Yamashita Yumiko, Ishii Yasutaka, Hanada Keiji, Sasaki Tamito, Fujimoto Yoshifumi, Yamaguchi Atsushi, Hirao Ken, Serikawa Masahiro, Noma Bunjiro, Minami Tomoyuki, Okazaki Akihito, Yukutake Masanobu, Mouri Teruo, Tatsukawa Yumiko, Nakamura Shinya, Ikemoto Juri, Oka Shiro
Department of Gastroenterology, Graduate School of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8441, Japan.
Department of Gastroenterology, Onomichi General Hospital, Hiroshima, Japan.
Sci Rep. 2025 Jul 8;15(1):24518. doi: 10.1038/s41598-025-10478-0.
Elevated serum IgG4 is a key diagnostic marker for type 1 autoimmune pancreatitis (AIP), but some patients lack IgG4 elevation, complicating diagnosis. This study investigated the clinicopathological features of AIP without elevated serum IgG4 levels. A total of 323 patients diagnosed with AIP at Hiroshima University Hospital and affiliated institutions were analyzed. Patients were categorized into IgG4-positive (≥ 135 mg/dL), IgG4-negative (< 135 mg/dL with "definite" or "probable" diagnosis), and possible (with "possible" diagnosis) groups. Comparative analysis was performed between the IgG4-positive (n = 281) and IgG4-negative (n = 20) groups. Segmental or focal narrowing of the main pancreatic duct (MPD) and retroperitoneal fibrosis were significantly more common in the IgG4-negative group (90.0% vs. 58.7%, P = 0.011; and 35.0% vs. 12.5%, P = 0.012, respectively). Although the number of pathological findings was comparable, the rate of surgical intervention was significantly higher in the IgG4-negative group (P < 0.001). No significant differences were observed in relapse rates or relapse sites between the two groups. These findings suggest that MPD narrowing and retroperitoneal fibrosis may be characteristic of AIP without elevated IgG4. Vigilant monitoring for relapse is warranted, regardless of serum IgG4 levels.
血清IgG4升高是1型自身免疫性胰腺炎（AIP）的关键诊断标志物，但部分患者缺乏IgG4升高，这使诊断变得复杂。本研究调查了血清IgG4水平未升高的AIP的临床病理特征。对广岛大学医院及其附属医院诊断为AIP的323例患者进行了分析。患者被分为IgG4阳性（≥135mg/dL）、IgG4阴性（<135mg/dL且诊断为“肯定”或“可能”）和可能（诊断为“可能”）组。对IgG4阳性组（n = 281）和IgG4阴性组（n = 20）进行了比较分析。IgG4阴性组主胰管（MPD）节段性或局灶性狭窄及腹膜后纤维化明显更常见（分别为90.0%对58.7%，P = 0.011；35.0%对12.5%，P = 0.012）。尽管病理结果数量相当，但IgG4阴性组的手术干预率明显更高（P < 0.001）。两组之间的复发率和复发部位未观察到显著差异。这些发现表明，MPD狭窄和腹膜后纤维化可能是血清IgG4未升高的AIP的特征。无论血清IgG4水平如何，都有必要对复发进行密切监测。
