Mal-positioning of a dialysis catheter: One lumen with arterial blood and the other with venous blood?

Partial anomalous pulmonary vein drainage is a rare congenital defect, where the pulmonary vein drains into a systemic vein instead of draining into the left atrium. We present a case of a 63-year-old woman on hemodialysis who was found to have a right pulmonary vein with anomalous drainage to the superior vena cava after mal-positioning of a dialysis catheter, which demonstrated unexpected blood results from the different lumina of the catheter. Multiple imaging techniques were used to deal with this rare clinical situation. This is the first case reporting a mal-positioning of a left-side internal jugular vein tunneled catheter into a right-side pulmonary vein.

Hypomagnesemia: a potential underlooked cause of persistent vitamin D deficiency in chronic kidney disease

Magnesium and vitamin D play important roles in most cells of the body. These nutrients act in a coordinated fashion to maintain physiologic functions of various organs, and their abnormal balance could adversely affect these functions. Therefore, deficient states of both nutrients may lead to several chronic medical conditions and increased cardiovascular and all-cause mortality. Chronic kidney disease (CKD) patients have altered metabolism of both magnesium and vitamin D. Some studies indicate that magnesium could have a role in the synthesis and metabolism of vitamin D, and that magnesium supplementation substantially reversed the resistance to vitamin D treatment in some clinical situations. Recent observational studies also found that magnesium intake significantly interacted with vitamin D status and, particularly with the risk of cardiovascular mortality. It is therefore essential to ensure adequate levels of magnesium to obtain the optimal benefits of vitamin D supplementation in CKD patients. In this review, we discuss magnesium physiology, magnesium and vitamin D metabolism in CKD, potential metabolic interactions between magnesium and vitamin D and its clinical relevance, as well as the possible role of magnesium supplementation to assure adequate vitamin D levels.

Penile and digital calciphylaxis: A case report and literature review

Calcific uremic arteriolopathy (CUA) represents a rare but severe disease with high morbimortality. The authors present the case of a 58-year-old male patient with chronic kidney disease due to obstructive uropathy, on hemodialysis (HD). He started HD due to uremic syndrome with a severe renal dysfunction, dysregulation of calcium and phosphate metabolism, and he presented with distal penile ischemia, which was treated with surgical debridement and hyperbaric oxygen therapy. Four months later, painful distal digital necrosis of both hands was observed. Extensive arterial calcification was observed on X-ray. A skin biopsy confirmed the presence of CUA. Sodium thiosulfate was administered for 3 months, HD was intensified, and hyperphosphatemia control was achieved, with progressive improvement of the lesions. This case illustrates an uncommon presentation of CUA in a patient on HD for a few months, non-diabetic and not anticoagulated, but with a severe dysregulation of calcium and phosphate metabolism.

Long-term cholecalciferol supplementation in hemodialysis patients: Effects on mineral metabolism, inflammation, and cardiac parameters

BACKGROUND

Low levels of 25-hydroxyvitamin D [25(OH)D] are frequent in chronic kidney disease and are associated with adverse outcomes. The aim of this 5-year prospective study was to evaluate the effects of cholecalciferol supplementation on mineral metabolism, inflammation and cardiac parameters in hemodialysis (HD) patients.

METHODS

The study included 97 patients. Cholecalciferol was given after HD according to 25(OH)D baseline levels measured twice (end of winter and of summer). The 25(OH)D levels, circulating bone metabolism, inflammation parameters, brain natriuretic peptide (BNP), pulse pressure (PP), and left ventricular mass index (LVMI) were evaluated before and after supplementation.

RESULTS

There was a significant increase in 25(OH)D levels after supplementation (p < 0.001); however, serum calcium (p = 0.02), phosphorus (p = 0.018), and iPTH (p = 0.03) were decreased. Magnesium levels increased during the study (p = 0.03). A reduction in the number of patients under active vitamin D (p < 0.001) and in the dose and number of patients treated with darbepoetin (p = 0.02) was observed. Serum albumin increased (p < 0.001), and C-reactive protein decreased (p = 0.01). BNP (p < 0.001), PP (p = 0.007), and LVMI (p = 0.02) were significantly reduced after supplementation.

CONCLUSIONS

Long-term cholecalciferol supplementation allowed correction of 25(OH)D deficiency, improved mineral metabolism with less use of active vitamin D, attenuated inflammation, reduced the dose of the erythropoiesis-stimulating agent, and improved cardiac dysfunction.

Strategies to prevent SARS-CoV-2 transmission in hemodialysis centres across Europe - Lessons for the future

Background

Early reports on the pandemic nature of COVID-19 directed the nephrology community to develop infection prevention and control guidance. We aimed to make an inventory of strategies that dialysis centres followed to prevent infection with COVID-19 in the first pandemic wave.

