Giovanni B. Fogazzi

Corticosteroid Effectiveness in IgA Nephropathy: Long-Term Results of a Randomized, Controlled Trial

Proteinuria plays a causal role in the progression of IgA nephropathy (IgAN). A previous controlled trial showed that steroids are effective in reducing proteinuria and preserving renal function in patients with IgAN. The objective of this study was to evaluate the long-term effectiveness of steroids in IgAN, examine the trend of proteinuria during follow-up (starting from the hypothesis that the degree of reduction in proteinuria may influence IgAN outcome), and evaluate how histologic scores can influence steroid response. A secondary analysis of a multicenter, randomized, controlled trial of 86 adult IgAN patients who were receiving supportive therapy or intravenous methylprednisolone plus oral prednisone for 6 mo was conducted. Ten-year renal survival was significantly better in the steroid than in the control group (97% versus 53%; log rank test P = 0.0003). In the 72 patients who did not reach the end point (doubling in baseline serum creatinine), median proteinuria significantly decreased (1.9 g/24 h at baseline, 1.1 g/24 h after 6 mo, and 0.6 g/24 h after a median of 7 yr). In the 14 progressive patients, proteinuria increased from a median of 1.7 g/24 h at baseline to 2.0 g/24 h after 6 mo and 3.3 g/24 h after a median of 5 yr. Steroids were effective in every histologic class. Cox multivariate regression analyses showed that, in addition to steroids, a low baseline histologic score, a reduction in proteinuria after 6 mo, and no increase in proteinuria during follow-up all were independent predictors of a beneficial outcome. Steroids significantly reduce proteinuria and protect against renal function deterioration in IgAN. The histologic picture and proteinuria during early and late follow-up improve the prediction of outcome, but considerable variability remains outside the model.

Autosomal dominant Alport syndrome: molecular analysis of the COL4A4 gene and clinical outcome

BACKGROUND Alport syndrome is a clinically and genetically heterogeneous nephropathy characterized by glomerular basement membrane lesions often associated with hearing loss and ocular anomalies. While the X-linked and the autosomal recessive forms are well known, the autosomal dominant form is not well acknowledged. METHODS We have clinically investigated 38 patients with a diagnosis of autosomal dominant Alport syndrome belonging to eight different families. The analysis of the COL4A4 gene was performed by denaturing high performance liquid chromatography and automated DNA sequencing. RESULTS In our cohort of patients, only 24.3% (9/37) reached end-stage renal disease, at the mean age of 51.2 years. Four patients had hearing loss (13.3%) and none ocular changes. Molecular analysis revealed eight novel private COL4A4 gene mutations: three frameshift, three missense and two splice-site mutations. CONCLUSIONS These data indicate autosomal dominant Alport syndrome as a disease with a low risk of ocular and hearing anomalies but with a significant risk to develop renal failure although at an older age than the X-linked form. We were unable to demonstrate a genotype-phenotype correlation. Altogether, these data make difficult the differential diagnosis with the benign familial haematuria due to heterozygous mutations of COL4A4 and COL4A3, especially in young patients, and with the X-linked form of Alport syndrome in families where only females are affected. A correct diagnosis and prognosis is based on a comprehensive clinical investigation in as many family members as possible associated with a broadly formal genetic analysis of the pedigree.

Urine sediment analysis: Analytical and diagnostic performance of sediMAX® — A new automated microscopy image-based urine sediment analyser

BACKGROUND We evaluated the analytical and diagnostic performance of sediMAX (77 Elektronika, Budapest, Hungary), a new automated microscopy image-based urine sediment analyser (which in some countries is also called Urised) in comparison with visual phase-contrast microscopy. METHODS Precision, linearity, carry-over and method comparison were carried out according to well-established guidelines. The diagnostic performance with respect to visual phase-contrast microscopy was evaluated with results from two centres (n(1)=910, n(2)=1233). Uncentrifuged urine samples were used in visual microscopy in centre 1, while urine sediments were used in centre 2. RESULTS Within-run precision for RBC was 17.8% and 6.7% at 18xE6 RBC/L and 447xE6 RBC/L respectively and for WBC it was 17% and 4.4% at 4xE6 WBC/L and 258xE6/L respectively. Between-run imprecision for RBC was 14.7% for 30xE6/L and 7.2% for 283xE6/L. For WBC it was 5.4% at 25xE6/L and 3% at 166xE6/L. In both studies areas under ROC curves (AUC) were 80-90% for RBC, WBC, squamous epithelial cells, yeast and calcium-oxalate crystals. For non-squamous epithelial cells and pathological and hyaline casts the AUC ranged 73-74%. There was no carry-over. CONCLUSIONS The sediMAX is well able to count and identify RBC, WBC, squamous epithelial cells, yeast, bacteria and calcium-oxalate crystals. Recognition of pathological casts and non-squamous epithelial cells is adequate but needs to be improved.

