Multicentre, double-blind, crossover trial to identify the Optimal Pathway for TreatIng neurOpathic paiN in Diabetes Mellitus (OPTION-DM): study protocol for a randomised controlled trial

BACKGROUND: The number of people with diabetes is growing rapidly. Diabetes can cause nerve damage leading to severe pain in the feet, legs and hands, which is known as diabetic peripheral neuropathic pain (DPNP). In the UK, the National Institute for Health and Care Excellence (NICE) recommends amitriptyline, duloxetine, pregabalin or gabapentin as initial treatment for DPNP. If this is not effective, adding one of the other drugs in combination with the first is recommended. NICE points out that these recommendations are not based on robust evidence. The OPTION-DM randomised controlled trial has been designed to address this evidence deficit, with the aims of determining the most clinically beneficial, cost-effective and tolerated treatment pathway for patients with DPNP. METHODS/DESIGN: A multicentre, double-blind, centre-stratified, multi-period crossover study with equal allocation to sequences (1:1:1:1:1:1) of treatment pathways. Three hundred and ninety-two participants will be recruited from secondary care DPNP centres in the UK. There are three treatment pathways: amitriptyline supplemented with pregabalin, pregabalin supplemented with amitriptyline and duloxetine supplemented with pregabalin. All participants will receive all three pathways and randomisation will determine the order in which they are received. The primary outcome is the difference between 7-day average 24-h pain scores on an 11-point NRS scale measured during the final follow-up week of the treatment pathway. Secondary outcomes for efficacy, cost-effectiveness, safety, patient-perceived tolerability and subgroup analysis will be measured at week 6 and week 16 of each pathway. DISCUSSION: The study includes direct comparisons of the mainstay treatment for DPNP. This novel study is designed to examine treatment pathways and capture clinically relevant outcomes which will make the results generalisable to current clinical practice. The study will also provide information on health economic outcomes and will include a subgroup study to provide information on whether patient phenotypes predict response to treatment. TRIAL REGISTRATION: ISRCTN17545443 . Registered on 12 September 2016

Albumin and multiple sclerosis

A grant from the One-University Open Access Fund at the University of Kansas was used to defray the author's publication fees in this Open Access journal. The Open Access Fund, administered by librarians from the KU, KU Law, and KUMC libraries, is made possible by contributions from the offices of KU Provost, KU Vice Chancellor for Research & Graduate Studies, and KUMC Vice Chancellor for Research. For more information about the Open Access Fund, please see http://library.kumc.edu/authors-fund.xml.Leakage of the blood–brain barrier (BBB) is a common pathological feature in multiple sclerosis (MS). Following a breach of the BBB, albumin, the most abundant protein in plasma, gains access to CNS tissue where it is exposed to an inflammatory milieu and tissue damage, e.g., demyelination. Once in the CNS, albumin can participate in protective mechanisms. For example, due to its high concentration and molecular properties, albumin becomes a target for oxidation and nitration reactions. Furthermore, albumin binds metals and heme thereby limiting their ability to produce reactive oxygen and reactive nitrogen species. Albumin also has the potential to worsen disease. Similar to pathogenic processes that occur during epilepsy, extravasated albumin could induce the expression of proinflammatory cytokines and affect the ability of astrocytes to maintain potassium homeostasis thereby possibly making neurons more vulnerable to glutamate exicitotoxicity, which is thought to be a pathogenic mechanism in MS. The albumin quotient, albumin in cerebrospinal fluid (CSF)/albumin in serum, is used as a measure of blood-CSF barrier dysfunction in MS, but it may be inaccurate since albumin levels in the CSF can be influenced by multiple factors including: 1) albumin becomes proteolytically cleaved during disease, 2) extravasated albumin is taken up by macrophages, microglia, and astrocytes, and 3) the location of BBB damage affects the entry of extravasated albumin into ventricular CSF. A discussion of the roles that albumin performs during MS is put forth