Methods

We analyzed IPC measures taken by hemodialysis centres treating patients presenting with COVID-19 between March 1, 2020 and July 31, 2020 and that completed the European Renal Association COVID-19 Database centre questionnaire. Additionally, we made an inventory of guidelines published in European countries to prevent spread of SARS-CoV-2 in dialysis centres.

Results

Data from 73 dialysis units located in and bordering Europe were analyzed. All participating centres implemented IPC measures to mitigate the impact of SARS-CoV-2 during the first pandemic wave. Measures mentioned most often included triage with questions before entering the dialysis ward, measuring body temperature, hand disinfection, masking for all patients and staff, and personal protective equipment for staff members. These measures were also recommended in most of the 14 guidelines that were identified in the inventory of national guidelines and were also scored as being among the most important measures by the authors of this paper. Heterogeneity existed between centres and national guidelines regarding the minimal distance between dialysis chairs and recommendations regarding isolation and cohorting.

Conclusions

Although variation existed, measures to prevent transmission of SARS-CoV-2 were relatively similar across centres and national guidelines. Further research is needed to assess causal relationships between measures taken and spread of SARS-CoV-2.

MO538: Lower Serum Levels of Magnesium are Associated With Higher Risk of Fractures in Haemodialysis Patients

BACKGROUND AND AIMS

Magnesium (Mg) deficiency is associated with altered bone metabolism, However, the relationship between Mg and the risk of fragility fractures haemodialysis (HD) patients is still unclear. The aim of this study was to evaluate the association between pre-dialysis Mg serum levels and the risk of incident bone fractures in a cohort of prevalent HD patients.

METHOD

We performed a prospective study of 206 prevalent HD patients followed from 2009 until 2021. Demographic, clinical and biochemical parameters were evaluated.

RESULTS

A total of 37 episodes of fragility fractures were identified with a median HD vintage of 42 months, which corresponds to an incidence rate of 29/1000 person-years. The mean age of the studied population was 68.3 ± 13.1 years, 121 (59%) were male and the median follow-up time on HD was 58 months.

Patients with incident fractures showed significantly lower Mg levels compared with those without fractures (2.3 ± 0.3 versus 2.8 ± 0.4 mg/dL, P &lt; 0.001). In a multivariable analysis, lower Mg levels (P = 0.02) were independently associated with increased risk of fracture, in a model adjusted to age, female gender, albumin and dialysis vintage.

Patients with a Mg serum level &lt; 2.2 mg/dL (lowest quartile) had a 1.32-fold higher risk for fragility fractures than those in the highest quartile [95% confidence interval (95% CI), 1.15–1.48; P &lt; 0.001].

CONCLUSION

This study shows that the incidence of bone fragility fractures in HD patients is high and significantly associated with lower pre-dialysis Mg levels. Management of fracture risk in HD patients and assessment of its risk factors requires further study.

MO147: Fat Check: Lipid Abnormalities in Nephrotic Primary Glomerulopathies

BACKGROUND AND AIMS

Lipid abnormalities are a defining feature of nephrotic syndrome. In nephrotic patients, changes such as increased total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and triglycerides (TG) and decreased high-density lipoprotein cholesterol (HDL-C) as well as decreased HDL-C: TC ratio are more frequently found than in healthy subjects.

 The aims of this study were to evaluate the differences in the serum lipidic profile at baseline (diagnosis) among each primary glomerulopathies (PG) presenting with nephrotic syndrome (NS) and its association with several clinical parameters such as serum albumin (SAbl) and proteinuria.

METHOD

We conducted a retrospective cohort study with patients older than 18 years who presented with nephrotic syndrome and diagnosed with a PG by kidney biopsy in the last 10 years in a tertiary-level hospital.

RESULTS

The study included 60 patients: 38 were male (63.3%), with median age of 52 (IQR 27) years, 43.3% had hypertension, median serum creatinine (SCr) was 1.11 mg/dL (IQR 0.86), median protein-creatinine ratio was 7443 (IQR 5033.5) mg/g and median SAlb of 2.0 (IQR 1.03) mg/dL. At baseline, the median TC was 320.5 mg/dL (IQR 184.5), HDL-C 55 (IQR 25.5) mg/dL, LDL-C 225mg/dL (IQR 174),  TG 176 (IQR 122.6) mg/dL and HDL: TC ratio 0.19 (IQR 0.13). Median follow-up time was 24 (IQR 51) months.