Urinalysis: Core Curriculum 2008

Urinalysis is one of the most ancient and basic ests to evaluate the presence, severity, and course f diseases of the kidney and urinary tract. Thereore, when a patient is first seen by a nephroloist, a complete basic investigation of the urine hould always be requested. In most instances, this is done by means of ipstick, a widely accepted method for screening urposes because of its quick, simple, and inexensive use. However, clinicians too often are naware of the principles and limits of this pproach, which allows one to detect and obtain n approximate estimation of concentrations of a umber of analytes, including albumin, blood, eukocytes, and bacteria. Clinicians, and nephrologists among them, lso often are unaware of the valuable informaion that can be obtained with examination of rinary sediment. Today, this usually is perormed in central laboratories, where too many amples are analyzed every day (several hunreds in many situations), far from the bedside of he patient, and without the correct methods, quipment, and professional qualification. It is our firm belief that nephrologists should egain possession of the examination of the urine ediments of their patients. This would result in ore correct diagnoses, as shown by a recent tudy in which examination of the urine of 26 atients with acute renal failure carried out by he personnel of clinical laboratories missed sigificant particles (renal tubular epithelial cells RTECs] and various types of casts) that were dentified correctly by trained nephrologists.

IgA nephropathy with severe chronic renal failure: a randomized controlled trial of corticosteroids and azathioprine.

BACKGROUND Therapeutic nihilism is common in IgA nephropathy (IgAN) and renal insufficiency. METHODS In a randomized controlled trial comparing steroids alone or combined with azathioprine in 253 IgAN patients, we used a separate randomization list for patients with creatinine >2.0 mg/dL. Twenty patients (group 1) were randomized to 3 intravenous pulses of methylprednisolone 1 g at months 1, 3 and 5, and oral prednisone 0.5 mg/kg every other day plus azathioprine 1.5 mg/kg/day for 6 months, followed by oral prednisone 0.2 mg/kg every other day plus azathioprine 50 mg/day for a further 6 months; 26 patients (group 2) received steroids alone. The primary outcome was renal survival (50% increase in plasma creatinine from baseline); secondary outcomes were proteinuria over time and adverse events. RESULTS Six-year renal survival was not different between the 2 groups (50% vs. 57%; log-rank p=0.34). Median proteinuria decreased during follow-up in the whole population (from 2.45 g/day [interquartile range (IQR) 1.50-3.78] to 1.09 g/day [IQR 0.56- 2.46]; p<0.001), with no between-group difference. Multivariate predictors associated with renal survival were sex of patient, proteinuria during follow-up, number of antihypertensive drugs, angiotensin-converting enzyme inhibitors and treatment including azathioprine. Six patients in group 1 (30%) and 4 in group 2 (15%) did not complete the therapy, because of side effects (p=0.406). CONCLUSIONS Six-year renal survival was similar in the 2 groups. At Cox analysis the addition of azathioprine may be slightly more effective than corticosteroids alone in patients with chronic renal insufficiency, although with an increase of side effects.

Towards European urinalysis guidelines: Introduction of a project under European Confederation of Laboratory Medicine

Improved standardized performance is needed because urinalysis continues to be one of the most frequently requested laboratory tests. Since 1997, the European Confederation of Laboratory Medicine (ECLM) has been supporting an interdisciplinary project aiming to produce European urinalysis guidelines. More than seventy clinical chemists, microbiologists and ward-based clinicians, as well as representatives of manufacturers are taking part. These guidelines aim to improve the quality and consistency of chemical urinalysis, particle counting and bacterial culture by suggesting optimal investigative processes that could be applied in Europe. The approach is based on medical needs for urinalysis. The importance of the pre-analytical stage for total quality is stressed by detailed illustrative advice for specimen collection. Attention is also given to emerging automated technology. For cost containment reasons, both optimum (ideal) procedures and minimum analytical approaches are suggested. Since urinalysis mostly lacks genuine reference methods (primary reference measurement procedures; Level 4), a novel classification of the methods is proposed: comparison measurement procedures (Level 3), quantitative routine procedures (Level 2), and ordinal scale examinations (Level 1). Stepwise strategies are suggested to save costs, applying different rules for general and specific patient populations. New analytical quality specifications have been created. After a consultation period, the final written text will be published in full as a separate document.

Crystalluria: prevalence, different types of crystals and the role of infrared spectroscopy.

