Diagnosing Fabry nephropathy: the challenge of multiple kidney disease.

Fabry disease (FD) is an X-linked inherited lysosomal disorder due to a deficiency of the enzyme alpha-galactosidase A (α-gla) due to mutations in the GLA gene. These mutations result in plasma and lysosome accumulation of glycosphingolipids, leading to progressive organ damage and reduced life expectancy. Due to the availability of specific disease-modifying treatments, proper and timely diagnosis and therapy are essential to prevent irreversible complications. However, diagnosis of FD is often delayed because of the wide clinical heterogeneity of the disease and multiple organ involvement developing in variable temporal sequences. This observation is also valid for renal involvement, which may manifest with non-specific signs, such as proteinuria and chronic kidney disease, which are also common in many other nephropathies. Moreover, an additional confounding factor is the possibility of the coexistence of FD with other kidney disorders. Thus, suspecting and diagnosing FD nephropathy in patients with signs of kidney disease may be challenging for the clinical nephrologist. Herein, also through the presentation of a unique case of co-occurrence of autosomal dominant polycystic kidney disease and FD, we review the available literature on cases of coexistence of FD and other renal diseases and discuss the implications of these conditions. Moreover, we highlight the clinical, laboratory, and histological elements that may suggest clinical suspicion and address a proper diagnosis of Fabry nephropathy.

Histology for nephrology, from pre-implantation to post-transplant kidney biopsy. Lesson learned from ReBIrth (Renal BIopsy for Kidney Transplantation Therapy).

A meeting entitled Renal BIopsy for Kidney Transplantation Therapy (ReBIrth) took place on May 31st, 2022 in Bologna, Italy. The meeting drew together nephrologists, surgeons, and pathologists and recognized as experts in the field of kidney transplantation in Italy. In this paper, we present our experience working with kidney transplants in the current era of immunosuppression therapy. The primary aim is to report the histopathological characteristics of failed kidney allografts after a consensus of experts reviewed the cases on a wholeslide imaging digital platform. Regardless of the cases discussed, digital pathology was reliable in identifying all the morphological and immunohistochemical features required to improve the correct use of immunosuppressive therapy to prevent graft failure and optimize patient management.

The Evolving Scenario of COVID-19 in Hemodialysis Patients.

Coronavirus disease 2019 (COVID-19) is a rapidly changing disease. Therefore, in this study, to evaluate the evolution of COVID-19 in hemodialysis patients, we retrospectively compared patients affected by COVID-19 during the first pandemic waves of 2020 (from March to December 2020-Group 1) with patients with COVID-19 from September 2021 to February 2022 (Group 2) after the full completion of vaccination. Group 1 was constituted of 44 patients (69.3 ± 14.6 years), and Group 2 of 55 patients (67.4 ± 15.3 years). Among Group 2, 52 patients (95%) were vaccinated. Patients of Group 2, compared with Group 1, were more often asymptomatic (38 vs. 10%, p = 0.002) and reported less frequent fever and pulmonary involvement. At diagnosis, Group 2 showed a significantly higher number of lymphocytes and lower levels of circulating IL-6 (16 ± 13.3 vs. 41 ± 39.4 pg/mL, p = 0.002). Moreover, in Group 2, inflammatory parameters significantly improved after a few days from diagnosis. Patients of Group 2 presented a lower hospitalization rate (12.7 vs. 38%, p = 0.004), illness duration (18.8 ± 7.7 vs. 29.2 ± 19.5 days, p = 0.005), and mortality rate (5.4 vs. 25%, p = 0.008). Finally, responders to the vaccination (80% of vaccinated patients) compared with nonresponders showed a reduction in infection duration and hospitalization (5 vs. 40%, p = 0.018). In conclusion, we found that COVID-19 presentation and course in hemodialysis patients have improved over time after the implementation of vaccine campaigns. However, due to the evolving nature of the disease, active surveillance is necessary.

Secondary Membranous Nephropathy Due to Benign Tumors in 2 Young Women: A Case Report.

