Monoclonal Light Chain Deposits Within the Stomach Manifesting as Immunotactoid Gastropathy

Immunotactoid deposits are defined by their ultrastructural appearance and are characterized by microtubular or cylindrical structures typically measuring greater than 30?nm in diameter. Although a rare entity, immunotactoid deposition most often manifests as immunotactoid glomerulopathy and is associated with underlying lymphoplasmacytic disorders. Corneal immunotactoid deposition known as immunotactoid keratopathy has also been reported in patients with paraproteinemia. Here, we describe the first reported case of immunotactoid deposition in the stomach. The deposits were composed solely of kappa immunoglobulin light chains without significant lambda light chain or immunoglobulin heavy chain components. The patient displayed no renal signs or symptoms, and additional thorough clinical examination failed to detect any evidence of a paraproteinemia or plasma cell dyscrasia. Thus, the gastric immunotactoid deposits in this case appear to be an isolated finding of light chain deposition, of which the significance and etiology are unclear.     

Immunotactoid Glomerulopathy and Cryoglobulinemic Nephropathy: Two Entities with Many Similarities. A Unified Conceptual Approach

Immunotactoid glomerulopathy is a rare disorder that has been characterized at the ultrastructural level. Due to its rarity, there are few comprehensive studies relating to this disorder. Electron microscopy essentially characterizes this disease. The glomerular electron dense deposits which are typical of this condition consist of aggregates of highly organized microtubular structures of various diameters, but generally measuring 30–50?nm in width with a propensity to dispose themselves in parallel bundles intersecting in different planes. This study compares a large series of patients with cryoglobulinemic nephropathy with a series of patients with immunotactoid glomerulopathy to address whether there may be similarities that warrant considering these two entities part of a spectrum. This study reviews the clinicopathologic features of both entities and emphasizes ultrastructural findings that characterize them. Significant immunomorphologic overlap was found when these two disorders were compared in this study. There were also striking similarities in clinical presentation/behavior, laboratory findings and prognosis. Proteomic analysis has also demonstrated similar spectra for both entities. We postulate that immunotactoid glomerulopathy and cryoglobulinemic nephropathy are part of the spectrum of renal manifestations in patients with circulating cryoglobulins and renal disease.     

Glomerulopathies with fibrillary deposits

Renal diseases involving glomerular deposits of fibrillary material are an important diagnostic challenge for the ultrastructural pathologist. Two primary disorders of this type, termed 'fibrillary glomerulonephritis' (characterized by fibrils measuring approximately 20nm in diameter) and 'immunotactoid glomerulopathy' (characterized by larger, microtubular deposits), have been described. The possible relatedness of these two disorders and their potential association with other systemic illnesses are subjects of current debate. Other multisystemic diseases, including amyloidosis and various forms of cryoglobulinemia, can also present with fibrillary or microtubular deposits in the kidney. Five cases are presented in which fibrillar or microtubular structures were identified in renal biopsies by ultrastructural examination. The distinction between fibrillary glomerulonephritis,immunotactoid glomerulopathy, and other processes that have similar ultrastructural features are discussed.     

Glomerulonephritis with microtubular deposits associated with cryoglobulinemia and chronic active hepatitis

A 65-year-old-woman presented with edema, ascites, proteinuria and abnormal liver function tests. A small amount of mixed cryoglobulin was detected in her serum. Liver biopsy revealed mild chronic active hepatitis, but tests for hepatotropic viral infection were negative. Electron microscopy of the renal biopsy revealed glomerular electron-dense deposits that contained numerous tubular structures. Renal amyloidosis and light chain deposition disease were ruled out by appropriate histological techniques. The ultrastructural findings of renal biopsy suggested either cryoglobulinemic glomerulonephritis or immunotactoid glomerulopathy. Although the exact interrelationship among the peculiar glomerulopathy, cryoglobulinemia and chronic active hepatitis in the present case remains undetermined, this report enlarges the spectrum of glomerulopathy characterized by extracellular deposition of microtubules.     

