Gastrointestinal Pathologies in Patients After Successful Renal Transplantation-A Pilot Study

De novo colorectal cancer after kidney transplantation: a systematic review and meta-analysis

BACKGROUND

Kidney transplant (KT) patients have higher risks of developing de novo colorectal cancer (CRC) compared to the general population. However, there is still a knowledge gap in their clinical characteristics, as most single- or multi-center efforts are underpowered and lack generalizability.

METHODS

PubMed, Web of Science, Cochrane CENTRAL, and Scopus databases were queried for studies published until July 22nd, 2024. Studies reporting the clinicopathologic characteristics and outcomes of de novo CRC among KT recipients were included.

RESULTS

There were 49 articles included involving 1855 KT patients who developed CRC. The mean time from transplantation to CRC diagnosis was 8·7 years (95%CI 7·2, 10·3 years; I2 = 98·3%). De novo CRC was most commonly located in the ascending colon (43·6%; 95%CI 29·5%, 58·9%; I2 = 55·3%), and 37·1% had advanced CRC at diagnosis (95%CI 22·3%, 54·8%; I2 = 64·1%). Although 68·8% underwent curative intent treatment (95%CI 45·4%, 85·4%; I2 = 65·4%), pooled 5-year survival rate was 31·8% (95%CI 10·5%, 65·1%; I2 = 82·5%).

CONCLUSIONS

De novo CRC was diagnosed in under 10 years after KT, and nearly 40% of patients already have advanced stage disease at diagnosis. The pooled rate of 5-year survival was 31.8%. However, there was wide heterogeneity between studies and further research is required. PROSPERO Registration: CRD42023415767.

Common contributing factors to COVID-19 and inflammatory bowel disease

The devastating complications of coronavirus disease 2019 (COVID-19) result from an individual's dysfunctional immune response following the initial severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Multiple toxic stressors and behaviors contribute to underlying immune system dysfunction. SARS-CoV-2 exploits the dysfunctional immune system to trigger a chain of events ultimately leading to COVID-19. We have previously identified many contributing factors (CFs) (representing toxic exposure, lifestyle factors and psychosocial stressors) common to myriad chronic diseases. We hypothesized significant overlap between CFs associated with COVID-19 and inflammatory bowel disease (IBD), because of the strong role immune dysfunction plays in each disease. A streamlined dot-product approach was used to identify potential CFs to COVID-19 and IBD. Of the fifty CFs to COVID-19 that were validated for demonstration purposes, approximately half had direct impact on COVID-19 (the CF and COVID-19 were mentioned in the same record; i.e., CF---→COVID-19), and the other half had indirect impact. The nascent character of the COVID-19 core literature (∼ one year old) did not allow sufficient time for the direct impacts of many CFs on COVID-19 to be identified. Therefore, an immune system dysfunction (ID) literature directly related to the COVID-19 core literature was used to augment the COVID-19 core literature and provide the remaining CFs that impacted COVID-19 indirectly (i.e., CF---→immune system dysfunction---→COVID-19). Approximately 13000 potential CFs for myriad diseases (obtained from government and university toxic substance lists) served as the starting point for the dot-product identification process. These phrases were intersected (dot-product) with phrases extracted from a PubMed-derived IBD core literature, a nascent COVID-19 core literature, and the COVID-19-related immune system dysfunction (ID) core literature to identify common ID/COVID-19 and IBD CFs. Approximately 3000 potential CFs common to both ID and IBD, almost 2300 potential CFs common to ID and COVID-19, and over 1900 potential CFs common to IBD and COVID-19 were identified. As proof of concept, we validated fifty of these ∼3000 overlapping ID/IBD candidate CFs with biologic plausibility. We further validated 24 of the fifty as common CFs in the IBD and nascent COVID-19 core literatures. This significant finding demonstrated that the CFs indirectly related to COVID-19 -- identified with use of the immune system dysfunction literature -- are strong candidates to emerge eventually as CFs directly related to COVID-19. As discussed in the main text, many more CFs common to all these core literatures could be identified and validated. ID and IBD share many common risk/contributing factors, including behaviors and toxic exposures that impair immune function. A key component to immune system health is removal of those factors that contribute to immune system dysfunction in the first place. This requires a paradigm shift from traditional Western medicine, which often focuses on treatment, rather than prevention.