Membranous nephropathy (MN) is one of the most common causes of adult-onset nephrotic syndrome. We describe the cases of 2 young women in their 20s presenting with nephrotic syndrome due to antiphospholipase A2 receptor (anti-PLA2R)-negative MN, that was found to be associated with benign tumors. Both women had no extrarenal symptoms of a connective tissue disease, infection, or malignancy. They both had been previously healthy and were not receiving treatment with any drugs. Both had MN on kidney biopsy. Biopsies were negative for PLA2R antigen, and their serum did not demonstrate the presence of anti-PLA2R antibodies. Both were investigated for a secondary cause on the basis of negative anti-PLA2R serology and biopsy features supportive of secondary MN and were found to have benign tumors on radioimaging: a uterine leiomyoma and mesenteric fibromatosis, respectively. In both instances, the nephrotic syndrome remitted following resection of the tumors. To our knowledge, uterine leiomyoma and mesenteric fibromatosis have not previously been described in association with MN. These cases highlight the importance of pursuing a secondary cause of MN in patients without anti-PLA2R antibodies in serum or PLA2R antigen on kidney biopsy.

Everolimus for BKV nephropathy in kidney transplant recipients: a prospective, controlled study.

There is no specific therapy for polyoma BK virus nephropathy (BKVN) in kidney transplant recipients, a condition associated with poor outcomes. Everolimus showed promising antiviral effects, but data from prospective studies are limited. Therefore, we converted ten consecutive kidney transplant recipients with biopsy-proven BKVN from standard exposure Calcineurin inhibitors and Mycophenolate to Everolimus and reduced exposure Calcineurin inhibitors. Ten patients not administered Everolimus, on reduced exposure Calcineurin inhibitor and halved MPA doses served as controls. All kidney transplant recipients continued steroid therapy. Each patient underwent kidney graft biopsy, BKV replication by PCR, and de novo DSA determination. During a 3-year follow-up no graft loss occurred in kidney transplant recipients on Everolimus but it was observed in 5/10 controls (P = 0.032). eGFR improved on Everolimus and worsened in controls (between group difference + 25.6 ml/min/1.73 m2, 95% CI 10.5-40.7, P = 0.002). BKV replication declined in the Everolimus group alone (from 6.4 ± 0.8 to 3.6 ± 1.6 Log 10 genomic copies, P = 0.0001), and we found a significant inverse relationship between eGFR and BKV genomic copy changes (P = 0.022). Average Calcineurin inhibitors trough levels did not differ between the two study groups during follow-up. By multivariable Cox regression analysis, Everolimus treatment resulted the only significant predictor of survival free of a combined endpoint of graft loss and 57% eGFR reduction (P = 0.02). Kidney transplant recipients on Everolimus had a higher survival free of adverse graft outcome (log-rank test, P = 0.009). In conclusion an Everolimus-based immunosuppressive protocol with minimization of Calcineurin inhibitors and antimetabolite discontinuation effectively treated BKVN in kidney transplant recipients.

Early interstitial macrophage infiltration with mild dysfunction is associated with subsequent kidney graft loss.

Macrophage infiltration is associated with unfavorable kidney graft outcome in protocol biopsies, but few studies have evaluated its impact on clinical practice. We therefore prospectively evaluated 37 kidney transplant recipients (KTRs) who underwent kidney biopsy due to slight increases in serum creatinine, or mild proteinuria (>0.3 g/24 hr), in the first post-transplant year. Banff score, CD68+ count (score 0-3) by immunohistochemistry, and 1-year DSA were assessed. DGF was reported in 10 (27%) patients, 6 (16%) had normal biopsy, 7 (19%) borderline lesions, 13 (35%) IFTA, and 11 (30%) other lesions. Fifteen KTRs had grade 3 CD68+ infiltration, and 47% developed de novo DSA. During a 6.2 ± 2.7 year follow-up, four patients (11%) suffered from biopsy-proven T-cell rejection, 17 KTRs (46%) lost their graft (12 in the grade 3 CD68+ group). Graft survival was lower in KTRs with grade 3 CD68+ infiltration (P = 0.0074; log-rank test). Grade 3 CD68+ infiltrate was an independent predictor of graft loss (HR 5.41, 95% CI 1.74-16.8; P = 0.003), together with more severe graft dysfunction at biopsy (HR 6.41, 95% CI 2.57-16; P < 0.001). We conclude that grade 3 CD68+ interstitial infiltration is associated with increased risk of subsequent graft loss independent of other factors.

Posttransplant soluble B-cell activating factor kinetics in pediatric recipients of first kidney allograft.

