Glomerular crescents predominantly express cadherin-catenin complex in pauci-immune-type crescentic glomerulonephritis

AIMS

To investigate the expression of the cadherin complex in human crescentic glomerulonephritis to elucidate the role of intercellular adherens junction molecules in crescent formation.

METHODS AND RESULTS

Immunostaining revealed cadherin complexes localized in Bowman's epithelial cells, but not in podocytes, of normal human glomeruli. Eight adult cases with myeloperoxidase anti-neutrophil cytoplasmic autoantibodies (MPO-ANCA)-related (pauci-immune type) crescentic glomerulonephritis were examined on immunofluorescence microscopy with anti-pan cadherin, p120 catenin, and beta-catenin antibodies. The specimens provided six cellular crescents, 12 fibrocellular crescents, and four fibrotic crescents. Immunofluorescence was semiquantitatively estimated by the rate of the field of localization within the whole area of the crescent, according to the four-grade system [(-) - (++)]. All the tested molecules consisting of the cadherin complex were abundantly observed in cytokeratin-positive epithelial components in crescents, each with an equivalent area of localization. The expression of the cadherin complex was closely associated with that of cytokeratin and both diminished as the crescents developed from cellular to fibrotic.

CONCLUSIONS

The cadherin-catenin complex is a specific marker of Bowman's epithelial cells in human glomeruli. The cellular crescents in pauci-immune-type crescentic glomerulonephritis possess adherens junction molecules, indicating a principle parietal epithelial cell phenotype.

Clinical and pathological assessment of acute vascular rejection in the transplant kidney

Acute vascular rejection (AVR) in kidney transplantation is the most important factor influencing graft prognosis. We focus on patients whose grafts were lost because of AVR, and assessed their clinical characteristics and histological findings of biopsied renal grafts. Biopsied specimens exhibited AVR in 43 patients who underwent kidney transplantation in the Kidney Center of Tokyo Women's Medical University from 1995 to 1999. In the follow-up from 1 to 5 yr (median: 2.5 yr) we classified these patients into three groups: favourable prognosis group (FPG), relatively poor prognosis group (RPPG) and poor prognosis group (PPG). Light microscopic study for histological grading of acute rejection according to the Banff scheme and detection of the C4d complement deposition on peritubular capillaries by the immunofluorescence method were performed. Based on the results, the donors of RPPG and PPG were significantly older than those of FPG, and all factors of acute rejection according to the Banff scheme were not statistically significantly different among the three groups. However, an acute tubular injury mimicking acute tubular necrosis (ATN) was observed in the biopsy specimens from PPG. In conclusion, an older donor is a risk factor of poor prognosis of the graft with AVR, and acute tubular injury mimicking ATN is one of the important features that enables the prediction of graft failure originating from AVR in kidney transplantation.

Inherited factor H dysfunction and complement-associated glomerulonephritis in renal grafts of first and second transplantations

A 38-yr-old man with factor H dysfunction and unknown glomerular disease received first and second renal transplantations (Tx) from living-related donors. His examination showed a low percentage activity of factor H (31%). Factor H dysfunction has been known to be associated with type II or III membranoproliferative glomerulonephritis (MPGN), haemolytic uraemic syndrome and IgA GN. The first graft from his mother showed diffuse mesangial deposit of IgA. His son has had IgA GN and his data also revealed a low percentage activity of factor H (33%). He and his son both showed a low activity of C3. Moreover, his father, who was the donor of the second Tx, had a low percentage activity of factor H (25%), and presented with mild glomerular deposit of C3 at operation, while he has been healthy through his entire 67 yr of life. Each of them had a low percentage activity of factor H. These findings through three generations suggested the inheritance of factor H dysfunction. The patient presented with proteinuria 3 months after the first Tx. At the first biopsy 30 months after the first Tx, light microscopy revealed minor glomerular abnormalities with electron dense deposits in subepithelial, intramembranous and mesangial regions, while immunofluorescence showed massive glomerular deposits of C3. In the second biopsy 51 months after the first Tx, the glomerulonephritis developed mesangial proliferation and crescent formation, accompanied by more massive C3 deposit and intramembranous, mesangial and subepithelial dense deposits. He then required redialysis. At the second and third biopsies within 2 months after the second Tx, the renal graft showed similar findings to the first biopsy after the first Tx. He perhaps presented with a recurrence of complement-associated GN, showing an atypical form of MPGN after Tx. These findings suggest that factor H dysfunction may play an important role of a certain pathogenesis of GN.

