Evidence Of Intrathecal Synthesis Research Articles

When the rhythm moves you

A 47-year-old lady presented with a 6-year history of increasing refractory seizures and scoliosis despite trials of multiple anti-epileptic drugs(AEDs). She described seizures of temporal lobe(TLE) semiology provoked mainly by music which evoked elation. These musicogenic reflex seizures (MRS) were occurring up to twice weekly.CT and MRI brain, paraspinal EMG, and routine EEG were unremarkable. Provoked EEG captured a gen- eralised seizure with focal left mid-anterior temporal focus with rapid bilateral spreading within 2 minutes of playing a piece of music and lasted for 90 seconds, followed by a prolonged post-ictal phase. Auto- antibody screen revealed persistently elevated and rising serum GAD-Ab(glutamic acid decarboxylase antibodies) at 11618 U/mL with GAD positive on CSF testing. CT body, PET and transvaginal ultrasound revealed no significant abnormalities. Plasmapheresis was trialled with some effect.We present a rare case of GAD-Ab mediated MRS. MRS are well described, with 9% mediated by GAD-Ab. This mechanistically accounts for the limbic MRS semiology. We highlight the importance of GAD-Ab screening for refractory new onset TLE in an adult, with high serum GAD-Ab titre (≥2000 U/mL) and evidence of intrathecal synthesis. Unlike other immune-mediated epilepsies, GAD-Ab-mediated epilepsy responds poorly to AEDs and may require immunosuppression with rituximab or cyclophosphamide.

The C6 Lyme antibody test has low sensitivity for antibody detection in cerebrospinal fluid

Our aim was to evaluate the performance of the commercial Immunetics C6 Lyme ELISA assay as a screening assay for anti- Borrelia burgdorferi antibodies in cerebrospinal fluid (CSF). Sensitivity of C6 ELISA was determined in 28 consecutive patients who were diagnosed with neuroborreliosis and had evidence for intrathecal antibody synthesis on immunoblot analysis. The presence of additional bands in CSF or of bands with a stronger intensity in CSF compared with serum was considered evidence of intrathecal synthesis. All 28 patients tested borderline or positive with C6 ELISA on serum. Of the 28 CSF samples, 17 (61%) and 19 (68%) tested positive with C6 ELISA using a threshold of 0.9 and 0.5 (optical density/cutoff). The C6 Lyme ELISA tested has a low sensitivity for antibody detection in cerebrospinal fluid compared with immunoblot analysis.

Tetranectin in cerebrospinal fluid: Biochemical characterisation and evidence of intrathecal synthesis or selective uptake into CSF

Background Tetranectin (TN) is a 67 kDa glycoprotein thought to play a prominent role in the regulation of proteolytic processes via its binding to plasminogen and indirect activation of plasminogen. The TN concentration in serum is approximately 10 mg/l and is reduced in patients with several cancers. The TN concentration in the normal CSF has not been examined. Methods The TN concentration in the serum and CSF of 47 normal subjects without neurological disorders was established using a polyclonal sandwich ELISA. Results The median TN concentration (quartile range) was 10.8 mg/l (9.0–12.1) in serum and 0.43 mg/l (0.3–0.53) in CSF. The TN index median (quartile range), defined as (TN CSF concentration/TN serum concentration)/(Albumin CSF concentration/Albumin serum concentration), was found to be 5.5 (4.7–7.6), suggesting intrathecal synthesis or selective uptake of TN in CNS. Immunohistochemistry showed TN immunoreactivity in neurons and dendrites, but no staining in glial cells in the cerebrum and cerebellum. In plexus choroideus, the ependymal cells exhibited strong immunoreactivity. TN in serum and CSF were immunochemically identical and of similar size. Conclusion TN is present in normal brain and CSF, and the TN index is very high, but further studies are necessary to decide whether TN is synthesised in the CNS or selectively transported over the blood–brain barrier.

P/Q type calcium-channel antibodies in paraneoplastic cerebellar degeneration with lung cancer.

Raised levels of P/Q type voltage-gated calcium-channel (VGCC) antibodies were found in 16 (41%) of 39 patients with paraneoplastic cerebellar degeneration (PCD) and Hu antibodies were found in nine (23%). Seven of the 16 VGCC antibody-positive patients had Lambert-Eaton myasthenic syndrome (LEMS). Seven of 15 CSF samples had VGCC antibodies, with evidence of intrathecal synthesis in four. VGCC antibodies should be looked for in PCD, even if there are no symptoms of LEMS, and may be related to the cerebellar dysfunction.

Synthesis of the complement factors C3 and C4 within the central nervous system over the course of aseptic meningitis.

The concentrations of complement factors C3 and C4 were quantified by single radial immunodiffusion in unconcentrated cerebrospinal fluid (CSF) and in serum from 38 patients up to 2 months after onset of acute aseptic meningitigs (AM). Elevated absolute concentrations were found in CSF in 26 and 35 patients, respectively, and in serum in 8 and 31, respectively. Elevation of the CSF C3 index, equal to (CSF/serum C3):(CSF/serum albumin), and of the corresponding CSF C4 index were found in 16 and 7 patients, respectively, as evidence of intrathecal synthesis. Only minor differences of the frequencies of elevated CSF C3 and C4 indices were encountered over the course of AM up to 2 months after onset. The occurrence of intrathecal C3 and C4 synthesis in AM is proposed as reflecting activation of hitherto unknown significance within the central nervous system.