BACKGROUND: Development of de novo donor-specific antibodies (dnDSA) is associated with late or chronic antibody-mediated rejection (CAMR) and poor graft outcome in low-risk kidney transplant recipients. High-level soluble B-cell activating factor (sBAFF) was observed in kidney recipients at higher risk of developing dnDSA. METHODS: We longitudinally analyzed sBAFF levels in 81 consecutive primary pediatric kidney recipients monitored for de novo human leukocyte antigen (HLA) antibody (Ab) occurrence to gain insight into the events conditioning B-cell activation posttransplant and to analyze the usefulness of paired DSA-sBAFF monitoring in this clinical setting. RESULTS: At a median follow-up of 65 months, 23 patients (28%) developed dnDSA, with 13 of 23 developing CAMR. Irrespective of HLA Ab status, sBAFF levels progressively increased in all patients in the first posttransplant year, thereafter reaching a plateau. sBAFF levels were influenced by the degree of HLA class I antigen match and donor age. Despite higher levels of sBAFF in HLA Ab-positive patients (median and 95% confidence interval sBAFF in DSA+non-DSA patients: 568, 534-608 pg/mL vs. 502, 422-548 pg/mL in Ab-negative patients; P<0.05), we found that sBAFF monitoring could not predict DSA development by a time to event longitudinal analysis. Moreover, sBAFF kinetics up to CAMR onset could not anticipate CAMR development in the DSA cohort. CONCLUSION: Our findings provide evidence of early posttransplant B-cell activation even in unsensitized recipients of first kidney allograft. The significance of this activation, likely induced by exposition to the allograft, is yet unclear.

Three-yr safety and efficacy of everolimus and low-dose cyclosporine in de novo pediatric kidney transplant patients.

The three yr results of a multicenter trial in de novo pediatric KT treated with a proliferative signal inhibitor and low dose CNI are presented. Thirty-seven children (9.1 ± 5 yr old) received basiliximab, cyclosporine A (CyA C2:1400 ng/mL), (MMF C0:1.5-3 µg/mL), and prednisone. Three wk later everolimus was started (C0:5-10 ng/mL), CyA was reduced (C2:600 ng/mL after 90 days 300 ng/mL), and MMF discontinued. During the three-yr period patient and graft survivals were 96%. One patient died for causes unrelated to the immunosuppression. Cumulative acute rejection rate including protocol and indication biopsies was 21.9%. None of the patients had signs of chronic humoral rejection. Incidence of dnDSA was 5%, 11%, and 22% at one, two, and three yr post-transplant, respectively. Mean glomerular filtration rate measured at one yr and three yr post-transplant was 105.5 ± 31 and 110.7 ± 27 mL/min/1.73 m(2), respectively. A growth velocity of 7.7 ± 6.7 cm/yr was achieved with positive catch-up growth. No malignancy or post-transplant lymphoproliferative diseases were diagnosed. In conclusion, the treatment based on basiliximab induction, everolimus, low-dose cyclosporine, and low-dose prednisone leads to good long-term efficacy in de novo pediatric KT recipients.

[Polyomavirus BK-associated nephropathy after kidney transplant]. / Infezione da polyomavirus BK e patologia correlata dopo trapianto renale.

Advances in immunosuppression have lowered the acute rejection rates in kidney transplant recipients but have impacted negatively on the viral infection rates. Polyomavirus-associated interstitial nephropathy (PyVA N) affects up to 10% of kidney transplant recipients and can progress to irreversible allograft failure in up to 45% of affected cases. Nowadays, thanks to increased awareness of PyVA N and improved diagnostic techniques, the rate of graft loss has decreased, most markedly in centers with active screening and intervention programs. The diagnosis of PyVA N is made by allograft histology. However, systematic screening by quantitative molecular-genetic techniques allows intervention in the early stages of the disease, before the occurrence of irreversible parenchymal changes. So far, the only proven measure affecting PyVA N progression and outcome is the reduction of immunosuppression. Other therapeutic approaches including cidofovir, leflunomide, fluoroquinolones and intravenous immunoglobulins have been explored, but there is no clinical evidence supporting their efficacy. It has been largely demonstrated that BKV-specific T-cell immunity plays a pivotal role in controlling viral replication and disease progression. For this reason viral-specific T-cell immunity can help in monitoring PyVA N. Protocols of adoptive T-cell transfer based on infusion of BKV-specific T cells are the object of many studies and should be considered an innovative treatment approach for PyVA N.

