C3-glomerulonephritis in New Zealand - a case series.

BACKGROUND: C3-glomerulonephritis can lead to progressive renal impairment from complement-mediated glomerular injury. Incidence and outcomes of C3-glomerulonephritis are not known in the New Zealand population. METHODS: We reviewed all cases of C3-glomerulonephritis from the past 10 years at a tertiary referral centre in New Zealand. Descriptive information on baseline characteristics and clinical outcomes was collected. RESULTS: Twenty-six patients were included (16 men; mean ± SD age 44 ± 25 years) with a median follow-up of 30 months. Disease incidence was 1.3 cases per million individuals, of which 42% were Pacific Islanders. Most patients presented with renal impairment, with a median (IQR) creatinine at diagnosis of 210 (146-300) µmol/L, and 11 (42%) patients presented with nephrotic syndrome. Seven (27%) patients progressed to end stage renal disease and 2 (8%) had died. End stage renal disease occurred in 20% of patients treated with immunosuppression and in 50% of those not treated. Complete remission was seen in 25% of patients treated with some form of immunosuppression and in 17% of those not treated. CONCLUSIONS: Our results are consistent with previous descriptions of C3-glomerulonephritis. There was a suggestion of better clinical outcomes in patients treated with immunosuppression. There was a higher disease incidence in Pacific Islanders, which may indicate an underlying susceptibility to complement dysfunction in this population.

A consensus statement on the use of angiotensin receptor blockers and angiotensin converting enzyme inhibitors in relation to COVID-19 (corona virus disease 2019).

There has been a lot of speculation that patients with coronavirus disease 2019 (COVID-19) who are receiving angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) may be at increased risk for adverse outcomes. We reviewed the available evidence, and have not found this to be the case. We recommend that patients on such medications should continue on them unless there is a clinical indication to stop their use.

Does Iodinated Contrast Affect Residual Renal Function in Dialysis Patients? A Systematic Review and Meta-Analysis.

BACKGROUND: It is important for medical practitioners to be aware of the effect of iodinated contrast media on the residual renal function (RRF) of dialysis patients who require diagnostic or therapeutic imaging procedures. Preservation of RRF is important given that it is a robust predictor of higher survival. However, the absence of any effect would allow for easier diagnostic or therapeutic imaging tests to be performed. OBJECTIVE: This systematic review with meta-analysis will quantify the effect of intravascular administration of iodinated contrast on the residual function of adult dialysis patients. STUDY DESIGN: The selection criteria included adult (age ≥ 18 years) populations undergoing dialysis, who have been administered an intravascular contrast. The primary outcome was the measurement of residual function. Secondary outcomes were disease progression from peritoneal dialysis to hemodialysis, hospitalization following contrast administration, and all-cause mortality. RESULTS: Nine studies including 434 patients met the inclusion criteria. A meta-analysis was performed on 7 trials with complete quantitative data. The weighted difference in means was -0.16 mL/min (95% confidence interval -0.66 to 0.34 mL/min; p = 0.53), suggesting a small reduction in residual function following contrast administration. Significant heterogeneity in the data was observed, with a Cochran Q of 35.83 and an I2 of 83.25 (p < 0.0001). Subgroup analysis of retrospective versus prospective study design resolved heterogeneity. Few data were reported for clinical outcomes. LIMITATIONS: Small sample size of included studies. CONCLUSION: Intravascularly administered contrast media may not result in a significant reduction of residual function in dialysis patients.

Burkholderia cepacia: An Outbreak in the Peritoneal Dialysis Unit.

Burkholderia cepacia is a ubiquitous, opportunistic, environmental gram-negative bacillus which most commonly affects cystic fibrosis and immunocompromised patients. Rarely, it can cause peritoneal dialysis (PD) exit-site infection (ESI). Information relating to predisposing factors, clinical course, and treatment options for B. cepacia ESIs is limited. Although reports of B. cepacia healthcare-associated infections exist, outbreaks in PD units have not previously been reported. A recent outbreak of B. cepacia ESI in our PD unit provided a unique opportunity to study B. cepacia ESIs and to outline an approach to investigating such an outbreak.After unexpectedly identifying B. cepacia as the cause of PD catheter ESIs in 3 patients over an 11-week period, we began systematically screening our PD population for B. cepacia exit-site colonization. A further 6 patients were found to be affected, 3 with asymptomatic colonization and 3 with symptomatic B. cepacia ESI. Four of the 6 developed tunnel infections requiring multiple courses of antibiotic treatment, and 3 patients required catheter removal; 2 patients with symptomatic ESIs without tunnel involvement responded to oral and topical antibiotics. Further investigation implicated 4% chlorhexidine aqueous bodywash used by all patients as the probable source of the outbreak.This is the first reported outbreak of B. cepacia ESIs. We noted an association between diabetes mellitus and refractory/more extensive infection. Our experience suggests that isolated ESIs can be treated successfully with oral antibiotics whereas tunnel infections generally require catheter removal.

Endoluminal dilatation for embedded hemodialysis catheters: A case-control study of factors associated with embedding and clinical outcomes.

