Ultrasonography parameters and histopathology findings in transplanted kidney.

BACKGROUND: Until now studies have shown conflicting results about morphologic and hemodynamic parameters in predicting histopathology results in renal graft malfunction. We sought to analyze whether parenchymal thickness relative to graft length and resistive index (RI) measured by ultrasonography can predict histopathology findings on renal biopsy. PATIENTS AND METHODS: We retrospectively analyzed 72 deceased donor renal allograft biopsies and respective allograft ultrasounds, performed on 68 patients (57% men) with mean age of 50 years (range, 21-73), with kidney graft dysfunction in 2010 and 2011. Parenchymal thickness relative to graft length and RI were compared with different histopathology diagnoses: Acute rejection, chronic rejection, chronic kidney changes, acute tubular necrosis (ATN), and other diagnoses. RESULTS: The mean value of the RI and of the parenchymal thickness/graft length ratio (parenchyma size index [PSI]) was 0.81 ± 0.10 (SD) and 1.48 ± 0.27 (SD), respectively. Enlarged PSI was significantly higher in ATN (mean 1.72 ± 0.26) compared with no ATN (mean 1.39 ± 0.23; P < .001), and lower when chronic changes were present (mean 1.40 ± 0.25 for chronic changes vs mean 1.62 ± 0.28 for no chronic changes; P = .004). In the group without ATN, PSI was enlarged in acute graft rejection compared with no graft rejection (mean 1.50 ± 0.24 vs 1.24 ± 0.13, respectively; P < .001), whereas in the whole group, including ATN, PSI showed no differentiating power for acute rejection (P = .526). RI was significantly higher in ATN than without it (mean 0.91 ± 0.10 vs 0.79 ± 0.08, respectively; P < .001), whereas the RI was not increased (but was actually lower) in acute graft rejection compared with no graft rejection, neither in the whole group (mean 0.81 ± 0.09 vs 0.82 ± 0.12, respectively; P = .611). CONCLUSIONS: Enlarged parenchymal thickness/graft length ratio on ultrasonography was observed in ATN and acute allograft rejection. The RI was increased in ATN, but not in acute allograft rejection. Decreased parenchymal thickness/graft length ratio was observed in chronic kidney changes.

Sixteen novel mutations identified in COL4A3, COL4A4, and COL4A5 genes in Slovenian families with Alport syndrome and benign familial hematuria.

Alport syndrome (ATS) and benign familial hematuria (BFH) are type IV collagen inherited disorders. Mutations in COL4A5 are generally believed to cause X-linked ATS, whereas mutations in COL4A3 and COL4A4 genes can be associated with the autosomal-recessive and -dominant type of ATS or BFH. In view of the wide spectrum of phenotypes, an exact diagnosis is sometimes difficult to achieve. This study involved screening each exon with boundary intronic sequences of COL4A3, COL4A4, and COL4A5 genes by optimized polymerase chain reaction-single-stranded conformational polymorphism analysis in 17 families with ATS and in 40 families diagnosed as having BFH. Twelve different mutations were found in the COL4A5 gene in ATS patients, comprising nine missense mutations, a splice site mutation, a mutation causing frameshift, and a nonsense mutation. One of the missense mutations (p.G624D) was present not only in one family with ATS but also in five families with suspected BFH. Three heterozygous mutations in the COL4A3 gene (two missense and one frameshift) and four heterozygous mutations in COL4A4 (two splice site, one in-frame deletion, and one missense) were identified in patients with BFH. Sixteen mutations are to the best of our knowledge new and private.

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.

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.

Clinical presentations and vascular histopathology in autopsied patients with systemic lupus erythematosus and anticardiolipin antibodies.