Use of rituximab in focal glomerulosclerosis relapses after renal transplantation.

BACKGROUND: Focal and segmental glomerulosclerosis (FSGS) accounts for more than 10% of all cases of renal diseases leading to renal failure in children. After renal transplantation, 20% to 40% of FSGS relapse, frequently leading to renal loss.Plasmapheresis is considered the first option to treat relapses by several authors but is often ineffective. The anti-CD20 monoclonal antibody rituximab has been proposed as a possible treatment. METHODS: We reviewed the effect of rituximab in seven children or young adults with pretransplant FSGS and relapse of proteinuria after transplantation who did not respond to intensive plasmapheresis. RESULTS: After treatment, urine protein disappeared in three patients, was reduced by 70% in one patient and by 50% in one patient. No response was observed in one patient who had a quick deterioration of renal function and reached end-stage renal failure after 3 months. One additional patient developed a severe reaction a few minutes after the start of the first rituximab infusion. CONCLUSION: Rituximab is a possible option to treat some resistant cases of FSGS with relapsing proteinuria after transplantation. It is important that therapy is started early after evidence of failure of plasmapheresis, before sclerosis develops in the glomeruli. The response to treatment can occur after several months. During the follow-up period, CD19 cells should be monitored carefully, and additional rituximab infusions considered to maintain B-cell depletion.

Vascular permeability, blood pressure, and organ damage in primary hypertension.

Sub-clinical organ damage is a strong independent predictor of cardiovascular mortality in primary hypertension, and its changes over time parallel those in risk of cardiovascular events. A better understanding of the pathogenetic mechanisms underlying the development of target organ damage may help us devise more effective therapeutic strategies. We therefore investigated the relationship between the presence of organ damage and some of its potential determinants, such as blood pressure severity and early atherosclerotic abnormalities. Thirty-seven untreated, non-diabetic hypertensive patients were enrolled. Target organ damage was assessed by albuminuria and left ventricular mass index; systemic vascular permeability was evaluated by transcapillary escape rate of albumin (TERalb); and blood pressure was measured by 24h ambulatory blood pressure monitoring. The albumin-to-creatinine ratio and left ventricular mass index were directly related to TERalb (r = 0.48, p = 0.003 and r = 0.39, p < 0.020, respectively) and 24-h systolic blood pressure values (r = 0.54, p < 0.001; r = 0.60, p < 0.001). The simultaneous occurrence of increased blood pressure load and TERalb was associated with higher left ventricular mass index values (p = 0.012) and entailed an increased risk of having at least one sign of damage (chi2 = 17.4; p < 0.001). Logistic regression analysis showed that the risk of presenting at least one sign of organ damage increased more than ten-fold when TERalb was above the median and more than five-fold with each 10 mmHg increase in 24-h systolic blood pressure. Blood pressure load and vascular permeability are potentially modifiable factors that are independently associated with the occurrence of sub-clinical signs of renal and cardiac damage in hypertensive patients.

Global risk stratification in primary hypertension: the role of the kidney.

OBJECTIVE: Microalbuminuria and a reduction in creatinine clearance are well known, independent predictors of unfavourable cardiovascular prognosis. Our aim was to evaluate the impact of renal damage on global risk stratification in 459 non-diabetic, untreated hypertensive patients (64% men, mean age 47.3 years). METHODS: Renal damage was defined as creatinine clearance < 60 ml/min per 1.73 m2 (Cockcroft-Gault formula) or the presence of microalbuminuria (albumin to creatinine ratio). Cardiac and vascular organ damage was assessed by ultrasound scan. We evaluated the impact of renal damage, left ventricular hypertrophy and carotid atherosclerosis on risk stratification as recommended by the 2007 European Society of Hypertension-European Society of Cardiology Guidelines. RESULTS: The prevalence of renal damage, microalbuminuria and creatinine clearance < 60 ml/min per 1.73 m2 was 24, 12 and 13%, respectively. There was no correlation between albuminuria and estimated creatinine clearance, and only 0.9% of patients showed microalbuminuria and reduced creatinine clearance simultaneously. The presence of renal damage entailed a 3.3 times higher risk of having cardiovascular abnormalities. Based on routine work-up, 58% of our study patients were classified as high-very high risk. The simultaneous evaluation of albuminuria and creatinine clearance resulted in a significant change in risk stratification, since 68% of patients were classified in the high-very high risk class. The search for left ventricular hypertrophy or carotid atherosclerosis by ultrasonography did not improve risk stratification significantly as compared to the assessment of renal damage. CONCLUSIONS: Our findings support the assessment of renal abnormalities as the first step when evaluating target organ damage for cardiovascular risk assessment in hypertensive patients.