 Patients were grouped in four categories regarding the PG subtype: membranous nephropathy (MN, 38.3%), minimal change disease (MCD, 38.3%), IgA nephropathy (IgAN, 11.7%) and focal segmental glomerulosclerosis (FSGS, 11.7%).

 Evaluating all the patients enrolled, we found a strong negative correlation between SAlb and TC (r = –0.511, P &lt; .001), LDL-C (r = –0.529, P &lt; .001) and a weaker negative correlation with TG (r = –0.282, P = .030), but not with HDL-C. We did not find a statistically significant correlation between proteinuria and each cholesterol subtype or TG levels.

 A Kruskal–Wallis test showed that different subtypes of PG were associated with different median HDL-C (H(3) = 12.073, P = .007) and TG serum levels (H(3) = 10.128, P = .018). No statistically significant differences in the TC, LDL-C or HDL-C: TC ratio were found. Comparing all pairs of groups, we found that HDL-C levels were statistically different between MN and MCD (45.5 versus 67 mg/dL, P &lt; .001), but not in the other pairs. The same analysis found that TG serum levels were only significantly different between IgAN and MN (114 versus 187 mg/dL, P = .008) and between IgAN and FSGS (114 versus 200 mg/dL, P = .012).

 MN patients that progressed to CKD stage 5D had lower median HDL-C levels at diagnosis, when compared to the patients who did not progress (41 versus 49 mg/dL,  P = .037). This difference was not observed in IgA, FSGS or MCD.

CONCLUSION

Each GP subtype presents a different lipid profile, particularly differing on HDL and TG. Patients with MCD presented with the highest levels of HDL-C, while MN with the lowest. Regarding TG levels, FSGS presented with the highest levels while IgAN presented with the lowest. In the membranous nephropathy group, patients that progressed to ESRD had statistically significantly lower serum levels of HDL-C.

 As expected, SAlb is significantly associated with TC, LDL-C and TG levels, in nephrotic patients. This could be due to different levels of lecithin–cholesterol acyltransferase (an enzyme responsible for the maturation of HDL), which is increasingly lost through urine in nephrotic syndromes.

 The differences found in the lipidic profile between PG subtypes could have screening, therapeutic and prognosis implications in the management of cardiovascular risk in these patients.

 More studies are needed to understand the pathophysiology and the prognosis significance of each lipid profile.

MO355: Recovering From a Renal Vascular Catastrophe

BACKGROUND AND AIMS

Bilateral acute renal artery thrombosis (BARAT) is a rare and catastrophic condition. This diagnosis is often delayed or unrecognized and the true incidence may be underestimated. To the best of our knowledge, only three cases are reported in literature—all treated conservatively. We present two cases of BARAT who recovered kidney function under conservative approach.

METHOD

Data was obtained from the electronical medical record.

RESULTS: Case 1:A 73-year-old male with no history of cardiac disease, hypertension or recent trauma was admitted with right flank pain and vomiting. He had severe hypertension (204/103 mmHg), anuria with acute kidney injury (AKI) and elevated lactate dehydrogenase (LDH). He started haemodialysis on admission. Renal computerized tomography (CT) angiogram showed bilateral arterial thrombosis—left renal artery was totally occluded and partial occlusion of the right renal artery with slight enhancement of the corresponding kidney (Fig. 1).

Vascular surgery posed no surgical indication and systemic anticoagulation with low molecular weight heparin (LMWH) was started. A thorough screening for occult neoplasm and hypercoagulable state causes was negative.

He was independent from dialysis 54 days after. Currently (6 months after), he is on stage 3b chronic kidney disease (CKD) with a serum creatinine (sCr) 2.19 mg/dL.

Case 2: A 65-year-old female was admitted with dyspnea associated with right lumbar pain, severe hypertension (230/140 mmHg), peripheral edema and pulmonary congestion. Her prior history included heavy smoking and atherosclerotic artery disease with placement of aortoiliac stent 20 years before. She had no history of atrial fibrillation.

She was admitted with de novo cardiac insufficiency with a mild reduction of left ventricular ejection fraction. After admission, she developed anuric AKI with refractory fluid overload and started dialysis.

CT angiogram showed a large aortic thrombus that occluded both renal arteries. The right principal renal artery was occluded but the kidney had partial reperfusion from an accessory artery (Fig. 2). The left renal artery was totally occluded. Vascular surgery posed no surgical indication and the patient started LMWH.

She was independent from haemodialysis 30 days after. She has currently a stage 4 CKD with sCr 3.2 mg/dL.

CONCLUSION

There are currently no guidelines on both the acute and long-term management of BARAT. The few reported cases of BARAT were all treated conservatively with systemic anticoagulation and had late but consistent kidney function recovery. This suggests that renal parenchyma could still be viable after BARAT. Could early revascularization therapies accelerate recovery and minimize irreversible damage?