BACKGROUND: With the increasing frequency of tunneled hemodialysis catheter use there is a parallel increase in the need for removal and/or exchange. A small but significant minority of catheters become embedded or 'stuck' and cannot be removed by traditional means. Management of embedded catheters involves cutting the catheter, burying the retained fragment with a subsequent increased risk of infections and thrombosis. Endoluminal dilatation may provide a potential safe and effective technique for removing embedded catheters, however, to date, there is a paucity of data. OBJECTIVES: 1) To determine factors associated with catheters becoming embedded and 2) to determine outcomes associated with endoluminal dilatation. METHODS: All patients with endoluminal dilatation for embedded catheters at our institution since Jan. 2010 were included. Patients who had an embedded catheter were matched 1:3 with patients with uncomplicated catheter removal. Baseline patient and catheter characteristics were compared. Outcomes included procedural success and procedure-related infection. Logistic regression models were used to determine factors associated with embedded catheters. RESULTS: We matched 15 cases of embedded tunneled catheters with 45 controls. Among patients with embedded catheters, there were no complications with endoluminal dilatation. Factors independently associated with embedded catheters included catheter dwell time (> 2 years) and history of central venous stenosis. CONCLUSION: Embedded catheters can be successfully managed by endoluminal dilatation with minimal complications and factors associated with embedding include dwell times > 2 years and/or with a history of central venous stenosis.

Classification of Kidney Transplant Recipients Using a Combination of Estimated GFR and Albuminuria Reflects Risk.

BACKGROUND: The 2012 Kidney Dialysis Initiative Global Outcomes chronic kidney disease (CKD) classification scheme subdivides stage 3 CKD and incorporates the urinary albumin-to-creatinine ratio (ACR). The aim of this study was to evaluate whether the novel scheme provides graded risk in kidney transplant recipients (KTRs). METHODS: Prevalent KTRs with available laboratory data were included. The primary outcome was a composite of doubling of serum creatinine, graft failure, or death. Patients were stratified using the CKD-Epidemiolgic Collaboration equation, and ACR and the event rate per 1000 patient-years in each CKD category were calculated. RESULTS: There were 269 KTRs with a mean follow-up of 4.5 ± 2.0 years. There was a graded increase in outcomes with increasing ACR and decreasing estimated glomerular filtration rate (eGFR). For the primary outcome, the event rate was 15.3 (95% confidence interval, 4.2-39.2) per 1000 patient-years for those with an eGFR greater than 60 mL/min per 1.73 m2 and an ACR less than 30 mg/g, whereas it was 375 (95% confidence interval, 193.8-655.1) for those with an eGFR less than 30 mL/min per 1.73 m2 and an ACR greater than 300 mg/g. CONCLUSIONS: The novel Kidney Dialysis Initiative Global Outcomes classification scheme provides graded risk for important clinical events in KTRs. This information can be used to identify high-risk patients and to tailor follow-up and management strategies aimed at improving outcomes.

Predicting kidney transplantation outcomes using proteinuria ascertained from spot urine samples versus timed urine collections.

BACKGROUND: Proteinuria has been associated with transplant loss and mortality in kidney transplant recipients. Both spot samples (albumin-creatinine ratio [ACR] and protein-creatinine ratio [PCR]) and 24-hour collections (albumin excretion rate [AER] and protein excretion rate [PER]) have been used to quantify protein excretion, but which measurement is a better predictor of outcomes in kidney transplantation remains uncertain. STUDY DESIGN: Observational cohort study. SETTING & PARTICIPANTS: Tertiary care center, 207 kidney transplant recipients who were enrolled in a prospective study to measure glomerular filtration rate. Consecutive patients who met inclusion criteria were approached. PREDICTORS: ACR and PCR in spot urine samples, AER and PER in 24-hour urine collections. OUTCOMES: Primary outcome included transplant loss, doubling of serum creatinine level, or death. MEASUREMENTS: Urine and serum creatinine were measured using a modified Jaffé reaction that had not been standardized by isotope-dilution mass spectrometry. Urine albumin was measured by immunoturbidimetry. Urine protein was measured by pyrogallol red molybdate complex formation using a timed end point method. RESULTS: Mean follow-up was 6.4 years and 22% developed the primary end point. Multivariable-adjusted areas under the receiver operating characteristic curves were similar for the different protein measurements: ACR (0.85; 95% CI, 0.79-0.89), PCR (0.84; 95% CI, 0.79-0.89), PER (0.86; 95% CI, 0.80-0.90), and AER (0.83; 95% CI, 0.78-0.88). C Index values also were similar for the different proteinuria measurements: 0.87 (95% CI, 0.79-0.95), 0.86 (95% CI, 0.79-0.94), 0.88 (95% CI, 0.82-0.94), and 0.86 (95% CI, 0.77-0.95) for log(ACR), log(PCR), log(PER), and log(AER), respectively. LIMITATIONS: Single-center study. Measurement of proteinuria was at variable times posttransplantation. CONCLUSIONS: Spot and 24-hour measurements of albumin and protein excretion are similar predictors of doubling of serum creatinine level, transplant loss, and death. Thus, spot urine samples are a suitable alternative to 24-hour urine collection for measuring protein excretion in this population.

Pharmacologic treatment of hypertension in patients with chronic kidney disease.

Hypertension remains an important cause of morbidity and mortality in patients with chronic kidney disease. It both contributes to and is a consequence of chronic renal dysfunction. There is a high prevalence of hypertension in chronic kidney disease, and rates of control remain sub-optimal. Numerous studies have highlighted the benefit of treating hypertension in reducing the overall mortality as well as progression of renal disease in this population. Non-pharmacologic treatment strategies remain the primary intervention in all patients but are insufficient on their own to control hypertension in most cases. Pharmacologic treatment recommendations, however, vary depending on the specific etiology of disease as well as patient characteristics. Though most classes of anti-hypertensive drugs can be used to lower blood pressure in chronic kidney disease, therapy needs to be selected based on the presence of specific co-morbidities as well as the etiology of the kidney disease. Most patients will require multi-drug therapy for achieving target blood pressure goals. This review discusses the pharmacologic options in management of hypertension in various forms of chronic kidney disease.