Francisco Rivera

Spontaneous Remission of Nephrotic Syndrome in Idiopathic Membranous Nephropathy

Spontaneous remission is a well known characteristic of idiopathic membranous nephropathy, but contemporary studies describing predictors of remission and long-term outcomes are lacking. We conducted a retrospective, multicenter cohort study of 328 patients with nephrotic syndrome resulting from idiopathic membranous nephropathy that initially received conservative therapy. Spontaneous remission occurred in 104 (32%) patients: proteinuria progressively declined after diagnosis until remission of disease at 14.7 +/- 11.4 months. Although spontaneous remission was more frequent with lower levels of baseline proteinuria, it also frequently occurred in patients with massive proteinuria: 26% among those with baseline proteinuria 8 to 12 g/24 h and 22% among those with proteinuria >12 g/24 h. Baseline serum creatinine and proteinuria, treatment with angiotensin-converting enzyme inhibitors or angiotensin receptor antagonists, and a >50% decline of proteinuria from baseline during the first year of follow-up were significant independent predictors for spontaneous remission. Only six patients (5.7%) experienced a relapse of nephrotic syndrome. The incidence of death and ESRD were significantly lower among patients with spontaneous remission. In conclusion, spontaneous remission is common among patients with nephrotic syndrome resulting from membranous nephropathy and carries a favorable long-term outcome with a low incidence of relapse. A decrease in proteinuria >50% from baseline during the first year predicts spontaneous remission.

Renal Biopsy Findings in Acute Renal Failure in the Cohort of Patients in the Spanish Registry of Glomerulonephritis

BACKGROUND AND OBJECTIVES Renal biopsy in acute renal failure of unknown origin provides irreplaceable information for diagnosis, treatment, and prognosis. This study analyzed the frequency and clinicopathologic correlations of renal native biopsied acute renal failure in Spain during the period 1994 through 2006. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Acute renal failure was defined as a rapid deterioration of glomerular filtration rate, with or without oligoanuria or rapidly progressive renal insufficiency, including acute-on-chronic renal failure. Patients who were younger than 15 yr were considered children, those between 15 and 65 yr adults, and those >65 elderly. RESULTS Between 1994 and 2006, data on 14,190 native renal biopsies were collected from 112 renal units in Spain. Of these, 16.1% (2281 biopsies) were diagnosed with acute renal failure. The prevalence of the main clinical syndromes was different in the three age groups: Biopsy-confirmed acute renal failure in children was 5.7%, in adults was 12.5%, and in elderly increased significantly to 32.9%. The prevalence of biopsy-confirmed acute renal failure according to cause was as follows: Vasculitis, 23.3%; acute tubulointerstitial nephritis, 11.3%; and crescentic glomerulonephritis types 1 and 2, 10.1%. The prevalence of the different causes differed significantly according to age group. CONCLUSIONS The Spanish Registry of Glomerulonephritis provides useful information about renal histopathology in biopsy-confirmed acute renal failure. The prevalence of vasculitis and crescentic glomerulonephritis is high, especially in elderly patients. These data obtained from a national large registry highlight the value of renal biopsy in undetermined acute renal failure.

Renal biopsy in very elderly patients: data from the Spanish Registry of Glomerulonephritis.

Background: Studies on renal histology results in very elderly patients are extremely rare. Methods: We analyzed histology and clinical findings in patients aged over 85 years undergoing renal biopsy and whose data were included in the Spanish Registry of Glomerulonephritis between 1994 and 2009. Results: A total of 17,680 native kidney biopsies were taken: 71 (0.4%) were from patients aged over 85 years. Acute kidney injury (AKI) was the main indication for biopsy (47%), followed by nephrotic syndrome (32%). Amyloidosis was the most common histological diagnosis (16.9%), followed by crescentic glomerulonephritis type 3 associated with systemic vasculitis (14.1%). When histological findings were correlated with clinical syndromes, we found that amyloidosis was the leading cause of AKI (18.8%), and also the main determinant of nephrotic syndrome, with the same frequency as membranous nephropathy (22%). Crescentic glomerulonephritis type 3 associated with vasculitis was related to a greater diversity of clinical syndromes, especially chronic kidney disease (40%) and AKI (40%). Conclusions: Renal biopsy in the very elderly provides us with useful information, despite the advanced age of the patients. AKI and nephrotic syndrome are the main indication for renal biopsy in this subgroup of patients, and amyloidosis is the most frequent histological pattern associated with both syndromes.

