Subepithelial electron-dense deposits in proliferative glomerulonephritis of systemic lupus erythematosus

Anaplastic large cell Ki-1 lymphoma of the stomach with villopodial projections: an immunocytochemical and ultrastructural study and review of the literature

The report describes a case of anaplastic large cell Ki-1 lymphoma of the stomach with a rapidly fatal course observed in a 28-year-old woman. By electron microscopy the neoplastic cells presented long projections of the cytoplasmic membrane arranged uniformly along all the cell circumference. The morphology and distribution of these projections were characteristic, and the term villopodial is proposed for them. A review of the literature revealed 18 cases of lymphoma and 7 cases of nonlymphoid neoplasms composed of cells with projections similar to those observed in the present case. It is suggested that such tumors be denominated villopodial lymphomas and villopodial tumors. The present case is the first anaplastic large cell Ki-1 lymphoma with villopodial projections reported in the literature.

Immunotactoid glomerulopathy

During the past 10 years, immunotactoid glomerulopathy has become recognized with increasing frequency. The lesion is characterized histologically by highly organized ultrastructural deposits that appear to be composed of immunoglobulin and complement and are negative for amyloid by Congo red stain. Clinically and/or serologically, patients have no evidence of cryoglobulinemia, amyloidosis, systemic lupus erythematosus, or a paraproteinemia, disorders associated with glomerular deposits, which also have a highly organized tactoidal or fibrillar characteristic. Immunotactoid glomerulopathy does not appear to be a multisystemic disease process and thus may represent a primary glomerulopathy. Patients with immunotactoid glomerulopathy present with proteinuria (nephrotic range in more than 60%) and over half of the patients have hypertension, hematuria, and renal insufficiency. Progression to end stage renal disease has occurred in more than 40% of patients reported to date. The experience in treating this disorder using prednisone and/or immunosuppression is limited and has not been impressive. Four patients have successfully undergone renal transplantation, but proteinuria recurred in two and was associated with the recurrence of immunotactoid glomerulopathy in the renal allograft. Although we have gained insight into the clinical course and histopathology of this disorder over the past few years, we still know little about its pathogenesis, an area for further research.

"Anemone" cell (villiform) tumor of the brain

At age 31, the patient developed hydrocephalus secondary to a brain lesion that had been present for 12 years. A ventriculoperitoneal shunt was performed, but a stereotactic biopsy did not establish a definitive diagnosis at that time. At age 34 the patient experienced spontaneous intratumoral and ventricular hemorrhage, which prompted radical surgical resection of the lesion. Histologic and immunocytochemical findings established a diagnosis of ependymoma; review of the ultrastructure of the tumor from the biopsy performed when the patient was 31 years old revealed the characteristics of an "anemone" cell neoplasm.

Fibrillary glomerulonephritis--a report of two cases

Two patients with an uncommon form of glomerulonephritis are described. The main clinical features were hematuria and proteinuria associated with normal renal function. The glomerular lesions consisted of mesangial hypercellularity and capillary wall thickening. Immunofluorescence was positive for IgG and C3 in both cases. Widespread deposition of microfibrils (mean diameters 17.0 nm and 18.4 nm) within mesangial areas and capillary basement membranes was seen on electron microscopy. Congo red staining for amyloid was negative. In both patients there was no evidence of underlying disease or extra-glomerular involvement and hence the disorder appeared to represent a primary glomerulonephritis.

Immunotactoid glomerulopathy with fingerprint immune deposits. A variant of lupus nephritis?

