IgG4-related kidney disease with systemic Epstein-Barr virus infection: A case report.

IgG4-related disease (IgG4-RD) is a newly recognized multi-organ fibro-inflammatory condition with characteristic histopathological findings of increased IgG4+ plasma cells in tissue and usually with increased IgG4 serum levels. Kidney involvement in IgG4-RD has been well described since 2006. Epstein-Barr virus (EBV) has reportedly been associated with nodal IgG4-RD, but not in extra-nodal disease. We report a case of renal IgG4-RD in the setting of acute EBV infection in a young healthy man, resulting in severe renal failure. Biopsy of kidney revealed IgG4+ plasma cell-rich tubulointerstitial nephritis, tissue eosinophilia, early-stage membranous nephropathy, and scattered EBV-positive cells. Oral prednisone and acyclovir only partially rescued his renal function.

Effect of Blood Pressure Control on Long-Term Risk of End-Stage Renal Disease and Death Among Subgroups of Patients With Chronic Kidney Disease.

Background Our objective was to explore the effect of intensive blood pressure (BP) control on kidney and death outcomes among subgroups of patients with chronic kidney disease divided by baseline proteinuria, glomerular filtration rate, age, and body mass index. Methods and Results We included 840 MDRD (Modification of Diet in Renal Disease) trial and 1067 AASK (African American Study of Kidney Disease and Hypertension) participants. We used Cox models to examine whether the association between intensive BP control and risk of end-stage renal disease (ESRD) or death is modified by baseline proteinuria (≥0.44 versus <0.44 g/g), glomerular filtration rate (≥30 versus <30 mL/min per 1.73 m2), age (≥40 versus <40 years), or body mass index (≥30 versus <30 kg/m2). The median follow-up was 14.9 years. Strict (versus usual) BP control was protective against ESRD (hazard ratio [HR]ESRD, 0.77; 95% CI, 0.64-0.92) among those with proteinuria ≥0.44 g/g but not proteinuria <0.44 g/g. Strict (versus usual) BP control was protective against death (HRdeath, 0.73; 95% CI, 0.59-0.92) among those with glomerular filtration rate <30 mL/min per 1.73 m2 but not glomerular filtration rate ≥30 mL/min per 1.73 m2 (HRdeath, 0.98; 95% CI, 0.84-1.15). Strict (versus usual) BP control was protective against ESRD among those ≥40 years (HRESRD, 0.82; 95% CI, 0.71-0.94) but not <40 years. Strict (versus usual) BP control was also protective against ESRD among those with body mass index ≥30 kg/m2 (HRESRD, 0.75; 95% CI, 0.61-0.92) but not body mass index <30 kg/m2. Conclusions The ESRD and all-cause mortality benefits of intensive BP lowering may not be uniform across all subgroups of patients with chronic kidney disease. But intensive BP lowering was not associated with increased risk of ESRD or death among any subgroups that we examined.

Magnitude of the Difference Between Clinic and Ambulatory Blood Pressures and Risk of Adverse Outcomes in Patients With Chronic Kidney Disease.

Background Obtaining 24-hour ambulatory blood pressure ( BP ) is recommended for the detection of masked or white-coat hypertension. Our objective was to determine whether the magnitude of the difference between ambulatory and clinic BP s has prognostic implications. Methods and Results We included 610 participants of the AASK (African American Study of Kidney Disease and Hypertension) Cohort Study who had clinic and ambulatory BPs performed in close proximity in time. We used Cox models to determine the association between the absolute systolic BP ( SBP ) difference between clinic and awake ambulatory BPs (primary predictor) and death and end-stage renal disease. Of 610 AASK Cohort Study participants, 200 (32.8%) died during a median follow-up of 9.9 years; 178 (29.2%) developed end-stage renal disease. There was a U-shaped association between the clinic and ambulatory SBP difference with risk of death, but not end-stage renal disease. A 5- to <10-mm Hg higher clinic versus awake SBP (white-coat effect) was associated with a trend toward higher (adjusted) mortality risk (adjusted hazard ratio, 1.84; 95% CI, 0.94-3.56) compared with a 0- to <5-mm Hg clinic-awake SBP difference (reference group). A ≥10-mm Hg clinic-awake SBP difference was associated with even higher mortality risk (adjusted hazard ratio, 2.31; 95% CI, 1.27-4.22). A ≥-5-mm Hg clinic-awake SBP difference was also associated with higher mortality (adjusted hazard ratio, 1.82; 95% CI, 1.05-3.15) compared with the reference group. Conclusions A U-shaped association exists between the magnitude of the difference between clinic and ambulatory SBP and mortality. Higher clinic versus ambulatory BPs (as in white-coat effect) may be associated with higher risk of death in black patients with chronic kidney disease.