Increased prevalence of acute tubulointerstitial nephritis

Acute tubulointerstitial nephritis (ATIN) is a common cause of acute kidney injury (AKI) for which early treatment improves prognosis. The recent increase in prevalence has not been reflected in the literature. The aim of our study was to analyse all native kidney biopsies performed from 1994 to 2009 and included in the Spanish Registry of Glomerulonephritis with a histological diagnosis of ATIN. We assessed the prevalence of ATIN, associated clinical syndromes and urinary sediment abnormalities. We divided the population into two groups according to age: adults (15-65 years) and elderly patients (>65 years). We collected a total of 17 680 native kidney biopsies from 120 hospitals in Spain. The overall prevalence of ATIN was 2.7%. When the analysis was restricted to patients with AKI, the prevalence increased to 12.9%. During the 16 years of follow-up, there was a significant increase in prevalence (from 3.6% in the first 4 years to 10.5% in the last 4 years), which was more marked among elderly patients (from 1.6 to 12.3%). The most common clinical manifestations were AKI, microscopic haematuria, non-nephrotic proteinuria, leucocyturia and arterial hypertension, which were more frequent in the elderly. The prevalence of ATIN has increased in recent years, especially in patients aged >65 years. This could be due to an increase in drug-associated ATIN, which would justify early renal biopsy to identify ATIN and reduce the probability of progression to chronic kidney disease. Although, our data are not able to corroborate this fact.

Spontaneous remission of nephrotic syndrome in membranous nephropathy with chronic renal impairment

BACKGROUND Spontaneous remission (SR) of nephrotic syndrome, in the absence of immunosuppressive treatment, is relatively common among patients with idiopathic membranous nephropathy (IMN) and normal renal function. However, it has not been reported in patients with chronic renal impairment. METHODS All patients with IMN who had developed SR in the presence of chronic renal insufficiency were identified among the nephrology departments that belong to the Spanish Group for the Study of Glomerular Diseases (GLOSEN). Their characteristics and outcome after SR were studied. RESULTS Eleven patients were identified. All of them showed renal insufficiency and nephrotic syndrome at the time of renal biopsy. Serum creatinine (Scr) continued to increase in the following months, reaching a peak value of 2.6 ± 1.5 mg/dL (range 1.7-6.5). Angiotensin converting enzyme inhibitors or spironolactone were prescribed in 10/11 patients at renal biopsy or shortly after it. Nephrotic proteinuria persisted during the first months of follow-up, but it started to spontaneously decrease 12 ± 7 months (2-30 months) after renal biopsy. Finally, complete (nine patients) or partial (two patients) remission of nephrotic syndrome was observed. Coinciding with proteinuria remission, renal function tended to improve. Nephrotic syndrome relapsed in two patients, accompanied by a rapid deterioration of renal function. In the remaining nine patients, remission persisted throughout a follow-up of 146 ± 64 months. Mean Scr at the last visit was 1.9 ± 0.9 mg/dL and proteinuria 0.2 g/24 h. CONCLUSION SR of nephrotic syndrome can also be observed in membranous nephropathy patients exhibiting chronic renal impairment.

Decreasing incidence of AA amyloidosis in Spain.

The main objectives of our study were to review all cases of amyloidosis diagnosed by renal biopsy in Spain from 1994 to 2009 and to analyse variations in the incidence over time.

Mycophenolate as Induction Therapy in Lupus Nephritis with Renal Function Impairment

Background: Mycophenolate (MF) is effective as induction therapy for lupus nephritis (LN) in patients with normal renal function; however, little is known about its role in patients with impaired renal failure. The purpose of this study was to evaluate the response to MF in LN and its association with baseline renal function. Methods: Data were obtained for 90 patients from 12 Spanish renal units who were receiving MF as induction therapy for LN. Patients were classified into 2 groups: group 1 (estimated glomerular filtration rate [eGFR] ≥60 ml/min/1.73 m2) and group 2 (eGFR <60 ml/min/ 1.73 m2). The primary outcome measure was the percentage of patients who achieved any response and its relationship with initial eGFR. The secondary outcome measures were the percentage of patients who achieved a complete response (CR) or partial response (PR) and the appearance of relapses during treatment and side effects. Results: At initiation of MF treatment, there were no differences in the main parameters between group 1 (n = 63; eGFR 87 ± 23 ml/min/ 1.73 m2) and group 2 (n = 27; eGFR 44 ± 12 ml/min/1.73 m2). Exposure to prednisone and MF was similar. The percentages of patients who achieved a response in groups 1 and 2 were, respectively, 69.2 and 43.8% at 6 months and 81.3 and 73.7% at 12 months. CR was more frequent in group 1, whereas PR was similar in both groups. Four patients relapsed and side effects were unremarkable. Conclusions: MF is effective and safe as induction therapy for LN, and response is even achieved in patients with baseline renal impairment.

