Spatial arrangement of subepithelial deposits in lupus and nonlupus membranous nephropathy.

Subepithelial deposits are a common feature of idiopathic membranous glomerulonephritis (MGN) and lupus membranous glomerulopathy (LMGN). We investigated the spatial arrangement of immunoglobulin G (IgG) and C3c fraction of complement (C3c) in the immune deposits of MGN and LMGN with confocal laser scanning microscopy to correlate specific patterns of IgG-C3 interactions with different diseases. Ten patients with MGN and 8 patients with LMGN (World Health Organization class VB) were selected. A determination of the spatial arrangement of the two fluorochromes and the glomerular area occupied by each fluorochrome was performed for each case. Our results showed MGN specimens have an orderly distribution of IgG and C3c, with each deposit showing an outer ring of sole IgG. IgG was always more abundant than C3c (1,619 +/- 271 v 790 +/- 105 micrometer(2), P = 0.002). In LMGN, IgG and C3c were haphazardly arranged, with deposits made of C3c only and an outer ring of IgG only rarely present. Also, the relative amounts of the two antigens were variable, and two groups could be identified (group 1: IgG, 5,515 +/- 1,179 micrometer(2) v C3c, 4,810 +/- 1,174 micrometer(2); P = 0.02; group 2: IgG, 3,358 +/- 658 micrometer(2) v C3c, 4,047 +/- 740 micrometer(2); P = 0.03). Our data show that diffuse IgG capping of the subepithelial immune deposits is diagnostic of MGN. The absence of an orderly three-dimensional arrangement in LMGN deposits (ie, outer ring of IgG) is likely to render active complement components more readily available to inflammatory activities.

Ultrastructural investigation of circulating villous lymphoid cells: a tool in the differential diagnosis of splenic lymphoma with villous lymphocytes.

Ultrastructural examination of circulating lymphoid cells was performed in three cases of splenic lymphoma with circulating lymphocytes (SLVL) in order to define morphological features helpful to distinguish this lymphoma from hairy cell leukemia (HCL). The samples for ultrastructural investigation were obtained by Ficoll sedimentation from peripheral blood and routinely processed for electron microscopy. The ultrastructural features examined were: morphology of villi, morphology of nuclei, presence of nucleoli, distribution of heterochromatin, type of cytoplasmic organelles, presence of specific intracytoplasmic structures such as the ribosome-lamella complex, lysosome-like bodies and perinuclear microfibrils. Our results and a careful review of the literature seemed to confirm that SLVL has electron microscopic features typical enough to be relevant in the differential diagnosis with HCL.

Sepsis-induced acute renal failure: unusual clinical presentation.

We report 4 cases of sepsis-induced acute renal failure (ARF) with peculiar clinical presentation in which the renal biopsy was the only clue to a correct diagnosis. We observed 66 cases of ARF in a 4-year experience. Seven (11%) were associated with sepsis; in 3 of these (4.5%) a shock was present. Clinical picture of the remaining 4 cases (6%) was characterized by ARF with oligoanuria and proteinuria (> 2 g/L), fever, resistant to antimicrobial therapy, negative hemocultures and severe systemic symptoms. Such a presentation could suggest a non-infectious systemic disease; renal biopsies were carried out. Histological findings consisted of microabscesses of variable size in the interstitium and within the tubular lumina. A full-dose, broad-spectrum, i.v. antimicrobial therapy was started, with favourable outcome and recovery of renal function. Our clinical experience points out that the clinical picture of ARF in course of sepsis may be variable and that its relationship with septicaemia could not be readily discernible.

IgA nephropathy: multivariate statistical analysis aimed at predicting outcome.

