Unexpectedly high prevalence of rare genetic disorders in kidney transplant recipients with an unknown causal nephropathy.

BACKGROUND: Patients with a rare genetic disease may receive renal transplantation (KTx) without a correct diagnosis of causal nephropathy and therefore develop unexpected and even severe complications. The aim of the study was to describe the cases of rare genetic disorders diagnosed after KTx, in order to draw clinical lessons for the transplant physician. METHODS: We retrospectively assessed all patients who had received a diagnosis of a rare genetic disorder after KTx. RESULTS: In our center, more than 30% (278/911) of kidney transplant (KTx) recipients were diagnosed with a causal nephropathy: Prevalence of rare genetic disorders in this group was 4.32% (12/278), including 2,8-dihydroxyadeninuria (2,8-DHA) disease (n = 2), HNF-1B-associated nephropathy (n = 2), UMOD-related nephropathy (n = 5), Fabry disease (n = 1), INF2 focal segmental glomerulosclerosis (n = 1), and Senior-Løken syndrome (n = 1). 2,8-DHA nephropathy relapsed in both patients causing an acute renal failure and jeopardizing the graft. CONCLUSIONS: Kidney transplant recipients without a diagnosis of causal nephropathy appear to be a selected population in which rare genetic diseases might be more common than expected. As even a belated diagnosis after KTx can have a significant impact on graft and patient survival and on other family members, this possibility should be evaluated in KTx recipients without a known causal nephropathy.

A case of acute kidney injury due to ethylene glycol intoxication.

In this article we describe a case of acute kidney injury caused by ethylene glycol intoxication which partially reversed after temporary hemodialysis treatment. The diagnosis was obtained after the patient's clinical history and the finding of ethylene glycol in the blood, numerous intratubular crystals at renal biopsy, and the presence of large amounts of atypical - spindle-like and needle-like - calcium oxalate crystals in the urinary sediment.

Antiviral therapy for HCV-associated cryoglobulinemic glomerulonephritis: case report and review of the literature.

We describe the case of a 51-year-old woman with HCV-associated cryoglobulinemic glomerulonephritis (GN). She presented mild deterioration of kidney function, non-nephrotic proteinuria, and active urinary sediment. Kidney biopsy showed features of membranoproliferative changes with some sclerosis. Sustained viral response (SVR) was obtained by 6 months of antiviral therapy (peg-IFN-α2a plus ribavirin). SVR was linked with improvement of kidney function and remission of proteinuria. Clinical and virological remission persists over a 25-month follow-up. This case report emphasizes efficacy and safety of antiviral treatment of HCV-associated glomerulonephritis--preliminary but encouraging results exist. We identified by systematic review of the literature 9 studies (156 unique patients); the pooled estimate of frequency of sustained virological response after IFN-based therapy was 0.49 (95% confidence interval, CI: 0.21, 0.77; p < 0.0005; random effects model). Heterogeneity was found (I(2) = 98.9%, p < 0.0001). Two possible regimens should be considered for the treatment of HCV-associated cryoglobulinemic GN according to the clinical presentation. Immunosuppressive therapy is recommended for HCV-related kidney disease having aggressive course, and recent evidence supports rituximab (RTX) use with a reduced exposure to corticosteroids. We identified six studies (66 unique patients) on RTX therapy for HCV-associated kidney disease; at the end of RTX therapy, the pooled estimate of the mean decrease in proteinuria was 1.4 g/24 h (95% CI: 0.75, 2.05, p < 0.001); The p test for heterogeneity gave a value of 0.94 (I(2) = 0). Several questions related to RTX use remain. HCV-induced GN is uncommon among CKD patients of developed countries, and this clearly hampers prospective controlled clinical trials aimed to evaluate efficacy and safety of antiviral or immunosuppressive therapy in this population.

Spheroplasts, poorly known but clinically relevant particles of urinary sediment.

BACKGROUND: In two patients under treatment with various antibiotics, spheroplasts were detected with an automated urine sediment analyzer. METHODS: Urinalysis was performed by an AutionMAX AX 4030-sediMAX platform. RESULTS: Spheroplasts can be easily misclassified as yeasts or erythrocytes, but when automated urine sediment analyzers are used by well-trained, and experienced operators they can be correctly identified and classified. CONCLUSION: Appropriate training of urine laboratory professionals in spheroplast detection and association with UTI, together with timely communication with the microbiologist and caring clinician, will provide prompt targeted treatment.

