Correlation between intestinal flora disruption and protein-energy wasting in patients with end-stage renal disease.

BACKGROUND: Different dialysis treatments may affect the composition and structure of the intestinal flora of dialysis-treated chronic kidney disease (CKD) patients. This study aimed to analyze the correlations between the different flora and the nutritional indexes and further explore the potential metabolic pathways in patients with CKD in end-stage renal disease (ESRD). METHODS: Altogether, 102 patients with ESRD were recruited and categorized into the hemodialysis (HD) group (N = 49) and the peritoneal dialysis (PD) group (N = 53). Their biochemical indexes, anthropometric indicators, and inflammatory markers were determined. The total genomic DNA was extracted for 16S ribosomal DNA sequencing. Furthermore, bioinformatics analysis was employed for functional analysis. RESULTS: Anthropometric indicators, including handgrip strength, mid-upper arm circumference, mid-upper arm muscle circumference, and body mass index, in the HD and PD groups showed a positive correlation with butyric acid-producing bacteria (Rosella and Phascolarctobacterium) and a negative correlation with conditional pathogens (Escherichia spp.). Meanwhile, the inflammatory markers, including high-sensitivity C-reactive protein and interleukin-6, were significantly higher in the PD-protein-energy wasting (PEW) group than in the PD-non-protein-energy wasting (NPEW) group; although they showed an increasing trend in the HD-PEW group, no significant difference was noted. Rosella was considerably scarce in the HD-PEW group than in the HD-NPEW group, whereas Escherichia was substantially more abundant in the PD-PEW group than in the PD-NPEW group. Compared with the HD group, the essential amino acid synthesis pathway, amino acid metabolism-related enzyme pathways, and aminoacyl-transfer RNA biosynthesis pathways were weakened in the PD group. Most carbohydrate metabolic pathways were weakened, although the tricarboxylic acid cycle was slightly enhanced. Concurrently, the fatty acid metabolism was enhanced, whereas fatty acid synthesis was weakened; the metabolic pathways of B vitamins were also weakened. These potential metabolic pathways of the various compounds released by intestinal flora showed a significant correlation with blood biochemical indexes, anthropometric indicators, and inflammatory markers. CONCLUSION: In patients with ESRD, different dialysis treatments affected the abundance of butyric acid-producing bacteria (Rosella and Phascolarctobacterium) and conditional pathogens (Escherichia spp.). Butyric acid-producing bacteria showed a positive correlation with PEW and showed a negative correlation with Escherichia. Improving the intestinal diversity and increasing the amount of butyric acid-producing bacteria, such as Blautella, Faecococcus, and Phascolarctobacterium, are potential therapeutic approaches to enhance protein-energy consumption in patients with ESRD.

Associations Between Blood Trace Element Levels and Nutritional Status in Maintenance Hemodialysis.

OBJECTIVE(S): We aimed to investigate the associations between blood trace element levels and nutritional status in patients undergoing maintenance hemodialysis (MHD). METHODS: This cross-sectional study included patients undergoing MHD who were treated at our center in September 2019. Clinical and demographic data and blood samples were collected before hemodialysis sessions, and the levels of manganese, lead, selenium, zinc, and copper were measured by inductively coupled plasma mass spectrometry. The Simplified Nutritional Appetite Questionnaire scale was used to assess patient appetite. Skinfold thickness, bicep circumference, upper arm muscle circumference, 7-point Subjective Global Assessment, Nutritional Risk Screening 2002 (NRS 2002), and Geriatric Nutritional Risk Index (GNRI) were used to assess patient nutritional status. Univariate and multivariate logistic regression analyses were performed to study the relationship between trace elements and nutritional indicators. RESULTS: In total, 118 patients (64 males and 54 females) were included, with a median dialysis vintage of 34.0 months (16.0-54.5 months) and an average age of 63.20 ± 14.26 years. Malnourished patients, as defined by the GNRI, Subjective Global Assessment, and NRS 2002, accounted for 28.0%, 49.2%, and 26.3% of enrolled patients, respectively. The multivariate binary logistic regression showed that higher blood copper levels were independently associated with nutritional risk defined as GNRI ≤91.2 (odds ratio [OR] = 1.003, 95% confidence interval [CI] = 1.000-1.006; P = .020), whereas lower blood zinc levels (OR = 0.634, 95% CI = 0.439-0.916; P = .015), blood zinc < 4.220 mg/L (OR = 3.723, 95% CI = 1.274-10.879; P = .016), lower blood selenium levels (OR = 0.959, 95% CI = 0.929-0.990; P = .010), and blood selenium < 85 µg/L (OR = 5.568, 95% CI = 1.039-29.840; P = .045) were independently associated with a nutritional risk defined as NRS 2002 ≥ 3. CONCLUSION(S): Higher levels of blood copper and lower levels of blood zinc and selenium were independently associated with higher nutritional risk in MHD patients.