BACKGROUND: Several risk factors of IgA nephropathy (IgAN) have been identified, but their importance in predicting outcome is still controversial. METHODS: We conducted a retrospective study on 119 patients (pts) with IgAN. All had a follow-up of over five years (mean 134+/-56 months). For each patient we recorded age, 24h proteinuria, hematuria, renal function (RF), arterial hypertension (AH) and histological features. Multivariate analysis was done for predictive purposes (segmentation, using Chi-squared Automatic Interaction Detection-CHAID). RESULTS: AH at the time of renal biopsy was the principal and independent predicting factor: 30/50 (60%) hypertensive pts had serum creatinine > or =1.5 mg/dL at the end of follow-up compared to 9/69 (13%) pts with normal blood pressure. Age was a further predictive parameter: 21/28 (75%) pts with AH and age over 39 years had reduced RF at the last examination. In this subgroup, 18/19 (95%) with evidence of tubulo-interstitial lesions showed a decline of RF. CONCLUSIONS: AH and age alone are significant prognostic factors; tubulo-interstitial lesions are an additional pointer to poor outcome in these pts. The algorithm obtained with segmentation analysis may be a guideline for prognosis in single patients with IgA nephropathy.

Fibrosarcoma of the thymic region. A case report.

Fibrosarcoma of the mediastinum is an unusual tumor and only few cases have been reported. We describe the clinical and pathologic findings of a case of mediastinal mass in a 34 year old woman. The histologic, histochemical, immunocytochemical and ultrastructural features of the tumor were consistent with a diagnosis of fibrosarcoma. Furthermore, the tumor displayed evidence of close relations with the thymus capsule; the possibility that it may arise from the thymic stroma is considered. The differential diagnosis of spindle cell tumors of the mediastinum is also discussed.

Ultrastructural histochemistry of mesotheliomas and adenocarcinomas in malignant effusions.

The results of electron microscopic examination of cytologic specimens from six cases of mesothelioma and 10 cases of metastatic carcinoma of different origins are presented. The formation of cell clusters in malignant effusions from the two neoplasms has been thoroughly investigated: in mesotheliomas, cells had longer, more slender microvilli than in carcinomas and more abundant bundles of intermediate filaments; the central cavity often seen in the clusters frequently contained collagen and showed basement membrane production. The application of periodic acid-silver methenamine (PASM) and phosphotungstic acid (PTA) demonstrated a peculiar ultrastructural difference in cell coat staining in the two tumor types: in mesotheliomas, PTA and PASM were consistently negative along the outer surface of the cell aggregates, while carcinomas displayed a positive reaction either on the outer surface or on both inner and outer surfaces of the clusters. The diagnostic significance of the above-mentioned difference between the two neoplasms will require further investigation in a larger number of cases.

Chondroblastoma of the rib presenting as an intrathoracic mass. Report of a case with fine needle aspiration biopsy, immunocytochemistry and electron microscopy.

We describe an unusual case of chondroblastoma of the rib, initially presenting as a mediastinal mass eroding a vertebra, in which the preoperative diagnosis was made by fine needle aspiration (FNA) cytology and confirmed by histology and electron microscopy of the surgical specimen. Cytologic study of the smears revealed osteoclastlike giant cells and dishesive, mononucleate tumor cells; sections of the paraffin-embedded, aspirated material showed the chondroid matrix and typical chicken wire calcific deposits. Supporting diagnostic evidence was provided by immunohistochemical demonstration of S-100 protein. Unusual features were the presence of intranuclear pseudoinclusions and cytoplasmic granular deposits, which proved to contain iron on histochemical staining, ultrastructural morphology and x-ray analysis. This case emphasizes the value of FNA cytology in providing a correct diagnosis of chondroblastoma as well as the utility of embedding the aspirated material for histologic, immunohistochemical and ultrastructural studies.

Lipoid proteinosis: clinical, histologic, and ultrastructural investigations.

The case of a 12-year-old boy with lipoid proteinosis is reported. Physical examination revealed long-standing varicella-like scars and areas of hyperpigmentation on the face and upper limbs with no evidence of photosensitivity, hoarseness, small papules along the free margins of eyelids, tongue firmness with short frenulum, and widespread papular lesions of the oral cavity. Histologic and ultrastructural examination revealed the characteristic skin changes: pink, hyaline-like, strongly periodic acid-Schiff-positive material in the dermis, surrounding blood vessels, and sweat glands; thin (30 to 35 nm) collagen fibrils interspersed in abundant amorphous material; blood vessels surrounded by thickened, multilayered basement membranes, in which layers of typical, homogeneous basement membrane material were alternating with electronlucent areas filled by various amounts of thin, cross-striated fibrils, arranged perpendicularly. These findings are of great interest since they show a complex relationship between type IV and type III-like collagen components.