In both cases, a cause was not found. Much is still unknown about the pathophysiology, and further research is warranted.

The Role of Vascular Lesions in Diabetes Across a Spectrum of Clinical Kidney Disease

Introduction

The clinical-histologic correlation in diabetic nephropathy is not completely known.

Methods

We analyzed nephrectomy specimens from 90 patients with diabetes and diverse degrees of proteinuria and glomerular filtration rate (GFR).

Results

Thirty-six (40%) subjects had normoalbuminuria, 33 (37%) microalbuminuria, and 21 (23%) non-nephrotic proteinuria. Mean estimated GFR (eGFR) was 65±23 (40% <60 ml/min per 1.73 m²). About 170 glomeruli per patient were analyzed, and all samples included vascular tissue. Six subjects (7%) were classified in diabetic nephropathy class I, 61 (68%) in class II-a, 13 (14%) in class II-b, 9 (10%) class III, and 1 (1%) in class IV. Eighty percent to 90% of those with normoalbuminuria or microalbuminuria were classified in class II-a or II-b and <10% in class III; 52% of those with proteinuria were in class II-a, 15% in class II-b, and 19% in class III. Nodular sclerosis (57%) and mesangial expansion (15%) were more frequent in cases with proteinuria than in normoalbuminuria (28% and 8%; P = 0.028 and 0.017). About 20% to 30% of all cases, regardless the level of albuminuria or proteinuria or the histologic class had tubular atrophy, interstitial fibrosis, or inflammation in >10% to 20% of the sample. Moderate hyalinosis and arteriolar sclerosis were observed in 80% to 100% of cases with normoalbuminuria, microalbuminuria, proteinuria, as well as in class I, II, or III.

Conclusions

Weak correspondence between analytical parameters and kidney histology was found. Thus, disease may progress undetected from the early clinical stages of the disease. Finally, vascular damage was a very common finding, which highlights the role of ischemic intrarenal disease in diabetes.

Glycosuria in primary glomerulopathies: prevalence and prognostic significance

Introduction:

Tubular damage is common in glomerular diseases (GD). Glycosuria is a marker of tubular dysfunction and may be used to detect tubular lesion and CKD progression. The aim of this study was to evaluate the prevalence and prognostic value of glycosuria at the time of diagnosis in primary glomerulopathies (PG).

Methods:

We conducted a 24-month retrospective study in patients diagnosed with PG in our center between 2009 and 2020. We excluded diabetic patients, use of SGLT2 inhibitors, transplant patients, and secondary GD. Patients were divided in two groups according to their glycosuria status at diagnosis.

Results:

We studied 115 patients. Global prevalence of glycosuria was 10% (n=11) and membranous nephropathy (MN) had the highest prevalence (n=5, 17.9%). We found that patients with glycosuria had higher serum creatinine (2.4 vs. 1.2 mg/dL, p=0.030), higher albuminuria (4.8 vs. 1.9 g/g, p=0.004), and lower serum albumin (2.3 vs. 3.2 g/dL, p=0.021). We did not find association with histological prognostic factors. At the end of follow-up, patients with glycosuria had higher prevalence of the composite outcome of stage 5D CKD or 50% increase in basal SCr (45.5% vs. 17.3%, p=0.037). In patients with MN, results were similar but we were able to find an association of glycosuria with more severe interstitial fibrosis and tubular atrophy (25.0 vs. 0.0 %, p=0.032).

Conclusion:

Ten percent of our patients with PG have glycosuria. Glycosuria at the time of diagnosis was associated with more severe clinical presentation and worst renal outcome. The association with higher albuminuria suggests that tubular function has an impact on the severity and outcomes of PG.

P0452GLYCOSURIA IN MEMBRANOUS NEPHROPATHY: AN UNDERESTIMATED MARKER?

Background and Aims

Membranous nephropathy (MN) is one of the most common causes of nephrotic syndrome in adults. Some studies have suggested that glycosuria is present in the most severe cases of MN and this finding may be associated with tubular injury caused by the overload of filtered proteins. The aim of this study was to evaluate the association between glycosuria in MN and severity and prognosis of the disease.

Method

We conducted a 36-month retrospective cohort study with all patients diagnosed in the last 10 years in our centre with primary MN confirmed by renal biopsy. Data collection was made from patients’ charts. Patients were divided in two groups according to their glycosuric status at the diagnosis. Exclusion criteria: patients with diabetes and glucose intolerance, use of SGLT2 inhibitors, transplant kidney patients and secondary MN.