A case of idiopathic nodular glomerulosclerosis mimicking diabetic glomerulosclerosis (Kimmelstiel-Wilson type)

A case of idiopathic nodular glomerulosclerosis mimicking diabetic Kimmelstiel-Wilson glomerulopathy is reported. The patient was a 45-year-old man suffering from nephrotic syndrome. Light and electron microscopy revealed diffuse and nodular glomerulosclerosis indistinguishable from diabetic nodular glomerulosclerosis. Diabetes mellitus, however, had been excluded both by extensive clinical and by laboratory investigation. The differential diagnosis also included amyloidotic and non-amyloidotic fibrillary glomerulopathy, light chain glomerulopathy, collagen type III disease, immunotactoid glomerulopathy, and the sclerosing variant of membranoproliferative glomerulonephritis. Immunohistochemistry and ultrastructural investigations, however, excluded these entities, and the diagnosis of idiopathic nodular glomerulosclerosis was made. This variant has to be included in the differential diagnosis of nodular glomerulopathy associated with nephrotic syndrome.     

Glomerulopathies with Fibrillary Deposits

Renal diseases involving glomerular deposits of fibrillary material are an important diagnostic challenge for the ultrastructural pathologist. Two primary disorders of this type, termed ``fibrillary glomerulonephritis'' (characterized by fibrils measuring approximately 20nm in diameter) and ``immunotactoid glomerulopathy'' (characterized by larger, microtubular deposits), have been described. The possible relatedness of these two disorders and their potential association with other systemic illnesses are subjects of current debate. Other multisystemic diseases, including amyloidosis and various forms of cryoglobulinemia, can also present with fibrillary or microtubular deposits in the kidney. Five cases are presented in which fibrillar or microtubular structures were identified in renal biopsies by ultrastructural examination. The distinction between fibrillary glomerulonephritis,immunotactoid glomerulopathy, and other processes that have similar ultrastructural features are discussed.     

Immunotactoid glomerulopathy--an unusual deposition disease: report of the first Malaysian case

A 31-year-old Malay female presented with nephrotic syndrome without renal impairment. Renal biopsy features were in keeping with immunotactoid glomerulopathy (ITG). Non-Congophilic deposits were seen causing thickening of the glomerular capillary basement membrane with segmental accentuation, and widening of the mesangium. Immunofluorescence examination showed moderate amounts of IgG and C3 in the glomerular capillary walls with some in the mesangium. Ultrastructurally, 20-nm thick fibrils with microtubular organisation were present predominantly in the subendothelial region with similar fibrils in the mesangium. Although immunotactoid glomerulopathy and fibrillary glomerulonephritis (FG) have been recognised as entities with extracellular fibrillary material in the kidney, to date much remains to be clarified regarding these 2 conditions. While the renal biopsy findings in this patient are consistent with ITG, her clinical presentation is unlike that of usual ITG in that she is of a much younger age and has no associated haemopoietic disorder. Response to initial treatment of 8 weeks of prednisolone therapy was poor.     

Nephrotic syndrome in a patient with IgA deficiency-associated mesangioproliferative glomerulonephritis

A case of mesangioproliferative glomerulonephritis in a 55-year-old woman with selective IgA deficiency and serum antinuclear antibodies who presented with nephrotic syndrome is described. The patient did not have clinical or laboratory features of systemic lupus erythematosus (SLE) other than antinuclear antibodies. Histology of the patient's renal biopsy revealed a mesangioproliferative glomerulonephritis and direct immunofluorescence showed that paramesangial deposits contained predominant IgM with lesser IgG, C3 and C1q. These findings are identical to those previously described in a form of glomerulonephritis associated with IgA deficiency and would be atypical for lupus nephritis. Glomerulonephritis is not a well recognized complication of IgA deficiency, though it has been rarely reported in the literature. This case provides further evidence that IgA deficiency is associated with a unique immune complex-mediated glomerulopathy with characteristic immunopathological and ultrastructural features. It is the first reported case to present with nephrotic syndrome.     

