Patient-Centered Research and Outcomes in Cancer and Kidney Transplantation.

Cancer has been identified by kidney transplant recipients as a critically important outcome. The co-occurrence of cancer and kidney transplantation represents a complex intersection of diseases, symptoms, and competing priorities for treatments. Research that focuses on biochemical parameters and clinical events may not capture the priorities of patients. Patient-centered research can improve the relevance and efficiency of research and is particularly pertinent in the setting of cancer and kidney transplantation to facilitate shared decision-making in complex clinical situations. In addition, patient-reported outcomes can facilitate the assessment of patients' experiences, symptom burden, treatment side effects, and quality of life. This review discusses patient-centered research in the context of kidney transplantation and cancer, including consumer involvement in research and patient-centered outcomes and their measures and inclusion in core outcome sets.

Synbiotics, prebiotics and probiotics for people with chronic kidney disease.

BACKGROUND: Chronic kidney disease (CKD) is a major public health problem affecting 13% of the global population. Prior research has indicated that CKD is associated with gut dysbiosis. Gut dysbiosis may lead to the development and/or progression of CKD, which in turn may in turn lead to gut dysbiosis as a result of uraemic toxins, intestinal wall oedema, metabolic acidosis, prolonged intestinal transit times, polypharmacy (frequent antibiotic exposures) and dietary restrictions used to treat CKD. Interventions such as synbiotics, prebiotics, and probiotics may improve the balance of the gut flora by altering intestinal pH, improving gut microbiota balance and enhancing gut barrier function (i.e. reducing gut permeability). OBJECTIVES: This review aimed to evaluate the benefits and harms of synbiotics, prebiotics, and probiotics for people with CKD. SEARCH METHODS: We searched the Cochrane Kidney and Transplant Register of Studies up to 9 October 2023 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal and ClinicalTrials.gov. SELECTION CRITERIA: We included randomised controlled trials (RCTs) measuring and reporting the effects of synbiotics, prebiotics, or probiotics in any combination and any formulation given to people with CKD (CKD stages 1 to 5, including dialysis and kidney transplant). Two authors independently assessed the retrieved titles and abstracts and, where necessary, the full text to determine which satisfied the inclusion criteria. DATA COLLECTION AND ANALYSIS: Data extraction was independently carried out by two authors using a standard data extraction form. Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes, and mean difference (MD) or standardised mean difference (SMD) and 95% CI for continuous outcomes. The methodological quality of the included studies was assessed using the Cochrane risk of bias tool. Data entry was carried out by one author and cross-checked by another. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. MAIN RESULTS: Forty-five studies (2266 randomised participants) were included in this review. Study participants were adults (two studies in children) with CKD ranging from stages 1 to 5, with patients receiving and not receiving dialysis, of whom half also had diabetes and hypertension. No studies investigated the same synbiotic, prebiotic or probiotic of similar strains, doses, or frequencies. Most studies were judged to be low risk for selection bias, performance bias and reporting bias, unclear risk for detection bias and for control of confounding factors, and high risk for attrition and other biases. Compared to prebiotics, it is uncertain whether synbiotics improve estimated glomerular filtration rate (eGFR) at four weeks (1 study, 34 participants: MD -3.80 mL/min/1.73 m², 95% CI -17.98 to 10.38), indoxyl sulfate at four weeks (1 study, 42 participants: MD 128.30 ng/mL, 95% CI -242.77 to 499.37), change in gastrointestinal (GI) upset (borborymgi) at four weeks (1 study, 34 participants: RR 15.26, 95% CI 0.99 to 236.23), or change in GI upset (Gastrointestinal Symptom Rating Scale) at 12 months (1 study, 56 participants: MD 0.00, 95% CI -0.27 to 0.27), because the certainty of the evidence was very low. Compared to certain strains of prebiotics, it is uncertain whether a different strain of prebiotics improves eGFR at 12 weeks (1 study, 50 participants: MD 0.00 mL/min, 95% CI -1.73 to 1.73), indoxyl sulfate at six weeks (2 studies, 64 participants: MD -0.20 µg/mL, 95% CI -1.01 to 0.61; I² = 0%) or change in any GI upset, intolerance or microbiota composition, because the certainty of the evidence was very low. Compared to certain strains of probiotics, it is uncertain whether a different strain of probiotic improves eGFR at eight weeks (1 study, 30 participants: MD -0.64 mL/min, 95% CI -9.51 to 8.23; very low certainty evidence). Compared to placebo or no treatment, it is uncertain whether synbiotics improve eGFR at six or 12 weeks (2 studies, 98 participants: MD 1.42 mL/min, 95% CI 0.65 to 2.2) or change in any GI upset or intolerance at 12 weeks because the certainty of the evidence was very low. Compared to placebo or no treatment, it is uncertain whether prebiotics improves indoxyl sulfate at eight weeks (2 studies, 75 participants: SMD -0.14 mg/L, 95% CI -0.60 to 0.31; very low certainty evidence) or microbiota composition because the certainty of the evidence is very low. Compared to placebo or no treatment, it is uncertain whether probiotics improve eGFR at eight, 12 or 15 weeks (3 studies, 128 participants: MD 2.73 mL/min, 95% CI -2.28 to 7.75; I² = 78%), proteinuria at 12 or 24 weeks (1 study, 60 participants: MD -15.60 mg/dL, 95% CI -34.30 to 3.10), indoxyl sulfate at 12 or 24 weeks (2 studies, 83 participants: MD -4.42 mg/dL, 95% CI -9.83 to 1.35; I² = 0%), or any change in GI upset or intolerance because the certainty of the evidence was very low. Probiotics may have little or no effect on albuminuria at 12 or 24 weeks compared to placebo or no treatment (4 studies, 193 participants: MD 0.02 g/dL, 95% CI -0.08 to 0.13; I² = 0%; low certainty evidence). For all comparisons, adverse events were poorly reported and were minimal (flatulence, nausea, diarrhoea, abdominal pain) and non-serious, and withdrawals were not related to the study treatment. AUTHORS' CONCLUSIONS: We found very few studies that adequately test biotic supplementation as alternative treatments for improving kidney function, GI symptoms, dialysis outcomes, allograft function, patient-reported outcomes, CVD, cancer, reducing uraemic toxins, and adverse effects. We are not certain whether synbiotics, prebiotics, or probiotics are more or less effective compared to one another, antibiotics, or standard care for improving patient outcomes in people with CKD. Adverse events were uncommon and mild.