Results

We studied 27 patients with primary MN. Four patients (14.8%) presented glycosuria at the time of diagnosis. Glycosuric and non-glycosuric groups had comparable demographic data. We found that glycosuric patients had higher baseline albuminuria (10.7±8.6 vs 4.6±4.1 g/g, p=0.029) and lower estimated glomerular filtration rate (eGFR) (39.2±24.6 vs 75.2±30.7 ml/min/1.73m2, p=0.037). We also found that patients with glycosuria had higher interstitial fibrosis and tubular atrophy (IFTA) (33.8%±21.4 vs 10.7%±17.1, p=0.035) but no differences in the percentage of glomerular sclerosis. There were no differences between groups in serum albumin, haemoglobin or therapy. At the end of the follow-up period there was no difference in eGFR decline rate (ml/min/year), 3-year eGFR, 3-year albuminuria and 3-year chronic kidney disease stage 5D incidence.

Conclusion

Prevalence of glycosuria in primary MN is approximately 15%. Its presence at the time of diagnosis was associated with more severe clinical and histological markers: lower eGFR, higher albuminuria and higher IFTA. However, we did not find association between glycosuric status at diagnosis and disease progression. Prospective, bigger and longer studies are needed to evaluate these questions.

P0445PREVALENCE AND PREDICTORS OF GLYCOSURIA IN PRIMARY GLOMERULOPATHIES

Background and Aims

Albuminuria is a marker of glomerular lesion, however some studies have suggested that proximal tubule (endocytosis of albumin) is also essential to determine the amount of albumin excreted in the urine. It has been hypothesized that patients with glomerulopathies and concomitant tubular damage might present higher levels of albuminuria. Glycosuria is a marker of proximal tubular dysfunction and may be used as an easy and useful marker of tubular lesion in glomerular diseases. The aim of this transversal study was to evaluate the prevalence of glycosuria in primary glomerulopathies (GP) and identify its predictors.

Method

We included all patients diagnosed in the last 10 years in our centre with primary GP confirmed by renal biopsy. Clinical, laboratory and biopsy results were collected from patients’ charts. Patients were divided in two groups according to their glycosuric status at the diagnosis. Exclusion criteria: patients with diabetes and glucose intolerance, use of SGLT2 inhibitors, transplant kidney patients and secondary GP.

Results

We studied 110 patients – 39 (35.5%) IgA Nephropathy (IgAN), 27 (24.5%) Membranous Nephropathy (MN), 26 (23.6%) Focal Segmental Glomerulosclerosis (FSGS) and 18 (16.4%) Minimal Change Disease (MCD). Demographic data were not different between patients with and without glycosuria. Global prevalence of glycosuria was 9.1% (n=10) – patients with MN had higher prevalence of glycosuria (n=4, 17.4%), followed by FSGS (n=3, 15.5%), MCD (n=1, 5.9%) and IgAN (n=2, 5.4%). We found that patients with glycosuria had higher serum creatinine (3.9±5.1 vs 1.7±1.3 mg/dL, p=0.001), higher albuminuria (7.1±6.3 vs 3.2±3.4 g/g, p=0.002), lower serum albumin (2.3±0.7 vs 3.2±1.1 g/dL, p=0.022) and lower hemoglobin (12.0±2.5 vs 13.4±2.0 g/dL, p=0.050). Nevertheless, we did not find differences between glycosuric and non-glycosuric patients in percentage of glomerular sclerosis (%GS) or interstitial fibrosis and tubular atrophy (IFTA). In a multivariate analysis, glycosuria was positively associated with MN diagnosis, serum creatinine and albuminuria, but not with hematuria, %GS and IFTA.

Conclusion

Glycosuria is not frequent in primary GP. MN is the primary GP that most frequently presents glycosuria. Glycosuria is associated with higher albuminuria and lower serum albumin levels, corroborating the hypothesis that albuminuria as an offender to the tubules will affect the amount of albumin excreted in the urine. We also found that patients with glycosuria presented a more severe renal dysfunction (higher creatinine) at the GP diagnosis.

P0470IS GLYCOSURIA A MARKER OF TUBULO-INTERSTITITAL FIBROSIS AND PROGNOSIS IN PRIMARY GLOMERULOPATHIES?

Background and Aims

Multiple studies have shown that tubular damage is common in glomerular diseases and that it correlates better with chronic kidney disease (CKD) progression than glomerular lesion itself. The link between glomerular and tubular damage is not entirely established. Glycosuria can be found in (proximal) tubular dysfunction and may be used as a marker of tubular lesion and CKD progression. The aim of this study was to evaluate the association between glycosuria (at the diagnosis) and known histological prognostic markers (glomerular sclerosis (%GS) and interstitial fibrosis/tubular atrophy (IFTA)) and CKD progression, in patients with primary glomerulopathies (GP).

