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Biomedical subjects

A Vizjak

Publications and source records attributed to A Vizjak.

At least 19 recordsLinked to original sources

Follow-up of kidney graft recipients with cyclosporine-associated hemolytic-uremic syndrome and thrombotic microangiopathy.

The study was based on 462 patients who underwent kidney transplantation from 1986 through 2004. Cyclosporine (CsA)-related thrombotic microangiopathy (TMA) was observed in 15 (3.3%) patients. The donor ages ranged from 9 to 51 years and cold ischemia times from 12 to 31 hours. Hemolytic-uremic syndrome (HUS) developed 2 weeks after transplantation in 14 patients and later in 1 subject. Histopathologic examination demonstrated glomerular-type TMA in 3 patients, a mixed type (glomerular and vascular) in 11 patients, and a nonspecific mesangial widening with tubulointerstitial lesions in 1 patient. Follow-up biopsies revealed resolution of TMA in 4 patients and chronic vascular TMA in 1 patient. Six patients with mixed-type TMA needed transient hemodialysis. No patient with the glomerular-type TMA needed dialysis (P = .103), and 14 of 15 had good resolution of graft function after CsA dose reduction or temporary discontinuation or continuation of optimal dose. Only 1 graft with mixed-type TMA was lost due to irreversible HUS. The mean glomerular filtration rate (GFR), predicted by the Nankivell equation, was 76 +/- 13 mL/min and 80 +/- 27 mL/min at 1 month after discharge for glomerular- and mixed-type TMA, respectively (P > .05). GFRs 1 year after HUS were 82 +/- 12 and 87 +/- 21 mL/min for the glomerular and the mixed types, respectively (P > .05). We concluded that the mixed-type TMA was associated with a more severe early clinical course than the glomerular-type TMA. The 1-year prognosis was good in the majority of patients, with no significant differences between those with the glomerular- and mixed-type TMA.

Adolescent↗

Xanthogranulomatous pyelonephritis in nonfunctioning transplanted kidney.

Xanthogranulomatous pyelonephritis in native and allografted kidneys is a rare variant of severe chronic infection of the renal parenchyma. In a native kidney the diagnosis may sometimes be established by ultrasonography and computed tomography. In the renal allograft, the diagnosis could only be established by histologic evaluation of the transplant biopsy or nephrectomy. The reported case presents a febrile patient with a failing renal graft, in whom xanthogranulomatous pyelonephritis was established by histologic evaluation of transplantectomy specimens. Xanthogranulomatous pyelonephritis should therefore be included in the list of possible etiologies of the fever in patient with nonfunctioning transplanted kidney.

Cadaver↗

Antineutrophil cytoplasmic autoantibodies-antigen specificity and associated diseases.

Antineutrophil cytoplasmic antibodies (ANCA) are widely used as a useful diagnostic marker for small vessel vasculitides, although the test may occasionally be positive in various other conditions. The aim of this study was to assess ANCA in various clinical-pathological settings. ANCA were tested by indirect immunofluorescence and enzyme-linked immunosorbent assay and were found to be positive in 423 patients in the period from 1989-1999. Patients were grouped in accordance with their clinical-pathological setting as follows: 1. pauci-immune vasculitis confirmed by biopsy (n = 151), 2. clinically suspected vasculitis (n = 59), 3. inflammatory bowel diseases and autoimmune hepato-biliary disorders (n = 83), and 4. miscellaneous diseases (n = 130). The association of proteinase 3 ANCA with Wegener's granulomatosis (45/56) and myeloperoxidase ANCA with microscopic polyangiltis (45/54) and pauci-immune necrotising glomerulonephritis (24/28) was established. However, ANCA with other specificities were also shown to be present in these forms of vasculitides. ANCA, specific mostly for myeloperoxidase but also for other or unknown ANCA antigens, frequently revealing atypical immunofluorescence patterns, were characteristically found in other diseases. The titres of ANCA were significantly higher (p < 0.05) in patients with pauci-immune vasculitis than in those with clinically suspected vasculitis and other diseases. In conclusion, well standardised techniques for ANCA testing in conjunction with the clinical picture and histopathologic findings, if available, may significantly contribute to the diagnosis of small vessel vasculitides.

Antibodies, Antineutrophil Cytoplasmic↗

ANCA-associated vasculitis--an autopsy study.

