Serum claudin-5 levels among patients with unipolar and bipolar depression in relation to the pro-inflammatory cytokine tumor necrosis factor-alpha levels.

Accumulating evidence indicates that inflammation and neurovascular unit (NVU) dysfunction contribute to depression via disrupted blood-brain barrier (BBB) integrity. Claudin-5, an endothelial tight-junction protein expressed in the NVU and contributing to BBB integrity, has been implicated in psychiatric disorders, including major depressive disorder (MDD) and schizophrenia. In an animal model of depressive-like behavior, the pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-α) was found to affect BBB permeability and claudin-5 expression of NVU endothelial cells. To the best of the authors' knowledge, this study is the first to assess the relationship between serum claudin-5 and TNF-α levels, during major depressive episodes (MDEs). Serum levels of claudin-5 and TNF-α of 40 patients diagnosed with current MDE [19 with MDD and 21 with bipolar disorder (BD)] and 28 matched healthy controls (HCs) were analyzed. Claudin-5 and TNF-α serum levels in the MDE group were significantly higher than in the HC one. Discrete analysis according to MDE type indicated significantly increased claudin-5 serum levels in BD but not in MDD patients, compared to HCs, even after controlling for confounders. In the MDE group, a significant positive correlation was found between claudin-5 and TNF-α serum levels. In complementary analysis, serum levels of the pro-inflammatory cytokine interleukin-6 were significantly higher among MDE patients compared to HCs, however, no significant correlation was found with claudin-5 levels. In conclusion, as indicated by preclinical studies, our clinical study suggests a possible specific interaction between the NVU/BBB marker claudin-5 and the inflammatory marker TNF-α in the pathogenesis of depression.

Clozapine blood level assessment using a point-of-care device: feasibility and reliability.

Background: Therapeutic drug monitoring (TDM) is useful to assess clozapine adherence and optimize treatment. However, analysis of venous blood levels by liquid chromatography tandem mass spectrometry (LC-MS/MS) is often logistically complicated and process time is prolonged. Objective: To assess the feasibility and reliability of a new point-of-care device, (MyCare™ Insite), using capillary blood for clozapine therapeutic monitoring. Methods: Matched venous and capillary blood samples were collected from patients treated with clozapine on a stable dose. Samples were analyzed by LC-MS/MS and MyCare Insite Clozapine Test. Clozapine plasma levels were compared between methods using linear regression model. Both patients and treatment team completed questionnaires about the feasibility of blood sampling. Results: Of the total sample (44 patients, 61% males, mean age 43 ± 12 years), mean daily clozapine dose was 293 ± 134 mg/day. Linear regression model demonstrated high correlation with R 2 = 0.83 (p < 0.0001) and mean difference of 26 ± 162 ng/ml. More than 60% of the patients found the clozapine TDM to be important. Most of the participants (58%) favored the capillary sampling and 11% claimed that testing method would affect their adherence to TDM. Moreover, a larger portion (72%) strongly preferred to be tested at the office rather than at the lab. Conclusions: The point-of-care device offers an accessible and satisfactory measurement of clozapine blood levels. Both patients and healthcare providers reported preference for capillary sampling as well as for the in-office TDM procedure. The immediate results provided by the device can facilitate rapid and informed clinical decisions and therefore improve clozapine treatment outcomes.

Lack of association between unipolar or bipolar depression and serum aquaporin-4 autoantibodies.

Aquaporin-4 (AQP4), an astrocyte water channel protein, is the target antigen of serum immunoglobulin G (IgG) autoantibody in neuromyelitis optica spectrum disorders (NMOsd), a group of inflammatory, demyelinating diseases of the central nervous system. Recently, a reduction in blood vessels coverage by AQP4-immunoreactive astrocytes was demonstrated in depressed patients, indicating a role for AQP4 in mood disorders. Moreover, a possible association between depression and serum AQP4-IgG was suggested in a case report of a treatment resistant depression (TRD) patient diagnosed with NMOsd with positive serum AQP4 autoantibodies. We investigated, for the first time, the presence of serum AQP4-IgG in patients with unipolar and bipolar depression and healthy controls (HCs). In this multicenter study, 25 major depressive disorder (MDD) and 25 bipolar disorder (BD) patients, during an acute major depressive episode (MDE), and 30 matched HCs were screened for the presence of serum AQP4-IgG, using a cell-based assay. The MDE patients underwent a repeated AQP4-IgG assessment at a 3-month follow-up visit. The MDE group (N = 50) had illness duration of 12.7 years (SD = 10.5), 12% of them were psychotropic medication-free and 26% were defined as TRD. All MDE patients and HCs, including three BD patients who experienced a manic switch, were seronegative for AQP4-IgG at baseline and follow-up assessments. In conclusion, contrary to our hypothesis, AQP4 autoantibodies were not detected in serum of unipolar and bipolar depressed patients. However, AQP4 may still play a role in the pathogenesis of mood disorders through different mechanisms of action such as altered brain AQP4 expression.

Vitamin D Supplementation in Chronic Schizophrenia Patients Treated with Clozapine: A Randomized, Double-Blind, Placebo-controlled Clinical Trial.

BACKGROUND: While accumulating evidence suggests that vitamin D deficiency may be involved in the risk to develop schizophrenia and its outcome, there are no studies on vitamin D supplementation in this context. We sought to assess the effect of vitamin D supplementation on psychiatric, cognitive and metabolic parameters in chronic clozapine-treated schizophrenia patients. METHODS: This eight-week, randomized, double-blind, placebo-controlled clinical trial, recruited schizophrenia patients who had been maintained on clozapine treatment for at least 18weeks and had low levels of vitamin D (<75nmol/l) and total PANSS scores >70 (to ascertain the presence of residual symptoms). Patients were randomly allocated to either weekly oral drops of vitamin D (14,000IU) or placebo and subsequently assessed at two-week intervals for psychosis severity, mood, cognition and metabolic profile. RESULTS: Twenty four patients were randomly assigned to vitamin D (aged 39.4±9.6years, 75% males) and the other 23 patients to the placebo arm (aged 42.5±11.2years, 60.9% males). After eight weeks, the vitamin D group exhibited a significant increase in vitamin D levels (31.4 vs -0.4nmol/l, p<0.0001). There was no significant effect of vitamin D on psychotic, depressive or metabolic parameters. However, in the vitamin D group, there was a trend towards improved cognition (effect size=0.17, significance lost following Bonferroni correction). CONCLUSIONS: Vitamin D supplementation was associated with a trend towards improved cognition, but did not affect psychosis, mood or metabolic status. It is possible that the robust decrease in the PANSS scores in both groups may have obscured an effect of vitamin D supplementation.