Depressive Symptoms Associate With Race and All-Cause Mortality in Patients With CKD.

INTRODUCTION: Depression is common but underrecognized in patients with chronic kidney disease (CKD), especially among racial/ethnic minorities. We examined the association between depressive symptoms and all-cause mortality (including deaths before and after end-stage renal disease [ESRD]) and whether antidepressant use impacts this association, overall, and by race/ethnicity. METHODS: We ascertained whether the presence of depressive symptoms, defined by a Beck Depression Inventory II (BDI) score of >14 at cohort enrollment, was associated with all-cause mortality (before or after ESRD) among study participants of the Chronic Renal Insufficient Cohort (CRIC) overall and by race/ethnicity. Models were adjusted for socioeconomic factors, baseline CKD severity, time-updated comorbid conditions, and time-updated antidepressant use. Confirmatory analyses were performed among African American Study of Kidney Disease and Hypertension (AASK) participants. RESULTS: Among 3739 CRIC participants, 16.3% had a baseline BDI of >14; 18.2% reported antidepressant use. Crude mortality rate was 3.16 per 100 person-years during 6.8 years of median follow-up. Baseline BDI >14 was independently associated with higher risk of all-cause mortality (adjusted hazard ratio [aHR]: 1.27; 95% confidence interval: 1.07-1.52) without attenuation by antidepressant use. Differences among white and black individuals were noted (Pinteraction= 0.02) but not among white versus Hispanic individuals (Pinteraction = 0.43) or black versus Hispanic individuals (Pinteraction = 0.22). Depressive symptoms were associated with higher mortality among white individuals (aHR: 1.66; 1.21-2.28), but not Hispanic individuals (aHR: 1.47; 0.95-2.28) or black individuals (aHR: 1.06; 0.82-1.37). Similar results were noted among 611 AASK participants (aHR: 0.99; 0.69-1.42). CONCLUSIONS: The presence of depressive symptoms is a risk factor for all-cause mortality among patients with mild-moderate CKD, particularly among white individuals. Further studies are needed to understand the heterogeneity in the response to the presence of depressive symptoms by race.

Acute Declines in Renal Function during Intensive BP Lowering and Long-Term Risk of Death.

BACKGROUND: During intensive BP lowering, acute declines in renal function are common, thought to be hemodynamic, and potentially reversible. We previously showed that acute declines in renal function ≥20% during intensive BP lowering were associated with higher risk of ESRD. Here, we determined whether acute declines in renal function during intensive BP lowering were associated with mortality risk among 1660 participants of the African American Study of Kidney Disease and Hypertension and the Modification of Diet in Renal Disease Trial. METHODS: We used Cox models to examine the association between percentage decline in eGFR (<5%, 5% to <20%, or ≥20%) between randomization and months 3-4 of the trials (period of therapy intensification) and death. RESULTS: In adjusted analyses, compared with a <5% eGFR decline in the usual BP arm (reference), a 5% to <20% eGFR decline in the intensive BP arm was associated with a survival benefit (hazard ratio [HR], 0.77; 95% confidence interval [95% CI], 0.62 to 0.96), but a 5% to <20% eGFR decline in the usual BP arm was not (HR, 1.01; 95% CI, 0.81 to 1.26; P<0.05 for the interaction between intensive and usual BP arms for mortality risk). A ≥20% eGFR decline was not associated with risk of death in the intensive BP arm (HR, 1.18; 95% CI, 0.86 to 1.62), but it was associated with a higher risk of death in the usual BP arm (HR, 1.40; 95% CI, 1.04 to 1.89) compared with the reference group. CONCLUSIONS: Intensive BP lowering was associated with a mortality benefit only if declines in eGFR were <20%.

Longitudinal Weight Change During CKD Progression and Its Association With Subsequent Mortality.

