Department of Human Pathology in Adult and Developmental Age "Gaetano Barresi", University of Messina, Via Consolare Valeria 1, 98124, Messina, ME, Italy.
Institute for Maternal and Child Health IRCCS "Burlo Garofolo", 34137, Trieste, Italy.
BMC Pediatr. 2022 Nov 4;22(1):639. doi: 10.1186/s12887-022-03716-1.
COPA syndrome is a rare hereditary inflammatory disease caused by mutations in the gene encoding the coatomer protein subunit alpha, causing excessive production of type I interferon. This case is a reminder for the general paediatrician, highlighting the relevance of the association between arthritis and lung involvement in toddlers.
We report the case of a 2-year-old girl with intermittent limping and joint pain. Her family history was relevant for a Still disease with lung involvement in the mother. Physical examination showed moderate wrist swelling. Laboratory findings on admission showed an increase in inflammatory markers, positive rheumatoid factor, antibodies antinuclear antibody (ANA) and cyclic citrullinated peptide (anti-CCP). Wrists' ultrasound documented synovial thickening, and chest X-rays showed an unexpected severe interstitial pneumopathy. Genetic testing confirmed the diagnosis of a heterozygous mutation of the COPA gene in c.841C > T (p.R281W). Janus kinase treatment was started (baricitinib, 4 mg daily per os) with a remarkable improvement in limping and joint pain after two weeks.
In cases of recurrent arthritis with family history and multiple involvement organs, a genetic disorder should be suspected and genetic testing should be performed. Furthermore, this case suggests that therapy with jak inhibitors may be effective and safe in interferonopathies.
COPA 综合征是一种罕见的遗传性炎症性疾病，由编码衣壳蛋白亚单位α的基因突变引起，导致 I 型干扰素过度产生。本病例提醒儿科医生注意，幼儿关节炎和肺部受累之间存在相关性。
我们报告了一例 2 岁女孩间歇性跛行和关节痛的病例。其家族史中有一例与母亲肺部受累相关的斯蒂尔病。体格检查显示中度腕关节肿胀。入院时实验室检查发现炎症标志物升高，类风湿因子阳性，抗核抗体（ANA）和环瓜氨酸肽（抗-CCP）抗体阳性。腕关节超声显示滑膜增厚，胸部 X 线显示出乎意料的严重间质性肺疾病。基因检测证实 COPA 基因 c.841C > T（p.R281W）杂合突变。开始使用 Janus 激酶治疗（巴瑞替尼，每天 4mg 口服），两周后跛行和关节痛显著改善。
对于有家族史和多个受累器官的复发性关节炎，应怀疑遗传疾病并进行基因检测。此外，本病例提示 Jak 抑制剂治疗干扰素病可能有效且安全。
