End-Stage Renal Disease and Mortality Outcomes Across Different Glomerulonephropathies in a Large Diverse US Population.

OBJECTIVE: To compare renal function decline, incident end-stage renal disease (ESRD), and mortality among patients with 5 common glomerular diseases in a large diverse population. PATIENTS AND METHODS: A retrospective cohort study (between January 1, 2000, and December 31, 2011) of patients with glomerulonephropathy using the electronic health record of an integrated health system was performed. Estimated glomerular filtration rate (eGFR) change, incident ESRD, and mortality were compared among patients with biopsy-proven focal segmental glomerulosclerosis (FSGS), membranous glomerulonephritis (MN), minimal change disease (MCD), immunoglobulin A nephropathy (IgAN), and lupus nephritis (LN). Competing risk models were used to estimate hazard ratios for different glomerulonephropathies for incident ESRD, with mortality as a competing outcome after adjusting for potential confounders. RESULTS: Of the 2350 patients with glomerulonephropathy (208 patients [9%] younger than 18 years) with a mean follow-up of 4.5±3.6 years, 497 (21%) progressed to ESRD and 195 (8%) died before ESRD. The median eGFR decline was 1.0 mL/min per 1.73 m2 per year but varied across different glomerulonephropathies (P<.001). The highest ESRD incidence (per 100 person-years) was observed in FSGS 8.72 (95% CI, 3.93-16.72) followed by IgAN (4.54; 95% CI, 1.37-11.02), LN (2.38; 95% CI, 0.37-7.82), MN (2.15; 95% CI, 0.29-7.46), and MCD (1.67; 95% CI, 0.15-6.69). Compared with MCD, hazard ratios (95% CIs) for incident ESRD were 3.43 (2.32-5.08) and 2.35 (1.46-3.81), 1.28 (0.79-2.07), and 1.02 (0.62-1.68) for FSGS, IgAN, LN, and MN, respectively. No significant association between glomerulonephropathy types and mortality was detected (P=.24). CONCLUSION: Our findings from a real-world clinical environment revealed significant differences in eGFR decline and ESRD risk among patients with 5 glomerulonephropathies. These variations in presentation and outcomes warrant different management strategies and expectations.

Secondary Syphilis Associated with Membranous Nephropathy and Acute Hepatitis in a Patient with HIV: A Case Report.

INTRODUCTION: We present a case of membranous nephropathy associated with a secondary syphilis infection in a patient with HIV. CASE PRESENTATION: A 37-year-old white man with HIV who was receiving highly active antiretroviral therapy presented to the Emergency Department with 6 weeks of rectal pain. He had a CD3-CD4 count of 656 cells/mm3 and an undetectable viral load. On admission, he was found to have an anal ulcer, a serum creatinine of 1.4 mg/dL (baseline 0.7 to 1.0 mg/dL), elevated transaminases, positive rapid plasmin reagin, and a urine protein/creatinine ratio revealing nephrotic-range proteinuria. Renal biopsy demonstrated membranous nephropathy with features suggestive of a secondary cause. Our patient was treated with penicillin for secondary syphilis, with normalization of renal function, resolution of the nephrotic syndrome, and improvement of his elevated transaminases. DISCUSSION: This case is a reminder that patients with HIV are not infrequently coinfected with Treponema pallidum and that secondary syphilis can have systemic manifestations, including elevated transaminases and nephrotic syndrome. Prompt diagnosis and treatment will result in resolution of these problems.

Use of Phosphorus Binders among Non-Dialysis Chronic Kidney Disease Patients and Mortality Outcomes.