Synbiotics, prebiotics and probiotics for solid organ transplant recipients.

BACKGROUND: Solid organ transplantation has seen improvements in both surgical techniques and immunosuppression, achieving prolonged survival. Essential to graft acceptance and post-transplant recovery, immunosuppressive medications are often accompanied by a high prevalence of gastrointestinal (GI) symptoms and side effects. Apart from GI side effects, long-term exposure to immunosuppressive medications has seen an increase in drug-related morbidities such as diabetes mellitus, hyperlipidaemia, hypertension, and malignancy. Non-adherence to immunosuppression can lead to an increased risk of graft failure. Recent research has indicated that any microbial imbalances (otherwise known as gut dysbiosis or leaky gut) may be associated with cardiometabolic diseases in the long term. Current evidence suggests a link between the gut microbiome and the production of putative uraemic toxins, increased gut permeability, and transmural movement of bacteria and endotoxins and inflammation. Early observational and intervention studies have been investigating food-intake patterns, various synbiotic interventions (antibiotics, prebiotics, or probiotics), and faecal transplants to measure their effects on microbiota in treating cardiometabolic diseases. It is believed high doses of synbiotics, prebiotics and probiotics are able to modify and improve dysbiosis of gut micro-organisms by altering the population of the micro-organisms. With the right balance in the gut flora, a primary benefit is believed to be the suppression of pathogens through immunostimulation and gut barrier enhancement (less permeability of the gut). OBJECTIVES: To assess the benefits and harms of synbiotics, prebiotics, and probiotics for recipients of solid organ transplantation. SEARCH METHODS: We searched the Cochrane Kidney and Transplant Specialised Register up to 9 March 2022 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov. SELECTION CRITERIA: We included randomised controlled trials measuring and reporting the effects of synbiotics, prebiotics, or probiotics, in any combination and any formulation given to solid organ transplant recipients (any age and setting). Two authors independently assessed the retrieved titles and abstracts and, where necessary, the full text to determine which satisfied the inclusion criteria. DATA COLLECTION AND ANALYSIS: Data extraction was independently carried out by two authors using a standard data extraction form. The methodological quality of included studies was assessed using the Cochrane risk of bias tool. Data entry was carried out by one author and cross-checked by another. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. MAIN RESULTS: Five studies (250 participants) were included in this review. Study participants were adults with a kidney (one study) or liver (four studies) transplant. One study compared a synbiotic to placebo, two studies compared a probiotic to placebo, and two studies compared a synbiotic to a prebiotic. Overall, the quality of the evidence is poor. Most studies were judged to have unclear (or high) risk of bias across most domains. Of the available evidence, meta-analyses undertaken were of limited data from small studies. Across all comparisons, GRADE evaluations for all outcomes were judged to be very low certainty evidence. Very low certainty evidence implies that we are very uncertain about results (not estimable due to lack of data or poor quality). Synbiotics had uncertain effects on the change in microbiota composition (total plasma p-cresol), faecal characteristics, adverse events, kidney function or albumin concentration (1 study, 34 participants) compared to placebo. Probiotics had uncertain effects on GI side effects, infection rates immediately post-transplant, liver function, blood pressure, change in fatty liver, and lipids (1 study, 30 participants) compared to placebo. Synbiotics had uncertain effects on graft health (acute liver rejection) (2 studies, 129 participants: RR 0.73, 95% CI 0.43 to 1.25; 2 studies, 129 participants; I² = 0%), the use of immunosuppression, infection (2 studies, 129 participants: RR 0.18, 95% CI 0.03 to 1.17; I² = 66%), GI function (time to first bowel movement), adverse events (2 studies, 129 participants: RR 0.79, 95% CI 0.40 to 1.59; I² = 20%), serious adverse events (2 studies, 129 participants: RR 1.49, 95% CI 0.42 to 5.36; I² = 81%), death (2 studies, 129 participants), and organ function measures (2 studies; 129 participants) compared to prebiotics. AUTHORS' CONCLUSIONS: This review highlights the severe lack of high-quality RCTs testing the efficacy of synbiotics, prebiotics or probiotics in solid organ transplant recipients. We have identified significant gaps in the evidence. Despite GI symptoms and postoperative infection being the most common reasons for high antibiotic use in this patient population, along with increased morbidity and the growing antimicrobial resistance, we found very few studies that adequately tested these as alternative treatments. There is currently no evidence to support or refute the use of synbiotics, prebiotics, or probiotics in solid organ transplant recipients, and findings should be viewed with caution. We have identified an area of significant uncertainty about the efficacy of synbiotics, prebiotics, or probiotics in solid organ transplant recipients. Future research in this field requires adequately powered RCTs comparing synbiotics, prebiotics, and probiotics separately and with placebo measuring a standard set of core transplant outcomes. Six studies are currently ongoing (822 proposed participants); therefore, it is possible that findings may change with their inclusion in future updates.

D-mannose for preventing and treating urinary tract infections.