Method

We conducted a 36-month retrospective cohort study with 110 patients with primary GP confirmed by renal biopsy in the last 10 years in our centre – 39 (35.5%) IgA Nephropathy, 27 (24.5%) Membranous Nephropathy, 26 (23.6%) Focal Segmental Glomerulosclerosis and 18 (16.4%) Minimal Change Disease. Patients were divided in two groups according to their glycosuric status at the time of the diagnosis. Data was collected from patients’ charts. Exclusion criteria: patients with diabetes or glucose intolerance, use of SGLT2 inhibitors, secondary GP and transplant kidney patients.

Results

The global prevalence of glycosuria was 9.1% (n=10). Glycosuric patients had, at baseline, higher serum creatinine (3.9±5.1 vs 1.7±1.3mg/dL, p=0.001), higher baseline albuminuria (7.1±6.3 vs 3.2±3.4 g/g, p=0.002) and lower serum albumin (2.3±0.7 vs 3.2±1.1 g/dL, p=0.022). Both groups had similar proportion of patients that underwent immunosuppressive therapy. At the end of the follow-up, in glycosuric patients, only albuminuria was higher (3.3±0.6 vs 0.7±0.8 g/g, p&lt;0.0001); the eGFR decline rate (ml/min/year), 3-year eGFR and 3-year CKD stage 5D incidence were not statistically different. Glomerular sclerosis (%GS) and interstitial fibrosis and tubular atrophy (IFTA) were not different between groups. These results were confirmed by multivariate analysis.

Conclusion

Patients with primary GP with glycosuria at diagnosis had higher baseline creatinine and albuminuria. Even though a worse clinical presentation, glycosuria was not associated with well-known prognostic factors (%GS and IFTA) or CKD progression. We can hypothesize that patients with primary GP with glycosuria have severe diseases at diagnosis, but the lesions may have greater reversibility. Prospective and longer studies are needed to confirm these results.

Bone fracture risk factors in prevalent hemodialysis patients

Bone fractures are an important cause of morbidity and mortality in hemodialysis (HD) patients. The aim of this study was to quantify the incidence of fractures in a cohort of prevalent HD patients and evaluate its relationship with possible risk factors. We performed a retrospective analysis of 341 patients, since they started HD (median of 51 months). Demographic, clinical, and biochemical parameters as well as vascular calcifications (VC) were evaluated. Fifty-seven episodes of fracture were identified with a median HD vintage of 47 months (incidence rate of 31 per 1000 person-years). Age (p < 0.001), female gender (p < 0.001), lower albumin (p = 0.02), and higher VC score (p < 0.001) were independently associated with increased risk of fracture, while active vitamin D therapy (p = 0.03) was associated with decreased risk. A significantly higher risk of incident fracture was also associated with higher values of bone-specific alkaline phosphatase (bALP) (p = 0.01) and intact parathyroid hormone (iPTH) levels either < 300 pg/mL (p = 0.02) or > 800 pg/mL (p < 0.001) compared with 300-800 pg/mL. In conclusion, bone fracture incidence in HD patients is high and its risk increases with age, female gender, lower serum albumin, and with the presence of more VC. Prevalent HD patients with low or high iPTH levels or increased bALP also had a higher fracture risk. Therapy with active vitamin D seems to have a protective role. Assessment of fracture risk and management in dialysis patients at greatest risk requires further study.

The impact of functioning hemodialysis arteriovenous accesses on renal graft perfusion: Results of a pilot study

Introduction:

After a kidney transplant, it is unknown whether the maintenance of a functioning hemodialysis arteriovenous access could have deleterious effects on renal grafts. We hypothesize that maintaining an arteriovenous access can deviate a significant proportion of the cardiac output from the renal graft. The aim of this study was to investigate whether a temporary closure of the arteriovenous access could lead to an increase in graft perfusion.

Methods:

We conducted a study in 17 kidney-transplanted patients with a functioning arteriovenous access. We evaluated, at baseline and 30 s after compression of the arteriovenous access (access flow occlusion), the hemodynamic parameters and the renal resistive index of the graft by Doppler ultrasound.

Results:

After arteriovenous access occlusion 82.4% (n = 14) of the patients had a decrease in resistive index. All patients had a decrease in heart rate (67 vs 58 bpm, p < 0.001) and 14 (82.4%) had an increase in mean blood pressure (98.3 vs 101.7 mm Hg, p = 0.044). There was a significant decrease in the resistive index (ΔRI) after the access occlusion (0.68 vs 0.64, p = 0.030). We found a negative correlation in Qa (r2 = −0.55, p = 0.022) with the ΔRI, and Qa was an independent predictor of ΔRI in a model adjusted to pre-occlusion resistive index.