Inappropriate left ventricular mass is associated with microalbuminuria independently of left ventricular hypertrophy in primary hypertension.

OBJECTIVE: Inappropriate left ventricular mass (LVM) and microalbuminuria predict cardiovascular events in hypertension. We attempted to evaluate the relationship between inappropriate LVM and albuminuria in hypertensive patients. PATIENTS AND METHODS: Four hundred and two nondiabetic, untreated patients with primary hypertension were studied. The appropriateness of LVM to cardiac workload was calculated by the ratio of observed LVM to the predicted value using the reference equation. Albuminuria was evaluated by the urinary albumin to creatinine ratio. RESULTS: The deviation of LVM from the predicted value was positively related to albuminuria (P < 0.0001). Multiple regression analysis showed that albuminuria (0.0182), pulse pressure (P < 0.0001) and left ventricular hypertrophy (LVH) (P < 0.0001) were the only independent predictors of observed/predicted LVM. When subjects were divided into subgroups on the basis of the presence/absence of inappropriate LVM, patients with inappropriate LVM showed higher urinary albumin excretion (P < 0.0001), regardless of potential confounding factors, including LVH (analysis of covariance, P = 0.0453), and higher prevalence of microalbuminuria (P = 0.0024) compared to those without it. Analogous results were obtained by looking at the study patients on the basis of the presence of micro- or normoalbuminuria. Indeed, patients with microalbuminuria showed higher prevalence of inappropriate LVH compared to other left ventricular geometries (appropriate LVH and absence of LVH) (P < 0.0001). After adjusting for confounders, microalbuminuria entailed a three- and five-fold greater risk of having appropriate and inappropriate LVH, respectively. CONCLUSIONS: Inappropriate LVM is associated with albuminuria in hypertension. These data strengthen the role of microalbuminuria as an indicator of high cardiovascular risk.

Mild hyperuricemia and subclinical renal damage in untreated primary hypertension.

BACKGROUND: Subclinical renal damage and hyperuricemia are not uncommon in patients with primary hypertension. Whether mild hyperuricemia reflects a subclinical impairment of renal function or contributes to its development is currently debated. We investigated the relationship between serum uric-acid levels and the occurrence of early signs of kidney damage. METHODS: Four hundred eighteen patients with primary hypertension were studied. Albuminuria was measured as the albumin-to-creatinine ratio, and creatinine clearance was estimated by the formula of Cockcroft and Gault. Interlobar resistive index and renal abnormalities, ie, the renal volume-to-resistive index ratio, were evaluated by renal Doppler and ultrasound. RESULTS: Uric acid was directly related to resistive index (P = .007) in women and to albuminuria (P = .04) in men, and was inversely related to the renal volume-to-resistive index ratio in both men (P = .005) and women (P = .02). Patients with uric-acid levels above the median showed a higher prevalence of microalbuminuria (14% v 7%, P = .012) and of renal abnormalities (41% v 33%, P = .007). Moreover, when creatinine clearance was taken as a covariate, patients with increased uric-acid levels showed higher albuminuria and resistive indices, and a lower renal volume-to-resistive index ratio. Even after adjustment for several risk factors, each standard deviation increase in serum uric acid entailed a 69% higher risk of microalbuminuria, and a 39% greater risk of ultrasound detectable renal abnormalities. CONCLUSIONS: Mild hyperuricemia is associated with early signs of renal damage, ie, microalbuminuria and ultrasound-detectable abnormalities, regardless of the glomerular filtration rate in primary hypertension.

Improving cardiovascular risk stratification: the case for redefining microalbuminuria.