BACKGROUND: Few studies have investigated the changes in weight that may occur over time among adults with the progression of chronic kidney disease (CKD). Whether such weight changes are independently associated with death after the onset of end-stage renal disease has also not been rigorously examined. STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: We studied 3,933 participants of the Chronic Renal Insufficiency Cohort (CRIC) Study, a longitudinal cohort of patients with CKD. We also performed similar analyses among 1,067 participants of the African American Study of Kidney Disease and Hypertension (AASK). PREDICTORS: Estimated glomerular filtration rate (eGFR) and weight change during CKD. OUTCOME: Weight and all-cause mortality after dialysis therapy initiation. RESULTS: During a median follow-up of 5.7 years in CRIC, weight change was not linear. Weight was stable until cystatin C-based eGFR (eGFRcys) decreased to <35mL/min/1.73m2; thereafter, weight declined at a mean rate of 1.45 kg (95% CI, 1.19-1.70) for every 10 mL/min/1.73m2 decline in eGFRcys. Among the 770 CRIC participants who began hemodialysis or peritoneal dialysis therapy during follow-up, a >5% annualized weight loss after eGFR decreased to <35mL/min/1.73m2 was associated with a 54% higher risk for death after dialysis therapy initiation (95% CI, 1.17-2.03) compared with those with more stable weight (annualized weight changes within 5% of baseline) in adjusted analysis. Similar findings were observed in the AASK. LIMITATIONS: Inclusion of research participants only; inability to distinguish intentional versus unintentional weight loss. CONCLUSIONS: Significant weight loss began relatively early during the course of CKD and was associated with a substantially higher risk for death after dialysis therapy initiation. Further studies are needed to determine whether interventions to optimize weight and nutritional status before the initiation of dialysis therapy will improve outcomes after end-stage renal disease.

Skin Blood Flow and Vascular Endothelium Function in Uremia.

Prevalence of dermatological disorder in patients with end-stage kidney disease is estimated as 50% to 100% in various studies. Some of the skin lesions are specific for the diseases causing chronic kidney disease (CKD), some are associated with CKD, and still others are the dermatological manifestation of uremia. Microangiopathy was also found in both arterioles and venule in the skin biopsy of "normal looking" skin in patients with end-stage kidney disease. In a cross-sectional study in patients on dialysis, we measured skin blood flow (SBF) using laser Doppler device in a standardized way at various areas of lower extremities at 2 different local skin temperatures: 35°C and 44°C. Local heating increases skin perfusion by mechanisms dependent on nitric oxide (NO). SBF was impaired in CKD patients Stage 5 on HD, particularly in those with diabetes mellitus as a cause of CKD. The reduced response in the SBF to the heat in our patients may be due to decreased generation of NO in uremia. Endothelium-dependent vasodilatation in patients on dialysis and the response of the skin microcirculation to acetylcholine was diminished in hypertensive patients on dialysis. Similarly, patients with diabetes mellitus had decreased SBF during intradermal microdialysis with a NO synthase inhibitor. Multiple uremic toxins have been studied in vitro and show to cause various degree of endothelial cell dysfunction. Unfortunately, no clear benefit has been described in CKD patients to different intervention aimed to reduce uremic toxin effect on endothelium. There are no long-term data on the factors which can modify endothelium function in uremia, but non pharmacologic interventions, diet, and several pharmacologic approaches could be beneficial. Measurement of SBF can be useful in evaluation of vasculopathy in CKD population and can potentially be used for assessment of vascular response during specific clinical intervention.

Acute Declines in Renal Function during Intensive BP Lowering: Implications for Future ESRD Risk.

The magnitude of decline in renal function that should be tolerated during intensive BP lowering and its association with risk of ESRD are unclear. To determine whether the acute declines in kidney function in the intensive BP lowering arm of two trials in CKD associated with higher risk of ESRD, we performed a retrospective study of 899 African American Study of Kidney Disease and Hypertension (AASK) and 761 Modification of Diet in Renal Disease (MDRD) Trial participants previously randomized to strict versus usual BP control. The predictor was the percentage decline in eGFR (<5%, 5% to <20%, or ≥20%) between randomization and months 3 and 4 of the trial (time to achieve BP goals). ESRD was the outcome of interest. Compared with a <5% eGFR decline in the usual BP arm, a 5% to <20% eGFR decline during intensive BP lowering did not associate with a higher risk of ESRD in the AASK (adjusted hazard ratio [aHR], 1.19; 95% confidence interval [95% CI], 0.84 to 1.68) or the MDRD Trial (aHR, 1.08; 95% CI, 0.84 to 1.40). However, a 5% to <20% eGFR decline in the usual BP arm associated with higher risk of ESRD in AASK (aHR, 1.83; 95% CI, 1.30 to 2.57) and MDRD Trial (aHR, 1.62; 95% CI, 1.25 to 2.11). A ≥20% eGFR decline associated with higher risk of ESRD in both strict and usual BP arms. Thus, acute eGFR declines ≥20% during intensive BP lowering identified a subset of patients at higher risk for adverse outcomes.

