Immunoluminometric assay for copeptin measurement in cerebrospinal fluid: Technical aspects and pilot study.

BACKGROUND: Copeptin acts as surrogate marker under stress stimuli, as well as an outcome predictor based on serum or plasma concentration in patients suffering intracranial hemorrhage, aneurysmal subarachnoid hemorrhage (aSAH), and stroke. The aim of this study was to establish a method for quantification of copeptin levels in cerebrospinal fluid (CSF) and to demonstrate its clinical applicability in patients following aSAH. METHODS: This assay was validated for CSF samples using a commercial immunoluminometric assay (IMLA). For the control group (10 patients), CSF copeptin levels were determined in patients without signs of acute neurological diseases and who underwent a diagnostic lumbar puncture. The pilot cohort included calculation of copeptin levels in CSF and in serum of patients following aSAH. RESULTS: The control group had CSF copeptin levels lower than 0.78 pmol/L-1. Among patients with aSAH, CSF copeptin values had a mean of 20.1 pmol/L-1 and serum copeptin concentrations had a mean of 61.39 pmol/L-1. CONCLUSIONS: This assay provides to best of our knowledge for the first time initial ranges values of CSF copeptin for patients without acute neurological disease and in patients with aSAH. Thus, it opens new doors to develop further calculations and relationships between diseases biomarker and outcome prediction.

Calcium Microcrystal Formation in Recurrent Herniation Patients After Autologous Disc Cell Transplantation.

Autologous disc cell transplantation (ADCT) is a cell-based therapy aiming to initiate regeneration of intervertebral disc (IVD) tissue, but little is known about potential risks. This study aims to investigate the presence of structural phenomena accompanying the transformation process after ADCT treatment in IVD disease. Structural phenomena of ADCT-treated patients (Group 1, n = 10) with recurrent disc herniation were compared to conventionally-treated patients with recurrent herniation (Group 2, n = 10) and patients with a first-time herniation (Group 3, n = 10). For ethical reasons, a control group of ADCT patients who did not have a recurrent disc herniation was not possible. Tissue samples were obtained via micro-sequestrectomy after disc herniation and analyzed by micro-computed tomography, scanning electron microscopy, energy dispersive spectroscopy, and histology in terms of calcification zones, tissue structure, cell density, cell morphology, and elemental composition. The major differentiator between sample groups was calcium microcrystal formation in all ADCT samples, not found in any of the control group samples, which may indicate disc degradation. The incorporation of mineral particles provided clear contrast between the different materials and chemical analysis of a single particle indicated the presence of magnesium-containing calcium phosphate. As IVD calcification is a primary indicator of disc degeneration, further investigation of ADCT and detailed investigations assessing each patient's Pfirrmann degeneration grade following herniation is warranted. Structural phenomena unique to ADCT herniation prompt further investigation of the therapy's mechanisms and its effect on IVD tissue. However, the impossibility of a perfect control group limits the generalizable interpretation of the results.