Vitamin B6 status, immune response and inflammation markers in kidney transplant recipients treated with polyclonal anti-thymocyte globulin

Immunosuppressive Therapy and Nutritional Status of Patients after Kidney Transplantation: A Protocol for a Systematic Review

(1) Background: Kidney transplantation is widely recognized as the most effective method of treating end-stage renal disease. Immunosuppressive therapy plays a pivotal role in the treatment of kidney transplant patients, encompassing all patients (except identical twins), and is administered from organ transplantation until the end of its function. The aim of this systematic review is to identify the evidence of the association between immunosuppressive therapy and nutritional status of patients following kidney transplantation. (2) Methods: This protocol has been designed in line with Preferred Items for Systematic Reviews (PRISMA-P). Our search encompasses several databases, including MEDLINE (via PubMed), EMBASE (Elsevier), Scopus and Web of Science. We intend to include observational studies (cross-sectional, case-control, and cohort designs), randomized controlled trials (RCTs), as well as completed and ongoing non-randomized study designs. We will confine our search to studies published in English within the past decade (from inception to 17 February 2023). Qualitative studies, case studies, and conference reports will be excluded. The selection process will be done in Covidence by two independent reviewers. Data extraction will be conducted using a standardized MS Excel template version 16.0. Quality assessment of included studies will be performed using the Cochrane Risk of Bias tool for randomized trials (RoB2), or the Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I) tool. Risk-of-bias plots will be generated using the web application Robvis. Relevant data that have been extracted from eligible studies will be presented in a narrative synthesis. We expect the studies to be too heterogeneous to perform subgroup analyses. (3) Conclusion: This systematic review will offer insights into the evidence regarding association between immunosuppressive therapy and nutritional status of adult patients (18 years of age or older) within the initial year following kidney transplantation. To our knowledge, there is no systematic review addressing that question.

Comparison of the anti-inflammatory effects of vitamin E and vitamin D on a rat model of dextran sulfate sodium-induced ulcerative colitis

The present study aimed to compare the clinical effects of vitamin E and vitamin D on a rat model of dextran sulfate sodium (DSS)-induced ulcerative colitis (UC), and to elucidate the underlying mechanisms associated with changes in the levels of cytokines. After successful establishment of the rat model of DSS-induced UC, prednisolone (1 mg/kg), vitamin D (50 ng) and vitamin E (6, 30 and 150 IU/kg) were orally administered for 1 week. The pharmacodynamics were evaluated by a daily combination of clinical observation (CO) scores, histopathological evaluations and assessment of molecular markers of inflammation. Administration of vitamin D, vitamin E (30 and 150 IU/kg), prednisolone, and the combination of vitamin D and vitamin E resulted in a decrease in CO scores. The severity of inflammation of the colon was markedly alleviated in the treatment groups compared with that in the untreated DSS group according to the results of histopathological examination; however, they showed different inhibitory effects on the levels of some cytokines. In conclusion, the present results indicated that oral administration of vitamin E could promote recovery of DSS-induced UC by the inhibition of proinflammatory cytokines, and that its underlying mechanism may differ from that of vitamin D and glucocorticoid drugs.

Vitamin B6 improves blood parameters in rats fed a protein-deficient diet and subjected to moderate, long-term exercise

Vitamin B₆ is necessary for many enzymatic pathways (glucose and lipid metabolism, DNA/RNA synthesis, or modulation of gene expression) and affects immune cell function and blood-forming processes. We hypothesised that supplementing a protein-deficient diet with vitamin B₆ may reduce the negative impact of protein malnutrition. Here, we evaluated the effect of moderate, long-term exercise (ninety days) on selected blood parameters in rats fed a normal diet, a protein-deficient diet, or a protein-deficient diet supplemented with vitamin B₆. Selected haematological, immunological, and biochemical parameters were examined. A protein-deficient diet lasting 90 days caused significant reduction in body mass, increased activity of aminotransferases (asparagine and alanine), an increased percentage of innate cells in the blood, and decreased haemoglobin concentration in the blood. Adding vitamin B₆ significantly increased body and muscle mass, decreased liver parameters, and caused normalisation of haemoglobin concentration and the proportion of white blood cells in the blood. These results indicate that vitamin B₆ supplementation significantly improves the health of protein-malnourished rats and paves the way for the development of novel anti-malnutrition therapies.