Strict blood pressure control associates with decreased mortality risk by APOL1 genotype.

Although APOL1 high-risk genotype partially accounts for the increased susceptibility of blacks to chronic kidney disease (CKD), whether APOL1 associates differentially with mortality risk remains controversial. Here we evaluate the association between APOL1 genotype and risk of death and determine whether APOL1 status modifies the association between strict versus usual blood pressure control and mortality risk. We performed a retrospective analysis of the African American Study of Kidney Disease and Hypertension trial that randomized black participants with CKD to strict versus usual blood pressure control from 1995 to 2001. This included 682 participants with known APOL1 genotype (157 with high-risk genotype) previously assigned to either strict (mean arterial pressure [MAP] 92 mm Hg or less) versus usual blood pressure control (MAP 102-107 mm Hg) during the trial. During a median follow-up of 14.5 years, risk of death did not differ between individuals with high- versus low-risk APOL1 genotypes (unadjusted hazard ratio 1.00 [95% confidence interval 0.76-1.33]). However, a significant interaction was detected between the APOL1 risk group and blood pressure control strategy. In the APOL1 high-risk group, the risk of death was 42% lower comparing strict versus usual blood pressure control (0.58 [0.35-0.97]). In the APOL1 low-risk group, the risk of death comparing strict versus usual blood pressure control was not significantly different (1.09 [0.84-1.43]). Thus, strict blood pressure control during CKD associates with a lower risk of death in blacks with the high-risk CKD APOL1 genotype. Knowledge of APOL1 status could inform selection of blood pressure treatment targets in black CKD patients.

BP Control and Long-Term Risk of ESRD and Mortality.

We recently showed an association between strict BP control and lower mortality risk during two decades of follow-up of prior participants in the Modification of Diet in Renal Disease (MDRD) trial. Here, we determined the risk of ESRD and mortality during extended follow-up of the African American Study of Kidney Disease and Hypertension (AASK) trial. We linked 1067 former AASK participants with CKD previously randomized to strict or usual BP control (mean arterial pressure ≤92 mmHg or 102-107 mmHg, respectively) to the US Renal Data System and Social Security Death Index; 397 patients had ESRD and 475 deaths occurred during a median follow-up of 14.4 years from 1995 to 2012. Compared with the usual BP arm, the strict BP arm had unadjusted and adjusted relative risks of ESRD of 0.92 (95% confidence interval [95% CI], 0.75 to 1.12) and 0.95 (95% CI, 0.78 to 1.16; P=0.64), respectively, and unadjusted and adjusted relative risks of death of 0.92 (95% CI, 0.77 to 1.10) and 0.81 (95% CI, 0.68 to 0.98; P=0.03), respectively. In meta-analyses of individual-level data from the MDRD and the AASK trials, unadjusted relative risk of ESRD was 0.88 (95% CI, 0.78 to 1.00) and unadjusted relative risk of death was 0.87 (95% CI, 0.76 to 0.99) for strict versus usual BP arms. Our findings suggest that, during long-term follow-up, strict BP control does not delay the onset of ESRD but may reduce the relative risk of death in CKD.

William Osler and investigation on trench nephritis.

The first alarming reports about a new disease called "trench nephritis" affecting soldiers of the British Expeditionary Forces in Flanders appeared in British medical press in 1915th. Soon, the Medical Research Council initiated a special research investigation on trench nephritis at St. Bartholomews Hospital and the results of these studies were discussed during the Royal Society of Medicine meeting in February 1916. William Osler was invited as one of the four main speakers for this presentation. He had lived in England since 1906 and served as the Regius Professor of Medicine at Oxford. At the meeting, Osler summarizes the clinical presentation of trench nephritis as a sudden appearance of swelling with rare cases of anasarca. Fever was not a common early presentation in his experience. He found rapid improvement in most of the cases during hospitalization despite "persistence of a large amount of albumin, of blood, and of cast, with increasing high blood pressure, is an unusual combination in the nephritis of civil life, yet that has been common enough in these cases". He questioned the assumption of a good prognosis in trench nephritis especially in "Cases which are lasting from twelve to fourteen weeks, the chances are that it will become subacute or chronic".

Kidney transplantation in the Hispanic population.