Immunotactoid glomerulopathy is a distinct clinico-pathological entity which has recently been defined. The term immunotactoid refers to highly organized immune depositions appearing as rod-like microtubular structures in ultrastructural examination. We describe a patient with mixed connective tissue disease who demonstrates characteristic features of immunotactoid glomerulopathy. The diagnosis was made after excluding amyloidosis, cryoglobulinaemia and lupus nephritis. In addition to immunotactoid microtubules, ultrastructural examination also demonstrated presence of fingerprint depositions which were intimately mixed with immunotactoid structures. Fingerprint deposits have been described in lupus nephritis and cryoglobulin-related nephropathy, but rarely in other glomerulonephritis. These unique findings in our patient may suggest a previously unsuspected relationship between the syndrome of immunotactoid glomerulopathy and systemic lupus erythematosus.

The prognosis of segmental glomerulonephritis in systemic lupus erythematosus

Severe segmental glomerulonephritis (Seg GN) (greater than or equal to 50% involvement) in systemic lupus erythematosus (SLE) is classified as diffuse GN (DPGN) in the WHO classification. We tested the validity of the assumption that severe Seg GN and DPGN have the same prognosis by determining the proportion of glomeruli involved by active segmental inflammation in a series of 127 patients and by comparing the prognosis in various categories of Seg GN with patients with DPGN. In Seg GN we found mild involvement (1 to 19%) in 19 patients, moderate involvement (20 to 49%) in 9 patients and severe involvement (greater than or equal to 50%) in 17 patients. There were 28 cases of DPGN. The actuarial five-year survival of patients with mild and moderate Seg GN was 82%. The survival of patients with severe Seg GN and DPGN were 59 and 53%, respectively. The incidence of adverse outcomes, including death, end-stage kidney disease, and deterioration of renal function was similar in patients with severe Seg GN and DPGN, and greater than in patients with mild and moderate Seg GN. Although there was a trend associating increasing glomerular involvement with elevated urinary protein excretion and serum creatinine and decreased serum C3 and C4, the differences were not significant. Cumulative prednisone dose and prednisone given in the first and second years following biopsy were not different in the various categories of Seg GN and DPGN, suggesting that differences in outcome were not related to the amount of prednisone therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Lupus nephritis. Clinicopathology and immunopathology of 80 biopsy cases

The clinicopathology and immunopathology of 80 cases of lupus nephritis in a total of 1,187 biopsies were presented. Histologically, they consisted of 11 cases of mesangial lupus nephritis (13.8%), 51 cases of diffuse proliferative lupus nephritis (63.7%), and 18 cases of membranous lupus nephritis (22.5%). No cases of focal proliferative type, minimal changes or end-stage kidneys were included. Ten cases were male and they had no qualitative and quantitative differences with female ones in any respects. The microtubular structures were found in glomerular endothelial cells with a 70% frequency and in the interstitial endothelial cells with a 46% frequency. In the latter case, microtubular structures tended to be localized in the perinuclear space as well as in the endoplasmic reticulum. Spherical microparticles were found in 46% of all cases and the incidences were significantly higher in the membranous type. Organized deposits with straight parallel microfilaments were found only in a single case. Electron-dense deposits with fingerprint pattern were not seen. Immunohistochemically, various immunoglobulins, complement components, and fibrinogen were found deposited more frequently in diffuse proliferative lupus nephritis. IgG was the predominant immunoglobulin deposited in capillary loops in membranous types, and IgA in the mesangium in mesangial types. Extraglomerular deposition of immunoglobulins and complements were found in 26.3% of all cases.

"Anemone" cell (villiform) tumors: electron microscopy and immunohistochemistry of five cases

Five large cell malignant neoplasms were studied by immunohistochemistry and electron microscopy. Ultrastructural examination demonstrated numerous circumferential microvilli in 3 cases and a more polarized distribution in 2 cases. The tumor cells in 2 cases demonstrated the surface glycoprotein T29/33, indicative of a hematopoietic neoplasm. Two cases (including one positive for T29/33) contained intracytoplasmic IgG-kappa. Anti-keratin staining using both polyclonal and monoclonal antibodies was negative. Two patients are alive and in remission after treatment for lymphoma. One died with tumor following a progressive course, and one has been lost to follow-up. A fifth patient died of tumor and at autopsy was found to have a disseminated pancreatic tumor. Microvilli around large malignant cells have been commonly associated with epithelial tumors; however, our findings indicate that, in the absence of intercellular junctions and tonofilaments, the possibility of malignant lymphoma should be considered and pursued immunohistochemistry.

