Peripherin is a biomarker of axonal damage in peripheral nervous system disease.

Valid, responsive blood biomarkers specific to peripheral nerve damage would improve management of peripheral nervous system (PNS) diseases. Neurofilament light chain (NfL) is sensitive for detecting axonal pathology but is not specific to PNS damage, as it is expressed throughout the PNS and CNS. Peripherin, another intermediate filament protein, is almost exclusively expressed in peripheral nerve axons. We postulated that peripherin would be a promising blood biomarker of PNS axonal damage. We demonstrated that peripherin is distributed in sciatic nerve, and to a lesser extent spinal cord tissue lysates, but not in brain or extra-neural tissues. In the spinal cord, anti-peripherin antibody bound only to the primary cells of the periphery (anterior horn cells, motor axons and primary afferent sensory axons). In vitro models of antibody-mediated axonal and demyelinating nerve injury showed marked elevation of peripherin levels only in axonal damage and only a minimal rise in demyelination. We developed an immunoassay using single molecule array technology for the detection of serum peripherin as a biomarker for PNS axonal damage. We examined longitudinal serum peripherin and NfL concentrations in individuals with Guillain-Barré syndrome (GBS, n = 45, 179 time points), chronic inflammatory demyelinating polyradiculoneuropathy (CIDP, n = 35, 70 time points), multiple sclerosis (n = 30), dementia (as non-inflammatory CNS controls, n = 30) and healthy individuals (n = 24). Peak peripherin levels were higher in GBS than all other groups (median 18.75 pg/ml versus < 6.98 pg/ml, P < 0.0001). Peak NfL was highest in GBS (median 220.8 pg/ml) and lowest in healthy controls (median 5.6 pg/ml), but NfL did not distinguish between CIDP (17.3 pg/ml), multiple sclerosis (21.5 pg/ml) and dementia (29.9 pg/ml). While peak NfL levels were higher with older age (rho = +0.39, P < 0.0001), peak peripherin levels did not vary with age. In GBS, local regression analysis of serial peripherin in the majority of individuals with three or more time points of data (16/25) displayed a rise-and-fall pattern with the highest value within the first week of initial assessment. Similar analysis of serial NfL concentrations showed a later peak at 16 days. Group analysis of serum peripherin and NfL levels in GBS and CIDP patients were not significantly associated with clinical data, but in some individuals with GBS, peripherin levels appeared to better reflect clinical outcome measure improvement. Serum peripherin is a promising new, dynamic and specific biomarker of acute PNS axonal damage.

Progression in multiple sclerosis is associated with low endogenous NCAM.

Multiple sclerosis (MS) is a CNS disorder characterized by demyelination and neurodegeneration. Although hallmarks of recovery (remyelination and repair) have been documented in early MS, the regenerative capacity of the adult CNS per se remains uncertain with the wide held belief that it is either limited or non-existent. The neural cell adhesion molecule (NCAM) is a cell adhesion molecule that has been widely implicated in axonal outgrowth, guidance and fasciculation. Here, we used in vitro and in vivo of MS to investigate the role of NCAM in disease progression. We show that in health NCAM levels decrease over time, but this occurs acutely after demyelination and remains reduced in chronic disease. Our findings suggest that depletion of NCAM is one of the factors associated with or possibly responsible for disease progression in MS.

An audit of growth hormone replacement for GH-deficient adults in Scotland.

OBJECTIVE: Guidelines on the clinical use of growth hormone therapy in adults were issued by the UK National Institute for Clinical Excellence (NICE) in August 2003. We conducted a retrospective clinical audit on the use of growth hormone (GH) in Scotland to evaluate the use of these guidelines and their impact on clinical practice. The audit had two phases. In phase I, the impact of NICE criteria on specialist endocrine practice in starting and continuing GH replacement was assessed. In phase II, the reasons why some adults in Scotland with growth hormone deficiency were not on replacement therapy were evaluated. METHODS: A retrospective cross-sectional case note review was carried out of all adult patients being followed up for growth hormone deficiency during the study period (1 March 2005 to 31 March 2008). Phase I of the audit included 208 patients and phase II 108 patients. RESULTS: Sellar tumours were the main cause of GH deficiency in both phases of the audit. In phase I, 53 patients (77%) had an AGHDA-QoL score >11 documented before commencing GH post-NICE guidance, compared with 35 (25%) pre-NICE guidance. Overall, only 39 patients (18%) met the full NICE criteria for starting and continuing GH (pre-NICE, 11%; post-NICE, 35%). Phase II indicated that the main reasons for not starting GH included perceived satisfactory quality of life (n = 47, 43%), patient reluctance (16, 15%) or a medical contraindication (16, 15%). CONCLUSIONS: Although the use of quality of life assessments has increased following publication of the NICE guidelines, most adults on GH in Scotland did not fulfil the complete set of NICE criteria. The main reason for not starting GH therapy in adult GH-deficient patients was perceived satisfactory quality of life.