Large epidemiological studies have pointed out that regardless of the degree of hypertension, the cost-effectiveness of antihypertensive treatment increases in parallel with the global burden of risk. Therefore, there has been growing interest in developing sensitive and easy-to-perform ways to accurately and inexpensively identify patients at high cardiovascular risk. Numerous studies over the past years have provided evidence that microalbuminuria is a concomitant of extrarenal signs of hypertensive organ damage, as well as a strong, independent predictor of cardiovascular and cerebrovascular events. Recent clinical data indicate that the risk of cardiovascular morbidity and mortality is linearly related to the degree of urinary albumin excretion, with no identifiable threshold or plateau. Furthermore, it has been demonstrated that a reduction in albuminuria under antihypertensive treatment is paralleled by changes in cardiovascular risk. Therefore, the routine search for microalbuminuria could lead to a significant improvement in the evaluation and treatment of patients with primary hypertension.

Blood pressure load, vascular permeability and target organ damage in primary hypertension.

BACKGROUND: Target organ damage (TOD) is an often reversible subclinical condition that may precede major cardiovascular events in primary hypertensive patients. Furthermore, TOD has been shown to be a complex, multifactorial process which does not depend on blood pressure (BP) reduction alone. We therefore investigated the relationship between BP load, vascular permeability and the occurrence of TOD. PATIENTS AND METHODS: Thirty-seven never-treated, nondiabetic hypertensive patients were enrolled. Albuminuria was measured as the albumin to creatinine ratio (ACR), left ventricular mass index (LVMI) was assessed by echocardiography, systemic vascular permeability was evaluated by transcapillary escape rate of albumin (TERalb), and BP was measured by means of 24-hour ambulatory BP monitoring. RESULTS: Patients with microalbuminuria showed higher levels of body mass index (BMI) (p<0.034), 24-hour systolic BP levels (p<0.001), left ventricular mass index (LVMI) (p=0.003) and capillary permeability to albumin (p<0.005), as compared with normoalbuminurics. Increased BP load and vascular permeability were associated with higher LVMI (p=0.012) and with an increased risk of having microalbuminuria and/or left ventricular hypertrophy (Chi square=17.4; p<0.001). Logistic regression analysis showed that the risk of having at least 1 sign of TOD was 10-fold higher in patients with TERalb above the median, and almost 5-fold higher for each 10 mm Hg increase in systolic blood pressure. CONCLUSIONS: Abnormal vascular permeability and increased BP load are potentially modifiable risk factors that are independently associated with the development of subclinical cardiac and renal damage.

C-reactive protein and target organ damage in untreated patients with primary hypertension.

High sensitivity C-reactive protein (hs-CRP) has been recognized as a risk factor for cardiovascular disease. Asymptomatic organ damage is known to precede cardiovascular events in hypertension. The aim of the present study was to investigate the relationship between hs-CRP and signs of organ damage, namely left ventricular mass index (LVMI), albuminuria, and carotid atherosclerosis in a group of hypertensive patients. One hundred and eighty-two untreated patients with primary hypertension were studied. HS-CRP was measured by immunonephelometry. LVMI was assessed by echocardiography, albuminuria was measured as albumin to creatinine ratio, and carotid atherosclerosis by ultrasonography. Patient stratification according to quartiles of hs-CRP showed a significant trend toward higher age, prevalence of left ventricular hypertrophy, and carotid plaques. Moreover, there was a significant correlation among hs-CRP quartiles and left ventricular mass index, carotid cross-sectional area, carotid plaques, and albuminuria. Multiple regression analysis showed that, after adjusting for established cardiovascular risk factors (ie, age, duration of hypertension, smoking habit, body mass index (BMI), 24-hour systolic and diastolic blood pressures, glucose, creatinine, uric acid, triglycerides, total and low-density lipoprotein cholesterol), hs-CRP remained a strong correlate of target organ damage. These results support the importance of chronic microinflammation in the development of atherosclerotic disease in hypertension.

Microalbuminuria, blood pressure load, and systemic vascular permeability in primary hypertension.

