Melanie Field

The use of NGAL and IP‐10 in the prediction of early acute rejection in highly sensitized patients following HLA‐incompatible renal transplantation

Acute rejection is a significant problem for patients undergoing HLA‐incompatible renal transplantation, affecting between 12 and 53% of patients. Any mechanism of detecting rejection in advance of current methods would offer significant benefit. This study aimed to evaluate whether serum biomarkers could predict rejection in HLAi transplants recipients. Sera from 94 HLAi transplant recipients from a single centre were analysed for a panel of biomarkers including: NGAL, KIM‐1, IP‐10, cystatin C, cathepsin L and VEGF. Biomarker levels pre‐operatively, day 1 and at day 30 post‐transplant were correlated with the development of early rejection. Significantly higher levels of IP‐10 and NGAL were seen on day 1 following transplant in those patients who developed acute rejection (P < 0.001 and 0.005) and generated AUC of 0.73 and 0.67, respectively. No differences were seen for the other biomarkers or at the other time points. In this study cohort, IP‐10 and NGAL have demonstrated good predictive ability for the development of acute rejection at a very early time point. They may have a role in identifying patients at higher risk for rejection and stratifying immunosuppression or surveillance.

Urinary biomarkers of acute kidney injury in deceased organ donors--kidney injury molecule-1 as an adjunct to predicting outcome.

Deceased kidney donors are increasingly “marginal,” and many have risk factors for acute kidney injury (AKI) that may impact on subsequent renal transplant outcome. Despite this, determining the presence of AKI at the time of deceased organ donation remains difficult.

The brachiobasilic arteriovenous fistula: effect of patient variables

Purpose The hemodialysis population is constantly expanding as patients on dialysis have increased longevity and the number of kidneys available for transplantation remains static (1). After radiocephalic and brachiocephalic fistulas have been exhausted the use of the autologous brachiobasilic fistula (BBAVF) should be considered prior to use of a synthetic graft. We present our single center experience of 140 brachiobasilic fistulas in a five-year period and examine any factors that influence patency and long-term function. Methods Patients who had undergone formation of a BBAVF between January 2004 and January 2009 were identified; a review of all case notes and databases was undertaken. Details on demographics, cause of renal failure, co-morbidities (including diabetes, cardiac morbidity, hypertension, peripheral vascular disease), dialysis status at the time of fistula creation, hemoglobin, anti-coagulation regimens, and complications from surgery were recorded. Results Patency (defined as use of AVF for dialysis) was 83% at 3 months, 77% at 6 months, and 69% at 12 months. Length of patency ranged from 0 to 1918 days (at study cut-off) with a mean patency of 532 days. Factors found to significantly affect fistula patency included age over 60 (P=<0.001) and presence of peripheral vascular disease (P=0.048). Conclusions Our brachiobasilic fistula patency rates are comparable with published literature and other fistulas. Within our population patient variables including age over 60 and the presence of peripheral vascular disease are associated with worse outcomes as would be expected. In spite of these factors we feel the brachiobasilic fistula is an excellent option for patients with more challenging access and should certainly be undertaken prior to the use of prosthetic grafts.

Anti-tuberculosis prophylaxis following renal transplantation: acceptable variations?

Guidelines suggest tuberculosis (TB) prophylaxis in renal transplant recipients originating in endemic areas or in those at risk from non‐endemic countries. Concern remains that these guidelines may fail to provide adequate prophylaxis for a cohort of patients who remain at potential risk. We aimed to determine variation patterns among different transplant units within the United Kingdom (UK) with regard to TB prophylaxis policy.

Perianal Langerhans cell histiocytosis

Dear Editor, Langerhans cell histiocytosis (LCH) rarely occurs in adults and is usually a multi-focal systemic disease. We present the case of a 70-year-old male with sole perianal histiocytosis and discussion of current literature and management options. LCH is a rare disease characterised by the presence of Langerhans cell histiocytes in a variety of tissues and by a spectrum of clinical manifestations. Typically, LCH is a disease of childhood and is comparatively rarely reported in adults. LCH involving the GI tract is rare. A 70-year-old gentleman was referred to our colorectal clinic with a 3week history of fresh rectal bleeding associated with a 4-month history of perianal pain and mucous discharge. There was no associated change in bowel habit, weight loss or family history of colorectal disease. His past medical history included prostate cancer diagnosed in 2003. Anorectal examination revealed a 2-cm ulcerated lesion in the anal canal with perianal extension circumferentially. Further examination was prevented in the clinic setting by pain. Examination under anaesthetic confirmed that the lesion arose from the outside of the anal canal, with ulceration of the perianal skin, the rectum was normal. Biopsies were taken from different areas of the lesion for histological examination. Histological examination of the biopsies revealed squamous epithelial lined tissue with ulceration, granulation tissue and inflammation. Sheets of mononuclear cells with medium-sized normochromic, vesicular and indented nuclei along with abundant pale cytoplasm were present. A number of eosinophils were also present. Michaelis–Guttman bodies (characteristic findings in malakoplakia) were not identified. Mitotic figures were infrequent. This mononuclear infiltrate was positive for immunohistochemical markers for Langerhans cells and histiocytes including CD1a, S100 and CD68. The gentlemen went on to have topical treatment with potassium permanganate and steroids. Later, the patient developed a bone lesion in his left tibia which was biopsied and histological examination revealed histiocytic infiltration of bone with associated osteosclerosis. This was not associated with eosinophilic infiltrate and CD1a stain was negative. The diagnosis of Erdheim–Chester disease was made on this bone biopsy. Although Erdheim–Chester disease has been previously been classified as a type of LCH, it is now thought to be a distinct entity and no cases involving perianal lesions are described. The first published description of Langerhans histiocytosis was in 1865 in a 4 1/2-year-old with impetigo type M. Field . N. Inston . N. Cruickshank Department of Surgery, Sandwell and West Birmingham Hospital, Lyndon, West Bromwich, B71 4HJ, UK

