Honne Kyoko, Nagashima Takao, Iwamoto Masahiro, Kamesaki Toyomi, Minota Seiji
Division of Rheumatology and Clinical Immunology, Department of Medicine, Jichi Medical University, Yakushiji 3311-1, Shimotsuke, Tochigi 329-0498, Japan.
Center for Community Medicine, Jichi Medical University, Yakushiji 3311-1, Shimotsuke, Tochigi 329-0498, Japan.
Case Rep Rheumatol. 2015;2015:823563. doi: 10.1155/2015/823563. Epub 2015 Aug 6.
A 57-year-old man with rheumatoid arthritis developed severe anemia during treatment with adalimumab plus methotrexate. Cold agglutinin disease was diagnosed because haptoglobin was undetectable, cold agglutinin was positive (1 : 2048), and the direct Coombs test was positive (only to complement). Although the cold agglutinin titer was normalized (1 : 64) after treatment with prednisolone (0.7 mg/kg/day for two weeks), the patient's hemoglobin did not increase above 8 g/dL. When cold agglutinins were reexamined using red blood cells suspended in bovine serum albumin, the titer was still positive at 1 : 1024. Furthermore, the cold agglutinin had a wide thermal amplitude, since the titer was 1 : 16 at 30°C and 1 : 1 at 37°C. This suggested that the cold agglutinin would show pathogenicity even at body temperature. After the dose of prednisolone was increased to 1 mg/kg/day, the patient's hemoglobin rapidly returned to the normal range. The thermal amplitude test using red blood cells suspended in bovine serum albumin is more sensitive than the standard test for detecting pathogenic cold agglutinins.
一名57岁的类风湿关节炎男性患者在使用阿达木单抗联合甲氨蝶呤治疗期间出现了严重贫血。由于触珠蛋白检测不到、冷凝集素呈阳性（1∶2048）且直接抗人球蛋白试验呈阳性（仅针对补体），诊断为冷凝集素病。尽管使用泼尼松龙（0.7mg/kg/天，持续两周）治疗后冷凝集素效价恢复正常（1∶64），但患者的血红蛋白并未升至8g/dL以上。当使用悬浮于牛血清白蛋白中的红细胞重新检测冷凝集素时，效价仍为阳性，为1∶1024。此外，冷凝集素的热振幅较宽，因为在30℃时效价为1∶16，在37℃时效价为1∶1。这表明冷凝集素即使在体温下也可能具有致病性。将泼尼松龙剂量增加至1mg/kg/天后，患者的血红蛋白迅速恢复至正常范围。使用悬浮于牛血清白蛋白中的红细胞进行的热振幅试验在检测致病性冷凝集素方面比标准试验更敏感。