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.

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.

Dental amalgam, mercury toxicity, and renal autoimmunity.

Chronic exposure to elemental metallic mercury may induce an immunological glomerular disease. Since humans are exposed to mercury vapor (Hg0) from dental amalgam restorations and kidney is an important target organ of mercury vapor and mercury deposition in kidney increases proportionally with the dose, our aim was to test the occurrence of specific antibodies to antiglomerular basement membrane (anti-GBM-IgG) among individuals with adverse effects to mercury from dental amalgam fillings. We selected a group of patients (n=24) with a history of long-term exposure to mercury vapor from mercury-containing amalgam fillings and showing adverse effects that were laboratory confirmed. Enzyme-linked immunosorbent assays (ELISAs) were used to evaluate serum levels of antibodies to anti-GBM-IgG. None of the patients showed evidence of anti-GBM autoimmunity, either in subgroups with strong allergy to mercury or its compounds (i.e., organic mercury) or in those patients who had past thimerosal-containing vaccines coverage (7 of 24). There was no evidence of the presence of circulating anti-GBM antibodies in subjects suffering from adverse events due to long-term exposure to mercury from dental amalgams, even in individuals who presented allergy to mercury.

[PHYSICAL, CHEMICAL AND MORPHOLOGICAL URINE EXAMINATION: RECOMMENDATIONS FOR THE POST ANALYTICAL PHASE FROM THE INTERDISCIPLINARY URINALYSIS GROUP (GIAU)].

With these recommendations the Interdisciplinary Urinalysis Group (GIAU) aims to stimulate the following aspects : improvement and standardization of the post analytical approach to physical, chemical and morphological urine examination (ECMU); emphasize the value added to ECMU by selection of clinically significant parameters, indication of analytical methods, of units of measurement, of reference values; improvement of interpretation of dip stick urinalysis with particular regard to the reconsideration of the diagnostic significance of the evaluated parameters together with an increasing awareness of the limits of sensitivity and specificity of this analytical method. Accompanied by the skills to propose and carry out in-depth investigations with analytical methods that are more sensitive and specific;increase the awareness of the importance of professional skills in the field of urinary morphology and their relationships with the clinicians. through the introduction, in the report, of descriptive and interpretative comments depending on the type of request, the complexity of the laboratory, the competence of the pathologist;implement a policy of evaluation of the analytical quality by using, in addition to traditional internal and external controls, a program for the evaluation of morphological competence. The hope is to revalue the enormous potential diagnostic of ECMU, implementing a urinalysis on personalized diagnostic needs that each patient brings with it.

[Physical, chemical and morphological urine examination guidelines for the Analytical Phase from the Intersociety Urinalysis Group]. / Esame fisico, chimico e morfologico delle urine proposta di linee guida per la fase analitica del Gruppo Intersocietario Analisi delle Urine (GIAU).

With these guidelines the Intersociety Urinalysis Group (GIAU) aims to stimulate the following aspects: Improvement and standardization of the analytical approach to physical, chemical and morphological urine examination (ECMU). Improvement of the chemical analysis of urine with particular regard to the reconsideration of the diagnostic significance of the parameters that are traditionally evaluated in dipstick analysis together with an increasing awareness of the limits of sensitivity and specificity of this analytical method. Increase the awareness of the importance of professional skills in the field of urinary morphology and the relationship with the clinicians. Implement a policy of evaluation of the analytical quality by using, in addition to traditional internal and external controls, a program for the evaluation of morphological competence. Stimulate the diagnostics industry to focus research efforts and development methodology and instrumental catering on the needs of clinical diagnosis. The hope is to revalue the enormous diagnostic potential of 'ECMU, implementing a urinalysis on personalized diagnostic needs for each patient. Emphasize the value added to ECMU by automated analyzers for the study of the morphology of the corpuscular fraction urine. The hope is to revalue the enormous potential diagnostic of 'ECMU, implementing a urinalysis on personalized diagnostic needs that each patient brings with it.