The Beck Depression Inventory requires modification in scoring before use in a haemodialysis population in the UK.

BACKGROUND: There are high rates of mental illness, especially depression in people with end-stage renal disease (ESRD) on haemodialysis (HD). Depression can be difficult to diagnose, as depression and the medical problem share many symptoms. It is essential that the diagnosis of a depressive illness be accurately made in order that subsequent psychiatric management can occur. This is the first study done in the UK which aims to validate a simple method for detecting depression, the Beck Depression Inventory (BDI), in people on HD against a structured psychiatric interview with a trained psychiatrist using the ICD-10 classification of depression. The BDI is validated in a normal population, but in patients with physical ill health there has been a difficulty in defining appropriate cut-off scores. METHODS: Patients dialysing for over 3 months from a single HD unit were eligible for participation. Patients were excluded if a known psychiatric illness existed or if they were receiving medication for a psychiatric illness. Patients who had a recent major illness requiring hospitalisation were excluded. 57 consenting participants completed the self-reported BDI. Within the next week a psychiatrist carried out a clinical interview to diagnose depression, based on the ICD-10 classification of a depressive disorder. Patients were classified as not being depressed or having mild, moderate or severe depression according to their BDI score or the ICD-10 classification. RESULTS: The BDI gave more scores for depression and more severe scores than ICD-10. 30 cases had scores which agreed, 27 cases resulted in a higher BDI score than the ICD-10 classification, in no case was the ICD-10 classification more severe (Wilcoxon signed rank test p < 0.001). All 7 diagnosed as being depressed by clinical interview were also depressed by BDI, although in 2 cases the BDI worsened the depression score. CONCLUSIONS: Using the general population cut-off score, the BDI significantly overdiagnosed depression in this HD population. This study defines a BDI cut-off score which more reliably detects major depression in a HD population. Unrecognised depression remains high in those with no known psychiatric illness within the HD populations.

Serum neurofilament is associated with progression of brain atrophy and disability in early MS.

OBJECTIVE: To investigate a potential effect of riluzole on serum neurofilaments (Nf) compared to placebo and the relationship between longitudinal clinical and MRI outcomes and serum Nf levels. METHODS: Serum samples were obtained from participants enrolled in a randomized double-blind trial of neuroprotection with riluzole vs placebo as an add-on to weekly interferon-ß (IFN-ß)-1a IM initiated 3 months after randomization. Nf measurements were performed by ELISA and electrochemiluminescence immunoassay. RESULTS: Longitudinal serum samples were available from 22 riluzole and 20 placebo participants over 24 months. There was no observed treatment effect with riluzole. Nf light chain (NfL) levels decreased over time (p = 0.007 at 24 months), whereas the Nf heavy chain was unchanged (p = 0.997). Changes in NfL were correlated with EDSS change (p = 0.009) and neuropsychological outcomes. Brain volume decreased more rapidly in patients with high baseline NfL (p = 0.05 at 12 months and p = 0.008 at 24 months) and this relationship became stronger at 24 months (p = 0.024 for interaction). Higher and increasing NfL predicted higher number of gadolinium-enhancing lesions (p < 0.001 for both). CONCLUSIONS: Our findings support the potential value of serum NfL as a marker of neuroaxonal injury in early multiple sclerosis. Its reduction over time could represent regression to the mean, or a possible treatment effect of IFN-ß-1a. The association with whole brain atrophy and the formation of acute white matter lesions has relevant implications to use serum NfL as a noninvasive biomarker of the overall consequences of brain damage and ongoing disease activity. CLINICALTRIALSGOV IDENTIFIER: NCT00501943.

Novel diamino derivatives of [1,2,4]triazolo[1,5-a][1,3,5]triazine as potent and selective adenosine A2a receptor antagonists.

Piperazine derivatives of 2-furanyl[1,2,4]triazolo[1,5-a][1,3,5]triazine have recently been demonstrated to be potent and selective adenosine A(2a) receptor antagonists with oral activity in rodent models of Parkinson's disease. We have replaced the piperazinyl group with a variety of linear, monocyclic, and bicyclic diamines. Of these diamines, (R)-2-(aminomethyl)pyrrolidine is a particularly potent and selective replacement for the piperazinyl group. With this diamine component, we have been able to prepare numerous analogues with low nanomolar affinity toward the A(2a) receptor and good selectivity with respect to the A(1) receptor (>200-fold in some cases). Selected analogues from this series of [1,2,4]triazolo[1,5-a][1,3,5]triazine have now been shown to be orally active in the mouse catalepsy model.

Determination of pesticides in apple-based infant foods using liquid chromatography electrospray ionization tandem mass spectrometry.

