Infectious outcomes of fibrin sheath disruption in tunneled dialysis catheters.

BACKGROUND AND OBJECTIVES: Fibrin sheath (FS) formation around tunneled central venous catheters (CVC) increases the risk of catheter-related bloodstream infections due to bacterial adherence to a biofilm. We sought to investigate whether FS disruption (FSD) at the time of CVC removal or exchange affects infectious outcomes in patients with CVC-related infections. DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS: Retrospective cohort study of 307 adult maintenance hemodialysis patients aged 18 years or older at a single center academic-based hemodialysis program (UHN, Toronto) who developed CVC-related infections requiring CVC removal or exchange between January 2000 and January 2019. Exposure was FSD at the time of CVC removal or exchange. Outcomes were infectious metastatic complications, recurrent infection with the same organism within 1 year, or death due to infection. We created a Markov Multi-State Model (MMSM) to assess patients' trajectories through time as they transitioned between states. A time-to-event analysis was performed, adjusted for clinically relevant factors. RESULTS: There was no significant relationship between FSD status at the time of CVC removal, the development of infectious complications in the multivariable model (adjusted HR = 0.71, 95% CI 0.09-5.80, p = 0.76), or mortality from infection (HR = 0.84, 95% CI 0.34-2.11, p = 0.73). CONCLUSIONS: FSD at the time of CVC removal was not associated with increased risk of infectious complications or death due to infection. Further prospective study is needed to determine whether FSD contributes to reducing CVC infectious related complications.

The use of medium cutoff dialyzers in patients with multiple myeloma and acute kidney injury requiring hemodialysis: A systematic review.

BACKGROUND: Patients with multiple myeloma and high serum levels of circulating free light chains (FLC) have increased risk of acute kidney injury (AKI) secondary to cast nephropathy and is associated with poor survival. Despite removal of FLC by medium cutoff (MCO) dialyzer, the role of MCO hemodialysis (HD) in the treatment of cast nephropathy and its clinical benefits remain unknown. METHODS: A systematic review was conducted to establish the effectiveness of MCO dialyzer and clinical outcomes, compared to other forms of dialyzers in the removal of FLC, in myeloma patients with AKI. The primary outcome was effectiveness of MCO-HD in reducing serum FLC. The secondary outcomes were HD independence, estimated glomerular filtrate rate, mortality rates, length of hospitalization, rebound of serum FLC before the next dialysis, removal of other molecules during dialysis, and adverse events. RESULTS: We identified three case series, with a total of 17 patients. There were no randomized controlled trials (RCTs) or cohort studies. These case series showed that MCO dialyzer was effective in the removal of FLC and led to a reduction in FLC concentration post-dialysis. The majority of the case series did not have comparator arm and renal and/or other clinical outcomes. CONCLUSION: MCO dialyzer appeared to be effective in the removal of FLC based on the existing limited data. However, more data, particularly large-scale RCTs, are needed to assess the use of MCO dialyzer in reducing serum FLC and its effect on clinical outcomes in patients with multiple myeloma and AKI.

Incidence, risk factors and outcomes of malignancies after kidney transplantation in Singapore: a 12-year experience.

INTRODUCTION: Data on malignancy after kidney transplantation (KTX) is limited in our region, leading to challenges in the care of renal allograft recipients. We aimed to examine the epidemiology, risk factors and outcomes of post-KTX patients. METHODS: A retrospective cohort study was conducted of 491 patients who underwent KTX from 1 January 2000 to 31 December 2011. Data linkage analysis was done between our centre and the National Registry of Diseases Office to determine the standardised incidence ratio (SIR), standardised mortality ratio (SMR) and risk factors for malignancy after KTX. RESULTS: 31 patients (61.3% male) developed malignancy during this period, and their median age at diagnosis was 50 (range 18-65) years. Median time to malignancy diagnosis was 2.6 (range 0.3-7.9) years, with cumulative incidence of 1%, 4% and 10% at one, five and ten years, respectively. The commonest malignancy type was lymphoma, followed by kidney cancer, colorectal cancer and malignancy of the male genital organs. Multivariate analysis identified cyclosporine use as an independent risk factor for malignancy. Compared to the general population, KTX recipients had higher malignancy and mortality rates after malignancy diagnosis (SIR 3.36; SMR 9.45). Survival rates for KTX recipients with malignancy versus those without malignancy were 100%, 93% and 64% versus 97%, 93% and 83% at one, five and ten years, respectively. CONCLUSION: KTX was associated with higher mortality and incidence of malignancy. Newer immunosuppressive agents and induction therapies were not found to be risk factors for malignancy, possibly due to our relatively small sample size.

Renal thrombotic microangiopathy and pulmonary arterial hypertension in a patient with late-onset cobalamin C deficiency.

Cobalamin C (cblC) deficiency is the most commonly inherited inborn error of vitamin B12 metabolism. It is characterized by multisystem involvement with severe neurological, hematological, renal and cardiopulmonary manifestations. Disease is most commonly diagnosed early in the first decade of life. We report a case of a 20-year-old woman who developed severe pulmonary arterial hypertension while under nephrologic follow-up for chronic kidney disease. She had initially presented at 14 years of age with visual disturbance and acute renal failure and been diagnosed with thrombotic thrombocytopenic purpura on the basis of kidney biopsy findings of thrombotic microangiopathy and compatible ADAMTS13 (a disentegrin and metalloproteinase with a thrombospondin type 1 motif member 13). When cblC deficiency was eventually diagnosed, remarkable improvement in cardiopulmonary function was evident upon initiation of treatment. This case highlights the importance of a timely diagnosis and initiation of treatment for cblC deficiency. Clinical diagnosis may be challenged by asynchronous organ symptom presentation and by misleading laboratory tests, in this case: an initial low ADAMTS13. A simple test of plasma homocysteine level should be encouraged in cases of thrombotic microangiopathy and/or pulmonary artery hypertension.

Treatment of asymptomatic hyperuricemia in chronic kidney disease: A new target in an old enemy - A review.

Asymptomatic hyperuricemia is increasing in prevalence. There is a growing body of literature suggesting that uric acid has deleterious effects on vascular health and renal histological integrity. Several trials, reviewed herein, suggest that lowering the serum uric acid level is associated with a slowing in the rate of renal deterioration in those with chronic kidney disease. Given that there is little available in the general armamentarium to slow the rate of kidney deterioration, strong consideration could be given to the administration of agents or lifestyle changes that decrease uric acid production in hyperuricemic patients with deteriorating kidney function.