Auxiliary genetic analysis in a Chinese adolescent NPH family by single nucleotide polymorphism screening.

Hereditary nephropathy is a progressive fatal renal disease caused by genetic changes. In this study, genetic screening was used to reveal mutations in a family in Southern China, in which there are two patients with confirmed hereditary nephropathy, who are alive at the time of publication. Imaging tests, including color Doppler ultrasonography and magnetic resonance imaging (MRI), as well as pathological examinations, including hematoxylin­eosin staining, electron microscopy and immunohistochemistry were performed. Target sequencing of nephrosis 2 (NPHS2), wilms tumor 1 (WT1), phospholipase C ε 1 (PLCE1), actinin α 4 (ACTN4), angiotensin I converting enzyme (ACE), uromodulin (UMOD) and nephrocystin 1 (NPHP1) was also carried out. This study indicated that heterozygous genetic variants of NPHS2, WT1, ACTN4, PLCE1 and UMOD found in the patients were gene polymorphisms. A renal biopsy showed sclerosing glomerulonephritis, dilated tubules and lymphocyte/monocyte infiltration in the interstitium of the index patients. Genetic analysis showed vertical transmission of the disease­causing mutations, including a homozygous deletion in NPHP1 and a nonsense mutation in ACE found via PCR­based single nucleotide polymorphism screening. Further network analysis identified direct and indirect co­location genes between NPHP1 and ACE. To conclude, familial adolescent nephronophthisis was diagnosed in two index patients in this study. It is recommended that comprehensive gene mutation screening is used in the diagnosis of complex hereditary diseases.

High-throughput sequencing analysis of intestinal flora changes in ESRD and CKD patients.

BACKGROUND: Chronic kidney disease (CKD) disease affects gut flora by causing dysbiosis and lead to systemic inflammatory conditions. Here, we provide intestinal flora changes of CKD patients undertook different hemodialysis therapy. METHODS: From 2017 to 2019, a total of 166 patients from Guangzhou Red Cross Hospital were recruited and divided into four groups with 17 cases in healthy control group, 47 cases in CKD non-dialysis group, 49 cases in HD group, and 53 cases in PD group. Intestinal flora genome 16S rDNA sequencing and further bio-informatic analysis were performed. RESULTS: Decreased diversity and altered communities of intestinal flora in PD patients, in which microbial diversity was positive correlated with the albumin level were observed. A total of 20 intestinal flora phyla were detected in 166 fecal samples, divided into 3 dominant intestinal types including Bacteroides-dominant gut type, Firmicutes-dominant type and Proteobacteria-dominant gut type. Further analyses found 198 genera, the abundance of 86 genera were significantly different. Butyrate-producing taxa as Faecalibacterium in genera level and Bifidobacteriaceae and Prevotellaceae in family level were dominant genus in CT, CKD, and HD groups, while urease containing-, indole- and p-cresol-forming taxa as Escherichia in genera and Enterobacteriaceae, Enterococcaceae in family level was dominated genus in PD group. Number of differential expressed genes in KEGG enrichment pathways were significantly different in PD group in carbohydrate metabolism, amino acid metabolism, energy metabolism, translation, and membrane transport. CONCLUSION: Our results suggest peritoneal dialysis therapy could result in reduced diversity and altered microbial communities, with reduced probiotic butyrate-producing taxa and increased urease containing-, indole- and p-cresol-forming taxa. The disordered intestinal flora can seriously affect the nutrition level in CKD patients with PD therapy.

Sevelamer hydrochloride suppresses proliferation of parathyroid cells during the early phase of chronic renal failure in rats.

AIM: We examined the effects of sevelamer on parathyroid cell proliferation and secondary hyperparathyroidism in rats following induction of early-phase of chronic renal failure (CRF) by unilateral ureteral obstruction (UUO). METHODS: For 5 days, rats in the control group received normal food, rats in the sevelamer group (SH) received control food plus 5% sevelamer, and rats in the low protein group (LP) received low protein food. Five rats of each group were killed at baseline (day 0). All other rats were given UUO, and five rats per group were killed on days 3, 7, 14, and 28 after UUO. Changes in body weight, serum phosphorus, calcium, intact-parathyroid hormone (i-PTH), creatinine (SCr), creatinine clearance rate (CCR), blood urea nitrogen (BUN), and 24-h urinary phosphorus were determined. Parathyroid tissues were removed for histological examination of proliferating cell nuclear antigen-positive (PCNA+) cells. RESULTS: Measurement of body weight, BUN, and SCr in the controls indicated successful establishment of this model of early-phase CRF. The controls also had remarkable proliferation of PCNA+ cells beginning on day 3, but this did not occur in the SH or LP groups. After 28 days, serum phosphorus had decreased more in the SH and LP groups than in the control group, and phosphorus excretion was much greater in the control group than in the SH and LP groups. The three groups had similar increases in serum i-PTH. CONCLUSION: Sevelamer rapidly lowered the serum phosphorus and inhibited the proliferation of PCNA+ cells in this experimental model of early-phase CRF.

