Insight into the complex pathophysiology of sickle cell anaemia and possible treatment

Sickle cell anaemia (SCA) is the consequence of abnormal haemoglobin production due to an inherited point mutation in the β‐globin gene. The resulting haemoglobin tetramer is poorly soluble when deoxygenated, and when this is prolonged, intracellular gelation of sickle haemoglobin occurs, followed by haemoglobin polymerisation. If many cycles of sickling and unsickling occur, the red cell membrane will be disrupted leading to haemolysis and vaso‐occlusive events. Recent studies have also shown that leucocyte adhesion molecules and nitric oxide (NO) depletion are involved in endothelial damage. New insights in SCA pathophysiology and vascular biology have shown that cell‐derived microparticle (MP) generation is also involved in the vaso‐occlusion. Endothelial damage is perpetuated by impaired production or increased consumption of protective modulators such as protein C, protein S and NO. New therapeutic interventions should address these aspects of SCA pathogenesis. To date, the only US‐FDA‐approved therapy to prevent painful vaso‐occulsive episodes is hydroxyurea that reduces haemoglobin polymerisation in sickle cells by increasing the production of foetal haemoglobin and L‐glutamine. However, several new drugs have been tested in the last years in randomised clinical trials. We here report an update on the current status of knowledge on SCA.     

Relationship between saliva and plasma rufinamide concentrations in patients with epilepsy

The assay of saliva samples provides a valuable alternative to the use of blood samples for therapeutic drug monitoring (TDM), at least for certain categories of patients. To determine the feasibility of using saliva sampling for the TDM of rufinamide, we compared rufinamide concentrations in paired samples of saliva and plasma collected from 26 patients with epilepsy at steady state. Within-patient relationships between plasma rufinamide concentrations and dose, and the influence of comedication were also investigated. Assay results in the two tested fluids showed a good correlation (r² = .78, P < .0001), but concentrations in saliva were moderately lower than those in plasma (mean saliva to plasma ratio = 0.7 ± 0.2). In eight patients evaluated at three different dose levels, plasma rufinamide concentrations increased linearly with increasing dose. Patients receiving valproic acid comedication had higher dose-normalized plasma rufinamide levels than patients comedicated with drugs devoid of strong enzyme-inducing or enzyme-inhibiting activity. Overall, these findings indicate that use of saliva represents a feasible option for the application of TDM in patients treated with rufinamide. Because rufinamide concentrations are lower in saliva than in plasma, a correction factor is needed if measurements made in saliva are used as a surrogate for plasma concentrations.     

The diagnostic usefulness of the combined COMPASS 31 questionnaire and electrochemical skin conductance for diabetic cardiovascular autonomic neuropathy and diabetic polyneuropathy

The study investigated the diagnostic performance for diabetic cardiovascular autonomic neuropathy (CAN) and diabetic polyneuropathy (DPN) of the combined use of composite autonomic symptom score (COMPASS) 31, validated questionnaire for autonomic symptoms of CAN, and electrochemical skin conductance (ESC), proposed for detecting DPN and CAN. One‐hundred and two participants with diabetes (age 57 ± 14 years, duration 17 ± 13 years) completed the COMPASS 31 before assessing cardiovascular reflex tests (CARTs), neuropathic symptoms, signs, vibratory perception threshold (VPT), thermal thresholds (TT), and ESC using Sudoscan. Two patterns were evaluated: (a) the combined abnormalities in both tests (COMPASS 31+ESC), and (b) the abnormality in COMPASS 31 and/or ESC (COMPASS 31 and/or ESC). CAN (≥ 1 abnormal CART) and confirmed CAN (≥ 2 abnormal CARTs) were present in 28.1% and 12.5%, DPN (two abnormalities among symptoms, signs, VPT, and TT) in 52%, abnormal COMPASS 31 (total weighted score >16.44) in 48% and abnormal ESC (hands ESC <50 μS and/or feet ESC <70 μS) in 47.4%. Both the patterns—COMPASS 31+ESC and COMPASS 31 and/or ESC—were associated with CAN and DPN (P < .01). COMPASS 31 and ESC reached a sensitivity of 75% and 83% for confirmed CAN, and a specificity of 65% and 67% for DPN. When combining the tests, the sensitivity for CAN rose by up to 100% for CAN and the specificity up to 89% for DPN. The combination of the tests can allow a stepwise screening strategy for CAN, by suggesting CAN absence with combined normality, and prompting to CARTs with combined abnormality.     

Treating insomnia in Swiss primary care practices: A survey study based on case vignettes

Guidelines recommend cognitive behavioural therapy for insomnia (CBT‐I) as first‐line treatment for chronic insomnia, but it is not clear how many primary care physicians (PCPs) in Switzerland prescribe this treatment. We created a survey that asked PCPs how they would treat chronic insomnia and how much they knew about CBT‐I. The survey included two case vignettes that described patients with chronic insomnia, one with and one without comorbid depression. PCPs also answered general questions about treating chronic insomnia and about CBT‐I and CBT‐I providers. Of the 820 Swiss PCPs we invited, 395 (48%) completed the survey (mean age 54 years; 70% male); 87% of PCPs prescribed sleep hygiene and 65% phytopharmaceuticals for the patient who had only chronic insomnia; 95% prescribed antidepressants for the patient who had comorbid depression. In each case, 20% of PCPs prescribed benzodiazepines or benzodiazepine receptor agonists, 8% prescribed CBT‐I, 68% said they knew little about CBT‐I, and 78% did not know a CBT‐I provider. In the clinical case vignettes, most PCPs treated chronic insomnia with phytopharmaceuticals and sleep hygiene despite their lack of efficacy, but PCPs rarely prescribed CBT‐I, felt they knew little about it, and usually knew no CBT‐I providers. PCPs need more information about the benefits of CBT‐I and local CBT‐I providers and dedicated initiatives to implement CBT‐I in order to reduce the number of patients who are prescribed ineffective or potentially harmful medications.