Pathology of glomerular deposition diseases

In routine diagnosis on renal biopsy, one of the confusing fields for pathological diagnoses is the glomerulopathies with fibrillary structure. The primary glomerulopathies with a deposit of ultrastructural fibrillary structure, which are negative for Congo-red stain but positive for immunoglobulins, include fibrillary glomerulonephritis and immunotactoid glomerulopathy. Several paraproteinemias including cryoglobulinemia, monoclonal gammopathy, and light chain deposition disease as well as hematopoietic disorders including plasmacytoma, plasma cell dyscrasia, and B cell lymphoproliferative disorders involve glomerulopathy with an ultrastructural fibrillary structure. A rare glomerulopathy with fibrillary structure that stains negative for Congo-red as well as for immunoglobulins has been also reported. The pathological diagnoses of these glomerulopathies can include either glomerular diseases, or paraproteinemic diseases, or hematopoietic diseases. The terminology is still confusing when glomerular diseases can be combined with paraproteinemic diseases and/or hematopoietic diseases. Therefore, the generic term, 'glomerular deposition disease' (GDD), has been proposed by pathologists with a requirement for clinicians to detect autoantibodies, paraproteins as well as to carry out a bone marrow check. An attempt has been made to rearrange the diseases with related disorders of fibrillary deposits, based on detailed clinical and pathological finding and to elucidate the correlation between GDD, paraproteinemia, and hematopoietic disorder.     

A 59-year-old woman with immunotactoid glomerulopathy, heavy-chain disease, and non-hodgkin lymphoma

Immunotactoid glomerulopathy is one of several renal disorders characterized by the extracellular deposition of nonamyloid fibrillary deposits. There is considerable debate as to whether immunotactoid glomerulopathy should be distinguished from fibrillary glomerulonephritis, a closely related entity. Currently, the distinction is based on fibril size and arrangement. We report the case of a 59-year-old woman in whom a diagnosis of immunotactoid glomerulopathy was made after a 2-year history of proteinuria. Electron microscopy of her renal biopsy showed randomly arranged microtubular subepithelial and mesangial deposits, which measured 34 nm in average diameter. She was later discovered to have circulating immunoglobulin G heavy chains without associated light chains (gamma-heavy-chain disease) and, subsequently, non-Hodgkin lymphoma, follicular lymphoma, grade I (World Health Organization classification). Approximately 100 cases of gamma-heavy-chain disease have been reported in the literature since it was originally described by Franklin in 1964. However, while there are 10 reports in the literature of heavy-chain disease with fibrillary deposits in the kidney, none fit the criteria for immunotactoid glomerulopathy.     

One case of immunotactoid glomerulopathy: morphological-ultrastructural aspects

Starting from a group of 736 renal biopsy patients, evaluated by ultrastructural studies over a period of 22 years, the authors present a rare case of immunotactoid glomerulopathy, suggesting that these forms, until a few years ago considered in the same group as fibrillary glomerulonephritis, are in fact a separate entity; moreover, they may represent a very early manifestation of plasmacellular dyscrasia still at the initial stage.     

Congo red-negative amyloidosis-like glomerulopathy

Three cases of amyloidosis-like glomerulopathy are presented in which renal amyloidosis was initially diagnosed on the basis of ultrastructural findings, despite negative Congo red staining. The histologic and immunofluorescence findings and, on careful examination, ultrastructural features of this amyloidosis-like glomerulopathy all serve to distinguish it from true amyloidosis. The clinical behavior suggests that it is a primary glomerulopathy since, with time, no other systems become involved.     

A case of systemic lupus erythematosus which Parkinsonism was induced by tacrolimus

The present case is the first report of a systemic lupus erythematosus patient which has been induced Parkinsonism with the administration of tacrolimus (TAC). A 50-year-old woman was diagnosed as lupus nephritis on September 2003. The patient had been prescribed initially 40 mg/day of prednisolone, then cyclosporine was added on May 2005. One year later, she developed severe headache, so cyclosporine was stopped, and she was prescribed tacrolimus on February 2007. However her severe headache had been disappeared, she experienced rigidity and tremor around September 2007. The Dopamine-transporter-imaging examination reavealed that she had Parkinson's disease. The gene analysis on the genetic background showed her case was the sporadic type? Parkinson's disease. Washing out of Tacrolimus, her Parkinsonism was partially improved. This fact suggested that her Parkinsonism was drug-induced type Parkinsonism. In lupus nephritis patients who have been treated with TAC, a very careful observation should be considered because neurological disorders inducing Parkinsonism may occur.     