BACKGROUND: Urinary tract infections (UTIs) are very common, affecting more than 7 million people worldwide. Whilst many people may only experience a single episode in their lifetime and are generally responsive to standard antibiotics, a significant proportion of adults and children (approximately 15% to 25%) are chronic symptomatic UTI sufferers. Certain population groups are at greater risk than others, such as immunosuppressed and people with chronic kidney disease. D-mannose is a sugar part of normal human metabolism found within most diets. The mechanism of action is to prevent bacterial adherence to the uroepithelial cells. The D-mannose-based inhibitors can block uropathogenic Escherichia coli adhesion and invasion of the uroepithelial cells. The bacteria are then understood to essentially be eliminated by urination. Early pilot studies on animals and humans have trialled concentrated forms of D-mannose (tablets or sachets) in doses ranging from 200 mg up to 2 to 3 g and found possible efficacy in reducing UTI symptoms or recurrence. Although the anti-adhesive effects of D-mannose have been well-established, only recently have we seen a small number of pilot studies and small clinical trials conducted. OBJECTIVES: To assess the benefits and harms of D-mannose for preventing and treating UTIs in adults and children. SEARCH METHODS: We searched the Cochrane Kidney and Transplant Register of Studies up to 22 February 2022 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov. SELECTION CRITERIA: We included RCTs measuring and reporting the effect of D-mannose, in any combination and any formulation, to prevent or treat UTIs in adults and children, females and males, in any setting (including perioperative). Authors independently assessed the retrieved titles and abstracts and, where necessary, the full text to determine which satisfied the inclusion criteria. DATA COLLECTION AND ANALYSIS: Data extraction was independently carried out by two authors using a standard data extraction form. Methodological quality of the included studies was assessed using the Cochrane risk of bias tool. Data entry was carried out by one author and cross-checked by another author. The certainty of the evidence was assessed using the GRADE approach. MAIN RESULTS: We included seven RCTs (719 participants) in adult females and males who had either acute cystitis or a history of recurrent (at least two episodes in six months or three episodes in 12 months) UTIs (symptomatic or asymptomatic). Two were prevention studies, four were prevention and treatment studies (two perioperative and one in people with multiple sclerosis), and one was a treatment study. Time periods ranged from 15 days to six months. No two studies were comparable (by dose or treatments), and we could not undertake meta-analyses. Individual studies reported no clear evidence to determine whether D-mannose is more or less effective in preventing or treating UTIs. D-mannose (2 g) had uncertain effects on symptomatic and bacteriuria-confirmed UTIs when compared to no treatment (1 study, 205 participants; very low certainty evidence) and antibiotics (nitrofurantoin 50 mg) (1 study, 206 participants; very low certainty evidence). D-mannose, in combination with herbal supplements, had uncertain effects on symptomatic and bacteria-confirmed UTI and pain when compared to no treatment (1 study, 40 participants; very low certainty evidence). D-mannose 500 mg plus supplements (N-acetylcysteine and Morinda citrifolia fruit extract) had uncertain effects on symptomatic and bacteriuria-confirmed UTIs when compared to an antibiotic (prulifloxacin 400 mg) (1 study, 75 participants; very low certainty evidence). Adverse events were very few and poorly reported; none were serious (mostly diarrhoea and vaginal burning). Overall, the quality of the evidence is poor. Most studies were judged to have unclear or high risk of bias across most domains. Data was sparse and addressed very few outcomes. The GRADE evaluation was rated as very low certainty evidence due to very serious limitations in the study design or execution (high risk of bias across all studies) and sparse data (single study data and small sample sizes). AUTHORS' CONCLUSIONS: There is currently little to no evidence to support or refute the use of D-mannose to prevent or treat UTIs in all populations. This review highlights the severe lack of high-quality RCTs testing the efficacy of D-mannose for UTIs in any population. Despite UTIs being one of the most common adult infections (affecting 50% of women at least once in their lifetime) and the growing global antimicrobial resistance, we found very few studies that adequately test this alternative treatment. Future research in this field requires, in the first instance, a single adequately powered RCT comparing D-mannose with placebo.

Hypoxia-inducible factor stabilisers for the anaemia of chronic kidney disease.