Spatial arrangement of IgA and C3 as a prognostic indicator of IgA nephropathy.

The histological picture of primary glomerulonephritis with glomerular IgA deposition (IgA nephropathy and Henoch-Schönlein disease) can vary from minimal mesangial involvement to severe endocapillary and/or extracapillary proliferation. Local activation of the complement cascade by glomerular IgA deposits and release of anaphylactoid factor are considered to be major triggers of inflammation, but clear-cut correlations between the severity of the histological findings and the intensity of glomerular deposition of immunoglobulin and complement fractions are still lacking. The purpose of this study was to investigate the spatial distribution of IgA and complement in mesangial deposits with confocal laser scanning microscopy (CLSM) and to correlate specific patterns of IgA-complement interaction with glomerular damage. Two groups of patients have been studied, one with mild to moderate diffuse mesangial proliferation and the other with diffuse proliferative endocapillary and/or extracapillary patterns. In milder forms of the disease, the majority of the immune deposits are composed of both IgA and C3, coated by an outer layer of IgA alone. Large C3 deposits, or deposits composed of IgA and C3 without an outer coat of IgA, were associated with more severe histological lesions. The results suggest that free access of active complement components to cell and/or mesangial matrix receptors could trigger a cytolytic reaction and that immunoglobulins seem to act as a protective layer on C3 components.

Adult solitary cutaneous myofibroma: a case report.

The histologic and immunohistochemical features of a case of adult solitary cutaneous myofibroma are reported. The lesion consisted of interlacing bundles of spindle cells arranged around small vessels with hemangiopericytomatous appearance. Neoplastic cells were positive for vimentin and actin. Desmin, cytokeratins and Factor XIIIa were negative. Scattered Langerhans cells positive for S-100 protein and CD1a antigen, usually not reported within this type of neoplasm, were also present.

Ultrastructural histochemical investigations of "dense deposit disease". Pathogenetic approach to a special type of mesangiocapillary glomerulonephritis.

Dense deposit disease is characterized by the presence of intramembranous dense deposits; their constituents are unknown but immunological and biochemical studies have demonstrated that they contain no gamma-globulins or any other plasma protein. In order to clarify the nature of the dense deposits better, we investigated their most distinctive character, (marked electron-density) by means of ultrastructural histochemistry techniques using thin sections from Formaldehyde fixed, OsO4 postfixed and Epon embedded specimens collected for diagnostic electron microscopy. The dense deposits have a higher osmium affinity than the lamina densa of normal basement membranes, and the electron-density is strictly osmium-dependent suggesting the presence of a lipid component. Further data, obtained using an extraction method for lipids, seems to confirm our hypothesis.

Physico-chemical analysis of resorcin-fuchsin reagents and its relevance to staining quality of elastic fibres.

Three Weigert's resorcin-fuchsin reagents for elastic fibres were prepared by using different lots of basic fucsin and by preparing the staining solutions with ferric chloride or ferric perchlorate. The solutions were analyzed by spectrophotometry, thin layer chromatography (TLC) and spectrofluorimetry. Their ability to stain elastic fibres was tested on several human tissue. The strongest stain and faintest background were obtained with the fuchsin-chloride reagent, which showed the most significant reduction of the absorption at 575 nm by spectrofluorimetry, associated with an increased absorption at 510 nm with respect to the other stains. The results showed that physico-chemical analysis can represent a reliable, although empirical, way to predict the usefulness of a resorcin-fuchsin reagent for histological work.

Cephotaxime-associated allergic interstitial nephritis and MPO-ANCA positive vasculitis.

We report a case of reversible acute renal failure after cefotaxime treatment in a patient affected by non-Hodgkin lymphoma. Renal biopsy showed necrotizing vasculitis associated with eosinophil-rich interstitial inflammatory infiltrates and patchy infiltrates of CD20+ lymphoid cells. High serum p-ANCA titers were also detected. Drug withdrawal was closely related with recovery of renal function and disappearance of ANCA. Acute renal failure therefore represented a consequence of ANCA-mediated renal vasculitis and acute interstitial nephritis related to cefotaxime treatment.