Hyaline glomerulopathy with tubulo-fibrillary deposits in young ddY mice

Hyaline glomerulopathy with tubulo-fibrillary deposits was observed in two young female ddY mice. One of the mice showed gross systemic edema and bilateral enlargement and pale color of the kidneys, whereas no significant gross findings were noted in the other mouse. Microscopically, a large number of the glomeruli in both mice were enlarged because of diffuse and global deposition of amorphous eosinophilic materials. The deposits were negatively stained with Congo red and positively stained with IgG, IgM, IgA, C3, and periodic acid-Schiff. Electron microscopic examination revealed microtubular and fibrillary deposits with diameters of 80-100 and 9-16 nm, respectively, in the subendothelial space of the glomeruli. These features are histopathologically similar to immunotactoid glomerulopathy or fibrillary glomerulonephritis according to the classification of human glomerular lesions. Understanding of these characteristics of hyaline glomerulopathy in ddY mice is essential when evaluating pharmacological, pharmacokinetic, and toxicological studies using this mouse strain.     

IgA-associated glomerulonephritides: a study with monoclonal antibodies

Thirty-six renal biopsies from patients with various glomerulonephritides which exhibited prominent IgA deposits were studied by indirect immunofluorescence technique utilizing monoclonal antibodies specific for alpha chain (IgA), IgA1 and IgA2 subclasses, secretory IgA, and secretory component. The ability of the IgA deposits to bind free secretory component in vitro was examined in five biopsies of IgA nephropathy of Berger and in five biopsies of lupus nephritis. All the biopsies revealed IgA1 deposits. Associated IgA2 was found in lupus nephritides and hepatic glomerulopathy. Secretory IgA and free secretory component were not detected in any biopsy. In situ free secretory component binding was demonstrated in IgA nephropathy of Berger but not in lupus nephritides. These results indicate that polymeric IgA1 molecules are the chief nephritogenic antibodies in IgA nephropathy of Berger, that there is a high frequency of association of IgA1 and IgA2 in lupus nephritides and, perhaps, hepatic glomerulopathy, and that secretory IgA does not appear to play a role in IgA-associated glomerulonephritis.     

Hepatitis B virus-related nephropathy and lupus nephritis: morphologic similarities of two clinical entities.

We compared the clinicopathologic features of 22 patients with hepatitis B virus-related membranous nephropathy, all with detectable glomerular hepatitis B e antigen, and of 26 patients with lupus nephritis class V. Both groups of patients similarly presented with heavy proteinuria or nephrotic syndrome; however, the patients with hepatitis B virus-related membranous nephropathy, who were predominantly male, did not have the extrarenal manifestations and autoantibodies seen in systemic lupus erythematosus. The glomerular lesions in both clinical entities were similar and at times indistinguishable, demonstrating polyclonal immunoglobulins and polytypic complements in similar subepithelial ultrastructural distribution. No morphologic feature, single or combined, carrying a high positive predictive value for the diagnosis of either nephritis was identified. Lesions such as hematoxyphil bodies and fingerprint dense deposits, distinctive of systemic lupus erythematosus, were rarely found. At the time of biopsy, when systemic lupus erythematosus is not clinically suspected, the diagnosis between hepatitis B virus-related membranous nephropathy and lupus nephritis may be difficult or impossible to differentiate, especially in geographic areas where both lupus nephritis and hepatitis B surface antigen carriers are common. This study focused on the use of specific monoclonal antisera to detect glomerular hepatitis B virus antigens, which contribute to the diagnosis of hepatitis B virus-related nephritis.     

