam, Orang Elahe
Iradj Maleki, Mahmood Reza Aminafshari, Tarang Taghvaei, Vahid Hosseini, Elahe Orang, Inflammatory Diseases of Upper Gastrointestinal Tract Research Center, Mazandaran University of Medical Sciences, Sari 48166-33131, Iran.
World J Gastroenterol. 2014 Sep 21;20(35):12566-73. doi: 10.3748/wjg.v20.i35.12566.
To evaluate the diagnostic accuracy of serum Immunoglobulin A (IgA) for differentiating early stage nonalcoholic fatty liver disease (NAFLD) from nonalcoholic steatohepatitis (NASH).
All cases had fatty liver change confirmed by ultrasound and aminotransferases of at least twice the normal level. Clinical and biochemical data, including serum IgA, were obtained from 50 histologically proven NAFLD cases and 54 healthy controls. Fasting whole blood samples were obtained from the study population. Immunoturbidimetric methods were used to measure the IgA levels. All NAFLD cases were hospitalized for liver biopsy. Liver specimens were examined for steatosis, steatohepatitis and fibrosis within hepatocytes. Patients were categorized into two groups: NASH and non-NASH. Variables were compared within cases (NASH vs non-NASH) and controls. Cut-off values of serum IgA were evaluated using analysis of receiver operating characteristic (ROC curves). Associations between the variables were tested using calculations of correlation coefficients. Statistical significances were assigned to P values < 0.05.
The extent of liver fibrosis correlated positively with IgA levels. Subjects with no fibrosis in their liver biopsies had a lower IgA level (301.5 ± 91.2 mg/dL) than subjects with any degree of fibrosis (388.8 ± 140.8 mg/dL), (P = 0.01). IgA levels were higher in NASH cases, and its value was significantly higher for higher degrees of fibrosis. Patients with perisinusoidal or pericellular fibrosis had significantly higher levels of IgA (403.5 ± 133.9 mg/dL, 418.2 ± 129.5 mg/dL) compared to those without it (301.8 ± 94.9 mg/dL, 297.7 ± 91.5 mg/dL), respectively. No significant correlation was found between steatosis grade and serum IgA levels. Based on ROC analysis, the best predictive IgA cutoff value for detecting liver fibrosis was 360 mg/dL (61% sensitivity, 81% specificity).
The serum IgA level is useful to evaluate the severity of liver fibrosis and can be used serially for evaluation and follow-up of NAFLD cases.
评估血清免疫球蛋白A（IgA）在鉴别早期非酒精性脂肪性肝病（NAFLD）与非酒精性脂肪性肝炎（NASH）方面的诊断准确性。
所有病例均经超声证实有脂肪肝改变，且转氨酶至少为正常水平的两倍。从50例经组织学证实的NAFLD病例和54例健康对照中获取临床和生化数据，包括血清IgA。从研究人群中采集空腹全血样本。采用免疫比浊法测量IgA水平。所有NAFLD病例均住院接受肝活检。对肝组织标本进行肝细胞内脂肪变性、脂肪性肝炎和纤维化检查。患者分为两组：NASH组和非NASH组。对病例组（NASH组与非NASH组）和对照组的变量进行比较。使用受试者操作特征（ROC曲线）分析评估血清IgA的临界值。使用相关系数计算来检验变量之间的关联。P值<0.05具有统计学意义。
肝纤维化程度与IgA水平呈正相关。肝活检无纤维化的受试者IgA水平（301.5±91.2mg/dL）低于有任何程度纤维化的受试者（388.8±140.8mg/dL），（P = 0.01）。NASH病例的IgA水平较高，且纤维化程度越高其值越高。与无窦周或细胞周纤维化的患者相比，有窦周或细胞周纤维化的患者IgA水平显著更高（分别为403.5±133.9mg/dL，418.2±129.5mg/dL），而无纤维化的患者IgA水平分别为301.8±94.9mg/dL，297.7±91.5mg/dL。脂肪变性程度与血清IgA水平之间未发现显著相关性。基于ROC分析，检测肝纤维化的最佳预测IgA临界值为360mg/dL（灵敏度61%，特异性81%）。
血清IgA水平有助于评估肝纤维化的严重程度，可用于NAFLD病例的连续评估和随访。
