Portuguese Journal of Nephrology & Hypertension

Renal pathology in HCV infected patients - Report of 148 patients and review of the literature

Background: Hepatitis C virus infection (HCV) is a major public health problem with a reported incidence of 3-4 million cases per year. Renal injury secondary to HCV was initially observed in autopsy studies and later in kidney biopsies. Several types of renal disease have been recognized in association with HCV patients. Objectives: Characterize the type of renal disease found in HCV-infected patients and established as possible relation with clinical presentation. Methods: Unicentric retrospective study of HCV patients with a renal biopsy from January 1988 to December 2015. The clinical data at biopsy time was analyzed according to histological diagnosis. Results: HCV infection was present in 148 cases. Male gender was predominant (76.7%), as was Caucasian race (79.1%). Mean age was 41.46±11.47years. Histological study of renal biopsies revealed membranoproliferative glomerulonephritis (MPGN) type 1 to be the commonest lesion encountered (37.2%), followed by proliferative glomerulonephritis (16.9%), focal segmental glomerulosclerosis (FSGS) (10.1%), and tubulointerstitial nephropathy (10.1%). Other patterns (amyloidosis, diabetic nephropathy, membranous nephropathy, IgA nephropathy) were observed. Hypocomplementaemia and cryoglobulinaemia showed correlation with MPGN diagnosis. A statistically significant correlation was observed with human immunodeficiency virus (HIV) infection and FSGS diagnosis. Amyloidosis diagnosis was associated with advanced age. No other significant correlations were found. Conclusions: Renal disease in HCV patients has a broad spectrum. No strong correlations between clinical data and pattern of renal disease have been established and it seems that is not possible to predict the renal disease based on clinical criteria alone. Renal biopsy remains the gold standard for diagnosis.

**Recombinant tissue plasminogen activator plus citrate versus citrate alone as catheter lock for tunnelled catheters of haemodialysis**

Introduction: The solution used to fill the lumens of the tunnelled catheters for haemodialysis (lock) influences catheter-related complications, such as inadequate blood flow and dialysis efficacy. It is unknown whether a lock strategy with weekly administration of Recombinant Tissue Plasminogen Activator (rt-PA) and of citrate during the remaining dialysis sessions is associated with better catheter blood flow and increased dialysis dose compared with citrate alone. Methods: We performed a prospective cross-over study in 16 patients to compare weekly administration of 1mg per catheter lumen of rt-PA and citrate 4% in the remaining sessions with citrate 4% administration in all dialysis sessions. Each lock strategy was performed for 24 weeks, separated by a 4-week wash-out period. We performed a random effects model and two paired t-tests (in each intervention group and in each patient) to compare the mean blood flow and single-pool Kt/V (spKt/V) of each dialysis session. Results: In the 8 patients eligible for comparison, blood flow was higher in the rt-PA group (380.73 ± 33.43 mL/min versus 368.86 ±34.86 mL/min; p-value <0.001). The mean increase in the random-effects model after adjustment for time was 13.79 mL/min (95% CI 10.23-17.34 mL/min). There was a high variability between subjects on the difference in blood flow achieved with the two lock strategies (non-significant in 4 subjects; from 8 to 51 mL/min in the remainder). Mean spKt/V value was 1.43 in the rt-PA group and 1.39 in the citrate-alone group. Conclusions: When compared with citrate alone, weekly administration of rt-PA was associated with higher blood flow and spKt/V. The clinical benefit of this intervention is questionable, since the mean increase in blood flow was 13.79 mL/min and in 4 out of 8 patients was not significant. Dose of dialysis achieved the recommended target in both groups

Urinary tract infections under 24 months old: Is it possible to predict the risk of renal scarring?

Background: Urinary tract infection is one of the most common bacterial infections in the first two years of life and it can lead to irreversible renal scarring. Renal scintigraphy is the gold standard method for detection of renal scars. The aim of our work was to revise the cases of pyelonephritis, detect the possible predictors for renal scarring and compare those results we would have obtained if we had followed current NICE guidelines. Methods: Retrospective analysis of all patients aged under 24 months evaluated in the paediatric department and diagnosed with pyelonephritis during a three-year period. We excluded the cases in which no renal scintigraphy was performed. Results: Of the 59 children analysed, 50.8% were boys and 86.4% were under one-year old. Escherichia coli was the predominant bacteria. Renal ultrasonography showed abnormal findings in 23 patients (39%). The incidence of renal scarring was 15.3%. Age, atypical urinary tract infection and abnormal renal ultrasonography seem to be correlated with risk of renal scarring, although the results were not statistically significant. C-reactive protein level is significantly correlated with renal scarring risk (p=0.047). Working outside the NICE guidelines allowed us to catch 7 further renal scars. Conclusions: Its arguable if renal scintigraphy must be performed in all cases of pyelonephritis diagnosed in the first 24 months of life or only when there are other risk factors for renal scarring. Age, atypical urinary tract infection, C-reactive protein level and renal ultrasonography results must be taken into account in the decision to perform renal scintigraphy in a child. More prospective studies with larger cohorts are needed.

