Early markers of Fabry disease revealed by proteomics.

Fabry disease (FD) is an X-linked lysosomal storage disorder caused by a deficiency of the lysosomal hydrolase α-galactosidase A (α-GalA) that leads to the intra-lysosomal accumulation of globotriaosylceramide (Gb3) in various organ systems. As a consequence, a multisystems disorder develops, culminating in stroke, progressive renal and cardiac dysfunction. Enzyme replacement therapy (ERT) offers a specific treatment for patients affected by FD, though the monitoring of treatment is hindered by a lack of surrogate markers of response. Remarkably, due to the high heterogeneity of the Fabry phenotype, both diagnostic testing and treatment decisions are more challenging in females than in males; thus, reliable biomarkers for Fabry disease are needed, particularly for female patients. Here, we use a proteomic approach for the identification of disease-associated markers that can be used for the early diagnosis of FD as well as for monitoring the effectiveness of ERT. Our data show that the urinary proteome of Fabry naïve patients is different from that of normal subjects. In addition, biological pathways mainly affected by FD are related to immune response, inflammation, and energetic metabolism. In particular, the up-regulation of uromodulin, prostaglandin H2 d-isomerase and prosaposin in the urine of FD patients was demonstrated; these proteins might be involved in kidney damage at the tubular level, inflammation and immune response. Furthermore, comparing the expression of these proteins in Fabry patients before and after ERT treatment, a decrease of their concentration was observed, thus demonstrating the correlation between the identified markers and the effectiveness of the pharmacological treatment.

Ultrastructural study of renal involvement in two females with Anderson-Fabry disease.

Anderson-Fabry disease (AFD) is a rare X-linked lipid storage disorder due to a deficient lysosomal a-galactosidase A (a-Gal) activity. In males with the classic form of the disease the enzymatic defect leads to progressive accumulation of glycosphingolipids (GL) in different organs, mainly in the kidney, heart, and brain, causing severe multisystem failure. AFD is usually mild in heterozygous females, but severe cerebrovascular, renal, and cardiac manifestations have been rarely described. The aim of this study is to describe renal involvement of mild symptomatic female carriers by ultrastructural analysis focusing to microvascular lesions, considered to be one of the major causes of systemic disease in AFD. Resin-embedded renal biopsies from 2 sisters with isolated mild proteinuria and belonging to a family group with AFD were observed by light and electron microscopy. In spite of the mild clinical symptoms, diffuse GL storages were demonstrated in all types of glomerular cells and in interstitial endothelial cells. Moreover, platelets were frequently observed in glomerular vassels, a feature coherent with a possible role of prothrombotic state, and platelet activation, in early glomerular lesions.

[Acute kidney failure in the patient with multiple myeloma. An analysis of the authors' personal cases]. / L'insufficienza renale acuta del paziente con mieloma multiplo. Analisi di una casistica personale.

The renal involvement in a multiple myeloma case (MM) has a frequency of 50% and causes a worsening of the disease with a survival average of about 12 months. Myeloma cast nephropathy (MCN) represents the more frequent clinic, histological form of nephropathy in course of MM and it evolves when monoclonal light free chain deposit in the renal tubules together with some other worse cases like dehydration and/or hypercalcaemia. We analyze here the clinical and renal histological features of eight patients treated for acute renal failure found in MCN in course of MM grade B. This was discovered through renal bioptic check-up. We have evaluated the Bence-Jones proteinuria, the recurrence of the condition of risk and the course of the renal failure of these patients also in order to treat the hematological illness.

Lack of IgA antineutrophil cytoplasmic antibodies in Henoch-Schönlein purpura and IgA nephropathy.

To verify whether IgA antineutrophil cytoplasmic antibody (ANCA) represents a serologic marker in Henoch-Schönlein purpura (HPS), we examined sera from 41 patients with the disease. Control sera from 28 patients with primary IgA nephropathy (IgA-N), 26 IgG-ANCA-positive vasculitis, and 28 normal controls were also studied. An increased IgA binding to neutrophil cytoplasmic extracts but not to purified ANCA antigens was found in 12.2-14.6% of HSP patients and in 14.3-21.4% of IgA-N patients versus 3.5% of normal controls. IgA binding to neutrophil cytoplasmic extracts correlated with serum IgA levels, IgA-rheumatoid factor, and IgA-fibronectin binding capacity. Moreover, low amounts of IgG and fibronectin were detected as contaminants in neutrophil cytoplasmic extracts and fibronectin could partly inhibit the binding of IgA to "crude" extracts. We conclude that IgA-ANCA are neither diagnostically nor immunologically specific in HSP and IgA-N. Several factors present in the sera of patients with IgA-related nephropathies seem to contribute to the "false-positive" IgA-ANCA demonstrable in these patients.