Soluble osteopontin and vascular calcification in hemodialysis patients

BACKGROUND

Vascular calcification often occurs in patients with uremia. As osteopontin (OPN) is not only involved in the physiological but also the pathological calcification of tissues, OPN may be associated with the pathogenesis of aortic calcification in hemodialysis (HD) patients.

METHODS

We examined the expression of OPN in atherosclerotic aortas of HD patients. In addition, we performed a prospective longitudinal study by using CT scans to detect aortic calcifications and by measuring the plasma OPN concentration by ELISA in HD patients (20 men, 16 women; mean age 55.2 +/- 21.3 years) and in healthy volunteers (18 men, 17 women; mean age 54.0 +/- 13.2 years).

RESULTS

By immunohistochemical staining, OPN was abundantly localized in atherosclerotic plaques of HD patients. The macrophages surrounding the atheromatous plaques were identified as the OPN-expressing cells. We furthermore found that the concentration of soluble plasma OPN was significantly higher in HD patients as compared with the concentrations in age-matched healthy volunteers (837.3 +/- 443.2 vs. 315.1 +/- 117.4 ng/ml, p < 0.01). The OPN concentration was positively correlated with the aortic calcification index in HD patients (r = 0.749, p < 0.01).

CONCLUSION

These data suggest that OPN, secreted by macrophages, plays a role in the calcification of atheromatous plaques in HD patients.

Tubular osteopontin expression in patients with ANCA-associated glomerulonephritis

OBJECTIVE

To elucidate the role of osteopontin (OPN) in monocyte recruitment in crescentic glomerulonephritis, we investigated immunohistochemical localization of OPN in the kidney and its correlation with clinical and histopathologic parameters in biopsy specimens of patients with myeloperoxidase antineutrophil cytoplasmic autoantibody- (MPO-ANCA) associated glomerulonephritis.

METHODS

Twelve patients with MPO-ANCA-associated glomerulonephritis were enrolled in this study. Clinical parameters such as creatinine clearance and urinary protein excretion of each patient were obtained at the time of biopsy. Paraffin-embedded sections were used for immunohistochemical staining using the LSAB method. Five cortical interstitial fields randomly selected at original magnification x 200 were assessed using a computer-assisted color image analyzer. Tubular OPN expression was assessed as the percentage of positive area in the tubulointerstitium. Double immunofluorescent staining using antibodies against OPN and alpha(v)beta3 was performed.

RESULTS

In all of the cases studied, OPN was occasionally localized within the glomeruli, and expressed slightly in proximal tubular epithelium and significantly in distal tubular epithelium. Tubular OPN expression tended to be promoted in the interstitium infiltrating by numerous monocytes/macrophages. The extent of tubular OPN expression was positively correlated with serum ANCA titers and urinary OPN concentrations. Enhanced alpha(v)beta3 expression appeared in the distal tubular epithelium expressing OPN.

CONCLUSION

These results suggest that inducible expression of OPN and alpha(v)beta3 in the tubular epithelium seems to be associated with interstitial moncyte infiltration and subsequent tubulointerstitial changes in human MPO-ANCA-associated glomerulonephritis.