OBJECTIVE: To examine histomorphological and immunohistological changes in an autopsy series of systemic lupus erythematosus (SLE) patients with or without anticardiolipin antibodies (aCL). METHODS: Fourteen SLE patients who died at our department from 1988 to 1996 were included. The patients' medical files were reviewed for the clinical history and the presence of IgG and IgM aCL. Autopsy samples of various organs, including regularly the kidneys, heart, brain and skin, were studied by standard histological methods and the direct immunofluorescence technique. RESULTS: Thirteen of 14 (93%) autopsied SLE patients were persistently positive for IgG aCL and had common overt thrombotic complications and/or other clinical features related to the antiphospholipid syndrome. Their autopsy tissue samples showed frequent occlusive vascular changes such as bland thromboses, thrombotic microangiopathy (TMA) related changes and arterial intimalfibrous hyperplasia. The immune complex related vascular changes were mostly unremarkable and present mainly in low aCL positive patients, who also had more aggressive types of lupus glomerulonephritis (GN). CONCLUSION: Increased IgG aCL were found in 13 out of 14 autopsied SLE patients who had predominant occlusive vascular histopathologic changes. The coincidence of bland thromboses with a characteristic TMA histopathology suggested two pathogenetic mechanisms associated with the presence of aCL, one related to abnormal coagulation and the other to endothelial cell injury. The extent of granular vascular immune deposits, typical of SLE, and the severity of lupus GN were inversely related to the aCL level.

Interstitial capillary in normal and in transplanted kidneys: an ultrastructural study.

Knowledge about the normal structure and pathology of interstitial capillary is limited. Splitting and multilayering of the basal membrane (BM), as a marker of chronic rejection, has been published in association with transplant glomerulopathy. The authors investigated the ultrastructural features of the interstitial capillary basal membrane in normal (15 biopsies) and in transplanted kidneys (27 biopsies from 21 patients), expressing transplant glomerulopathy (8 biopsies from 6 patients), acute tubulo-interstitial rejection (9 biopsies from 6 patients), and recurrent or de novo glomerulonephritis (10 biopsies from 8 patients). All biopsies were fixed in 1% OsO4, embedded in Epon, and examined by electron microscope. Measurements of the interstitial capillary BM were made. The BM of interstitial capillary of intact kidney was a homogenous continuous structure, 88 nm in width on average. Thickening with diffuse multilayering of BM was most intensive in patients with transplant glomerulopathy, and much less intensive in patients with acute tubulointerstitial rejection and in patients with recurrent or de novo glomerulonephritis. These findings may provide the first information about the morphology of the normal basal lamina of interstitial capillary and support the diagnostic value of interstitial capillary changes in chronic rejection.

Real-time ultrasound-guided renal biopsy with a biopsy gun in children: safety and efficacy.

UNLABELLED: Real-time ultrasound-guided renal biopsy (RB) with a biopsy gun has become a standard procedure in the treatment of children. The purpose of the study was to establish the complication rate after real-time ultrasound-guided RB with a biopsy gun, the adequacy of renal tissue samples for pathohistological tests, the rate of concurrence between clinical and pathohistological diagnoses, and the benefits of the procedure. From January 1994 to October 1999, 88 renal biopsies were performed on 82 children, 81 of whom (35M, 46F, aged 3-20 y) were included in this retrospective study. The nephrotic syndrome (in infants, older children, those with evidence of nephritis or failing corticosteroid therapy) was the most frequent indication of RB. Other indications were non-nephrotic proteinuria, nephritic syndrome, glomerular haematuria, renal allograft dysfunction, unexplained acute or chronic renal failure, and kidney disease progression monitoring. No serious complications were noted. The adequacy rate of renal tissue samples ranged from 93.1 to 96.6%, depending on which definition of the adequacy of renal tissue samples was used. Clinical and pathohistological diagnoses matched in 81.4% of the cases. Data obtained by RB were very beneficial to patients in terms of establishing, confirming or altering the diagnosis and, consequently, the treatment. CONCLUSION: The results confirm that real-time ultrasound-guided RB with a biopsy gun is a safe procedure and provides information that is very beneficial to patients.

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.

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.

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.

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.

Fingerprint and other organised deposits in lupus nephritis.