Abstract Background: Studies on the frequency of the different types of urinary crystals and the role of Fourier transform infrared microspectroscopy (FTIRM) for identification are few. We describe the results of a retrospective study on the prevalence and typology of crystalluria and on the role of FTIRM. Methods: Urinary crystals were identified using the combined knowledge of crystal morphology, birefringence features and urine pH (combined approach). When this was inconclusive, FTIRM was performed. Results: Crystalluria was found in 807 out of 9834 samples (8.2%). In 793, the combined approach identified “typical” crystals, while in 14 FTIRM was needed to identify “atypical” crystals. Among “typical crystals”, calcium oxalate (75.9%), uric acid (25.9%) and amorphous urates (7.9%), alone or in combination, were the most frequent. Brushite, ammonium biurate and cystine were the most rare (0.1%–0.7%). FTIRM identified 12 of 14 atypical crystals: three crystals were due to a drug (amoxicillin, indinavir, doubtful phenytoloxamine); four were due to calcium oxalate mono- or bihydrate, uric acid bihydrate or struvite; five were due to calcium carbonate, Tamm-Horsfall glycoprotein, or rare salt combinations. Conclusions: Crystalluria is not rare and most crystals can be identified by the combined approach. Occasionally, identification of crystals will require FTIRM.

Urine erythrocyte morphology in patients with microscopic haematuria caused by a glomerulopathy

The evaluation of urinary erythrocyte morphology (UEM) has been proposed for patients with isolated microscopic haematuria (IMH) to early orientate the diagnosis towards a glomerular or a nonglomerular disease. However, to date, the role of this test in patients with IMH has very rarely been investigated. Sixteen patients (ten children, six adults) with persistent IMH classified as glomerular on the basis of repeated UEM evaluations (55 urine samples, two to eight per patient) were submitted to renal biopsy. This showed a glomerular disease in 14/16 patients (87.5%) (nine thin basement membrane disease; three Alport syndrome; two other), whereas in two patients, no abnormalities were found. Of four microscopic criteria investigated to define a IMH as glomerular, >80% dysmorphic erythrocytes were not found in any sample, ≥40% dysmorphic erythrocytes alone were seen in seven samples (12.7%), ≥5% acanthocytes alone in 15 samples (27.3%) and erythrocytic casts in six samples (10.9%). There was ≥40% dysmorphic erythrocytes associated with ≥5% acanthocytes in 25 samples (45.5%). Sensitivity and positive predictive values in diagnosing a glomerular haematuria were 59.2% and 90.6%, respectively, for ≥40% dysmorphic erythrocytes, 69.4% and 85% for ≥5% acanthocytes/G1 cells and 12.2% and 100% for erythrocytic casts. Our findings demonstrate that the evaluation of UEM is useful to identify patients with an IMH of glomerular origin.

Decreased Kidney Function and Crystal Deposition in the Tubules After Kidney Transplant

Adenine phosphoribosyltransferase (APRT) deficiency is an autosomal recessive purine enzyme defect that results in the inability to utilize adenine, which consequently is oxidized by xanthine dehydrogenase to 2,8-dihydroxyadenine (2,8-DHA), an extremely insoluble substance eventually leading to crystalluria, nephrolithiasis, and kidney injury. We describe a case of APRT deficiency not diagnosed until the evaluation of a poorly functioning kidney transplant in a 67-year-old white woman. After the transplant, there was delayed transplant function, urine specimens showed crystals with unusual appearance, and the transplant biopsy specimen showed intratubular obstruction by crystals identified as 2,8-DHA using infrared spectroscopy. APRT enzymatic activity was undetectable in red blood cell lysates, and analysis of the APRT gene showed 1 heterozygous sequence variant, a duplication of T at position 1832. The patient was treated with allopurinol, 300 mg/d, and transplant function progressively normalized. Because patients with undiagnosed APRT deficiency who undergo kidney transplant may risk losing the transplant because of an otherwise treatable disease, increased physician awareness may hasten the diagnosis and limit the morbidity associated with this disease.

Urinary Sediment Findings in Acute Interstitial Nephritis

RESEARCH LETTERS Urinary Sediment Findings in Acute Interstitial Nephritis To the Editor: Acute interstitial nephritis (AIN) is a condition characterized by acute kidney injury associated with acute cellular infiltrate of the renal interstitium due to various causes. Published data for urinary sediment findings in AIN are few. In this case series, we describe detailed findings observed in 21 patients with biopsy-proven AIN due to different causes. We reviewed all reports of biopsies performed on native kidneys at our institution during a 14-year period (January 1, 1997, to February 1, 2011) and identified AIN cases. All patients with AIN were considered for inclusion. All microscopic slides arising from these kidney biopsies were reviewed by 2 of us for the presence or absence of interstitial cellular infiltrate, tubulitis, tubular necrosis, tubular basement membrane gaps, interstitial red blood cell (RBC) extravasation, RBCs, and intratubular RBC casts. Of 839 kidney biopsies, 23 (2.7%) were found to have AIN in the absence of significant glomerular lesions. We included 21 patients (Table 1), having excluded one because of bacteria (2 ) in the urinary sediment and another for focal glomerular immunoglobulin A and C3 by immunofluorescence (which was negative at the glomerular level in all other cases).