Cancer-prone syndrome of mosaic variegated aneuploidy and total premature chromatid separation: report of five infants

Five infants (two girls and three boys) from four families all had severe pre- and postnatal growth retardation, profound developmental delay, microcephaly, hypoplasia of the brain with Dandy-Walker complex or other posterior fossa malformations, and developed uncontrollable clonic seizures. Four infants developed Wilms tumors, and one showed cystic lesions in bilateral kidneys. All five infants showed variegated mosaic aneuploidy in cultured lymphocytes. In two infants whose chromosomes were prepared by us, 48.5%-83.2% lymphocytes showed total premature chromatid separation (PCS). Their parents had 3.5%-41.7% of their lymphocytes in total PCS. The remaining three infants and their parents, whose chromosomes were prepared at outside laboratories, tended to show lower frequencies of total PCS. Another five infants reported with the disorder were reviewed together with the five infants we described. Together, their clinical and cytogenetic manifestations were similar enough to suggest a syndrome. Seven of the 10 infants developed proven or probable Wilms tumors. The age at diagnosis of the tumors was younger than usual at 2-16 months. The tumors were bilateral in four infants and unilateral in three infants, and cystic changes were present in six infants. Two infants developed botryoid rhabdomyosarcoma. The carriers of the syndrome are thus liable to tumorigenesis. The possible role of mitotic checkpoint defects, proven in two infants with the syndrome (Matsuura et al. [2000: Am J Hum Genet 69:483-486]), was discussed in connection with tumor development and progression.

Opposing effects of anti-activation-inducible lymphocyte-immunomodulatory molecule/inducible costimulator antibody on the development of acute versus chronic graft-versus-host disease

The functional role of inducible costimulator (ICOS)-mediated costimulation was examined in an in vivo model of alloantigen-driven Th1 or Th2 cytokine responses, the parent-into-F(1) model of acute or chronic graft-vs-host disease (GVHD), respectively. When the Ab specific for mouse ICOS was injected into chronic GVHD-induced mice, activation of B cells, production of autoantibody, and development of glomerulonephritis were strongly suppressed. In contrast, the same treatment enhanced donor T cell chimerism and host B cell depletion in acute GVHD induced host mice. Blocking of B7-CD28 interaction by injection of anti-B7-1 and anti-B7-2 Abs inhibited both acute and chronic GVHD. These observations clearly indicate that the costimulatory signal mediated by CD28 caused the initial allorecognition resulting in the clonal expansion of alloreactive T cells, whereas the costimulatory signal mediated by ICOS played a critical role in the functional differentiation and manifestation of alloreactive T cells. Furthermore, treatment with anti-ICOS Ab selectively suppresses Th2-dominant autoimmune disease.

Adrenal hemangioma removed by a retroperitoneoscopic procedure

Only about 50 surgical cases of adrenal hemangioma have been reported in the literature. Presented here is the first case of a large adrenal hemangioma that was removed by a retroperitoneoscopic procedure.

A peculiar vacuolization in the kidney transplant of a child treated with tacrolimus

Tacrolimus (TAC) is a useful immunosuppressive agent in the prevention of rejection. However, the blood level between its therapeutic and toxic levels is narrow such that its nephrotoxicity is a problem. Moreover, its bioavailability and pharmacokinetics are highly variable. We experienced a case of acute nephrotoxicity, in which the blood level rose about 10 times above the expected level. We found a peculiar vacuolization in the transplant biopsy specimen. This change showed a marked vacuolization of the tubular cells, suggestive of acute nephrotoxicity by TAC.

Super long-term surviving two renal grafts with severe arteriolosclerosis and glomerulosclerosis

Two long-term renal transplant survivors, for about 20 yr, with unusual histological features in the allograft kidney are reported. In both cases, marked hyalinosis was observed in the arterioles of the transplanted kidney, despite never having been administered cyclosporine or tacrolimus. The cause remains unknown at the present time, but we think that the changes could be multifactorial in origin, including due to aging of the graft, hypertension, hyperlipidemia and chronic rejection. We conclude that histological analysis of the allograft kidney must be performed in long-term renal transplant survivors, in order to understand the histological changes in the chronic phase after kidney transplantation and to predict the prognosis of the graft.