[The kidney in multiple myeloma. The physiopathological and clinical aspects]. / Il rene nel mieloma multiplo. Aspetti fisio-patologici e clinici.

The renal concern in a multiple myeloma (MM) case has a frequency of 50% and causes a worsening of the disease with a survival average of about 12 months. The monoclonal light free chains (CLL) produced in excess by the plasmacytes are present in the urine as proteinuria of Bence Jones (PBJ) in 60-70% of patients affected by MM. They represent the major pathogenetic factor of the nephropathy in course of MM as they can deposit in shape of intratubular "casts" in the myeloma casts nephropathy (MCN). In some worse cases, dehydration or hypercalcaemia can cause an irreversible acute renal insufficiency (RI). It is therefore important in a patient affected with MM with PBJ to prevent, locate and opportunely treat these situations which worsen the nephropathy. Beside the tubular cast nephropathy, the CLL "accumulate" in the kidney even though with a lower frequency compared to MCN, in the light chains deposition disease (LCDD) and in the amyloidosis AL (AL). LCDD is characterized by a deposit of nodular amorphous materials PAS positive in the glomerulus and sometimes even in the tubulus. It usually presents itself as a chronic RI and a proteinuria causing nephrotic syndrome (NS). This quickly evolves into uraemia and its evolution can be lessened by the MM treatment. AL in course of MM also reveals with a chronic RI and NS. CLLs deposit in the typical fibrillar structure, on the vessel walls, in the glomerulus, in the mesangium and can be marked out with the Congo red colouring and the subsequent green birefringence through microscope with polarized light. Prognosis of AL is extremely severe and no benefit is given by the treatment of the hematological illness. It is therefore absolutely necessary to study the renal histology through biopsy when MM is grade B, that is, with serumal creatinine above 2 mg/dl as: MCN imposes the MM treatment programme in order to reduce the tubular excess of PBJ and to attempt to make RI reversible; MCN with tubular atrophy and interstitial fibrosis results in an unfavourable prognosis as it expresses a nephropathic irreversibility due to the loss nephrons. It will therefore necessary to start on a renal substitutional treatment programme. Renal damage in course of MM is not always tubular, rather an unexpected glomerular damage of LCDD or amyloidosis AL type can be found.(ABSTRACT TRUNCATED AT 400 WORDS)

Clinical significance of antineutrophil cytoplasmic autoantibodies with specificity for lactoferrin in renal diseases.

The prevalence and clinical significance of antineutrophil cytoplasmic antibodies with specificity for lactoferrin was determined in patients with renal diseases. Antilactoferrin antibodies were found in only 12 of 920 patients (1.3%). These patients had either "pauci-immune" necrotizing crescentic glomerulonephritis (three cases) or lupus nephritis (nine cases). To verify whether antilactoferrin antibodies were specific for patients with systemic lupus erythematosus (SLE) and renal involvement, we studied 61 additional lupus patients, 40 with active lupus nephritis and 21 with active SLE and no renal involvement. Antilactoferrin antibodies were found in approximately 15% to 20% of patients with SLE, irrespective of the presence of renal involvement. We conclude that antineutrophil cytoplasmic antibodies with specificity for lactoferrin are only sporadically found in patients with renal diseases; these patients have either necrotizing crescentic glomerulonephritis or lupus nephritis. However, antilactoferrin antibodies are not a marker for renal involvement in SLE.

A new catheter for peritoneal dialysis (two years of experience with Valli catheter).

The authors analyze the experience of more than 2 yrs of peritoneal dialysis with a new type of catheter. The catheter proposed allows higher flow rates and the maximum outflow of fluid even if malpositioned. The possibility of migration of the catheter is also reduced. The main new feature of this catheter consists in a perforated silastic balloon which protects the distal end of a standard Tenckhoff catheter.