Pyridoxine Deficiency After Solid Organ Transplant

OBJECTIVE

Pyridoxine is 1 of 8 B vitamins that assist in a variety of essential functions including immune functions. The purpose of this study was to assess the risk factors associated with low pyridoxine levels in solid organ transplantation recipients.

DESIGN

The study cohort was divided into 2 groups: (a) patients with normal pyridoxine levels or (b) patients with low pyridoxine levels. Dietary evaluation and clinical characteristics of all patients, rejection episodes, and immunosuppression were collected. Simple descriptive statistics were used to analyze the overall cohort.

RESULTS

Of the 48 patients, 29 (60%) in the study cohort were identified to have low pyridoxine levels. The mean interval between transplantation and pyridoxine level check was 910 days (standard deviation [SD] 456). The mean weight at the time of dietary consultation was 80 kg (SD 20.7). More patients in the deficient group received thymoglobulin for rejection treatment (56% vs 0%; P = .01) and were thymoglobulin recipients (78% vs 10%; odds ratio [OR] = 31.5; 95% confidence interval [CI], 2.35-422.30; P < .01). A strong correlation was identified between thymoglobulin treatment for induction and a low level of pyridoxine (correlation coefficient R = 0.6, P = .004) and between thymoglobulin treatment for rejection and a low pyridoxine level (correlation coefficient R = 0.5, P = .05). Based on multivariate logistic regression analysis, only thymoglobulin treatment (induction or rejection treatment) was significantly associated with low pyridoxine levels (OR = 19.5, 95% CI, 1.01-375.24; P < .05).

CONCLUSIONS

Low levels of pyridoxine appear to be relatively common, and thymoglobulin treatments are associated with low pyridoxine levels. Prospective studies are needed to confirm and valuate the significance of these findings.

Vitamin B-6, Independent of Homocysteine, Is a Significant Factor in Relation to Inflammatory Responses for Chronic Kidney Disease and Hemodialysis Patients

The purpose of this study was to investigate whether plasma pyridoxal 5′-phosphate (PLP) and homocysteine were dependent on or independent of each other in order to be associated with inflammatory markers in patients with chronic kidney disease (CKD) or those receiving hemodialysis treatment. This was a cross-sectional study. Sixty-eight stage 2–5 CKD patients and 68 hemodialysis patients had one time fasting blood drawn for measurements of plasma PLP, pyridoxal (PL), homocysteine, and several inflammatory markers. Early CKD stage (stages 2-3) patients showed significantly lower plasma PLP levels and homocysteine concentrations than patients in an advanced CKD stage (stages 4-5) and those undergoing hemodialysis. Plasma PLP significantly correlated with CRP levels (partial r_s = −0.21, p < 0.05) and plasma PL significantly correlated with IL-10 levels (partial r_s = −0.24, p < 0.01), while plasma PLP plus PL significantly correlated with both CRP levels (partial r_s = −0.20, p < 0.05) and interleukin-1β (partial r_s = 0.22, p < 0.05) levels after adjusting for plasma homocysteine and other potential confounders. Plasma homocysteine displayed no significant correlations with any inflammatory markers. Vitamin B-6 status, rather than homocysteine, appeared to be a significant factor in relation to inflammatory responses for CKD and hemodialysis patients.

Vitamins and Microelement Bioavailability in Different Stages of Chronic Kidney Disease

Chronic kidney disease (CKD) predisposes one to either deficiency or toxic excess of different micronutrients. The knowledge on micronutrients—specifically water-soluble vitamins and trace elements—in CKD is very limited. Consequently, current guidelines and recommendations are mostly based on expert opinions or poor-quality evidence. Abnormalities of micronutrient resources in CKD develop for several reasons. Dietary restrictions and anorexia lead to an insufficient micronutrient intake, while diuretics use and renal replacement therapy lead to their excessive losses. Absorption is unpredictable, and metabolism impaired. Better understanding of the micronutrient needs of CKD patients could have an impact on many complications linked to vitamin and trace element disorders, including high mortality, increased risk of atherosclerosis, inflammation, oxidative stress, anemia, polyneuropathy, encephalopathy, weakness and fragility, muscle cramps, bone disease, depression, or insomnia. Here, we summarize the up-to-date knowledge on micronutrient resources in different stages of CKD, and share our experience with the assessment of micronutrient status.