CD28 knockout mice as a useful clue to examine the pathogenesis of chronic graft-versus-host reaction

BACKGROUND

Injection of BALB/c or DBA/2 spleen cells into F1 C57BL/6 (B6) hybrids induces a graft-versus-host reaction (GVHR) of a chronic stimulatory type that results in clinical and pathologic manifestations that resemble the human systemic lupus erythematosus (SLE). The aim of the present study was to examine the role of a major T-cell costimulatory signal receptor, CD28, in the production of autoantibody and the development of an immune complex glomerulonephritis, which are common in SLE pathology.

METHODS

For this purpose, CD28-deficient (CD28KO) mice were used for the source of donor lymphocytes. Chronic GVHR was induced by an injection of BALB/c or BALB. CD28KO donor cells into normal BCF1 mice. Serum titers of anti-dsDNA antibodies were assessed by enzyme-linked immunosorbent assay (ELISA) and major histocompatibility complex (MHC) class II antigen expression on B cells were tested by flow cytometry. In addition, depositions of immunoglobulin (Ig) were examined by direct immunofluorescence staining on frozen kidney sections.

RESULTS

When (BALB/c x B6)F1 mice were injected with parental BALB/c lymphocytes, serum anti-dsDNA titer was significantly increased in association with nonspecific B-cell activation and IgG deposition in the glomerular basement membrane. In sharp contrast, none of these signs were observed in F1 mice, which were injected with CD28KO spleen cells.

CONCLUSION

The CD28-mediated T-cell costimulatory pathway plays a pivotal role in the development of polyclonal B-cell activation, autoantibody production, and an immune complex glomerulonephritis. We propose that CD28KO mice are useful clues in examining the pathogenesis of experimental lupus nephritis.

A simple histological method differentiating AL-type from AA-type amyloidosis

Amyloidosis is a disease caused by deposition of amyloid protein in various tissues and organs, and is also an important cause of chronic renal failure, usually occurring within 3 years of the development of nephrotic syndrome. To date, 13 types of amyloid proteins have been identified in humans, regardless of systemic or localized amyloidosis. Amyloid proteins derived from serum amyloid A (AA), immunoglobulin light chains (AL), transthyretin, and β₂-microglobulin are constituents in systemic amyloidosis. Despite the close histological resemblance of each amyloid deposit, the pathogenesis appears to differ according to individual amyloidosis.

Phenotypic characteristics and cyclin-dependent kinase inhibitors repression in hyperplastic epithelial pathology in idiopathic focal segmental glomerulosclerosis

Hyperplastic glomerular epithelial lesion is an important determinant of the progression of idiopathic focal segmental glomerulosclerosis (FGS). The proliferation and differentiation of glomerular epithelial cells and parietal epithelial cells (PECs) are regulated differently by cyclin and cyclin-dependent kinase inhibitors (CKIs) during nephrogenesis. To access the cellular mechanism underlying epithelial hyperplasia in the development of FGS, the present study applied immunohistochemistry to 21 cases of FGS to demonstrate expression of cell-cycle molecules and phenotypic characterization in proliferative epithelial lesions in FGS. The materials included segmental sclerosis (18.1%), which was divided into monolayer epithelial lesions (64.6%) and cellular lesions (35.4%). All of the cellular lesions expressed cytokeratin, frequently with Ki-67 (82.4%) and less frequently with cyclin A (17.7%), but were invariably negative for podocyte markers (PHM-5 and synaptopodin) and CKIs (p27kip1 and p57kip2). Podocytes in nonsclerotic tuft in the same glomeruli with cellular lesions strongly expressed CKIs and podocyte markers. Moreover, electron microscopy showed that some large proliferating cells with prominent nucleoli have a broad cell base attached to Bowman's capsule. These cells have cilia and a junctional complex with neighboring hyperplastic cells, some of which directly cover the glomerular basement membrane. This suggests that cellular lesions are of PEC origin. Monolayer epithelial lesions also exclusively exhibited a PEC phenotype with reciprocal expression of podocyte markers and cytokeratin. In addition, CKIs are weakly expressed in monolayer epithelial lesions, suggesting a re-entry of cell-cycle quiescent. In conclusion, proliferation of PEC, sustained by repression of CKIs in nature and simultaneous activation of cyclin A, is the actual molecular background to the cellular lesions in FGS. Cellular lesions may result in monolayer epithelial lesions that retain the PEC phenotype and enter a common pathway to glomerulosclerosis.