Risk factors for renal failure in patients with lupus nephritis: data from the spanish registry of glomerulonephritis.

Background: Lupus nephritis (LN) is a severe complication of systemic lupus erythematosus. Data from national registries based on renal biopsies are scarce. The aim of our study was to analyze the demographic characteristics, clinicopathological correlations, and risk factors associated with renal failure in patients with LN at the time of renal biopsy. Methods: We performed a cross-sectional observational study based on data from the Spanish Registry of Glomerulonephritis for the years 1994–2009. The outcome measure was the presence of renal failure (eGFR <60 ml/min/1.73 m2). We also recorded age, gender, proteinuria levels, hypertension, and histological class. Results: We collected 17,525 native renal biopsies, of which 1,648 biopsies showed LN lesions. In total, 609 patients (37%) showed renal failure at the time of renal biopsy. The univariate analysis showed that these patients were older, had higher levels of proteinuria, and a higher prevalence of hypertension than the group with eGFR ≥60 ml/min/ 1.73 m2. The histological class of LN was recorded for 566 patients, and multivariate logistic regression analysis showed that the independent risk factors for renal failure at the time of renal biopsy were age (OR 1.03; 95% CI 1.01–1.04), male gender (OR 1.94; 95% CI 1.12–3.10), hypertension (OR 3.18; 95% CI 2.16–4.67), proteinuria (OR 1.15; 95% CI 1.08–1.24), and histological classes III and IV (OR 1.82; 95% CI 1.16–2.87). Conclusions: Data from the Spanish Registry of Glomerulonephritis provide valuable information about risk factors for renal failure in patients with LN at the time of renal biopsy.

Crescentic glomerulonephritis: data from the Spanish Glomerulonephritis Registry.

Crescentic glomerulonephritis (CGN) is a histological finding that implies rapid deterioration of renal function and can be related to different diseases, such as type 1 or anti‐glomerular basement membrane antibody (Goodpasture) disease, type 2 or immune complex CGN and type 3 or pauci‐immune disease.

Mycophenolate as Maintenance Therapy for Lupus Nephritis with Impaired Renal Function

Background: Mycophenolate (MF) is effective as a maintenance therapy after induction therapy in patients with lupus nephritis (LN). However, little is known about its role in patients with impaired renal function. The purpose of this study was to evaluate the efficacy and safety of MF as a maintenance therapy for LN and its association with renal function. Methods: Data were obtained for 56 Spanish patients who were receiving MF as a maintenance therapy for LN. Patients were classified into two groups according to renal function at the initiation of MF treatment: group 1 [estimated glomerular filtration rate (eGFR) ≥60 ml/min/1.73 m2] and group 2 (eGFR <60 ml/min/1.73 m2). The primary endpoints of the study were the rates of renal relapse and responses, and their relationship with baseline renal function. Secondary outcomes were the appearance of side effects during treatment. Results: At initiation of MF treatment, the only differences between the groups were for age, hemoglobin levels, anti-DNA antibody titer, proteinuria, and renal function. In group 1 (n = 38), the eGFR was 98 ± 34 ml/min/1.73 m2 and in group 2 (n = 18) the eGFR was 43 ± 14 ml/min/1.73 m2. Only 3 cases had an eGFR <30 ml/min/1.73 m2. No significant differences were observed in the rate of relapse at 6 months (group 1: 20%; group 2: 23%) or at 12 months (group 1: 25%; group 2: 17%). Response rates were also similar in both groups. Side effects were unremarkable. Conclusions: MF is effective and safe as a maintenance therapy for LN both in patients with normal renal function and in those with renal impairment.