BACKGROUND: Whether the benefits of phosphorus binders extend to those without end stage renal disease is uncertain. Among a large diverse non-dialysis chronic kidney disease (CKD) population with hyperphosphatemia, we sought to evaluate phosphorus binder use and compare mortality risk between patients prescribed and not prescribed binders. METHODS: A retrospective cohort study within an integrated health system (January 1, 1998 - December 31, 2012) among CKD patients (age ≥18) was performed. Non-dialysis CKD patients with 2 separate estimated glomerular filtrate rate (eGFR) <30 mL/min/1.73 m2 and serum phosphorus ≥5.0 mg/dL within 180 days of eGFR were included. Multivariable cox proportional hazards and inverse probability of treatment-weighted models were used to estimate mortality hazard ratios (HRs) for patients who received phosphorus binders compared to no binders. RESULTS: Among 10,165 study patients, 2,733 subjects (27%) received phosphorus binders. Compared to the no-phosphorus-binder group, the binder group had mortality HRs (95% CI) of 0.86 (0.79-0.94) and 0.86 (0.80-0.93) using traditional multivariable and inverse probability of treatment-weighted models respectively. Sensitivity analyses removing patients who were prescribed binders >180 days after index date revealed no difference in mortality between those with binders and with no binders. CONCLUSION: Our findings from a real-world clinical environment revealed that 27% of hyperphosphatemic non-dialysis CKD patients were prescribed binders. They also had lower risk of mortality compared to those not prescribed phosphorus binders. However, the lower mortality risk was not observed when we accounted for immortal time bias. Whether phosphorus binder use in CKD improves survival remains to be determined.

Focal Segmental Glomerulosclerosis in a Patient with Ambiguous Genitalia: A Diagnostic Dilemma.

INTRODUCTION: The renal condition referred to as focal segmental glomerulosclerosis (FSGS) presents a diagnostic dilemma for the clinician. It encompasses and displays a nonspecific histologic appearance on a kidney biopsy specimen, rather than a unique disease entity. This characteristic of FSGS often makes treatment decisions and prognostication difficult. A 34-year-old man, who was born with ambiguous genitalia, had received a diagnosis of FSGS in young adulthood and now had advanced kidney disease. He underwent genetic testing to determine whether a genetic disorder was underlying his kidney disease and to ascertain his risk of FSGS recurrence if he were to receive a kidney transplant. The literature pertaining to genetic causes of FSGS is reviewed. We present here a diagnostic dilemma that clinicians face when confronted by a case of FSGS for which the underlying cause is unclear.

Beer Potomania--An Unusual Cause of Hyponatremia.

The first case of severe hyponatremia, since referred to as beer potomania, in a heavy beer drinker patient was reported in 1972. Excessive consumption of beer in particular, which has a low solute content, may result in severe hyponatremia. We report a case of severe hyponatremia that occurred in a patient who, owing to his underlying colon cancer, was drinking beer and ingesting little food.

Systemic mastocytosis presenting with acute oliguric renal failure: report of a case and review of the literature.

A 61-year old African-American woman presented with abdominal pain, tender splenomegaly, anemia, and renal insufficiency. Bone marrow biopsy demonstrated systemic mastocytosis. She was treated with mediator-specific therapy and imatinib, but her renal and hepatic function deteriorated and she required maintenance hemodialysis. Renal biopsy demonstrated interstitial infiltration with mast cells and acute tubular necrosis. Acute kidney injury in the setting of systemic mastocytosis and imatinib therapy is discussed.

25-hydroxyvitamin D levels and hypertension rates.

Vitamin D deficiency has been linked to cardiovascular disease and risk factors including hypertension. The authors sought to determine prevalence rates of hypertension in adults tested for 25-hydroxyvitamin D categorized by their levels and evaluate odds ratios for hypertension at lower 25-hydroxyvitamin D levels compared with optimal levels. A cross-sectional study was conducted January 1, 2004, through December 31, 2006, of patients aged 18 years and older within a large ethnically diverse population. Diagnosis of hypertension was determined by International Statistical Classification of Diseases and Related Health Problems codes. Patients were categorized into quartiles according to 25-hydroxyvitamin D levels: ideal (≥40 ng/mL), adequate (30-39 ng/mL), deficient (15-29 ng/mL), and severely deficient (<15 ng/mL). Prevalence rates of hypertension and odds ratios were calculated for each 25-hydroxyvitamin D quartile, adjusting for age, sex, race, and renal insufficiency. A total of 2722 individuals met the inclusion criteria for the study. The overall prevalence of hypertension in the study population was 24%. Hypertension rates were 52%, 41%, 27%, and 20% in 25-hydroxyvitamin D quartiles <15 ng/mL, 15 to 29 ng/mL, 30 to 39 ng/mL, and ≥40 ng/mL, respectively (P<.001). Odds ratios (95% confidence intervals) for hypertension adjusting for age, sex, race, and renal insufficiency were 2.7 (1.4-5.2), 2.0 (1.5-2.6), and 1.3 (1.2-1.6) for 25-hydroxyvitamin D levels <15 ng/mL, 15 to 29 ng/mL, and 30 to 39 ng/mL, respectively, compared with the ≥40 ng/mL group. This study demonstrates increased rates of hypertension in individuals who tested for lower levels of 25-hydroxyvitamin D starting at levels <40 ng/mL. This retrospective analysis raises the question of whether supplementing to optimal vitamin D levels can prevent or improve hypertension.