Patient survival following arteriovenous fistula formation

Purpose Efforts to promote arteriovenous fistulas (AVFs) have been successful in increasing the prevalence of AVF use as the primary vascular access for haemodialysis (HD). Sustained preference for AVF use may not be the most appropriate vascular access choice for all patient groups. Arteriovenous grafts (AVGs) offer advantages of earlier use and lower primary failure rates compared to AVFs so may be preferable for patients where short-term vascular access is needed. This study was designed to assess comparative mortality in different age groups following AVF formation. Methods A prospective cohort of patients having AVF creation was recruited. Patients were subdivided into three age groups: Group A: <50 years; Group B: 50-74 years and Group C: ≥75 years. Survival curves and Cox regression analysis were performed on each of these groups. Results One hundred and thirty-four patients (n = 134) were recruited into the study. The prevalence of diabetes increased significantly with age. As expected, mortality was higher in older age groups (log rank (Mantel-Cox) 19.227; p = 0.0001). Mortality rates at 1 year were 0% in group A, 12.5% in group B and 29.1% in group C. Medium-term mortality at 4 years was 7.9% in group A, 39.1% in group B and 54.8% in group C. Conclusions We found a significantly higher mortality rate in patients ≥75 years in comparison to those <75 years. The choice of vascular access modality should be tailored to the individual with particular reference to the patients expected survival.

End-stage vascular access failure: can we define and can we classify?

Background Renal replacement therapy using dialysis has evolved dramatically over recent years with an improvement in patient survival. With this increased longevity, a cohort of patients are in the precarious position of having exhausted the standard routes of vascular access. The extent of this problem of failed access or ‘desperate measures’ access is difficult to determine, as there are no uniform definitions or classification allowing standardization and few studies have been performed. The aim of this study is to propose a classification of end-stage vascular access (VA) failure and subsequently test its applicability in a dialysis population. Methods Using anatomical stratification, a simple hierarchical classification is proposed. This has been applied to a large dialysis population and in particular to patients referred to the complex access clinic dedicated to patients identified as having exhausted standard VA options and also those dialysing on permanent central venous catheters (CVC). Results A simple classification is proposed based on a progressive anatomical grading of (I) standard upper arm options exhausted, (II) femoral options exhausted and (III) other options exhausted. These are further subdivided anatomically to allow ease of classification. When applied to a complex group of patients (n = 145) referred to a dedicated complex access clinic, 21 patients were Class I, 26 Class II and 2 Class III. Ninety-six patients did not fall into the classification despite being referred as permanent CVC. Conclusions The numbers of patients who have exhausted definitive access options will continue to increase. This simple classification allows the scope of the problem and proposed solutions to be identified. Furthermore, these solutions can be studied and treatments compared in a standardized fashion. The classification may also be applied if patients have the option of transplantation where iliac vessel preservation is desirable and prioritization policies may be instituted.

Novel use of infrared thermal imaging to predict arteriovenous fistula patency and maturation

Objective The arteriovenous fistula (AVF) is the preferred method of long-term haemodialysis. However, it has been shown to have a substantial rate of maturation failure. The formation of an AVF creates haemodynamic changes to blood flow in the arm with diversion of blood away from the distal circulation into the low pressure venous system, in turn, leading to thermal changes distally. In this study, we aimed to assess the novel use of infrared thermal imaging as a predictor of arteriovenous maturation. Methods A prospective cohort study was conducted on 100 consecutive patients who had AVF formation from December 2015 to June 2016. Infrared thermal imaging was undertaken pre- and post-operatively on the day of surgery to assess thermal changes to the arms and to assess them as predictors of clinical patency and functional maturation. Results For clinical patency, infrared thermal imaging was found to have a positive predictive value of 88% and a negative predictive value of 86%. For functional maturation, it was found to have a positive predictive value of 84%, a negative predictive value of 95%. In addition, it was shown to have superiority to the commonly used intra-operative predictor of thrill as well as other independent pre-operative patient factors. Conclusions Infrared thermal imaging has been found to be a very useful tool in accurately predicting fistula patency and maturation.

Survival following arteriovenous fistula formation: are grafts indicated in the elderly?

We maintain that in a select group of patients where projected survival is expected to be limited (less than 2 years) grafts represent a viable option. Benefits of AVG over AVF are a superior primary patency, reduction in time required for maturation and a potential reduction in the number of patients commencing dialysis on a CVC. The dogmatic approach of an AVF first in this patient group may result in worse outcome, longer time to a working AVF and overall detriment of patient care.

Do arteriovenous fistulae cause technical/local complications after renal transplantation?

cations in AV fistulas is reassuringly low. This study excludes the cardiac sequelae of AVFs post transplantation as this has previously been demonstrated whilst surgical and technical complications within this group have not previously been reported. While the debate continues to define the physiologic cardiac sequelae of AVFs in the transplant population, we have demonstrated that the rate of development of technical complications commonly encountered in fistulas over a longitudinal period remains acceptable. Further study will hopefully unequivocally demonstrate whether cardiac effects because of AVFs are sufficient to suggest ligation in all working transplants; the incidence of other complications appears sufficiently low to not routinely mandate this action at present. This is of particular relevance with the increased use of marginal kidneys for transplantation, because of a decreased donor pool, with concomitant limited expectations of long-term graft survival.