Basaloid-squamous carcinoma of the esophagus: report of a case

We report herein the case of a 69-year-old man with basaloid-squamous carcinoma (BSC) of the esophagus. To the best of our knowledge, this is the 60th case of BSC of the esophagus to be reported in Japan, and a review of the other 59 cases is presented after this case report. In our patient, endoscopic findings revealed a circumferential erosion in the middle intrathoracic esophagus (Im), and a protruding tumor with friable ulceration in the center of the erosion. A biopsy suggested that it was moderately differentiated squamous cell carcinoma (SCC), and a thoracoscopic total thoracic esophagectomy was performed. Histologically, the protruding-type lesion with ulceration was composed of BSC, and the circumferential 0 -I + IIc type lesion was composed of moderately differentiated SCC. The immunohistochemical findings of these resected specimens led us to suspect that the basal-layer-type SCC had transformed into BSC by undergoing differentiation and expansive proliferation.

Glomerular expression of cell-cycle-regulatory proteins in human crescentic glomerulonephritis

To elucidate the mechanism underlying crescentic formation, we assessed the phenotypic characterization and cell-cycle protein expression in human crescentic glomerulonephritis (CRGN). Kidney tissue specimens taken from CRGN patients (10 patients with pauci-immune type rapidly progressive glomerulonephritis (RPGN), 2 patients with Henoch-Schönlein purpura nephritis, and 1 patient with IgA nephropathy) were examined immunohistochemically. Most of the cellular components of the crescents expressed cytokeratin, whereas few cells expressed PHM-5. CD68-positive cells were minor components of cellular crescents, indicating that the major principal cellular component of the crescents is made up of cells with the parietal glomerular epithelial cell (PEC) phenotype. Additionally, serial section analysis revealed that Ki-67-positive cells in the crescents were frequently cyclin-A positive and Bcl-2 positive, but seldom cyclin-B(1) positive. Moreover, the expression of cyclin-dependent kinase inhibitor p27(Kip1) was low in the cellular crescents, despite being exclusively positive in podocytes within the same section. We concluded that the major component of the cellular crescents is made up of PECs and that apparent expression of cyclins and Bcl-2 and restrained expression of p27(Kip1) may be synergistically associated with the development of cellular crescents in human CRGN.

Clinical significance of hepatocyte growth factor and c-Met expression in extrahepatic biliary tract cancers

Hepatocyte growth factor (HGF)/c-Met expression is known to be correlated with poor prognosis in several cancers. We investigated HGF/c-Met immunoreactivity and its correlation with clinical features in 51 patients with curatively resected extrahepatic biliary tract carcinoma. c-Met showed significant correlations with tumor location, T category, stage, perineural invasion and local recurrence. Overall survival in patients with HGF and c-Met immunopositivity was significantly worse than in those who were negative. Our findings suggest that HGF/c-Met play some roles in tumor development and that HGF/c-Met immunoreactivity could be a predictor of the mode of recurrence and poor prognosis.

Increased serum levels of vascular endothelial growth factor in human crescentic glomerulonephritis

OBJECTIVE

To investigate the serum levels of vascular endothelial growth factor (VEGF) in human crescentic glomerulonephritis (CRGN).