The effects of protein intake on albuminuria in different estimated glomerular filtration rate: A population-based study.

BACKGROUND: Chronic kidney disease (CKD) is a serious condition associated with early mortality, decreased quality of life, and increased health-care expenditures. METHODS: Data from the National Health and Nutrition Examination Survey (NHANES) collected from 1999 to 2012 were used. Subjects were divided into 4 estimated glomerular filtration rate (eGFR) categories: stage 1: eGFR≥90mL/min/1.73m2, stage 2: eGFR 60-89, stage 3: eGFR 30-59, and stage 4/5: eGFR<30, and 3 age strata (<45y, 45-64, 65+). Associations between protein intake and albuminuria were determined. RESULTS: A total of 45,259 subjects were included. Despite decreasing protein intake, there was a significant increase in the prevalence of albuminuria with decreasing levels of eGFR. Multivariable analysis showed that albuminuria was associated with daily protein intake in patients ≥65years old with stage 1 disease, and that diabetes was associated with albuminuria in patients ≥65years old with stage 2 and 3 diseases. Overall, albuminuria in patients with stage 1 disease was associated with hours of sitting per day and blood glucose level. CONCLUSION: Albuminuria was associated with daily protein intake in patients of 45-64years old with stage 1 CKD disease, and was associated with hours of sitting per day and blood glucose level. These data further support the importance of lifestyle changes in the management of CKD, especially in patients with early-stage disease.

Comparison of Intradialytic Parenteral Nutrition with Glucose or Amino Acid Mixtures in Maintenance Hemodialysis Patients.

Many long-term maintenance hemodialysis patients have symptoms of protein-energy wasting caused by malnutrition. Each session of hemodialysis removes about 10 to 12 g of amino acids and 200 to 480 kcal of energy. Patients receiving hemodialysis for chronic kidney disease may be undernourished for energy, protein consumption, or both. Non-diabetic hemodialysis patients were randomized to three treatment groups: oral supplementation, oral supplementation plus high-concentration glucose solution (250 mL containing 50% glucose) and these two interventions plus 8.5% amino acids solution. The post-treatment energy status of the glucose group was significantly higher than its baseline level, whereas the control group's status was significantly lower. The glucose group had significantly higher concentrations of asparagine, glutamine, glycine, alanine, and lysine after treatment. All treatment groups had significantly increased hemoglobin levels but significantly decreased transferrin levels after treatment compared to baseline. After treatment, the amino acid group had significantly higher albumin level compared to the glucose group (p = 0.001) and significantly higher prealbumin level compared to the control group (p = 0.017). In conclusion, long-term intervention with high-concentration glucose solution at each hemodialysis session is a simple and cheap method that replenished energy stores lost during hemodialysis of non-diabetic patients.

Association between MTHFR C677T polymorphism and diabetic nephropathy in the Chinese population: An updated meta-analysis and review.

To clarify the effects of MTHFR C677T polymorphism on the risk of diabetic nephropathy (DN) in the Chinese population, an updated meta-analysis was performed. Related studies were identified from PubMed, Springer Link, Ovid and Chinese Databases up to 24 February 2015. A total of 15 studies including 1227 DN cases, 586 healthy controls and 1277 diabetes mellitus (DM) controls were involved in this meta-analysis. Overall, a significantly elevated risk of DN was associated with all variants of MTHFR C677T when compared with the healthy group (T vs C, odds ratio (OR) = 2.22, 95% confidence interval (CI) = 1.88-2.61; TT vs CC, OR = 4.22, 95% CI = 3.02-5.90; TT + CT vs CC, OR = 2.62, 95% CI = 2.07-3.31; TT vs CC + CT, OR = 2.81, 95% CI = 2.08-3.81) or DM (T vs C, OR = 1.78, 95% CI = 1.59-2.00; TT vs CC, OR = 2.95, 95% CI = 2.33-3.73; TT + CT vs CC, OR = 1.93, 95% CI = 1.63-2.29; TT vs CC + CT, OR = 2.31, 95% CI = 1.87-2.84). In subgroup analyses stratified by ethnicity and geographic areas, it revealed the significant results in Chinese Han, in North and South China. The risk conferred by MTHFR C677T polymorphism is higher in North China than in South China. This meta-analysis showed that the MTHFR C677T variants may influence DN risk in Chinese, and further studies with gene-gene and gene-environment interactions are required for definite conclusions.