Vitamin D supplementation and recombinant human erythropoietin utilization in vitamin D-deficient hemodialysis patients.

INTRODUCTION: We sought to examine the impact of ergocalciferol (ERGO) on recombinant human erythropoietin (EPO) use in a cohort of 25-OH vitamin D (25-D)-deficient hemodialysis (HD) patients. METHODS: Baseline 25-D levels were obtained for all patients who received HD >6 months in our unit. Patients with levels between 10 and 30 ng/mL received ERGO 50,000 IU x 4 doses and patients with levels <10 ng/mL received 50,000 IU x 6 doses over a 4-month period. Monthly dose of EPO was recorded at baseline and after ERGO supplementation. RESULTS: Baseline 25-D levels were <30 ng/mL in 89% of tested patients. Eighty-one patients were included in this study. Mean baseline 25-D level was 15.3 ± 7.1 ng/mL and increased to 28.5 ± 8.6 ng/mL after ERGO (p<0.0001), and median baseline EPO dose was 21,933 U/month (interquartile range [IQR] 13,867-35,967) and decreased to 18,400 U/month (IQR 11,050-33,000) after ERGO (p=0.17). Forty-six patients (57%) required less EPO after ERGO compared with baseline: 15,450 U/month (IQR 10,056-23,575) vs. 26,242 U/month (IQR 15,717-40,167), respectively (p<0.0001). Thirty-five patients (43%) required a higher dose of EPO after ERGO, 26,350 U/month (IQR 15,875-46,075) vs. 17,667 U/month (IQR 12,021-23,392), respectively (p=0.016). Mean age, sex, vintage, diabetes status, race and 25-D levels did not differ in these 2 groups of patients, either at baseline or after ERGO. Monthly hemoglobin, iron saturation, albumin, intact parathyroid hormone, calcium and phosphorus were unchanged after ERGO in these 2 groups. CONCLUSIONS: ERGO use in 25-D-deficient HD patients may lessen the need for EPO. We recommend more aggressive supplementation with ERGO in future studies to achieve levels >30 ng/mL.

Hyponatremia-what is cerebral salt wasting?

BACKGROUND: Hyponatremia is a common electrolyte imbalance in hospitalized patients. It is associated with significant morbidity and mortality, especially if the underlying cause is incorrectly diagnosed and not treated appropriately. Often, the hospitalist is faced with a clinical dilemma when a patient presents with hyponatremia of an unclear etiology and with uncertain volume status. Syndrome of inappropriate antidiuretic hormone (SIADH) is frequently diagnosed in this clinical setting, but cerebral salt wasting (CSW) is an important diagnosis to consider. OBJECTIVE: We wanted to describe the diagnosis, treatment, and history of CSW to provide clinicians with a better understanding of the differential diagnosis for hyponatremia. CONCLUSION: CSW is a process of extracellular volume depletion due to a tubular defect in sodium transport. Two postulated mechanisms for CSW are the excess secretion of natriuretic peptides and the loss of sympathetic stimulation to the kidney. Making the distinction between CSW and SIADH is important because the treatment for the two conditions is very different.

Vitamin D deficiency and anemia: a cross-sectional study.

