Antibodies to Borrelia burgdorferi and Bartonella species in serum and synovial fluid from people with rheumatic diseases

Vector-borne infections may underlie some rheumatic diseases, particularly
in people with joint effusions. The aim of this study was to compare serum
and synovial fluid antibodies to B. burgdorferi and Bartonella spp. in
patients with rheumatic diseases. This observational, cross-sectional
study examined paired synovial fluid and serum specimens collected from
110 patients with joint effusion between October 2017 and January 2022.
Testing for antibodies to B. burgdorferi (using CDC criteria) and
Bartonella spp. via two Indirect Fluorescent Antibody [IFA] assays, was
performed as part of routine patient care. There were 30 participants
(27%) with positive two-tier B. burgdorferi serology, and 26
participants (24%) with IFA seroreactivity (≥1:256) to B. henselae and/or
B. quintana. Both B. burgdorferi IgM and IgG were detected more frequently
in synovial fluid than serum: 27% of patients were either IgM or IgG
positive in synovial fluid, compared to 15.5% in serum (p = 0.048).
Conversely, B. henselae and B. quintana antibodies were detected more
frequently in serum than synovial fluid; overall only 2% of patients had
positive IFA titers in synovial fluid, compared to 24% who had positive
IFA titers in serum (p <0.001). There were no significant
associations between B. burgdorferi or Bartonella spp. seroreactivity with
any of the clinical rheumatological diagnoses. This study provides
preliminary support for the importance of synovial fluid antibody testing
for documenting exposure to B. burgdorferi, but not for
documenting exposure to Bartonella spp.

虫媒感染可能是部分风湿性疾病的潜在病因，尤其在伴有关节积液的患者群体中更为显著。本研究旨在对比风湿性疾病患者体内针对伯氏疏螺旋体（B. burgdorferi）和巴尔通体属（Bartonella spp.）的血清与滑液抗体水平。本项观察性横断面研究纳入了2017年10月至2022年1月期间收集的110例关节积液患者的配对滑液与血清标本。针对伯氏疏螺旋体的抗体检测遵循美国疾病控制与预防中心（CDC）制定的标准，同时通过两项间接荧光抗体（IFA）试验完成巴尔通体属的抗体检测，上述检测均作为患者常规诊疗的一部分开展。本研究中共30例受试者（占比27%）的双相伯氏疏螺旋体血清学检测结果呈阳性；另有26例受试者（占比24%）的汉赛巴尔通体（B. henselae）和/或五日热巴尔通体（B. quintana）IFA血清学反应呈阳性（滴度≥1:256）。伯氏疏螺旋体IgM与IgG抗体在滑液中的检出率均高于血清：27%的患者滑液标本中IgM或IgG抗体呈阳性，而血清标本的阳性占比仅为15.5%（p = 0.048）。与之相反，汉赛巴尔通体与五日热巴尔通体抗体在血清中的检出率更高：整体仅2%的患者滑液标本IFA滴度呈阳性，而血清标本阳性占比达24%（p <0.001）。伯氏疏螺旋体或巴尔通体属的血清学反应与任何临床风湿性疾病诊断均无显著关联。本研究初步证实，滑液抗体检测可辅助佐证伯氏疏螺旋体暴露史，但无法用于验证巴尔通体属的暴露情况。