A prominent feature of lupus glomerulonephritis is extracellular, predominantly homogeneous electron dense deposits. Fingerprint-like deposits have been reported in 6 to 10% of cases. On electron microscopy, we studied the frequency and characteristics of organised deposits in 227 kidney tissue samples obtained by biopsy in 185 patients with systemic lupus erythematosus (SLE). Fingerprint forms of deposits were demonstrated in 34 biopsies of 32 patients (17.3%). In the control group of 626 kidney biopsies of patients with primary renal and systemic diseases other than SLE, no fingerprint deposits were found. In 227 kidney biopsy samples, fingerprint deposits were found to be associated with mesangial (8.8%), mesangial-subendothelial (3.8%), subepithelial (28.6%), mesangial-subepithelial (11.1%) and mesangial-transmembranous (19.4%) glomerular deposit distribution patterns. They were demonstrated more often at different locations along the peripheral capillary glomerular basal membrane (77.4%) than within the mesangial matrix (43.7%). In extraglomerular locations, fingerprint deposits were present in the interstitium in 8.8%, along the tubular in 23.5% and peritubular capillary basal membrane in 20.5%, in the wall of the arterioles in 64.7% and in the juxtaglomerular apparatus in 18.2% of biopsies. Organised fingerprint deposits consisted of semicircular dark and light lines, each with a diameter of about 10 to 15 nm. Unilaterally, spiky processes at a periodicity of 10 to 15 nm were seen. Among 14 of 185 SLE patients with cryoglobulinemia, fingerprint deposits were demonstrated in only 2 patients. We conclude that fingerprint deposits are characteristic, diagnostically relevant for SLE and represent morphologically a homogeneous group of organised deposits unrelated to cryoglobulins. In 3 SLE patients, 20 to 100 nm tubules and in 2 SLE patients, 10 and 18 nm Congo red negative fibrils were found. By their morphology and their structural characteristics, the tubules and fibrils resemble the tubules in primary immunotactoid glomerulopathy and fibrils in primary fibrillary glomerulonephritis.

Role of lipids in the progression of renal disease in systemic lupus erythematosus patients.

Systemic lupus erythematosus (SLE) is an autoimmune connective tissue disease marked by immune-complex mediated lesions in small blood vessels of various organs, especially the kidneys, although other factors may also be implicated in the pathogenesis of the disease. This article focuses on the role of lipids in the progression of glomerular, vascular and tubulo-interstitial lesions in two patients with lupus nephritis associated with pronounced hyper- and dyslipidemia. The pathogenesis of progressive glomerulosclerosis in both patients appears to be multifactorial. In addition to immune complex mediated lupus glomerulonephritis, progressively active in the first patient, severe nephrotic-range persistent proteinuria, arterial hypertension associated with hyperfiltration and hyperperfusion injuries and, to a minor extent, hyper- and dyslipidemia were observed. Immunological and non-immunological factors were shown to contribute to the development of tubulo-interstitial lesions. In both patients, in addition to local immune deposits, prominent tubulo-interstitial lipid deposits were probably causally related to both hyperlipidemia and the increased permeability of the glomerular filtration barrier. Tubular lesions were highlighted by intracytoplasmic lipid droplets as well as small cleft-like spaces found to be impacted in the tubular lumina. They were seen to penetrate tubular epithelial cells and eventually lodge in the interstitium, surrounded by mononuclear cell infiltrates and foam cells. In both patients, hypertensive angiopathy and extraglomerular vascular immune deposits were demonstrated. In addition, in the second patient, arteriolar and small arterial hyaline was found at the age of 28 years to be full of lipids and calcium precipitates, suggesting a peripheral atherosclerosis-like process which never occurs as a natural age-related condition. In conclusion, all parts of the nephron may be involved in the pathogenetic process causally related or influenced by hyper- or dyslipidemia. Associated either with endothelial cell injury and consequent insudation of lipids in the vascular walls, glomerular filtration barrier injury with hyperfiltration, or tubulo-interstitial lipid deposition, the mechanism of tissue damage by lipids in all parts of the nephron shares similarities with the pathogenesis of systemic atherosclerosis.