In end-stage kidney disease, inflammation, erythron abnormalities and declined kidney function tests are accompanied by increased affective symptoms, chronic-fatigue, and fibromyalgia.. [DOI: 10.1101/2023.01.12.23284460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Background

Numerous neuropsychiatric symptoms, including affective symptoms, chronic fatigue syndrome, and fibromyalgia symptoms, are present in patients with end-stage renal disease (ESRD). This study examines the relationship between neuropsychiatric symptoms and red blood cell (RBC) parameters, kidney function tests, zinc, C-reactive protein, and calcium levels in patients with ESRD.

Methods

The above biomarkers and the Beck-Depression Inventory, the Hamilton Anxiety Rating Scale, and the Fibro-Fatigue Rating Scale were measured in 70 patients with end-stage renal disease (ESRD) and 46 healthy controls.

Results

Increased scores of depressive, anxious, cognitive, and physiosomatic symptoms (including chronic fatigue, fibromyalgia, and autonomous symptoms) characterise ESRD. One latent vector could be extracted from these diverse symptom domains, which are, therefore, manifestations of a common core referred to as the physio-affective phenome. The combined effects of aberrations in red blood cells (RBC) (number of RBC, hematocrit, and haemoglobin), kidney function tests (glomerular filtration rate, ureum, creatinine, albumin, and total serum protein), C-reactive protein, zinc, and copper explained 85.0% of the variance in the physio-affective phenome. In addition, the effects of kidney function decline on the phenome were partially mediated by RBC aberrations and elevated copper, whereas the effects of dialysis frequency were entirely mediated by decreased zinc and elevated CRP.

Conclusions

Affective (depression and anxiety), cognitive, and physiosomatic symptoms due to ESRD are interrelated manifestations of the physio-affective phenome, which is driven by (in descending order of importance) kidney dysfunctions, erythron deficits, inflammation, elevated copper, and decreased zinc.

Predialysis and Dialysis Therapies Differently Affect Nitric Oxide Synthetic Pathway in Red Blood Cells from Uremic Patients: Focus on Peritoneal Dialysis

Red blood cells (RBCs) have been found to synthesize and release both nitric oxide (NO) and cyclic guanosine monophosphate (cGMP), contributing to systemic NO bioavailability. These RBC functions resulted impaired in chronic kidney disease (CKD). This study aimed to evaluate whether predialysis (conservative therapy, CT) and dialysis (peritoneal dialysis, PD; hemodialysis, HD) therapies used during CKD progression may differently affect NO-synthetic pathway in RBCs. Our data demonstrated that compared to PD, although endothelial-NO-synthase activation was similarly increased, HD and CT were associated to cGMP RBCs accumulation, caused by reduced activity of cGMP membrane transporter (MRP4). In parallel, plasma cGMP levels were increased by both CT and HD and they significantly decreased after hemodialysis, suggesting that this might be caused by reduced cGMP renal clearance. As conceivable, compared to healthy subjects, plasma nitrite levels were significantly reduced by HD and CT but not in patients on PD. Additionally, the increased carotid intima-media thickness (IMT) values did not reach the significance exclusively in patients on PD. Therefore, our results show that PD might better preserve the synthetic NO-pathway in CKD-erythrocytes. Whether this translates into a reduced development of uremic vascular complications requires further investigation.

MALDI TOF Mass Spectrometry Imaging of Blood Smear: Method Development and Evaluation

The aim of this study was to develop and evaluate matrix assisted LASER desorption ionization (MALDI) time-of-flight (TOF) mass spectrometry imaging (MSI) of blood smear. Integrated light microscope and MALDI IT-TOF mass spectrometer, together with a matrix sublimation device, were used for analysis of blood smears coming from healthy male donors. Different blood plasma removal, matrix deposition, and instrumental settings were evaluated using the negative and positive ionization modes while agreement between the light microscopy images and the lateral distributions of cellular marker compounds served as the MSI quality indicator. Red and white blood cells chemical composition was analyzed using the differential m/z expression. Five seconds of exposure to ethanol followed by the 5 min of 9-aminoacridine or α-cyano-4-hydroxycinnamic acid deposition, together with two sets of instrumental settings, were selected for the MALDI TOF MSI experiments. Application of the thin and transparent matrix layers assured good correspondence between the LASER footprints and the preselected regions of interest. Cellular marker m/z signals coincided well with the appropriate cells. A metabolite databases search using the differentially expressed m/z produced hits which were consistent with the respective cell types. This study sets the foundations for application of blood smear MALDI TOF MSI in clinical diagnostics and research.