背景:培养阴性感染性心内膜炎(IE)约占所有IE病例的10%。巴尔通体心内膜炎是培养阴性心内膜炎的常见原因,并与高死亡率相关。迄今为止,在英国,没有报告IE巴尔通体与冷球蛋白血症相关的病例.我们介绍了一例在年轻女性中引起继发性冷球蛋白血症的BartonellaIE的独特病例。
方法:一名17岁女性,在4岁时用心脏导管修复肺动脉闭锁和室间隔缺损,有一年的体重减轻史(53至39公斤)和食欲不振。随后,她出现了血管性皮疹和血液蛋白尿,肾功能下降,需要紧急入院。最初的血液检查显示肌酐接近正常,但是胱抑素C升高。肾活检显示局灶性坏死性肾小球肾炎,无急性肾小管坏死或慢性改变。随后的血液检查支持冷球蛋白血症性血管炎的诊断(高类风湿因子,低补充,多克隆丙种球蛋白病,3型冷球蛋白)。弱阳性PR3意味着这是否可能是原发性ANCA相关性血管炎(AAV)存在一定的不确定性。感染原因的初步检查,包括多种血液培养,是阴性的。然而,超声心动图显示她的手术导管上有明确的植被。患者对经验性抗微生物药物没有反应,因此被转诊为手术翻修她的导管。术中获得的组织样本证明了巴尔通体物种。术后有针对性的抗菌药物,随着免疫学异常的解决,她得到了改善,并且在最后的审查中肾脏轮廓正常。回顾她的社会历史,她在前一年收养了几只流浪猫;因此,确定了巴尔通体感染的原因。
结论:这是英国报道的首例巴尔通体心内膜炎导致继发性冷球蛋白血症的病例。该病例的关键学习点包括巴尔通体心内膜炎可表现为冷球蛋白血症性血管炎,当冷球蛋白血症的病因不明确时,应考虑任何差异,并询问相关暴露,尤其是怀疑培养阴性心内膜炎时。
BACKGROUND: Culture-negative infective endocarditis (IE) constitutes approximately 10% of all cases of IE. Bartonella endocarditis is a common cause of culture-negative endocarditis and is associated with a high mortality rate. To date, no cases of Bartonella IE has been reported in association with cryoglobulinemia in the UK. We present a unique case of Bartonella IE causing secondary cryoglobulinemia in a young female.
METHODS: A 17-year-old female with a background of pulmonary atresia and ventricular septal defect repaired with a cardiac conduit at the age of 4, presented with a one-year history of weight loss (from 53 to 39 kg) and poor appetite. She subsequently developed a vasculitic rash and haematoproteinuria with decline in renal function, requiring urgent hospital admission. Initial blood tests showed a near normal creatinine, but a raised cystatin C. Renal biopsy showed focal necrotizing glomerulonephritis with no acute tubular necrosis or chronic change. Subsequent blood tests supported a diagnosis of cryoglobulinaemic vasculitis (high rheumatoid factor, low complement, polyclonal gammopathy, Type 3 cryoglobulin). A weak positive PR3 meant there was some uncertainty about whether this could be a primary ANCA-associated vasculitis (AAV). Initial workup for an infectious cause, including multiple blood cultures, were negative. However, an echocardiogram showed definite vegetations on her surgical conduit. The patient did not respond to empirical antimicrobials and so was referred for surgical revision of her conduit. Tissue samples obtained intra-operatively demonstrated Bartonella species. With targeted antimicrobials post-operatively, she improved with resolution of immunologic abnormalities and at last review had a normal renal profile. On reviewing her social history, she had adopted several stray cats in the preceding year; and thus, the cause of the Bartonella infection was identified.
CONCLUSIONS: This is the first reported case of Bartonella endocarditis causing secondary cryoglobulinemia reported in the UK. The key learning points from this case include that Bartonella endocarditis can present as a cryoglobulinaemic vasculitis and should be considered in any differential when the cause of cryoglobulinaemia is not clear and to enquire about relevant exposures especially when culture-negative endocarditis is suspected.