Retrospective Evaluation of Various Serological Assays and Multiple Parameters for Optimal Diagnosis of Lyme Neuroborreliosis in a Routine Clinical Setting

A Step-by-Step Guide to Selecting an Optimal Cut-Off Value Based on the Receiver Operating Characteristic and Youden Index in Methods Designed to Diagnose Lyme Disease

Detection tools designed to diagnose complex diseases such as Lyme Borreliosis require an optimal cutoff point to distinguish the healthy from the diseased. The chapter will provide a practical guide to selecting an optimal cutoff mark by creating the receiver operating characteristic (ROC) in Microsoft Excel. To guide the creation of a ROC graphical plot, we will use example data from an enzyme-linked immunosorbent assay (ELISA) measuring anti-human immunoglobulin G (IgG) against whole-cell Borrelia lysates. Herein, the ROC method will demonstrate that an optical density (OD) value from ELISA with the highest Youden Index (J) is an optimal cutoff value to differentiate positive and negative IgG immune responses in human serum samples.

Case report: Successive ipsilateral and contralateral laryngeal nerve palsy as probable manifestation of neuroborreliosis

Neuroborreliosis is part of advanced stage of Lyme disease and often characterized by damage to the cranial and/or peripheral nerves. Involvement of one or both recurrent nerves is rare. Diagnosis is often difficult and based on a set of clinical manifestations, biological arguments, and cerebrospinal fluid (CSF) analysis. A 70-year-old man was referred to our Voice Clinic with a 3-month history of dysphonia caused by right vocal fold paralysis (VFP) without any cutaneous symptoms of tick bite or erythema migrans in the previous weeks and normal initial radiological examination (neck and thorax CT). Methylprednisolone had already been prescribed but without any clinical improvement. Late biological investigation 3 months after initial symptoms of VFP showed high IgG (93 U/mL; reference <10 U/mL) against Borrelia burgdorferi (BB), which was confirmed by two immunoblot markers (VIsE, p39 antigens). Therefore, a possible manifestation of Lyme disease with involvement of the right inferior laryngeal nerve was suspected, namely Lyme neuroborreliosis. However, given the spontaneous recovery of the patient after 7 months without any adapted antimicrobial regimen treatment, the diagnosis of neuroborreliosis was not confirmed by a lumbar puncture. Nineteen months later, the patient presented again for the same symptomatology but as left VFP. High IgG (68 U/mL) and IgM (>6, reference <0.90) levels against BB were confirmed by immunoblot. Subsequently, lumbar puncture was performed and revealed IgG against BB at 46.1 UA/mL (reference<5.5 UA/mL) in the CSF, with an extremely high IgG intrathecal synthesis antibody index (281.33, positive if > 1.5). Intrathecal antibody synthesis is the gold standard for Lyme neuroborreliosis demonstrating a specific immune response to BB in the central nervous system, but with the limitation of persistence for years after eradication. Our patient did not exhibit pleocytosis in the CSF. Therefore, two criteria of the European Federation of Neurological Societies (EFNS) guidelines are fulfilled for possible neuroborreliosis. Doxycycline treatment led to rapid recovery in less than 8 weeks and normal mobility of the left vocal fold. Because of this very uncommon clinical presentation with two successive episodes of VFP for no other obvious reason and serological evidence from the serum and CSF during the second episode, we consider it possible that the first episode of VFP could also have been a manifestation of neuroborreliosis. This case is the first report of possible relapse of laryngeal palsy successively on the right, and then the left side as a manifestation of Lyme neuroborreliosis.

Differential proteomic profile of lumbar and ventricular cerebrospinal fluid

BACKGROUND

Pathological cerebral conditions may manifest in altered composition of the cerebrospinal fluid (CSF). Although diagnostic CSF analysis seeks to establish pathological disturbances in the brain proper, CSF is generally sampled from the lumbar compartment for reasons of technical ease and ethical considerations. We here aimed to compare the molecular composition of CSF obtained from the ventricular versus the lumbar CSF compartments to establish a relevance for employing lumbar CSF as a proxy for the CSF bathing the brain tissue.

METHODS

CSF was collected from 46 patients with idiopathic normal pressure hydrocephalus (iNPH) patients during their diagnostic workup (lumbar samples) and in connection with their subsequent CSF diversion shunt surgery (ventricular samples). The mass-spectrometry-based proteomic profile was determined in these samples and in addition, selected biomarkers were quantified with ELISA (S100B, neurofilament light (NfL), amyloid-β (Aβ₄₀, Aβ₄₂), and total tau (T-tau) and phosphorylated tau (P-tau) forms). The latter analysis was extended to include paired porcine samples obtained from the lumbar compartment and the cerebromedullary cistern closely related to the ventricles.

RESULTS

In total 1231 proteins were detected in the human CSF. Of these, 216 distributed equally in the two CSF compartments, whereas 22 were preferentially (or solely) present in the ventricular CSF and four in the lumbar CSF. The selected biomarkers of neurodegeneration and Alzheimer's disease displayed differential distribution, some with higher (S100B, T-tau, and P-tau) and some with lower (NfL, Aβ₄₀, Aβ₄₂) levels in the ventricular compartment. In the porcine samples, all biomarkers were most abundant in the lumbar CSF.

CONCLUSIONS

The overall proteomic profile differs between the ventricular and the lumbar CSF compartments, and so does the distribution of clinically employed biomarkers. However, for a range of CSF proteins and biomarkers, one can reliably employ lumbar CSF as a proxy for ventricular CSF if or a lumbar/cranial index for the particular molecule has been established. It is therefore important to verify the compartmental preference of the proteins or biomarkers of interest prior to extrapolating from lumbar CSF to that of the ventricular fluid bordering the brain.