Post-transplant colitis after kidney transplantation: clinical, endoscopic and histological features

Chronic immunosuppression may increase the risk of post-transplant infection and medication-related injury and may also be responsible for the increased risk of gastrointestinal complications in kidney transplant recipients. Differentiating the various forms of post-transplant colitis is challenging, since most have similar clinical and histological features. This study evaluated the incidence of post-transplant gastrointestinal complications during screening colonoscopy. Kidney transplant recipients undergoing a colonoscopy for any reasons in the period 2014-2018 were included. Among the 134 patients completing the colonoscopy, 74 patients (56%) had an abnormal finding: an adenoma was found in 25 patients (18.6%), while 19 patients (14.1%) had colitis. Mycophenolic acid/related colitis was the most common colitis (6%), while 7 patients (5.2%) developed a de novo inflammatory bowel disease. Patients with post-transplant colitis were younger and with shorter time from transplant compared to patients without colitis. In conclusions, immunosuppression may predispose kidney transplant recipients to an increased risk of post-transplant colitis. Diagnostic colonoscopy should be encouraged in all transplant patients with refractory diarrhea and gastrointestinal symptoms to allow a prompt diagnosis and a timely treatment, finally improving the quality of life and long-term outcomes of affected patients.

Gastrointestinal complications after kidney transplantation

Gastrointestinal complications are common after renal transplantation, and they have a wide clinical spectrum, varying from diarrhoea to post-transplant inflammatory bowel disease (IBD). Chronic immunosuppression may increase the risk of post-transplant infection and medication-related injury and may also be responsible for IBD in kidney transplant re-cipients despite immunosuppression. Differentiating the various forms of post-transplant colitis is challenging, since most have similar clinical and histological features. Drug-related colitis are the most frequently encountered colitis after kidney transplantation, particularly those related to the chronic use of mycophenolate mofetil, while de novo IBDs are quite rare. This review will explore colitis after kidney transplantation, with a particular focus on different clinical and histological features, attempting to clearly identify the right treatment, thereby improving the final outcome of patients.

Incidence and Impacts of Inflammatory Bowel Diseases among Kidney Transplant Recipients: A Meta-Analysis

Background: The incidence of inflammatory bowel diseases (IBD) and its significance in kidney transplant recipients is not well established. We conducted this systematic review and meta-analysis to assess the incidence of and complications from IBD in adult kidney transplant recipients. Methods: Eligible articles were searched through Ovid MEDLINE, EMBASE, and the Cochrane Library from inception through April 2020. The inclusion criteria were adult kidney transplant patients with reported IBD. Effect estimates from the individual studies were extracted and combined using the fixed-effects model when I2 ≤ 50% and random-effects model when I2 > 50%. Results: of 641 citations, a total of seven studies (n = 212) were included in the systematic review. The mean age was 46.2 +/− 6.9 years and up to 51.1% were male. The mean duration of follow-up was 57.8 +/− 16.8 months. The pooled incidence of recurrent IBD was 27.6% (95% CI, 17.7–40.5%; I2 0%) while the pooled incidence of de novo IBD was 18.8% (95% CI, 10.7–31.0%; I2 61.3%). The pooled incidence of post-transplant IBD was similar across subgroup analyses. Meta-regression analyses showed no association between the incidence of IBD and age, male sex, and follow-up duration. For post-transplant complications, the pooled incidence of post-transplant infection was 4.7% (95% CI, 0.5–33.3%; I2 73.7%). The pooled incidence of graft rejection and re-transplantation in IBD patients was 31.4% (95% CI, 14.1–56.1%; I2 76.9%) and 30.4% (95% CI, 22.6–39.5%; I2 0%). Conclusion: Recurrent and de novo IBD is common among kidney transplant recipients and may result in adverse outcomes.

Colonoscopy as Part of Pre-Transplant Work-Up in Successful Kidney Transplant Candidates: Single-Center Experience and Review of Literature

Background

Screening colonoscopy is not obligatory in kidney pre-transplant work-up guidelines. According to recommendations, only transplant recipients over age 50 years should be screened. The aim of this study was to characterize endoscopic findings revealed as part of pre-transplant work-up.

Material/Methods

We retrospectively reviewed pre-transplant work-up charts of 434 adult patients who received a cadaveric donor kidney transplantation (KT) from 2012 to 2015. Endoscopic findings analysis with age subgroup (<50 and ≥50) analysis were performed.

Results

Out of 434 of patients that underwent KT, 29% have had a colonoscopy. In 75.6% of those, pathologies were found. Hemorrhoids were found in 33% and polyps in 30.7% of patients. Adenoma detection rate (ADR) was 18.1% (67.5% distal predominance). Advanced ADR was 10.2% (distal predominance). Diverticulosis was found in 28.3% of patients and ulcerative colitis was found in 2.4%. In age subgroup analysis, ADR was higher in patients ≥50 years compared to those <50 years (21.6% vs. 4%; p=0.041).