BACKGROUND: Microalbuminuria, a powerful predictor of cardiovascular events, is thought to reflect widespread subclinical vascular abnormalities. To explore the pathogenesis of increased urinary albumin excretion in primary hypertension we evaluated systemic capillary permeability and ambulatory blood pressure (BP) measurement in two groups of matched untreated patients with (n = 11) and without (n = 29) microalbuminuria. METHODS: Albuminuria was measured as the mean of albumin-to-creatinine ratio (ACR) in three nonconsecutive first morning urine samples. Systemic capillary permeability was evaluated by transcapillary escape rate of albumin (TERalb) (ie, the 1-h decline rate of intravenous (125)I-albumin). Twenty-four-hour ambulatory BP, renal hemodynamics, and hormones of the renin-angiotensin-aldosterone system (RAAS) were also assessed. RESULTS: Patients with microalbuminuria showed greater body mass index (BMI) (P < .04), higher 24-h systolic and diastolic BP levels (P = .02), and higher capillary permeability to albumin (P < .02) as compared to normoalbuminurics. Renal hemodynamics and RAAS hormones were similar in the two groups. Univariate analysis showed that urinary ACR was related to ambulatory pressure components (P < .02), TERalb (r = 0.31, P < .05), smoking habits (r = 0.36, P = .02), and left ventricular mass index (LVMI) (r = 0.57, P < .001) among the whole study group. Logistic regression analysis showed that each 1% increment in TERalb or 10 mm Hg increase in systolic BP entailed an almost three times higher risk of having microalbuminuria. CONCLUSIONS: Microalbuminuria is associated with greater systemic BP load and increased vascular permeability in patients with primary hypertension.

Ambulatory arterial stiffness index and renal abnormalities in primary hypertension.

OBJECTIVE: Arterial stiffness is a predictor of cardiovascular mortality in the general population as well as in hypertension and end-stage renal disease. We investigated the relationship between a recently proposed ambulatory blood pressure monitoring-derived index of arterial stiffness and early signs of renal damage in patients with primary hypertension. DESIGN AND SETTING: A total of 168 untreated patients with sustained primary hypertension were studied. Ambulatory arterial stiffness index (AASI) was calculated based on 24-h ambulatory blood pressure readings. Albuminuria was measured as the albumin to creatinine ratio. Creatinine clearance was estimated using the Cockcroft-Gault formula, and the interlobar resistive index was evaluated by renal ultrasound and Doppler examination. RESULTS: AASI was positively related to urinary albumin excretion and resistive index, and was negatively related to estimated creatinine clearance and renal volume to the resistive index ratio. Patients with AASI above the median (i.e. > 0.51) showed a higher prevalence of microalbuminuria and a mild reduction in creatinine clearance. Moreover, patients with microalbuminuria or a mild reduction in creatinine clearance had significantly higher AASI values compared with those without, and the greater the renal involvement, the greater the AASI. After adjusting for several potentially confounding variables, we found that each standard deviation increase in AASI (i.e. 0.16) entails an almost twofold greater risk of renal involvement. CONCLUSION: Increased AASI is independently associated with early signs of renal damage in patients with sustained primary hypertension. These results strengthen the usefulness of AASI and ambulatory blood pressure monitoring in cardiovascular risk assessment.

Increased ambulatory arterial stiffness index is associated with target organ damage in primary hypertension.

Increased arterial stiffness has been shown to predict cardiovascular mortality in patients with primary hypertension. Asymptomatic organ damage is known to precede cardiovascular events. We investigated the relationship between a recently proposed index of stiffness derived from ambulatory blood pressure (BP) and target organ damage in 188 untreated patients with primary hypertension. Ambulatory arterial stiffness index was defined as 1 minus the regression slope of diastolic over systolic BP readings obtained from 24-hour recordings. Albuminuria was measured as the albumin:creatinine ratio, left ventricular mass index was assessed by echocardiography, and carotid abnormalities were evaluated by ultrasonography. The prevalence of microalbuminuria, left ventricular hypertrophy (LVH), and carotid abnormalities was 12%, 38%, and 19%, respectively. Ambulatory arterial stiffness index was positively related to age, triglycerides, office and 24-hour systolic BP, 24-hour pulse pressure, urinary albumin excretion, and carotid intima-media thickness. Patients with microalbuminuria, carotid abnormalities, or LVH showed higher ambulatory arterial stiffness index as compared with those without it. After adjusting for confounding factors, each SD increase in ambulatory arterial stiffness index entails an &2 times higher risk of microalbuminuria, carotid abnormalities, and LVH and doubles the risk of the occurrence of >or=1 sign of organ damage. Ambulatory arterial stiffness index is associated with organ damage in patients with primary hypertension. These data strengthen the role of this index as a marker of risk and help to explain the high cardiovascular mortality reported in patients with high ambulatory arterial stiffness index.