Vitamin D has been suggested to have an effect on erythropoiesis. We sought to evaluate the prevalence of anemia in a population of individuals with vitamin D deficiency compared with those with normal levels in a population of a large integrated healthplan. A cross-sectional analysis in the period 1 January 2004 through 31 December 2006 of subjects with documented concurrent levels of 25-hydroxyvitamin D and hemoglobin were evaluated. Vitamin D deficiency was defined as <30 ng/mL and anemia was defined as a hemoglobin <11 g/dL. A total of 554 subjects were included in the analysis. Anemia was present in 49% of 25-hydroxyvitamin D-deficient subjects compared with 36% with normal 25-hydroxyvitamin D levels (p < 0.01). Odds ratio for anemia in subjects with 25-hydroxyvitamin D deficiency using logistic regressions and controlling for age, gender, and chronic kidney disease was 1.9 (95% CI 1.3-2.7). 25-hydroxyvitamin D-deficient subjects had a lower mean Hb (11.0 vs. 11.7; p = 0.12 ) and a higher prevalence of erythrocyte stimulating agent use (47% vs. 24%; p < 0.05). This study demonstrates an association of vitamin D deficiency and a greater risk of anemia, lower mean hemoglobin, and higher usage of erythrocyte-stimulating agents. Future randomized studies are warranted to examine whether vitamin D directly affects erythropoiesis.

Sleep apnea in early and advanced chronic kidney disease: Kaiser Permanente Southern California cohort.

BACKGROUND: Sleep apnea (SA) has been reported to be highly prevalent in the dialysis population. The reported rates of SA in dialysis are severalfold greater than the 2 to 4% estimated in the general population. This study sought to determine whether an association exists between SA and early stages of chronic kidney disease (CKD) where SA may represent an important comorbidity and potential risk factor in kidney disease. METHODS: Cross-sectional study of adults from an integrated health plan with documented serum creatinine levels in the period January 1, 2002, through December 31, 2004. SA diagnosis determined by International Classification of Diseases, ninth revision, coding for SA and Current Procedural Terminology coding for positive airway pressure devices. Kidney function was determined by the estimated glomerular filtration rate (eGFR). Logistic was regression used to estimate the relative risk for SA. RESULTS: The overall prevalence of SA was 2.5% in the study population that included subjects with normal renal function and those with CKD. The odds ratios (ORs) for SA by eGFRs of 75 to 89, 60 to 74, 45 to 59, 30 to 44, and 15 to 29 mL/min per 1.73 m(2), respectively, compared to normal kidney function, after adjustment for age, sex, and number of visits, were as follows: 1.22 (95% confidence interval [CI], 1.18 to 1.25); 1.32 (95% CI, 1.27 to 1.37); 1.42 (95% CI, 1.35 to 1.50); 1.37 (95% CI, 1.25 to 1.50); and 1.32 (95% CI, 1.13 to 1.55). The increased ORs for eGFRs > 45 mL/min per 1.73 m(2) were sustained even after controlling for diabetes, heart failure, and hypertension. CONCLUSION: This study demonstrated an increased risk of SA in patients with early CKD. Further evidence of a causal relationship should be sought in the hope that the detection and management of SA may improve the course of CKD.

Comparison of outcomes of peritoneal dialysis catheters placed by the fluoroscopically guided percutaneous method versus directly visualized surgical method.

PURPOSE: To compare complications in catheters placed by the fluoroscopically guided percutaneous method versus directly visualized surgery. MATERIALS AND METHODS: A retrospective cohort analysis was performed. Mechanical complication rate data, including catheter leakage, malfunction, malposition, and bleeding, were compared between the two groups over a 1-year follow-up period. Additionally, exit site infection rates, tunnel infection rates, and peritonitis episodes were evaluated based on the incidence within 30 days of insertion and 30 days to 1 year after insertion. RESULTS: A total of 101 patients were analyzed (52 in the fluoroscopic guidance group, 49 in the direct visualization group). Prevalence of diabetes was similar: 56% in the directly visualized surgery group and 47% in the fluoroscopically guided treatment group (P = .37). Although the difference was not significant, complication rates tended to be higher in the directly visualized surgery group compared with the percutaneous placement group. These included catheter leakage (13% vs 4%; P = .093), malfunction (11% vs 9%; P = .73), malposition (13% vs 6%; P = .20), and bleeding (8% vs 2%; P = .21). There were no differences in early and late exit site infections and tunnel infections. Late peritonitis rates were lower in the percutaneous placement group (20%) than in the direct visualization group (42%) (P = .018). Diabetic patients had approximately six times greater risk of catheter malfunction than nondiabetic patients regardless of method of catheter insertion. CONCLUSIONS: Placement of peritoneal dialysis catheters percutaneously with fluoroscopic guidance is as safe as placement with direct visualization techniques.