The purpose of the study was to analyse the autopsies of 31 patients (20 female, mean age 67 years, range 28-87 years; and 11 male, mean age 66 years, range 47-80 years) with antineutrophil cytoplasmic antibodies (ANCA)-positive vasculitis, which was clinically confirmed in 25 patients and suspected in 6 patients, who had been treated and had died between 1989 and 1999. Kidney biopsy was performed in 22 patients on average 33 months (range, 1-132 months) prior to death. Biopsy and autopsy tissue specimens were examined by standard light and immunofluorescence microscopy techniques. Pauci-immune extracapillary glomerulonephritis was found in nearly the same percentage of 22 renal biopsies and 31 autopsies, namely in 91% and 84%, respectively. Active necrotising extracapillary glomerulonephritis was the prevailing lesion in 75% of biopsies, while advanced sclerosing glomerular lesions prevailed in 69% of autopsies. In the biopsies, necrotising lesions predominated in patients with ANCA of proteinase 3 specificity, while sclerotic lesions were more often associated with myeloperoxidase-ANCA. In the autopsies, florid necrotising systemic vasculitis coexisted in 2 patients with advanced sclerosing glomerulonephritis. Autopsies revealed the actual expansion of vasculitic disease, disclosed clinically silent vasculitic involvement of unusual locations and, in 3 patients, confirmed the clinically suspected vasculitis. The final diagnoses in 31 patients were as follows: Wegener's granulomatosis (5 men, 2 women), microscopic polyangitis (10 women, 2 men), pauci-immune crescentic glomerulonephritis (4 women, 3 men), a single case each of polyarteritis nodosa and isolated cutaneous vasculitis. In 3 patients, suspected vasculitis was not confirmed at autopsy. Nineteen of 31 patients died from septic infections or necrotising pneumonias, and 6 patients from progressive or recurrent vasculitis with complications, altogether nearly 80%. Cardiovascular failure, including pulmonary thrombembolism, caused death in 6 patients.

Adult↗

Correlation among WHO classes, histomorphologic patterns of glomerulonephritis and glomerular immune deposits in SLE.

In addition to the conventional World Health Organization (WHO) classification of lupus glomerulonephritis (GN), various concomitant approaches have been introduced in the evaluation of renal biopsies of patients with systemic lupus erythematosus (SLE) in order to increase the impact of biopsies on the decision concerning the most appropriate therapy as well as for establishing the prognosis. Three hundred and seventy kidney tissue samples from 267 SLE patients were analysed using standardised light, electron and immunofluorescence microscopic techniques. In 155 patients, a comparative clinical follow-up study and statistical analysis were performed. The study highlighted the heterogeneity of WHO classes IV and III, which include 5 and 6 different conventional histomorphologic types of GN, respectively. Mixed membranous and proliferative GN associated with "full-house" mesangial-transmembranous immune deposits, demonstrated in more than one third of our SLE cases, appears to be diagnostically most characteristic. Immune deposits distributed in the glomeruli in five different patterns, obviously play a major role in the pathogenesis of various WHO classes and histomorphologic types of lupus GN. Additional mechanisms related to the occurrence of antiphospholipid antibodies and antineutrophil cytoplasmic antibodies are suggested to contribute to the histomorphologic heterogeneity of WHO class III and IV lupus GN, particularly to the development of thrombotic, necrotising and crescentic glomerular lesions. In the present study, a statistically significant association was demonstrated between increasing mean values of the activity index and glomerular deposit distribution patterns labeled by subendothelial deposits. Furthermore, a significant correlation was established between an increasing risk of developing renal failure and increasing mean values of the chronicity index. Differences in the increasing risk of developing renal failure between groups with different histomorphologic types of GN and different immune deposit distribution patterns were not statistically significant. The surprisingly high renal survival rate of more than 80% noted in lupus patients with predominantly necrotising crescentic GN during the mean follow-up period of 40 months appears to be related to the more aggressive treatment of those patients. Our study confirmed a significant role of the WHO classification of lupus GN in the decision concerning the most appropriate treatment and prognostication. An increasing risk of irreversible renal failure in patients with WHO class IV lesions in contrast to those of WHO class III and in contrast to those of the category incorporating all other WHO classes was shown to be statistically significant.

Adolescent↗

Tubulo-interstitial involvement in lupus nephritis with emphasis on pathogenesis.

Glomerular lesions in lupus nephritis have been extensively studied in recent decades, but much less attention has been paid to the tubulo-interstitial compartment. The aim of this study was to contribute to the understanding of the pathogenesis of tubulo-interstitial lesions in lupus nephritis by analysing their incidence, character, and their associations. One hundred and ninety kidney biopsies of 190 patients fulfilling American Rheumatology Association (ARA) criteria of systemic lupus erythematosus (SLE) were examined by traditional light, immunofluorescence and electron microscopy. Interstitial inflammatory infiltration and tubulo-interstitial immune deposits concurred in 72 cases (37.9%). Their frequency was the highest in WHO class IV lupus glomerulonephritis. By multivariate analysis, the intensity of interstitial inflammatory infiltration correlated best with the percentage of renal corpuscules with extracapillary crescents and the extent of interstitial fibrosis. On immunohistochemical assessment, the inflammatory infiltrate was found to be composed of CD45RO positive T lymphocytes (191.3/mm2), CD68 positive macrophages (101.7/mm2) and CD45RA positive B lymphocytes (17.2/mm2). For all cell types the median value was higher in cases with extracapillary crescents, and did not correlate with presence and intensity of tubulo-interstitial immune deposits. Infiltration showed the tendency of periglomerular distribution, especially around glomeruli showing extracapillary proliferation and destruction of the capsular basal membrane. Rare S100 positive cells were only found in the interstitium. Tubulo-interstitial lesions estimated semiquantitatively correlated with the degree of proteinuria. Our findings suggest that tubulo-interstitial deposits do not play a major role in the pathogenesis of tubulo-interstitial lesions. The formation of interstitial cell infiltrates appears to be greatly influenced by the development of extracapillary crescents, perhaps by direct transmission of the severe inflammatory process to the adjacent interstitium. The composition of the infiltrate, including antigen presenting cells may signalize an additional involvement of cell-mediated immune mechanisms acting against so far hypothetical tubular epithelial neoantigens.