Are there benefits of a high potassium diet, even in the CKD patient?

Recent data have demonstrated dietary intake of potassium (K+) is well below current recommended nutritional guidelines, and K+ deficiency has been implicated in many diseases to include cardiovascular disease, kidney stones, and osteoporosis. Importantly, dietary supplementation of K+ has favorable effects in reducing blood pressure, decreasing the risk of stroke, improving bone health, and reducing the risk of nephrolithiasis. Unfortunately, the combination of westernized societies where consumption of foods enriched in K+ such as fresh fruits and vegetables is low, with the advent of widely prescribed hypertensive medications which cause hyperkalemia thereby requiring dietary K+ restriction, have led to societal concerns of low K+ consumption leading to decrements in overall public health. Importantly, there are new and novel drugs which have been developed which are capable of binding K+ in the gastrointestinal tract, allowing for diet liberalization affording patients the numerous health benefits of K+ rich diets. Here we highlight new findings indicating there are health-related benefits of K+ consumption even in the patient with reduced renal function such as the chronic kidney disease patient. Lastly we provide recommendations to include the use of new K+ binding agents which can allow liberalization of diets in patients with impaired renal function without development of hyperkalemia

Diabetic Nephropathy and its two phenotypes: the proteinuric and non-proteinuric

The typical progression of diabetic nephropathy is from the normoalbuminuric stage to microalbuminuria (urinary albumin creatinine rate, UACR, 30-300 mg/g) to end in overt proteinuria. A growing body of recent evidence has shown an accelerated decrease in glomerular filtration rate predominately seen in normoalbuminuric patients with type 2 diabetes. This discovery raises the the possibility of there being two independent diabetic nephropathy phenotypes. The aim of this review is to collect, summarize and compare the most relevant data referring to both the classical/proteinuric (UACR>300mg/g) and the non-classical/ non-proteinuric (UACR < 300 mg/g) phenotypes in type 2 diabetic patients. PubMed research into diabetic nephropathy and both proteinuric and non-proteinuric phenotypes was undertaken. A total of 67 articles were included. Several studies have shown that diabetic nephropathy may co-exist within a normal range of albumin excretion. This new emerging phenotype is nowadays extremely frequent in type 2 diabetic patients, and seems to be found more often in female sex, older adults, and patients with metabolic syndrome. Albumin does not seem to be the best marker for this phenotype. New possible markers for early stage renal disease were found. Treatment with Renin-Angiotensin-System inhibitors, according to evidence, might not be the most adequate therapy for non-proteinuric diabetic patients. Prognosis is still unclear. This new diabetic nephropathy phenotype exists and clinicians should be aware of it, to ensure these patients are not underdiagnosed. More research is needed to clarify this phenotypes epidemiology, pathogenesis, risk factors, diagnosis methods, new biomarkers, best treatment approach and its prognosis

Recurrence of anti-factor H associated C3 glomerulonephritis in the kidney allograft

C3 glomerulonephritis is a rare disease defined by deposits of C3 on immunofluorescence due to dysregulation of the alternative pathway of the complement cascade. We present a case of a female patient that presented with nephrotic syndrome at the age of 18 due to C3 glomerulonephritis and progressed to end-stage renal disease after 9 years. She lost the first kidney graft on the third day after transplantation due to vascular thrombosis. A second kidney transplant was performed when the patient was 30 years old. C3 glomerulonephritis recurred on the kidney graft and the patient returned to dialysis 10 years after the transplant. Study of the alternative complement pathway revealed anti-factor H antibodies. She is currently on evaluation for a third kidney transplant and there is no consensus on the best treatment strategy. We present the literature available for treatment of C3 glomerulonephritis and the therapeutic options for this patient

IgA nephropathy in a young adult with nephrotic syndrome: Case report

IgA nephropathy has many clinical presentations, of which nephrotic syndrome is possibly the rarest. Recently, the association of IgA nephropathy with minimal change disease was better described with patients having complete response to steroid therapy and no progression to CKD. We report a similar case in a young male presenting with nephrotic syndrome

Severe Systemic Lupus Erythematosus presentation in patient with alternative complement pathway mutations

Systemic lupus erythematosus (SLE) is an autoimmune disease which can involve almost any organ, making its difficult therapeutic approach. Immune complex deposition can often activate complement, accounting for many of SLE clinical manifestations and laboratory findings. We present a case of a patient who presented with acute pancreatitis and acute kidney injury as onset manifestations of SLE, later developing neurological manifestations, who was successfully treated with rituximab, plasma exchange and steroids as induction therapy. Persistently low C3 level led to a genetic analysis of the complement system components. We found three polymorphisms in the alternative pathway of complement regulators (complement factor H c2669 G>T, p.Ser890Ile and c3019 G>T, p.Val1007Leu and complement factor I c.482+6 G>T), two of which have been correlated with atypical haemolytic uraemic syndrome and dense deposit disease and also complement factor H-related protein (CFHR1 and CFHR3) mutations by deletion. This raises the question whether these polymorphisms and mutations played any role in our patients clinical course