An overview of nocturia and the syndrome of nocturnal polyuria in the elderly.

Nocturia is common in the elderly population and, aside from being a nuisance, it is associated with morbidity and mortality. Nocturia results from the complex interactions of several factors: changes in the urinary system and renal function with aging, the effects of sleep on renal function, changes in sleeping patterns associated with aging, and the presence of concurrent diseases and medications. Nocturia in the elderly can be caused by many conditions; a common cause is the syndrome of nocturnal polyuria. Although the pathophysiology of nocturnal polyuria remains obscure, some investigators believe that low night-time levels of antidiuretic hormone are involved. Proper management of nocturia requires identification of the specific underlying causes. This Review provides an overview of the mechanisms, evaluation and treatment of nocturia for the practicing nephrologist.

Spontaneous retroperitoneal hemorrhage due to acquired cystic kidney disease.

A patient with end-stage renal disease on maintenance hemodialysis developed sudden severe abdominal pain and distension. He suffered a decline in his hematocrit and subsequent abdominal imaging revealed a large left-sided retroperitoneal hemorrhage in the setting of atrophic, severely cystic kidneys. He underwent selective left renal artery angiography and embolization due to continued hemorrhage with stabilization in his condition. However, he became paraparetic within hours of the embolization procedure due to spinal cord infarct. Acquired cystic kidney disease is a very common entity in patients with chronic kidney disease. Complications include cystic hemorrhage or infection, erythrocytosis, and renal cell carcinoma. Screening of patients for cystic disease and malignant transformation remains a controversial topic; however, most advocate abdominal imaging after 3 to 5 years on dialysis.

Prevalence of nondiabetic renal disease in diabetic patients.

BACKGROUND: Diabetic nephropathy is the leading cause of end-stage renal disease in the USA, yet most patients with type 2 diabetes mellitus are not formally evaluated with a renal biopsy. Our aim was to evaluate the prevalence of nondiabetic renal disease (NDRD) in patients with type 2 diabetes mellitus to determine common clinical indicators suggestive of NDRD. METHODS: A retrospective analysis was performed on biopsy reports of patients who had undergone native renal biopsy between January 1, 1995, and December 31, 2005. RESULTS: After exclusion of 57 patients, 233 patients with DM2 were included in our analysis. Mean age at the time of biopsy was 58.1 +/- 13.7 years, and 53.0% of the study population were male. There were 124 cases (53.2%) with a pathologic diagnosis of NDRD, 64 (27.5%) with pure diabetic glomerulosclerosis (DGS) and 45 (19.3%) with concurrent NDRD and DGS (CD). Patients with NDRD tended to be younger than those with DGS and had significantly less associated diabetic retinopathy. Focal segmental glomerulosclerosis was the most common lesion found in patients with NDRD and accounted for 21.0% of all NDRD, followed by minimal-change disease (15.3%). IgA nephropathy (15.6%) and membranous glomerulonephritis (13.3%) were the most prevalent lesions found in patients with CD. CONCLUSIONS: The high prevalence of NDRD found in our population underscores the need for clinicians to consider renal biopsy in diabetic patients with an atypical clinical course, since additional disease-specific therapies may be helpful for this subset of the population.

Association of race, heart failure and chronic kidney disease.

Heart failure and kidney disease are two important emerging epidemics. The importance of pre-end stage kidney disease was introduced in the 2002 publication of the National Kidney Foundation's Chronic Kidney Disease Guidelines. One in nine US adults has some degree of kidney disease, many of whom also have heart failure. Among all patients with heart failure, approximately half have significant kidney disease. The distribution of etiologies of these conditions varies among races; blacks tend to have heart and kidney disease predominantly due to hypertension, while whites tend to be affected by ischemic heart disease and Hispanics by diabetic kidney disease. The burden of disease is disproportionately borne by minorities, the cause of which remains to be fully elucidated. The bulk of knowledge of these diseases is based on studies involving predominantly white subjects. Recent studies have suggested that there are racial differences in patients' responsiveness to various classes of drugs. Designs of future studies should take into account these differences.