Failure to detect Bartonella henselae infection in synovial fluid from sufferers of chronic arthritis

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. This study aimed 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 at the Institute for Specialized Medicine (San Diego, CA, USA). 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.

IMPORTANCE

This study focuses on diagnostic testing for two common vector-borne diseases in an affected patient population. In it, we provide data showing that antibodies to B. burgdorferi, but not Bartonella spp., are more commonly found in synovial fluid than serum of patients with joint effusion. Since Lyme arthritis is a common-and sometimes difficult to diagnose-rheumatic disease, improving diagnostic capabilities is of utmost importance. While our findings are certainly not definitive for changes to practice, they do suggest that synovial fluid could be a useful sample for the clinical diagnosis of Lyme disease, and future prospective studies evaluating this claim are warranted.

Bartonella spp. bacteremia and rheumatic symptoms in patients from Lyme disease-endemic region

Prevalence of Bartonella spp. was high, especially among patients with a history of Lyme disease.

Bartonella spp. infection has been reported in association with an expanding spectrum of symptoms and lesions. Among 296 patients examined by a rheumatologist, prevalence of antibodies against Bartonella henselae, B. koehlerae, or B. vinsonii subsp. berkhoffii (185 [62%]) and Bartonella spp. bacteremia (122 [41.1%]) was high. Conditions diagnosed before referral included Lyme disease (46.6%), arthralgia/arthritis (20.6%), chronic fatigue (19.6%), and fibromyalgia (6.1%). B. henselae bacteremia was significantly associated with prior referral to a neurologist, most often for blurred vision, subcortical neurologic deficits, or numbness in the extremities, whereas B. koehlerae bacteremia was associated with examination by an infectious disease physician. This cross-sectional study cannot establish a causal link between Bartonella spp. infection and the high frequency of neurologic symptoms, myalgia, joint pain, or progressive arthropathy in this population; however, the contribution of Bartonella spp. infection, if any, to these symptoms should be systematically investigated.

Schmerzhafte Weichteilschwellung am Oberarm

Cat-scratch disease is an infection by Bartonella henselea and resolves spontaneously. We present a case of untypical Bartonella infection which was misinterpreted by MRI as a soft-tissue sarcoma of the upper arm. The histological findings of an incision biopsy were unspecific, without signs of malignancy. The tumor was excised completely and the final histology, however, showed no evidence of malignant changes. The Bartonella henselae infection could be confirmed by polymerase chain reaction. The untypical presentation of cat-scratch disease should be considered in the differential diagnosis of clinically suspected soft tissue sarcoma.

Infectious agents in chronic rheumatic diseases

The possible role of infectious microorganisms in the disease process of both arthritis and autoimmunity continue to attract both basic and clinical researchers. However, proving a causal role for these suspects is a very difficult and complicated task. This article provides an update on various mechanisms in which microbes may play roles as inciting or perpetuating factors in the pathogenesis of connective tissue disease. It also focuses on current theories that specific microorganisms may play a role in rheumatoid arthritis and ankylosing spondylitis.