Conclusion:

Our results showed that temporary occlusion of an arteriovenous access causes a significant decline in renal graft resistive index and this decline is higher with the occlusion of accesses with higher Qa. These results suggest that the maintenance of arteriovenous accesses, mainly those with higher Qa, can decrease renal graft perfusion.

Are high flow arteriovenous accesses associated with worse haemodialysis?

Introduction:

An arteriovenous (AV) access flow (Qa) of 400 mL/min is usually sufficient for an effective hemodialysis (HD), but some accesses continue developing and become high flow accesses (HFA). Some authors postulated that an HFA might shift a significant portion of dialyzed blood from the cardiac output, which could decrease HD efficiency and lead to volume overload.

Objective:

The aim of our study was to evaluate if HFA is associated with reduced HD efficiency and/or volume overload in prevalent HD patients.

Methods:

We performed a 1-year retrospective study and assessed HD efficiency by the percentage of sessions in which the Kt/V > 1.4 and volume overload by bioimpedance spectroscopy.

Results:

The study included 304 prevalent HD patients with a mean age of 67.5 years; 62.5% were males, 36.2% were diabetics, with a median HD vintage of 48 months. Sixteen percent of the patients had a HFA (defined as Qa > 2 L/min). In multivariate analysis, patients with HFA presented higher risk of volume overload (OR = 2.67, 95%CI = 1.06-6.71) and severe volume overload (OR = 4.06, 95%CI = 1.01-16.39) and attained dry weight less frequently (OR = 0.37, 95%CI = 0.14-0.94). However, HFA was not associated with lower Kt/V.

Conclusion:

Our results suggest that patients with HFA have higher risk of volume overload. However, contrarily to what has been postulated, HFA was not associated with less efficient dialysis, measured by Kt/V. Randomized controlled trials are needed to clarify these questions.

IGA nephropathy - Are intravenous steroid pulses more effective than oral steroids in relapse prevention?

INTRODUCTION

It is recommended that IgA nephropathy (IgAN) is treated with steroids when the glomerular filtration rate (GFR) is >50ml/min and proteinuria >1g/day. Few studies have been performed comparing the two accepted steroid regimens (1g/day methylprednisolone pulses for 3 consecutive days at the beginning of months 1, 3 and 5, followed by 0.5mg/kg prednisolone on alternate days vs. 1mg/kg/day oral prednisolone). The aim of this study was to compare these two steroid regimens in IgAN treatment.

METHODS

We selected 39 patients with biopsy-proven IgAN treated with steroids. Mean age at diagnosis was 37.5 years, 23 males (59%), baseline proteinuria (Uprot) was 2.1 g/day and median serum creatinine (SCr) was 1.5mg/dl. The mean follow-up period was 56 months. Twenty-five patients (64%) were treated with methylprednisolone pulses and 14 (36%) with oral steroids.

RESULTS

Patients treated with steroid pulses presented lower relapse risk, defined as the reappearance of Uprot >1g/day and an Uprot increase of more than 50% (incidence rate ratio of 0.18, 95% CI 0.02-0.5). The Kaplan-Meier analysis showed longer relapse-free period (p=0.019). This result was confirmed in a multivariate analysis (p=0.026). However, we did not find other differences between the two steroid regimens.

CONCLUSIONS

In comparison to oral steroids, the intravenous pulse regimen was associated with a lower risk of relapse in IgAN, a known independent negative predictor of renal survival. No differences were found regarding the other renal outcomes.

Prognostic Factors of Human Immunodeficiency Virus-Infected Patients on Chronic Hemodialysis

BACKGROUND/AIMS

The number of human immunodeficiency virus (HIV)-infected patients on hemodialysis (HD) have increased, and their prognostic factors are still poorly clarified. The study aimed to identify factors that can influence the survival of HIV-infected patients on HD.

METHODS

We performed a retrospective cohort study of 44 HIV-infected patients on HD.

RESULTS

A total of 17 patients (39%) died. Median survival on HD was 30.8 months and the survival rate at 1 and 5 years was 82.5 and 62.9%, respectively. Male (relative risk [RR] 3.1, p = 0.040) and blacks (RR 2.5, p = 0.037) had higher risk of death. The patients who died had a shorter duration of HIV infection (p = 0.028), had a higher viral load (p = 0.044), more opportunistic infections (p = 0.013), and a lower serum albumin (p = 0.009). Lower serum albumin, nonsexual HIV transmission, viral load, opportunistic infections, and usage of catheters were associated with lower survival.

CONCLUSION

Several demographic, viral, and dialysis variables may help to predict survival of this population. The intervention in these factors could improve their prognosis.