Losartan preserves glomerular basement membrane anionic charge sites in a rat model of nephropathy.

BACKGROUND: Disruption of the size and charge selectivity of the glomerular basement membrane (GBM) leads to proteinuria. Blood pressure medications suppress proteinuria by preserving GBM function. We investigated the mechanism of losartan, an angiotensin II receptor blocker (ARB), in a rat model of nephropathy. METHODS: Male Wistar rats were given 25 mg/kg per day of losartan or the same volume of saline (control) from 5 days before, to 14 days after, induction of nephropathy by injection of puromycin aminonucleoside (PAN). Serum blood urea nitrogen (BUN) and creatinine, blood pressure, urinary protein, glomerular morphology and the number of GBM anionic sites were measured in the 2 groups on days 0, 7 and 14. RESULTS: The losartan group had significantly lower urinary protein on days 7 and 14, and higher BUN on day 14, but there were no significant differences between the losartan and control groups in serum creatinine or blood pressure. Light microscopy indicated reduced mesangial cell proliferation and expansion of the mesangial area in the losartan group relative to controls. There were more GBM anionic sites in the losartan group on days 7 and 14. In addition, all anionic sites on the surface of foot processes of epithelial cells disappeared in the control group but remained in the losartan group. CONCLUSIONS: A rat model of nephropathy indicates that losartan reduces urinary protein and preserves the number of anionic sites on the GBM, but has no apparent effect on hemodynamics.

Application of periodic acid-Schiff fluorescence emission for immunohistochemistry of living mouse renal glomeruli by an "in vivo cryotechnique".

To identify the distribution of endogenous serum proteins in living mouse renal glomeruli under various hemodynamic conditions, we used the periodic acid-Schiff (PAS) and its fluorescence emission as a marker for the glomerular basement membrane (GBM). The immunostaining for collagen type IV was hardly observed without microwave treatment in specimens prepared by an "in vivo cryotechnique". However, PAS staining and its fluorescence emission could be clearly visualized at the GBM with the "in vivo cryotechnique". Under normotensive conditions, immunoreaction products of albumin and immunoglobulin G heavy and light chains (IgG(H+L)) were localized within glomerular capillary loops (GCL) but not colocalized with the PAS fluorescence emission of the GBM. Under heart-arrest conditions and with quick-freezing of resected tissues, albumin, IgG (H+L), immunoglobulin kappa light chain, and IgG1 heavy chain (IgG1) were immunolocalized within the GCL and mesangial areas, but only albumin and the kappa light chain were additionally immunolocalized in Bowman's space, indicating their passage through the GBM. Under acute hypertensive conditions, both albumin and the kappa light chain, but not IgG1, were clearly immunolocalized along the GBM and in the Bowman's space, indicating their increased passage through the GBM. The overlapping areas of PAS fluorescence emission and the albumin or kappa light chain appeared to be larger with quick-freezing and under the heart arrest or acute hypertensive conditions than under normal circulation, whereas those of PAS emission and IgG1 did not differ among these conditions. The serum proteins passing through the GBM were clearly visualized with the "in vivo cryotechnique", immunofluorescence staining, and PAS fluorescence emission.

[Effects of LFA-1 costimulation on proliferation and IgG production of PBMCs from lupus nephritis patients].

AIM: To study the effect of lymphocyte function associated antigen-1(LFA-1) costimulation on proliferation and immunoglobin production of peripheral blood mononuclear cells(PBMCs) form lupus nephritis(LN) patients. METHODS: 29 LN patients were enrolled in this study, and 12 healthy persons served as control. PBMCs from LN patients and healthy persons were obtained by Ficoll density gradient centrifugation, and cell proliferation was detected by (3)H-TdR incorporation. IgG content in cultural supermatant was detected by ELISA. RESULTS: Stimulation of anti-CD3 mAb alone could enhance the proliferation and IgG production of PBMCs from 29 LN patients,while the effects on PBMCs from patients in active phase were stronger than those from the patients in the inactive phase (P<0.01). But anti-CD3 mAb had no influenence on PBMCs from healthy persons.The costimulation of anti-CD3 mAb and LFA-1 could increase proliferation and IgG production of PBMCs from LN patients and healthy persons. The effects of this costimulation decreased in turn from active and inactive LN patients to normal persons (P<0.01). The costimulant effects of LFA-1 was inhibited by anti-LFA-1 mAb. CONCLUSION: The effects of enhancing PBMC proliferation and IgG production by LFA-1 may be a mechanism of LN pathogenesis.