Hispanic race and low socioeconomic status are established predictors of disparity in access to kidney transplantation. This single-center retrospective review was undertaken to determine whether Hispanic race predicted kidney transplant outcomes. A total of 720 patients underwent kidney transplantation from January 1, 2004 to December 31, 2013, including 398 Hispanic patients and 322 non-Hispanic patients. Hispanic patients were significantly younger (p < 0.0001), on hemodialysis for longer (p = 0.0018), had a greater percentage with public insurance (p < 0.0001), more commonly had diabetes as the cause of end-stage renal disease (p = 0.0167), and had a lower percentage of living donors (p = 0.0013) compared to non-Hispanic patients. There was no difference in one-, five-, and 10-yr graft (97%, 81%, and 61% vs. 95%, 76%, and 42% p = 0.18) or patient survival (98%, 90%, and 84% vs. 97%, 87%, and 69% p = 0.11) between the Hispanic and non-Hispanic recipients. Multivariate analysis identified increased recipient age and kidney donor profile index to be predictive of lower graft survival and increasing recipient age to be predictive of lower patient survival. In the largest single-center study on kidney transplantation outcomes in Hispanic patients, there is no difference in graft and recipient survival between Hispanic and non-Hispanic kidney transplant patients, and in multivariate analysis, Hispanic race is not a risk factor for graft or patient survival.

Relationship of left ventricular hypertrophy and diastolic function with cardiovascular and renal outcomes in African Americans with hypertensive chronic kidney disease.

African Americans with hypertension are at high risk for adverse outcomes from cardiovascular and renal disease. Patients with stage 3 or greater chronic kidney disease have a high prevalence of left ventricular (LV) hypertrophy and diastolic dysfunction. Our goal was to study prospectively the relationships of LV mass and diastolic function with subsequent cardiovascular and renal outcomes in the African American Study of Kidney Disease and Hypertension cohort study. Of 691 patients enrolled in the cohort, 578 had interpretable echocardiograms and complete relevant clinical data. Exposures were LV hypertrophy and diastolic parameters. Outcomes were cardiovascular events requiring hospitalization or causing death; a renal composite outcome of doubling of serum creatinine or end-stage renal disease (censoring death); and heart failure. We found strong independent relationships between LV hypertrophy and subsequent cardiovascular (hazard ratio, 1.16; 95% confidence interval, 1.05-1.27) events, but not renal outcomes. After adjustment for LV mass and clinical variables, lower systolic tissue Doppler velocities and diastolic parameters reflecting a less compliant LV (shorter deceleration time and abnormal E/A ratio) were significantly (P<0.05) associated with future heart failure events. This is the first study to show a strong relationship among LV hypertrophy, diastolic parameters, and adverse cardiac outcomes in African Americans with hypertension and chronic kidney disease. These echocardiographic risk factors may help identify high-risk patients with chronic kidney disease for aggressive therapeutic intervention.

Relationship between ambulatory BP and clinical outcomes in patients with hypertensive CKD.

BACKGROUND AND OBJECTIVES: Abnormal ambulatory BP (ABP) profiles are commonplace in CKD, yet the prognostic value of ABP for renal and cardiovascular outcomes is uncertain. This study assessed the relationship of baseline ABP profiles with CKD progression and subsequent cardiovascular outcomes to determine the prognostic value of ABP beyond that of clinic BP measurements. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Between 2002 and 2003, 617 African Americans with hypertensive CKD treated to a clinic BP goal of <130/80 mmHg were enrolled in this prospective, observational study. Participants were followed for a median of 5 years. Primary renal outcome was a composite of doubling of serum creatinine, ESRD, or death. The primary cardiovascular outcome was a composite of myocardial infarction, hospitalized congestive heart failure, stroke, revascularization procedures, cardiovascular death, and ESRD. RESULTS: Multivariable Cox proportional hazard analysis showed that higher 24-hour systolic BP (SBP), daytime, night-time, and clinic SBP were each associated with subsequent renal (hazard ratio, 1.17-1.28; P<0.001) and cardiovascular outcomes (hazard ratio, 1.22-1.32; P<0.001). After controlling for clinic SBP, ABP measures were predictive of renal outcomes in participants with clinic SBP <130 mmHg (P<0.05 for interaction). ABP predicted cardiovascular outcomes with no interaction based on clinic BP control. CONCLUSIONS: ABP provides additional information beyond that of multiple clinic BP measures in predicting renal and cardiovascular outcomes in African Americans with hypertensive CKD. The primary utility of ABP in these CKD patients was to identify high-risk individuals among those patients with controlled clinic BP.