Morphological evidence of neutrophil-tumor cell phagocytosis (cannibalism) in human gastric adenocarcinomas.

The phenomenon of neutrophil-tumor cell emperipolesis or phagocytosis has been documented by light microscopy in various human carcinomas, but little is known about the cellular pathological processes and the morphological changes involved. In an attempt to clarify the nature of this phenomenon, the authors' ultrastructural studies on the relationships among neutrophils and tumor cells in human gastric carcinomas are reviewed and analyzed. At the electron microscopy level, apoptotic neutrophils were found within vacuoles of adenocarcinoma cells in 2 cases. They showed either early apoptotic morphology with perinuclear chromatin aggregation but cytoplasm integrity or late apoptotic morphology with uniform, collapsed nucleus and tightly packed cytoplasmic granules. A light microscopy review of 200 cases of resected gastric carcinomas identified 22 cases (11%) that were characterized by neutrophil-tumor cell phagocytosis (cannibalism). TUNEL staining confirmed the presence of apoptotic neutrophils within the cytoplasm of the tumor cells. This study provides light and electron microscopic evidence of apoptotic neutrophils phagocytosed by gastric adenocarcinoma cells. The morphological features of neutrophil-tumor cell phagocytosis (cannibalism) would suggest a particular mechanism of tumor-immune escape in human gastric carcinoma.

Glomerular hypertrophy and chronic renal failure in focal segmental glomerulosclerosis.

Focal segmental glomerulosclerosis evolves toward chronic renal failure (CRF) with a highly variable rate; in particular, a group of patients with a much more rapid decline of renal function has been described. The purpose of this study was to evaluate the usefulness of morphometry in identifying those cases with a faster decline in renal function. Two groups of patients have been studied: six with rapid evolution toward CRF (group 1) and six without reduction in renal function during a follow-up of up to 10 years (group 2). The results of the morphometric analysis of glomeruli were as follows: mean glomerular area: 30,550 +/- 5,259 microns2 (group 1) versus 22,667 +/- 5,078 microns2 (group 2) (P = 0.01); maximum glomerular area: 40,827 +/- 9,508 microns2 (group 1) versus 30,445 +/- 7,224 microns2 (group 2) (P = 0.02); mean glomerular diameter: 193.9 +/- 15.8 microns (group 1) versus 161.8 +/- 16.8 microns (group 2) (P = 0.003); and caliper diameter: 328.6 +/- 20.6 microns (group 1) versus 260.6 +/- 36 microns (group 2) (P = 0.001). Values of body surface area were not different between the two groups (1.85 +/- 0.34 m2 v 1.6 +/- 0.13 m2) (P = NS). Our results suggest that glomerular hypertrophy in the course of focal segmental glomerulosclerosis is correlated with a faster decline toward CRF. It might represent a compensatory hypertrophy that would immediately precede a rapid decline in renal function or it might be the expression of the preexisting condition (meganephronia), which predisposes to the development of CRF.

Three-dimensional distribution of basement membrane components in dystrophic recessive epidermolysis bullosa.

Absent or defective collagen VII at the dermo-epidermal junction is the hallmark of dystrophic recessive epidermolysis bullosa. Little is known of the alterations of other collagenous and non-collagenous components of the basement membrane; it is likely that their assembly may be disturbed by the lack of collagen VII molecules. The spatial relationship of collagen IV and laminin has been studied, both in bullous and in non-bullous areas. Skin biopsies from five patients affected by severe dystrophic recessive epidermolysis bullosa were rapidly frozen and freeze-dried. Collagen IV and laminin were labelled with specific monoclonal antibodies and FITC- or TRITC-conjugated secondary antibodies. Sections were observed with conventional light/fluorescence microscopy and with confocal laser scanning microscopy. Collagen IV and laminin were not co-localized: the former displayed a split image, being present at the floor and the roof of the blister, while the latter was confined to the roof. Confocal microscopy also allowed three-dimensional (3D) reconstruction of the dermo-epidermal junction from a series of optical sections, with viewing of the reconstructed specimen from a sequence of angles. By this procedure, laminin exhibits an irregular, coarsely granular distribution, both in affected and in apparently non-affected areas, while collagen IV appears as a homogeneous sheet. These results show that freeze-drying is the technique of choice for high-resolution immunofluorescence of skin samples and suggest that in dystrophic recessive epidermolysis bullosa, a complex disruption of the extracellular matrix assembly exists even before blister formation, probably due to the lack of collagen VII.

