Diagnostic value of cerebrospinal fluid CXCL13 for acute Lyme neuroborreliosis. A systematic review and meta-analysis

OBJECTIVES

The utility of cerebrospinal fluid (CSF) CXCL13 for diagnosis of acute Lyme neuroborreliosis (LNB) has been debated and the test is not yet routinely performed. This study's aim was to evaluate its overall diagnostic accuracy through meta-analysis.

METHODS

Electronic searches in PubMed MEDLINE and Web of Science were performed to identify relevant articles published before January 2018. A summary receiver operating characteristic curve and an optimal cut-off were estimated modelling multiple cut-offs. Publication bias was evaluated using a funnel plot and the associated regression test.

RESULTS

A total of 18 studies involving 618 individuals with acute LNB and 2326 individuals with other neurological disorders meeting the eligibility criteria were identified. The pooled sensitivity for CSF CXCL13 was 89% (95% CI 85%-93%) and the pooled specificity was 96% (95% CI 92%-98%), using the identified optimal cut-off value of 162 pg/mL. There was marked heterogeneity between studies, caused by differences in the designs of the study populations and age distribution. The optimal cut-off in the seven studies with a cross-sectional design was 91 pg/mL (sensitivity 96%, 95% CI 92%-98%; specificity 94%, 95% CI 86%-97%) and in the 11 case-control studies it was 164 pg/mL (sensitivity 85%, 95% CI 78%-91%; specificity 95%, 95% CI 90%-98%). CSF CXCL13 values above the optimal cut-off level (determined in this meta-analysis) were also detectable in some other central nervous system disorders, namely neurosyphilis and central nervous system lymphoma.

CONCLUSIONS

Our meta-analysis shows that CSF CXCL13 has the potential to become a useful adjunct in the diagnosis of acute LNB.

A case of relapsing-remitting neuroborreliosis? Challenges in the differential diagnosis of recurrent myelitis

We report the case of a 31-year-old woman with 4 episodes of myelitis with pleocytosis, a positive Borrelia burgdorferi serology with positive antibody indices, and full recovery each time after antibiotic and steroid treatment, suggesting neuroborreliosis. We nevertheless believe that recurrent neuroborreliosis is improbable based on the levels of the chemokine CXCL13 in cerebrospinal fluid and favor the diagnosis of post-infectious autoimmune-mediated transverse myelitis possibly triggered by an initial neuroborreliosis as the cause of the relapses observed in our patient. We demonstrate the diagnostic steps and procedures which were important in the differential diagnosis of this unusual and challenging case.

Polyneuropathy associated with cholesterol crystal embolism

INTRODUCTION

Cholesterol crystal embolism complicating arterial catheterization usually presents as a multiorgan disease with renal failure, abdominal problems, and skin manifestations.

METHODS

We present a patient with hypertension and generalized arteriosclerosis who presented with muscle weakness, diffuse pain in the extremities, and renal failure 3 weeks after coronary catheterization and angioplasty of the right coronary artery. Muscle weakness progressed during the following months.

RESULTS

Nerve conduction studies and nerve biopsy showed severe axonal nerve injury. Biopsy of the kidney revealed the diagnosis of cholesterol crystal embolism.

CONCLUSION

The clinical presentation indicates a direct association of cholesterol crystal embolism and polyneuropathy. Although cholesterol crystal embolism represents a rare cause of polyneuropathy, it should be considered in patients with acute onset polyneuropathy and sudden onset multiorgan disease after arterial catheterization.

Mimicking of cerebral herniation through gamma-hydroxybutyric acid therapy

Besides being a treatment option for narcolepsy, gamma-hydroxybutyrate is used as an adjuvant during anesthesia in Europe. In addition, it is illegally used as a recreational drug. Fixed and dilated, asymmetric pupils developed in 2 patients during continuous therapy with intravenous gamma-hydroxybutyrate, which was added to the long-term anesthetics fentanyl and midazolam. Cerebral herniation as an alternative cause for the pupillary changes was ruled out by using continuous intracranial pressure monitoring and computed tomography. In both patients, the pupillary abnormalities resolved after discontinuation of gamma-hydroxybutyrate. Thus, fixed and dilated pupils that are asymmetric seem to be an important side effect of gamma-hydroxybutyrate therapy that may mimic cerebral herniation in deeply anesthetized patients.

[Cytokine CXCL13--a possible early CSF marker for neuroborreliosis]

The definitive diagnosis of acute neuroborreliosis (NB) is based upon the presence of lymphomonocytic CSF pleocytosis and intrathecal Borrelia burgdorferi (B.b.)-specific antibody production (expressed by an antibody index of >2). However, the latter might be absent in early stages of the disease. Now a recently discovered additional CSF marker-the cytokine CXCL13-was found to be positive in every initial CSF sample from patients with NB and therefore could be a valuable tool for early diagnosis and initiation of antibiotic therapy. We report an unusual case of NB in a patient with a history of metastatic carcinoma of the prostate and unilateral polyradiculitis. While no intrathecal B.b.-specific antibody production could be demonstrated initially, the CSF CXCL13 level was high (>500 ng/g vs <1.7 ng/g in healthy controls). During the course of the disease, the antibody index turned positive (4.8) and the patient responded to antibiotic therapy, thus confirming the diagnosis. In this case, measuring CXCL13 in the CSF would have led to earlier diagnosis and treatment of NB.

Clinical experience with linezolid for the treatment of central nervous system infections

Linezolid, an oxazolidinone, exhibits bacteriostatic activity against virtually all Gram-positive bacteria and even covers atypical organisms like mycobacteria and Nocardia. However, little is known about its effectiveness for central nervous system (CNS) infections. We report on our good experience with linezolid for the treatment of CNS infections in 10 patients, amongst whom three were caused by mycobacteria. While six of our patients clinically improved during linezolid therapy even after failure of various antibiotics, it was unsuccessful in one case. Side-effects were only mild gastrointestinal problems in one patient after long term-treatment, which however led to the cessation of therapy. Linezolid appears to be a safe alternative to vancomycin for therapy-resistant CNS infections because of its good CSF penetration and few side-effects.

The chemokine CXCL13 (BLC): A putative diagnostic marker for neuroborreliosis

Using protein expression profiling, the authors identified an upregulation of the chemokine B lymphocyte chemoattractant (BLC) in the CSF of patients with neuroborreliosis but not in patients with noninflammatory and various other inflammatory neurologic diseases. This upregulation was confirmed by ELISA, showing increased BLC levels in every neuroborreliosis patient while being undetectable in patients with noninflammatory neurologic diseases. These results point to BLC as a putative additional diagnostic marker for neuroborreliosis.

[Nocturnal spinal fracture--first manifestation of epilepsy]

A 54-year-old patient suffered overnight a double thoracic burst-fracture. One week later during the investigation for a metabolic or endocrinological cause, a witnessed seizure led to an unstable fracture of the humerus and the scapula. The neurological work-up revealed a cerebral astrocytoma as the epileptogenic focus. Forces generated during a tonic-clonic seizure can result in axial skeletal trauma, including thoracic and lumbar burst fractures. Vertebral fractures unrelated to an exogenous trauma are therefore always suspicious of an underlying epileptic disease.