Membranous and vascular choroidopathy: two patterns of immune deposits in systemic lupus erythematosus

Two patterns of immune aggregate localization were demonstrated by immunofluorescence and electron microscopy in the choroid plexus of four young women with fatal systemic lupus erythematosus. The two patients with granular immune aggregates localized to the basement membrane of the choroid epithelium (membranous choroidopathy) had subepithelial and intramembranous electron-dense deposits and membranous glomerulopathy in their kidneys. The two patients with immune aggregates in the walls of choroidal blood vessels (vascular choroidopathy) had subendothelial electron-dense deposits and proliferative glomerulonephritis. Vascular deposits in the choroid plexus were associated with capillary thrombi and extravasation of fibrinoid material, while isolated membranous choroidopathy had no histopathologic evidence of inflammation. The clinical presentation and serological studies of blood and cerebrospinal fluid were compared in an effort to discriminate between patients with membranous and vascular choroidopathy. All patients had variable neuropsychiatric symptoms and major motor seizures. While those with vascular choroidopathy had more evidence of disease activity in their sera, both groups demonstrated elevated titers of immune-complexed antinuclear antibodies in cerebrospinal fluid. Although both patterns of choroidal localization of immune aggregates were associated with neuropsychiatric dysfunction, we were unable to identify discrete clinical-symptom complexes which differentiated patients with membranous and vascular choroidopathy. These contrasting patterns of choroid plexus immunopathology suggest that factors responsible for differential localization of immune aggregates are not restricted to the renal glomerulus.

Differential characteristics of immune-bound antibodies in diffuse proliferative and membranous forms of lupus glomerulonephritis

Diffuse proliferative (PGN) and membranous (MGN) glomerulonephritis represent contrasting histologic lesions in systemic lupus erythematosus (SLE). Serum, cryoglobulins, and renal biopsies in 8 SLE patients with PGN and 8 with MGN were studied in order to determine whether variations in the properties of immune-bound antibodies correlate with the pattern of glomerular involvement. Several immunologic parameters suggested differences in complement activation between the two groups. PGN cryoglobulins demonstrated immunoglobulin G (IgG) anti-native DNA (nDNA) subclass heterogeneity with highest titers of IgG3. These findings contrasted with the observation that MGN was characterized by a predominance of IgG4 in cryoglobulins. The major glomerular IgG subclasses in PGN were IgG3 and IgG1, while MGN biopsies demonstrated IgG4 in largest amount. Serum C1q was lower in PGN than in MGN. Serum anti-nDNA antibodies, solid-phase C1q-binding IgG immune complexes, and cryoglobulin protein concentrations were higher in PGN sera. Cryoglobulin complement component and control protein concentrations were greater in PGN than in MGN, while cryoglobulin Ig and immune-bound anti-nDNA were not different. In vitro C3 fixation by cryoglobulin anti-nDNA was greater in PGN than in MGN. Glomerular C1q, C4-binding protein (C4bp), and C3c were present in comparable amounts to IgG deposits in PGN biopsies, while in MGN IgG was demonstrable in greater quantities than C1q, C4bp, and C3c. In contrast, glomerular C3d (alpha 2d), C5, C6, P, and H were comparable in the two groups. It was concluded that immune-bound antibodies in cryoglobulins and in glomerular immune deposits in SLE PGN appear to activate complement via the classical and alternative pathways, while complement activation in MGN appears to occur predominantly via the alternative pathway. These differences in IgG subclass composition may account for the differential complement activation and may explain the contrasting histologic expression of immune aggregate localization in glomerular capillaries in these variants of lupus nephritis.