BACKGROUND: Anaemia occurs in chronic kidney disease (CKD) and is more prevalent with lower levels of kidney function. Anaemia in CKD is associated with death related to cardiovascular (CV) disease and infection. Established treatments include erythropoiesis-stimulating agents (ESAs), iron supplementation and blood transfusions. Oral hypoxia-inducible factors (HIF) stabilisers are now available to manage anaemia in people with CKD. OBJECTIVES: We aimed to assess the benefits and potential harms of HIF stabilisers for the management of anaemia in people with CKD. SEARCH METHODS: We searched the Cochrane Kidney and Transplant Register of Studies up to 22 November 2021 through contact with the Information Specialist using search terms relevant to our review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal, and ClinicalTrials.gov. SELECTION CRITERIA: Randomised and quasi-randomised studies evaluating hypoxia-inducible factors stabilisers compared to placebo, standard care, ESAs or iron supplementation in people with CKD were included. DATA COLLECTION AND ANALYSIS: Five authors independently extracted data and assessed the risk of bias. Treatment estimates were summarised using random effects pair-wise meta-analysis and expressed as a relative risk (RR) or mean difference (MD), with a corresponding 95% confidence interval (CI). Evidence certainty was assessed using GRADE. MAIN RESULTS: We included 51 studies randomising 30,994 adults. These studies compared HIF stabilisers to either placebo or an ESA. Compared to placebo, HIF stabiliser therapy had uncertain effects on CV death (10 studies, 1114 participants): RR 3.68, 95% CI 0.19 to 70.21; very low certainty evidence), and nonfatal myocardial infarction (MI) (3 studies, 822 participants): RR 1.29, 95% CI 0.31 to 5.36; I² = 0%; very low certainty evidence), probably decreases the proportion of patients requiring blood transfusion (8 studies, 4329 participants): RR 0.51, 95% CI 0.44 to 0.60; I² = 0%; moderate certainty evidence), and increases the proportion of patients reaching the target haemoglobin (Hb) (10 studies, 5102 participants): RR 8.36, 95% CI 6.42 to 10.89; I² = 37%; moderate certainty evidence). Compared to ESAs, HIF stabiliser therapy may make little or no difference to CV death (17 studies, 10,340 participants): RR 1.05, 95% CI 0.88 to 1.26; I² = 0%; low certainty evidence), nonfatal MI (7 studies, 7765 participants): RR 0.91, 95% CI 0.76 to 1.10; I² = 0%; low certainty evidence), and nonfatal stroke (5 studies, 7285 participants): RR 1.06, 95% CI 0.71 to 1.56; I² = 8%; low certainty evidence), and had uncertain effects on fatigue (2 studies, 3471 participants): RR 0.80, 95% CI 0.56 to 1.16; I² = 0%; very low certainty evidence). HIF stabiliser therapy probably decreased the proportion of patients requiring blood transfusion (11 studies, 10,786 participants): RR 0.87, 95% CI 0.76 to 1.00; I² = 25%; moderate certainty evidence), but may make little or no difference on the proportion of patients reaching the target Hb (14 studies, 4601 participants): RR 1.00, 95% CI 0.93 to 1.07; I² = 70%; low certainty evidence), compared to ESA. The effect of HIF stabilisers on hospitalisation for heart failure, peripheral arterial events, loss of unassisted dialysis vascular access patency, access intervention, cancer, infection, pulmonary hypertension and diabetic nephropathy was uncertain. None of the included studies reported life participation. Adverse events were rarely and inconsistently reported. AUTHORS' CONCLUSIONS: HIF stabiliser management of anaemia had uncertain effects on CV death, fatigue, death (any cause), CV outcomes, and kidney failure compared to placebo or ESAs. Compared to placebo or ESAs, HIF stabiliser management of anaemia probably decreased the proportion of patients requiring blood transfusions, and probably increased the proportion of patients reaching the target Hb when compared to placebo.