Diabetic kidney disease: Is there a non-albuminuric phenotype in type 2 diabetic patients?

BACKGROUND

Albuminuria was widely considered as the first clinical sign of diabetic kidney disease (DKD), which is why it has traditionally been used as a screening test for DKD. However, increasing evidence has shown that a significant number of type 2 diabetes mellitus (DM) patients have a decreased glomerular filtration rate (GFR) without significant albuminuria, known as non-albuminuric DKD (NA-DKD). The aim of this study was to determine the prevalence and the demographic and clinical characteristics of patients with NA-DKD.

METHODS

This was a 1-year retrospective study that included 146 type 2 diabetic patients with GFR<75mL/min followed-up in a diabetes outpatient department. Patients were divided into two groups according to their ACR status - NA-DKD and albuminuric DKD (A-DKD).

RESULTS

Of the 146 patients included in the study, 53.4% had A-DKD and 46.6% had NA-DKD. According to the multivariable analysis performed, patients with NA-DKD tended to be older (p=0.021), female (p=0.045) and with a lower GFR (p=0.004) than A-DKD patients. There was no difference between the groups in terms of body mass index, metabolic control of DM, duration of DM diagnosis and prevalence of metabolic syndrome.

CONCLUSIONS

The majority of patients with DKD had albuminuria, but a significant proportion had a non-albuminuric phenotype (46.6% in this population). These patients exhibit distinct clinical features that could have screening, therapeutic and prognosis implications.

Calcium Acetate/Magnesium Carbonate and Cardiovascular Risk Factors in Chronic Hemodialysis Patients

BACKGROUND/AIM

Calcium acetate/magnesium carbonate (CaMg) is a recent phosphate binder that has been shown to have protective cardiovascular (CV) effects in animal models. The aim of this study was to evaluate the relationship between CaMg therapy and CV risk markers like pulse pressure (PP), left ventricular mass index (LVMI) and valvular calcifications compared to sevelamer or no phosphate binder (NPB) therapy in chronic hemodialysis (HD) patients.

METHODS

We performed a 48-month prospective study in 138 HD patients under hemodiafiltration with a dialysate Mg concentration of 0.5 mmol/l. Patients underwent treatment with CaMg or sevelamer for at least 36 months or NPB therapy. Demographic, clinical, biochemical and echocardiographic parameters were evaluated at baseline and after a 48-month period.

RESULTS

At the end of the study, patients who had taken CaMg showed a significant reduction in PP (p < 0.001), LVMI (p = 0.003), aortic (p = 0.004) and mitral valve calcifications (p = 0.03) compared with NPB patients. Patients under CaMg showed a significant reduction of PP (p < 0.001), LVMI (p = 0.01) and aortic valve calcifications (p = 0.02) compared to sevelamer patients. In a multivariable analysis, CaMg therapy was negatively associated with progression of LVMI (p = 0.02) and aortic valve calcifications (p = 0.01). Patients under CaMg showed higher serum Mg levels (0.93 ± 0.14 mmol/l) compared to patients under sevelamer (0.87 ± 0.13) or NPB patients (0.82 ± 0.12; p < 0.001).

CONCLUSIONS

In prevalent HD patients, the use of CaMg over 48 months was associated with a reduction of PP and LVMI and with a stabilization of aortic valve calcifications. These protective and promising results of this new phosphate binder need to be confirmed in randomized controlled studies.

Lower serum magnesium is associated with cardiovascular risk factors and mortality in haemodialysis patients

BACKGROUND

Hypomagnesaemia is a cardiovascular (CV) risk factor in the general population. The aim of this study was to evaluate the relationship between pre-dialysis magnesium (Mg) and CV risk markers, [including pulse pressure (PP), left ventricular mass index (LVMI) and vascular calcifications (VC)], and mortality in haemodialysis (HD) patients.

METHODS

We performed a 48-month prospective study in 206 patients under pre-dilution haemodiafiltration with a dialysate Mg concentration of 1 mmol/l.

RESULTS

Lower Mg concentrations were predictors of an increased PP (≥65 mm Hg) (p = 0.002) and LVMI (≥140 g/m(2)) (p = 0.03) and of a higher VC score (≥3) (p = 0.01). Patients with Mg <1.15 mmol/l had a lower survival at the end of the study (p = 0.01). Serum Mg <1.15 mmol/l was an independent predictor of all-cause (p = 0.01) and CV mortality (p = 0.02) when adjusted for multiple CV risk factors.

CONCLUSIONS

Lower Mg levels seem to be associated with increased CV risk markers, like PP, LVMI and VC, and with higher mortality in HD patients.