Conclusions

Colonoscopy as part of pre-transplant work-up enables removal of precancerous lesions and management of benign findings. All candidates meeting criteria for the general population should be screened. Patients under age 50 years could also benefit from colonoscopy as part of the pre-transplant work-up. Therefore, we suggest that baseline colonoscopy should be included in pre-transplant work-up guidelines for all patients, regardless of age. However, further studies are needed to confirm this recommendation.

Upper gastrointestinal alterations in kidney transplant candidates

Introduction:

The incidence of gastrointestinal disorders among patients with chronic kidney disease (CKD) is high, despite the lack of a good correlation between endoscopic findings and symptoms. Many services thus perform upper gastrointestinal (UGI) endoscopy on kidney transplant candidates.

Objectives:

This study aims to describe the alterations seen on the upper endoscopies of 96 kidney-transplant candidates seen from 2014 to 2015.

Methods:

Ninety-six CKD patients underwent upper endoscopic examination as part of the preparation to receive kidney grafts. The data collected from the patients' medical records were charted on Microsoft Office Excel 2016 and presented descriptively. Mean values, medians, interquartile ranges and 95% confidence intervals of the clinic and epidemiological variables were calculated. Possible associations between endoscopic findings and infection by H. pylori were studied.

Results:

Males accounted for 54.17% of the 96 patients included in the study. Median age and time on dialysis were 50 years and 50 months, respectively. The most frequent upper endoscopy finding was enanthematous pangastritis (57.30%), followed by erosive esophagitis (30.20%). Gastric intestinal metaplasia and peptic ulcer were found in 8.33% and 7.30% of the patients, respectively. H. pylori tests were positive in 49 patients, and H. pylori infection was correlated only with non-erosive esophagitis (P = 0.046).

Conclusion:

Abnormal upper endoscopy findings were detected in all studied patients. This study suggested that upper endoscopy is a valid procedure for kidney transplant candidates. However, prospective studies are needed to shed more light on this matter.

Solid Organ Cancer and Melanoma in Kidney Transplant Recipients: TumorTx Base Preliminary Results

BACKGROUND

Incidence of malignancy in transplant recipients is higher than in the general population. Malignancy is a major cause of mortality following solid organ transplantation and a major barrier to long-term survival for the kidney. The aim of this study was to estimate the incidence of solid organ malignancy (SOM) and melanoma in renal transplant recipients (RTR) transplanted at 2 representative transplant centers in Poland based on data from the Polish Tumor Registry.

MATERIAL AND METHODS

We analyzed the medical data of 3069 patients who underwent kidney transplantation (KTx) between 1995 and 2015.

RESULTS

In our study 112 SOM (3.6%) were diagnosed. The majority of patients were male (n = 71; 63.4%; P < .01). The mean age at KTx was 48.0 ± 13.1 years and the mean age at the time of cancer diagnosis was 55.9 ± 12.7 years. The average time of malignancy occurrence was 5.9 ± 5.0 years after KTx. SOM was the cause of death in 60 patients (53%). The most common were malignancies of gastrointestinal tract (25%), urinary tract tumors (23.2%), lung cancer (n = 18; 16%), and lymphoma (13.4%). We found an increase in the percentage of chronic glomerular nephropathy in the group of SOM (n = 56; 50%) compared with renal insufficiency of other etiologies.

CONCLUSIONS

RTR in Poland are at a significant risk of malignancy development in a variety of organs, primarily urinary tract tumors and lymphoma. Cancers most frequently occurring in the general population such as lung and colorectal cancer are common in our RTR. On this basis an appropriate tumor screening schedule can be developed in individual countries.

The Gut-Kidney Axis: Putative Interconnections Between Gastrointestinal and Renal Disorders

Diabetic kidney disease (DKD) is a devastating condition associated with increased morbidity and premature mortality. The etiology of DKD is still largely unknown. However, the risk of DKD development and progression is most likely modulated by a combination of genetic and environmental factors. Patients with autoimmune diseases, like type 1 diabetes, inflammatory bowel disease, and celiac disease, share some genetic background. Furthermore, gastrointestinal disorders are associated with an increased risk of kidney disease, although the true mechanisms have still to be elucidated. Therefore, the principal aim of this review is to evaluate the impact of disturbances in the gastrointestinal tract on the development of renal disorders.