Hydroxychloroquine-induced Phospholipidosis in a Case of SLE: The Wolf in Zebra Clothing

Abstract

A 30 year old lady patient of SLE on steroid and hydroxychloroquine therapy presented with lupus nephritis and later developed cardiac symptoms. Her renal biopsy revealed features of Class III lupus nephritis. Also seen was typical lamellated myelinoid material in the glomerulus. The alpha-galactosidase A activity was normal. The clinical morphological and biochemical findings were consistent with Lupus nephritis showing changes of hydroxychloroquine induced phopholipidosis. Electron microscopy along with careful clinical examination and follow up status was instrumental in the diagnosis of the latter.     

Specificity of Intertubular Capillary Changes: Comparative Ultrastructural Studies in Renal Allografts and Native Kidneys

The pathophysiology of chronic rejection of renal allografts is poorly understood and specific morphologic markers are being sought for its diagnosis. Ultrastructural splitting and reduplication of the basal lamina of the intertubular capillaries (ITCs) have been shown to be consistently associated with transplant glomerulopathy (TG) in renal allografts and have been used as a marker of chronic allograft rejection. Although the presence of ITC abnormalities is extremely helpful diag-nostically and has been considered a surrogate for the diagnosis of TG when glomeruli are not available for examination, their specificity has not been tested. This study examined 135 biopsy specimens from renal allografts and native kidneys and categorized the ITC basal lamina alterations into 5 patterns. The results showed that although marked ITC basal lamina abnormalities are characteristically seen in association with TG, lesser degrees of these changes may also be found in native kidneys and in transplants with other types of glomerulopathies. In native kidneys, splitting and reduplication of the ITC basal lamina were observed in cases of active lupus nephritis, membranoproliferative glomerulonephritis type I, crescentic glomerulonephritis, cryoglobulinemia, and hypertension. In allografts, ITC changes were seen in postinfectious proliferative glomerulonephritis, acute cyclosporin toxicity, and hemolytic uremic syndrome, in addition to cases with TG. The histopathologic diagnosis in renal diseases relies heavily on clinical, immunofluorescence, and ultrastructural findings. Therefore, in the transplantation setting, with other less common pathological processes ruled out, the presence of abnormalities of the ITC basal lamina is highly indicative of TG. This association is particularly true for cases with severe ITC abnormalities.     

Hepatitis B virus-related glomerulopathy in patients with systemic lupus erythematosus

The clinical data and renal pathologic information from three patients with systemic lupus erythematosus (SLE), active glomerular disease, and hepatitis B virus (HBV) antigenemia are presented. All three patients fulfilled the American Rheumatism Association criteria for the diagnosis of SLE. However, the renal pathologic results excluded the diagnosis of lupus nephritis. The common findings shared by these patients included the following: presence of hepatitis B surface antigen (HBsAg) in both serum and glomeruli and of glomerular hepatitis B core antigen (HBcAg), and the absence of polyclonal immunoglobulins, C1q and C4, deposition in renal tissue. These common features and the renal pathologic results indicated that the glomerulopathy was associated with HBV antigenemia. The cases described here may represent a subset of patients with SLE in whom expression of lupus nephritis was altered by the concomitant HBV-related glomerulonephritis.     

Immunohistopathologic evaluation of C1q in 800 renal biopsy specimens

The frequency, distribution, and intensity of C1q localization were evaluated in 800 renal biopsy specimens, and these observations were correlated with light, immunofluorescence, and electron microscopy findings. Intense C1q immunostaining was most frequent in proliferative and membranous lupus glomerulonephritis and in a recently described form of proliferative glomerulonephritis designated "C1q nephropathy." Moderate intensity C1q immunostaining was observed in most cases of type I but not type II, membranoproliferative glomerulonephritis. Unlike lupus membranous glomerulopathy, non-lupus membranous glomerulopathy usually did not have extensive C1q localization. C1q was scanty or absent in IgA nephropathy and antiglomerular basement membrane antibody mediated glomerulonephritis. C1q, along with IgM and C3, was often present at sites of glomerular sclerosis, especially in focal segmental glomerulosclerosis. Extraglomerular C1q was most frequent and most intense in cases of lupus nephritis having extraglomerular immune deposits. The presence or absence and intensity of C1q immunostaining were shown to be useful in the differential diagnosis of some glomerulopathies.