Adult↗

Small vessel thrombosis without major thrombotic events in systemic lupus erythematosus patients with antiphospholipid syndrome.

Antiphospholipid syndrome has been defined by the presence of antiphospholipid antibodies or lupus anticoagulant in association with certain clinical events, including recurrent arterial or venous thromboses and recurrent fetal loss. It comprises two separate clinical entities: simple, characterized by large vessel occlusions, and catastrophic, with multiple occlusive events predominantly affecting small vessels. Three patients with systemic lupus erythematosus and permanently increased IgG anticardiolipin antibody levels are being described. Only postmortem histopathological examination revealed microangiopathic thrombotic changes in different organs, which were clinically silent in early stages of the disease and misinterpreted later in its course because of a peculiar clinical picture. All patients presented features of catastrophic antiphospholipid syndrome in the final stage of the disease.

Adolescent↗

The significance of histologic analysis of skin lesions in porphyria cutanea tarda. Light microscopy, electron microscopy, immunohistochemical and immunofluorescence analysis.

Porphyria cutanea tarda (PCT) is one of several entities in the differential diagnosis of scleroderma. We report a 62-year-old man with PCT diagnosed since two decades. Clinical data and the results of light microscopy, immunohistochemistry, immunofluorescence and electron microscopy of skin biopsies are presented. The biopsy revealed sclerosis of the dermis mainly due to increased collagens I and III, and accumulation of collagen IV, which had caused the vessel wall to thicken. Immunofluorescence for detection of immune reactants was negative. It was concluded that the histomorphology of PCT of long duration may be similar to that of scleroderma. Nevertheless, in addition to clinical findings, detailed skin biopsy studies including contemporary techniques can contribute to the differentiation of these diseases.

Adult↗

Skeletal muscle immune deposits in systemic lupus erythematosus. Correlation with histologic changes, autoantibodies, and clinical involvement.

Skeletal muscle biopsy and autopsy samples of 132 SLE patients were studied by immunofluorescence and light microscopic techniques. Immune deposits were compared to histologic abnormalities and clinical and serologic findings. Immune deposits with a mainly granular pattern were observed at different locations in 49 patients (37%). They correlated significantly (p<0.001) with inflammatory myopathy, demonstrated in 33(25%), with noninflammatory myopathy which occurred in 38 (29%) vasculitis, observed in 13(10%), and with noninflammatory vasculopathy which was noted in 10 patients (8%). The correlation of muscle immune deposits with anti-DNA antibodies was significant at p= 0.016. Anti-Sm and anti-U1 RNP antibodies were associated significantly with the intensity of immune deposits. Furthermore, a correlation of immune deposits with increased creatine phosphokinase and myopathic electromyogram, but not with evidence of clinical involvement, was shown. A key pathogenetic role of immune deposits in the development of skeletal muscle histologic abnormalities in SLE was demonstrated.

Adolescent↗

[Significance of histopathologic analysis of skin lesions in scleromyxedema. Light microscopy, electron microscopy, immunohistochemistry and immunofluorescence microscopy].

Scleromyxedema (SM) may be considered as a possible disease entity in the differential diagnosis of scleroderma. Clinical data and the results of light, immunohistochemical, immunofluorescence and electron microscopic study of skin biopsies taken from a 53-year old patient with SM are reported. In the patient with SM in which abnormal serum paraprotein was not identified, the skin biopsy showed mucinous material in the dermis and proliferation of fibroblasts accompanied by mild dermal sclerosis. Immunofluorescence showed scanty granular IgG along the epidermal basement membrane and IgG and C1q focally along the connective tissue fibres in the dermis of clinically involved skin. In addition to clinical findings, detailed skin biopsy studies including contemporary techniques can contribute to the diagnosis of the disease.

Biopsy↗

[Acquired generalized cutis laxa with paraproteinemia (IgG lambda). Immunofluorescence study, clinical and histologic findings with review of the literature].

A 49-year-old patient developed acquired generalized cutis laxa, manifest as involvement of the elastic fibres of the dermis and the internal organs, leading to pulmonary emphysema, bilateral inguinal hernia and two oesophageal diverticula. The patient's serum levels of IgG lambda paraprotein were elevated. Direct immunofluorescence examination revealed intensive linear deposits of IgG lambda light chains, an early component of complement C1q and discrete C3 deposits. The deposits were found along the preserved elastic fibres in the dermis, especially in the papillary dermis, at the dermoepidermal junction around the sweat and sebaceous glands and in the walls of small vessels. Dermal alterations of this kind have not been described previously.

Basement Membrane↗