Neoehrlichia mikurensis is uncommon in rheumatological patients receiving tumour necrosis factor inhibitors and in blood donors: a retrospective cohort study.

INTRODUCTION: Neoehrlichia mikurensis is a tick-borne bacterium that primarily causes disease in immunocompromised patients. The bacterium has been detected in ticks throughout Europe, with a 0%-25% prevalence. N. mikurensis infection presents unspecific symptoms, which can easily be mistaken for inflammatory disease activity. We aimed to determine the prevalence of N. mikurensis in rheumatological patients receiving tumour necrosis factor inhibitors (TNFi) and a cohort of healthy individuals. MATERIALS AND METHODS: This retrospective cohort study included 400 rheumatological patients treated with TNFi and 400 healthy blood donors. Plasma samples were retrieved from the Danish Rheumatological Biobank and the Danish Blood Donor Study between 2015 and 2022. Age, sex, diagnosis and duration of TNFi treatment were recovered from the Danish Rheumatological Database, DANBIO. Data on age and sex were available for the blood donors. One plasma sample per individual was tested for N. mikurensis DNA-specific real-time PCR targeting the groEL gene. RESULTS: In the rheumatological patients, the median age was 61 years (IQR 55-68 years), 62% were women, and 44% had a diagnosis of seropositive rheumatoid arthritis. In total, 54% of the patients were treated with infliximab. The median time from TNFi initiation to blood sampling was 20 months (IQR, 5-60 months). N. mikurensis DNA was not detected in any samples from patients or blood donors. CONCLUSION: N. mikurensis infection does not appear to represent a prevalent risk in Danish rheumatological patients receiving TNFi or in blood donors.

Classification of patients referred under suspicion of tick-borne diseases, Copenhagen, Denmark.

To provide better care for patients suspected of having a tick-transmitted infection, the Clinic for Tick-borne Diseases at Rigshospitalet, Copenhagen, Denmark was established. The aim of this prospective cohort study was to evaluate diagnostic outcome and to characterize demographics and clinical presentations of patients referred between the 1st of September 2017 to 31st of August 2019. A diagnosis of Lyme borreliosis was based on medical history, symptoms, serology and cerebrospinal fluid analysis. The patients were classified as definite Lyme borreliosis, possible Lyme borreliosis or post-treatment Lyme disease syndrome. Antibiotic treatment of Lyme borreliosis manifestations was initiated in accordance with the national guidelines. Patients not fulfilling the criteria of Lyme borreliosis were further investigated and discussed with an interdisciplinary team consisting of specialists from relevant specialties, according to individual clinical presentation and symptoms. Clinical information and demographics were registered and managed in a database. A total of 215 patients were included in the study period. Median age was 51 years (range 17-83 years), and 56 % were female. Definite Lyme borreliosis was diagnosed in 45 patients, of which 20 patients had erythema migrans, 14 patients had definite Lyme neuroborreliosis, six had acrodermatitis chronica atrophicans, four had multiple erythema migrans and one had Lyme carditis. Furthermore, 12 patients were classified as possible Lyme borreliosis and 12 patients as post-treatment Lyme disease syndrome. A total of 146 patients (68 %) did not fulfil the diagnostic criteria of Lyme borreliosis. Half of these patients (73 patients, 34 %) were diagnosed with an alternative diagnosis including inflammatory diseases, cancer diseases and two patients with a tick-associated disease other than Lyme borreliosis. A total of 73 patients (34 %) were discharged without sign of somatic disease. Lyme borreliosis patients had a shorter duration of symptoms prior to the first hospital encounter compared to patients discharged without a specific diagnosis (p<0.001). When comparing symptoms at presentation, patients discharged without a specific diagnosis suffered more often from general fatigue and cognitive dysfunction. In conclusion, 66 % of all referred patients were given a specific diagnosis after ended outpatient course. A total of 32 % was diagnosed with either definite Lyme borreliosis, possible Lyme borreliosis or post-treatment Lyme disease syndrome; 34 % was diagnosed with a non-tick-associated diagnosis. Our findings underscore the complexity in diagnosing Lyme borreliosis and the importance of ruling out other diseases through careful examination.

The clinical spectrum of tularemia-Two cases.

We report two cases of tularemia with different clinical manifestations, both suspected of tick-borne transmission and with near-complete remission of all symptoms within 3 months after antimicrobial treatment. The first patient presented with a classical ulceroglandular manifestation; general malaise, an ulcer and lymphadenopathy, occurring two weeks after a tick bite. Diagnosis was established by polymerase chain reaction of a skin biopsy from the ulcer. The second patient presented with a rare systemic manifestation including bacteremia and myocarditis resulting in severe clinical heart failure, pulmonary edema and secondary kidney failure. Previous tick bites were elucidated after the bacteremia was discovered. The cases underscore the heterogeneity of manifestations, the diagnostic approach and the importance of thorough medical history including recent exposures especially in cases with infection of unknown origin.

Lyme Neuroborreliosis in a Patient with Breast Cancer: MRI and PET/CT Findings.

We present a case demonstrating the performance of different radiographical and nuclear medicine imaging modalities in the diagnostic work-up of a patient with Lyme neuroborreliosis. The patient presented in late summer 2019 with radicular pains followed by a foot drop and peripheral facial palsy, both right-sided. Due to a history of breast cancer, disseminated malignant disease was initially suspected. Bone metastasis was ruled out by skeletal scintigraphy. Magnetic resonance imaging (MRI) of the neuroaxis and a whole body 18F-FDG PET-CT was performed within 48 hours. The MRI revealed a strong contrast enhancement of the conus medullaris and fibers of the cauda equina, while the 18F-FDG PET/CT was without pathological findings. Examination of cerebrospinal fluid led to the definitive diagnosis of Lyme neuroborreliosis with monocytic pleocytosis and a positive intrathecal test for Borrelia burgdorferi. The patient became pain-free after 10 days of ceftriaxone, and the paralysis slowly regressed the following month. This case highlights the difficulty of the diagnosis of Lyme neuroborreliosis and discusses the relevant imaging findings.

(18)F-FDG PET/CT Findings in Acute Epstein-Barr Virus Infection Mimicking Malignant Lymphoma.

We present a case demonstrating the diagnostic work-up and follow-up of a patient with acute Epstein-Barr virus (EBV) infection in which the clinical picture and imaging on (18)F-FDG PET/CT mimicked malignant lymphoma. Follow-up (18)F-FDG PET/CT scan in the patient performed 7 weeks after the abnormal scan revealed complete resolution of the metabolically active disease in the neck, axillas, lung hili, and spleen. This case highlights inflammation as one of the most well established false positives when interpreting (18)F-FDG PET/CT scans.