Ichikawa Tatsuki, Yamashima Mio, Yamamichi Shinobu, Koike Makiko, Nakano Yusuke, Yajima Hiroyuki, Miyazaki Osamu, Ikeda Tomonari, Okamura Takuma, Nagata Kazuyoshi, Sawa Kenichi, Niiya Kazutaka, Nakao Kazuhiko
Department of Gastroenterology, Nagasaki Harbor Medical Center, Nagasaki 850-8555, Japan.
Department of Comprehensive Community Care Systems, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8501, Japan.
Biomed Rep. 2024 Aug 1;21(4):142. doi: 10.3892/br.2024.1830. eCollection 2024 Oct.
The relationship between immunoglobulin A (IgA) levels and chronic liver disease remains poorly understood. The present study evaluated the clinical significance of IgA in 478 new patients who visited the Outpatient Clinic of Nagasaki Harbor Medical Center (Nagasaki, Japan). Serum IgA levels in comparison to liver stiffness (LS), as measured using a FibroScan device, were evaluated in 358 patients. Furthermore, in 270 patients, the associations between serum IgA levels and body composition were analyzed using computed tomography. The IgA levels of patients in the groups with Child-Pugh classification B and C (CPGBC), alcoholic liver disease (ALD), steatotic liver disease (SLD) or diabetes were higher than the IgA levels of patients in the groups with CPGA, non-ALD, non-SLD or no diabetes, respectively. Logistic regression analysis showed that CPGBC, ALD, high IgG (>1,700 mg/dl), high macrophage galactose-specific lectin-2 binding protein glycosylation isomer (M2BPGi) (>1 cut-off index) and diabetes were contributing factors for high serum IgA level (>410 mg/dl). The ratio of IgA level divided by IgG level was highest in patients with ALD, followed by those with metabolic dysfunction-associated SLD (MASLD) and non-SLD. In SLD, IgA level was associated more with LS than M2BPGi and fibrosis-4 (FIB-4) in multiple regression analysis. In the receiver operating characteristic analysis, IgA level, M2BPG, and FIB-4 had similar area under the curve values for discriminating high LS (>8 kPa) from low LS (≤8 kPa) in SLD. IgA levels were also associated with visceral fat, and this association was only found in women. In conclusion, elevated IgA is an indicator of liver fibrosis that also reflects the presence of diabetes and an increased visceral fat level. Therefore, IgA is considered a useful marker of liver disease severity in the current era of increased SLD.
免疫球蛋白A（IgA）水平与慢性肝病之间的关系仍未得到充分了解。本研究评估了478名到长崎港医疗中心（日本长崎）门诊就诊的新患者中IgA的临床意义。在358名患者中评估了血清IgA水平与使用FibroScan设备测量的肝脏硬度（LS）的关系。此外，在270名患者中，使用计算机断层扫描分析了血清IgA水平与身体成分之间的关联。Child-Pugh分类B和C组（CPGBC）、酒精性肝病（ALD）、脂肪性肝病（SLD）或糖尿病患者的IgA水平分别高于Child-Pugh分类A组（CPGA）、非ALD、非SLD或无糖尿病组患者的IgA水平。逻辑回归分析表明，CPGBC、ALD、高IgG（>1700mg/dl）、高巨噬细胞半乳糖特异性凝集素-2结合蛋白糖基化异构体（M2BPGi）（>1个临界指数）和糖尿病是血清IgA水平升高（>410mg/dl）的影响因素。IgA水平除以IgG水平的比值在ALD患者中最高，其次是代谢功能障碍相关脂肪性肝病（MASLD）和非SLD患者。在多因素回归分析中，在SLD中，IgA水平与LS的相关性比与M2BPGi和纤维化-4（FIB-4）的相关性更强。在接受者操作特征分析中，在SLD中，IgA水平、M2BPG和FIB-4在区分高LS（>8kPa）和低LS（≤8kPa）方面具有相似的曲线下面积值。IgA水平也与内脏脂肪有关，且这种关联仅在女性中发现。总之，IgA升高是肝纤维化的一个指标，也反映了糖尿病的存在和内脏脂肪水平的增加。因此，在当前SLD增加的时代，IgA被认为是肝病严重程度的一个有用标志物。