A liquid chromatography electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) method was developed and validated to quantify and confirm trace levels of 13 pesticides including aldicarb sulfoxide, aldicarb sulfone, oxamyl, methomyl, formetanate, 3-hydroxycarbofuran, carbendazim, thiabendazole, aldicarb, propoxur, carbofuran, carbaryl, and methiocarb in apple-based infant foods such as apple sauces, apples and strawberries, apples and blueberries, and apples and plums. Data acquisition under MS/MS was achieved by applying multiple reaction monitoring of two fragment ion transitions to provide a high degree of sensitivity and selectivity for both quantification and confirmation. LC/ESI-MS/MS quantitative results were significantly affected by matrices, and thus, the standard addition was employed to compensate for the matrix effects to achieve the best accuracy of the method. Recoveries of 13 pesticides, spiked at 5.0, 25.0, and 45.0 microg/kg, were around 100% using the LC/ESI-MS/MS standard addition. The method detection limits (S/N > or = 3:1) of 13 pesticides were less than 0.2 microg/kg.

Piperazine derivatives of [1,2,4]triazolo[1,5-a][1,3,5]triazine as potent and selective adenosine A2a receptor antagonists.

The [1,2,4]triazolo[1,5-a]triazine derivative 3, more commonly known in the field of adenosine research as ZM-241385, has previously been demonstrated to be a potent and selective adenosine A2a receptor antagonist, although with limited oral bioavailability. This [1,2,4]triazolo[1,5-a]triazine core structure has now been improved by incorporating various piperazine derivatives. With some preliminary optimization, the A2a binding affinity of some of the best piperazine derivatives is almost as good as that of compound 3. The selectivity level over the adenosine A1 receptor subtype for some of the more active analogues is also fairly high, > 400-fold in some cases. Many compounds within this piperazine series of [1,2,4]triazolo[1,5-a]triazine have now been shown to have good oral bioavailability in the rat, with some as high as 89% (compound 35). More significantly, some piperazines derivatives of [1,2,4]triazolo[1,5-a]triazine also possessed good oral efficacy in rodent models of Parkinson's disease. For instance, compound 34 was orally active in the rat catalepsy model at 3 mg/kg. In the 6-hydroxydopamine-lesioned rat model, this compound was also quite effective, with a minimum effective dose of 3 mg/kg po.

Growth associated protein (GAP-43): cloning and the development of a sensitive ELISA for neurological disorders.

GAP-43 has been studied in the rodent and mammalian brain and shown to be present specifically in areas undergoing axonal elongation and synapse formation. GAP-43 was cloned using the baculovirus expression system and purified. A sandwich ELISA was developed using the recombinant GAP-43 as standard and validated. CSF GAP-43 levels were analysed in benign intracranial hypertension, movement disorders, multiple sclerosis, neuropathy, CNS infections, motor neuron disease, and headache (neurological controls). GAP-43 levels were low in all disorders analysed (in particular motor neuron disease; p=0.001, and movement disorders and multiple sclerosis; p<0.0001) compared to controls, aside from CNS infections. GAP-43 is preferentially reduced in the CSF of neurological disorders associated with neurodegeneration.

Biomarker report from the phase II lamotrigine trial in secondary progressive MS - neurofilament as a surrogate of disease progression.

OBJECTIVE: Lamotrigine trial in SPMS was a randomised control trial to assess whether partial blockade of sodium channels has a neuroprotective effect. The current study was an additional study to investigate the value of neurofilament (NfH) and other biomarkers in predicting prognosis and/or response to treatment. METHODS: SPMS patients who attended the NHNN or the Royal Free Hospital, UK, eligible for inclusion were invited to participate in the biomarker study. Primary outcome was whether lamotrigine would significantly reduce detectable serum NfH at 0-12, 12-24 and 0-24 months compared to placebo. Other serum/plasma and CSF biomarkers were also explored. RESULTS: Treatment effect by comparing absolute changes in NfH between the lamotrigine and placebo group showed no difference, however based on serum lamotrigine adherence there was significant decline in NfH (NfH 12-24 months p=0.043, Nfh 0-24 months p=0.023). Serum NfH correlated with disability: walking times, 9-HPT (non-dominant hand), PASAT, z-score, MSIS-29 (psychological) and EDSS and MRI cerebral atrophy and MTR. Other biomarkers explored in this study were not found to be significantly associated, aside from that of plasma osteopontin. CONCLUSIONS: The relations between NfH and clinical scores of disability and MRI measures of atrophy and disease burden support NfH being a potential surrogate endpoint complementing MRI in neuroprotective trials and sample sizes for such trials are presented here. We did not observe a reduction in NfH levels between the Lamotrigine and placebo arms, however, the reduction in serum NfH levels based on lamotrigine adherence points to a possible neuroprotective effect of lamotrigine on axonal degeneration.