lncRNAs as a Biomarker to Assess the Therapeutic Impact of Oral Absorbent ± Probiotics in CKD Patients With PAD
lncRNAs as a Biomarker to Assess the Therapeutic Impact of Oral Absorbent ± Probiotics in CKD Patients With PAD
Participants with chronic kidney disease (CKD) are at a higher risk of developing
 atherosclerotic peripheral artery disease (PAD). Retention of uremic toxins such as indoxyl
 sulfate (IS), p-cresyl sulfate (PCS) and trimethylamine N-oxide (TMAO) during CKD is
 detrimental to endothelial and vascular function and can predispose to the development and
 progression of PAD. Many of the uremic toxins originate from gut microbial metabolism.
 Removal of these uremic toxins by carbonaceous oral adsorbent is beneficial, slowing down the
 deterioration of renal function and delaying the need for dialysis in CKD patients. However,
 if carbonaceous oral adsorbent could also improve vascular function and clinical outcomes in
 CKD patients with established PAD, remains unknown.

 In this proposal, the investigators aim to determine the therapeutic impact of a carbonaceous
 oral adsorbent made of activated bamboo charcoal (ABC) with/without probiotics on the
 endothelial/vascular function, CV outcome and mortality in CKD patients with PAD. In
 addition, the investigators hypothesize that circulating long noncoding RNA (lncRNA)
 expression profiles and metabolome may serve as a sensitive and reliable biomarker to predict
 the adverse CV outcomes and death in CKD patients with established PAD. In addition, it is
 hypothesized that circulating lncRNAs and linked to adverse CV outcomes in CKD patients with
 PAD are associated with dysbiosis of gut microbiota. The investigators also hypothesize that
 the administration of ABC could normalize the dysbiosis of gut microbiota, dysregulated
 circulating lncRNAs and metabolome that are linked to adverse CV/limb outcomes in CKD
 patients with PAD.

 This will be a prospective, randomized, open-labeled, blinded end-point trial for 6 months,
 followed by integrated assessment of endothelial/vascular function, changes in conventional
 athero- and inflammation-relevant biomarkers, circulating long noncoding RNAs, metabolome,
 and gut microbiota at baseline, ends of the 3rd and 6th month, as well as clinical CV, renal
 and limb outcomes up to 3 years.
This is a prospective, randomized, open-labeled, blinded end-point (so called PROBE) trial
 for 6 months. All patients presented to the clinics of participating sites with advanced CKD
 with eGFR 15 < eGFR < 60 ml/min/1.73m2 and symptomatic PAD will be screened for eligibility.
 The other healthy adults will be enrolled as control.

 Participants who fulfill the inclusion/exclusion criteria will be invited to participate in
 the current study. After the participants provides the written informed consents, detailed
 demographic data including genders, ages, body weights, body heights, smoking status (never,
 past, or active), the baseline creatinine (the nadir value in the past three months) and its
 corresponding eGFR and CKD stages, degrees of albuminuria (Urine albumin creatinine ratio,
 UACR), NYHA functional class, presence of atrial fibrillation, prior cardiovascular disease
 (CVD, including myocardial infarct, peripheral arterial occlusive diseases), presence of
 diabetes mellitus (DM), or hypertension. Detailed medication list will also be obtained, with
 the focus on angiotensin receptor blocker or angiotensin converting enzyme inhibitors,
 statins, and beta-blockers.

 The etiology of kidney injury will be non-mutual-exclusively categorized as:

 1. Hypertensive kidney disease, participants who received any kind of anti-hypertensive
 drugs.

 2. Diabetic kidney disease, patients who received any kind of anti-diabetics drugs.

 3. Glomerulonephritis, patients who have proteinuria more than 0.5mg/dL and kidney biopsy
 approved Glomerulonephritis.

 Eligible 120 participants (group I) with eGFR 15 < eGFR < 60 ml/min/1.73m2 and symptomatic
 PAD will be randomized into ABC-treatment (A) or no-treatment (B)participants with a 1:1
 ratio. The other 60 eligible controls (eGFR > 60 ml/min/1.73m2 and no PAD, group II) will be
 also randomized into ABC-treatment (A) or no-treatment (B) with a 1:1 ratio. The participants
 will receive CharXenPlus 4g (with ABC 2g) thrice daily for 6 months in subgroups IA and IIA,
 while the participants in subgroups IB and IIB will not receive any ABC. The subgroups IA and
 IB will be further randomly subdivided into IAa, IAb, IBa, and IBb subsubgroups. All the
 participants will receive probiotics APL-MIX2 (CharXprob) 0.8 g once a day in the last 3
 months except those in subsubgroups IAb and IBb.

 After being processed, urine, stool, and plasma samples will be stored in -80°C for further
 examinations. The names and chart numbers participants will be masked to provide adequate
 privacy. The coding book connecting codes and individual participants will be filed
 separately in order to protect participants' privacy. participants will be asked if
 investigators can keep the encrypted samples refrigerated for 10 years for further
 investigations.
Inclusion Criteria:

 I: Patients

 1. Age > 20 years old on the day of screening.

 2. CKD patients with eGFR 15 < eGFR < 60 ml/min/1.73m2 in a stable status, creatinine
 elevated less than 0.3 mg/dL in at least 30 days before enrollment.

 3. Symptomatic PAD with Rutherford Stage ≥ 2 and ABI < 0.9 (or documented by CT-angio,
 vascular duplex, etc.).

 II: Controls

 1. Age > 20 years old on the day of screening.

 2. With eGFR > 60 ml/min/1.73m2

 3. No clinical PAD.

 Exclusion Criteria:

 1. Baseline estimated glomerular filtration rates (eGFR) < 15 ml/min/1.73m2 according to
 MDRD equation.

 2. Patients in severe malnutrition status, albumin less than 2.0 g/dL

 3. Patients in severe anemia or active gastrointestinal bleeding with hemoglobulin < 8
 g/dL.

 4. Peptic ulcer, esophageal varices, ileus or under fasting status

 5. Previous gastrointestinal operation.

 6. Chronic constipation, as defined with less than 3 bowel movements per week, straining,
 hard stools, incomplete evacuation and inability to pass stool. If usage of oral
 laxatives can achieve bowel movement, this patient will not be excluded.

 7. Patients with major hemorrhage, as defined with acute hemorrhage and requirement of
 blood transfusion during index admission.

 8. Patients with a biopsy proved or clinically diagnosed advanced liver cirrhosis, Child
 classification B or C.

 9. Solid organ or hematological transplantation recipients.

 10. Patients with oliguric kidney injury, as defined with less than 500 cc/day.

 11. Evidence of obstructive kidney injury or polycystic kidney disease.

 12. Antibiotics or probiotics treatment within the last 2 weeks before enrollment and
 during follow-up period.