METHODS

The serum VEGF levels in CRGN patients were compared with those in healthy subjects and in various types of glomerulonephritis. In addition, we investigated the relationship between serum VEGF levels and creatinine levels (Scr) and pathological parameters.

RESULTS

The serum VEGF levels of the CRGN patients were significantly higher than in the healthy subjects and patients with MCNS, IgAN, and FGS. No correlation was found between serum VEGF levels and Scr in the RPGN patients. The serum VEGF levels in 6 CRGN patients had significantly decreased after 6 months of corticosteroid therapy. Moreover, there was a significant correlation between the serum VEGF levels and the crescent frequency or the grade of interstitial injury, and the rates of glomerular infiltration by macrophages.

CONCLUSIONS

In the CRGN patients, severe glomerular and interstitial damages would result in increased serum VEGF levels and corticosteroid therapy may exert its efficacy through reduction of serum VEGF levels.

Accumulation of advanced glycation end products in the peritoneal vasculature of continuous ambulatory peritoneal dialysis patients with low ultra-filtration

BACKGROUND

Ultra-filtration failure is a serious complication of long-term continuous ambulatory peritoneal dialysis (CAPD). This complication is related to histological changes of the peritoneum, i.e. severe interstitial fibrosis and microvascular sclerosis. Although their pathogenesis has not been elucidated yet, advanced glycation end products (AGEs) have been shown to accumulate in the peritoneal tissue of CAPD patients.

METHODS

Peritoneal biopsy specimens from 14 CAPD patients with low ultra-filtration (n = 9) and high ultra-filtration (n = 5) capacity were immunohistochemically investigated using a monoclonal antibody against AGEs (6D12). The severity of peritoneal fibrosis, microvascular sclerosis and intensity of AGE accumulation were semi-quantitatively evaluated. Peritoneal ultra-filtration capacity was evaluated by calculating daily ultrafiltration volume per body weight (UFV/BW) and D/D0 (glucose) of the peritoneal equilibration test.

RESULTS

In all patients with low ultra-filtration, AGE accumulated in the peritoneal fibrous tissue and microvascular walls. Remarkably, AGE accumulated more intensely in hyalinized fibrosis of small venular media. Extent of AGE accumulation in peritoneal interstitium and vascular walls correlated with the progression of interstitial fibrosis (rho = 0.727, P = 0.0088) and vascular sclerosis (rho = 0.915, P = 0.001). UFV/BW was inversely correlated to interstitial fibrosis (rho = -0.660, P = 0.0174), microvascular sclerosis (rho = -0.671, P = 0.0155) and microvascular AGE accumulation (rho = -0.678, P = 0.0145).

CONCLUSIONS

In CAPD patients, AGE formation in the peritoneum correlates with the development of severe interstitial fibrosis and microvascular sclerosis, which is associated clinically with impaired peritoneal ultra-filtration.

Vascular endothelial growth factor expression is an independent negative predictor in extrahepatic biliary tract carcinomas

BACKGROUND

Vascular endothelial growth factor (VEGF) is one of the most important factors for angiogenesis in various tumors. However, its clinical significance in extrahepatic biliary tract carcinoma remains unclear.

MATERIALS AND METHODS

To clarify the association of VEGF expression with the clinicopathological features of the disease, surgical specimens from 51 patients were examined for VEGF expression by immunohistochemistry.

RESULTS

Sixteen of 51 (31.4%) cases were positive for VEGF. VEGF immunoreactivity showed a tendency toward association with lymph node metastasis, M category and peritoneal recurrence (p = 0.059, 0.086 and 0.069, respectively). Overall survival in patients with VEGF positivity was significantly worse than in those with negativity (p = 0.033 by log-rank test). Multivariate Cox regression analysis revealed that VEGF expression was an independent negative predictor (p = 0.025).

CONCLUSION

VEGF immunoreactivity is an independent negative predictor in extrahepatic biliary tract carcinomas.