Acquired glomerulocystic kidney disease following hemolytic uremic syndrome.

Glomerulocystic kidney disease (GCKD) is a rare congenital condition that is usually reported in infants and young children. Only five cases of acquired GCKD after an acquired renal disease have been reported. Among these, two patients have developed cystic glomerular lesions following hemolytic uremic syndrome (HUS). We report a third case in a 2-year-old patient with this association. Common features between these three cases include atypical HUS, development of GCKD after prolonged peritoneal dialysis treatment, severe hypertension, and normal-sized kidneys without development of macroscopic cysts. Pathology findings in our patient include heavy expression of epidermal growth factor receptor in proximal tubules and evidence of obstruction of the glomerular outflow. We speculate that cystic dilatation of the Bowman's capsule may be secondary to ischemic lesions leading to proximal tubular obstruction.

Systemic lupus erythematosus with membranous glomerulonephritis and uterine vasculitis.

We report a case of lupus vasculitis with uterine localization and concurrent membranous nephropathy. Immunofluorescence study suggested the occurrence of an immune complex nephropathy and a pauci-immune pathogenesis of vasculitis. Our case points out the event of tissue damage in two organs mediated by different pathogenetic mechanisms. In addition, uterine vasculitis without pregnancy may be observed in patients with systemic lupus erythematosus nephritis.

Immunoglobulin A nephropathy complicating pulmonary tuberculosis.

A 31-year-old man who presented with smear- and culture-negative pulmonary tuberculosis had associated macroscopic hematuria, elevation of serum creatinine and immunoglobulin A (IgA) levels, overt proteinuria, and peripheral edema. Renal biopsy revealed focal mesangial proliferation with IgA deposits, and a diagnosis of IgA nephropathy was made. The patient received treatment with isoniazide and rifampin. After 4 months, pulmonary lesions were almost completely healed, and a significant improvement of creatinine clearance with normalization of serum creatinine and IgA levels and disappearance of proteinuria were observed. Treatment with isoniazide and rifampin was discontinued after 6 months, without reappearance of either pulmonary or renal symptoms. Two years after the diagnosis of IgA nephropathy, the patient is in good general condition. Serum creatinine and IgA levels are normal, proteinuria is absent, and there is neither macrohematuria nor microhematuria. These findings suggest that IgA nephropathy may be a consequence of tuberculosis, possibly due to an abnormal IgA-mediated immune response against Mycobacterium tuberculosis with formation of nephrotoxic immune complexes.

Ultrastructural immunocytochemistry of collagenous and non-collagenous proteins in fast-frozen, freeze-substituted, and low-temperature-embedded renal tissue in Alport syndrome.

This paper describes the ultrastructural immunolocalization of the alpha 2 chain of collagen IV, laminin, and the amino terminal propeptide of collagen I (N-Pro I) in glomeruli of rapidly frozen, freeze-substituted, and low-temperature-embedded renal biopsy specimens from two cases of Alport disease and from normal kidneys. The alpha 2 chain of collagen IV is present in the whole thickness of the basement membrane in glomeruli of Alport patients, while it is limited to the subendothelial portion of the basement membrane of normal glomeruli. Laminin has the same distribution in both normal and Alport glomeruli, but is apparently more concentrated along the basement membrane of normal glomeruli. N-Pro I is localized in mesangial areas and in the basement membrane in Alport cases, while it is not detected in normal glomeruli. These data suggest complex rearrangements of major constituents of the glomerular basement membrane network and demonstrate early deposition of fibrillary collagen proteins in the matrix before the appearance of banded collagen fibres. This finding could be an indicator of early evolution towards glomerulosclerosis.