BK polyomavirus interstitial nephritis in a renal transplant patient with no previous acute rejection episodes.

A renal transplant patient treated with tacrolimus and mycophenolate-mofetil (MMF) developed progressive graft function deterioration 10 months after transplantation. Biopsy of the graft showed severe, focally accentuated interstitial inflammation with focal tubulitis and tubular necrosis, and medium-severe interstitial fibrosis with focal tubular atrophy. Glomerular and vascular structures were preserved. On careful examination, in some sections, tubular epithelial cells showed a definite increase with deformation of the nuclear shape, chromatin irregularities with peripheral dislocation and inclusion bodies. These cytopathic changes suggested polyoma virus infection ("decoy cells"). Subsequent screening of the urinary sediment confirmed the presence of many "decoy cells". Immunohistochemical analysis of the biopsy showed many tubular cells were strongly positive for the SV 40 antigen, specific for BK polyoma virus. A diagnosis of interstitial nephritis due to BK polyoma virus was made, though the coexistence of cellular rejection could not be excluded. At variance with previous reports, our patient had not had repeated episodes of rejection before biopsy or heavy immunosuppressive treatment, such as ALG, OKT3, after transplantation. This case shows that even in the absence of vigorous anti-rejection therapy an immunosuppressive regimen based on tacrolimus and MMF may involve the risk of BK polyoma virus- associated interstitial nephritis.

Remission of HCV-associated glomerulonephritis with pegylated ifn and ribavirin therapy after liver transplantation: case report and literature review.

BACKGROUND: Hepatitis C virus infection is associated with a variety of extrahepatic disorders such as membrano-proliferative glomerulonephritis, which is generally due to cryoglobulinemia. 
 SETTING: We describe the case of one liver transplant recipient who received antiviral therapy (subcutaneous administration of peg-IFN-alpha-2a 180 mcg weekly and oral ribavirin 200 mg thrice a day) for HCV-related membrano-proliferative glomerulonephritis. He presented normal kidney function, non-nephrotic proteinuria (2 g/24 h) and mild hematuria.
 RESULTS: Urinary abnormalities disappeared within a few weeks after the initiation of antiviral therapy; however, combination antiviral therapy was not able to obtain viral clearance. After 11 months, IFN-therapy was interrupted and the patient continued low-dose ribavirin monotherapy (200 mg once per day) for one additional year- remission of proteinuria (<0.3 g/24 h) and hematuria persisted with intact kidney function. Although other mechanisms cannot be excluded, we suggest that ribavirin therapy was critically implicated in the remission of urinary abnormalities in our patient. The existing literature on the association between HCV-associated glomerulonephritis and therapy with ribavirin is reviewed. 
 CONCLUSIONS: Antiviral therapy may be effective in patients with HCV-induced glomerulonephritis. Further evidence is needed to evaluate efficacy and safety of ribavirin monotherapy for HCV-related glomerulonephritis.

Adenine phosphoribosyltransferase deficiency: an underdiagnosed cause of lithiasis and renal failure.

We describe an infant affected by adenine phosphoribosyltransferase (APRT) deficiency diagnosed at 18 months of age with a de novo mutation that has not been previously reported. APRT deficiency is a rare defect of uric acid catabolism that leads to the accumulation of 2,8 dihydroxyadenine (2,8-DHA), a highly insoluble substance excreted by the kidneys that may precipitate in urine and form stones. The child suffered from renal colic due to a stone found in the peno-scrotal junction of the bulbar urethra. Stone spectrophotometric analysis allowed us to diagnose the disease and start kidney-saving therapy in order to avoid irreversible chronic kidney damage. APRT deficiency should always be considered in the differential diagnosis of pediatric urolithiasis.

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.

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, >or=40% dysmorphic erythrocytes alone were seen in seven samples (12.7%), >or=5% acanthocytes alone in 15 samples (27.3%) and erythrocytic casts in six samples (10.9%). There was >or=40% dysmorphic erythrocytes associated with >or=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 >or=40% dysmorphic erythrocytes, 69.4% and 85% for >or=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.