Endothelial chimerism in association with vascular rejection in patients after kidney transplantation.
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Endothelium, Vascular↗
Biomedical subjects
Yutaka Yamaguchi
Publications and source records attributed to Yutaka Yamaguchi.
Incidence of latent mesangial IgA deposition in renal allograft donors in Japan.
BACKGROUND: Mesangial immunoglobulin A (IgA) deposition is incidentally encountered in asymptomatic individuals, but its precise frequency and significance had not been clarified. The background of the latent IgA deposition is related to the epidemiology and pathogenesis of IgA nephropathy. METHODS: Zero-hour allograft biopsies were performed in 510 renal transplantations (446 living donors, and 64 cadaveric donors) at the Kidney Center of Tokyo Women's Medical University. Mesangial IgA and C3 deposition were analyzed immunohistochemically, and the frequency and clinicopathologic features of mesangial IgA deposition were investigated. RESULTS: Mesangial IgA deposition was present in 82 (16.1%) of the total 510 allografts with no statistical difference between living donors (72/446, 16.1%) and cadaveric donors (10/64, 15.6%) or between blood-related donors (66/392, 16.8%) and nonblood-related donors (16/110, 14.5%). Mesangial C3 deposition was present in 16 (19.5%) of the 82 allografts with mesangial IgA deposition. The grade of hematuria in IgA(+) donors was significantly higher than IgA(-) donors (1.30 +/- 1.17 vs. 0.86 +/- 0.89, P = 0.025). Histologic investigation of IgA(+) allografts revealed the frequency of mesangioproliferative glomerulonephritis (PGN) was significantly higher in IgA(+)/C3(+) allografts (8/16, 50%) than in IgA(+)/C3(-) allografts (11/66, 16.7%) (P = 0.0084). Moreover, the number of infiltrated macrophages to glomerulus (cells/glomerular cross section) was significantly higher in the IgA(+)/C3(+) allografts than in IgA(+)/C3(-), IgA(-)/C3(+) and IgA(-)/C3(-) allografts (1.10 +/- 0.62 vs. 0.61 +/- 0.42, P = 0.0008; 0.47 +/- 0.34, P = 0.023; and 0.37 +/- 0.23, P = 0.002, respectively). CONCLUSION: The latent mesangial IgA deposition was a relatively common phenomenon in the healthy Japanese donors. This phenomenon was associated with mild degree of microhematuria, mesangial proliferation and glomerular macrophage infiltration in some of the affected individuals, especially with combined IgA and C3 deposition.
Adolescent↗
[Solitary fibrous tumor of the fourth ventricle: case report].
A rare case of solitary fibrous tumor, located wholly within the fourth ventricle, is reported. A 57-year-old male presented with headache and nausea. The preoperative magnetic resonance images revealed a well circumscribed mass in the fourth ventricle that exhibited a low intensity on T1-weighted images and homogeneously enhanced with gadolinium. Vertebral angiogram revealed a tumor stain supplied from the choroidal branches of the posterior inferior cerebellar artery. The tumor was totally resected through a midline suboccipital approach. Histologically, the tumor was composed of spindle-shaped cells growing in fascicles within a collagenous matrix. Immunohistochemical staining demonstrated vimentin and the CD34 positivity of tumor cells. Solitary fibrous tumor is a newly described entity, which should be considered in the differential diagnosis for dural-based lesions.
Cerebral Ventricle Neoplasms↗
Ultrastructure of human pheochromocytoma cells cultured for long periods.
We conducted ultrastructural analysis of human pheochromocytoma (PC) cells maintained in primary culture for about 10 months. The cells were first isolated by the enzymatic treatment of a surgically resected tissue specimen obtained from a 37-year-old man with PC, a condition which is characterized by elevated blood levels of adrenaline and noradrenaline. It was found that noradrenaline production in the medium continued until the 90th day of culture (1330 pg/ml). The production level decreased to 20 pg/ml on the 180th day, and to 18 pg/ml on the 300th day. Examination under a transmission electron microscope (TEM) at 4 weeks of culture revealed electron-dense granules (about 200 nm in size and, presumably, rich in catecholamines), which were also observed in the tumor cells from the original PC tissue. Neurite-like processes grew at around 1 week of culture, and were still maintained at 6 months of culture. But, after 6 months of culture, the neurite-like processes contained a rosary-like elevated structure, which was suggestive of cell degeneration, as determined by a plasma polymerization replica method and observed with a scanning electron microscope. When cells were examined under the TEM, fewer electron-dense granules were observed in the cell bodies, with more numerous lipofuscin-like granules and filaments. Thus, electron-dense granules, which, presumably, contain catecholamines, were seen in a long-term culture of human PC cells. These granules decreased in number in parallel with the decrease in catecholamine levels in the culture.
Adrenal Gland Neoplasms↗
A case of acute antidonor antibody-mediated humoral rejection after renal transplantation with specific consideration of serial graft biopsy histology.
A 61-year-old-woman with end-stage renal disease caused by IgA nephropathy received living unrelated kidney transplantation from her husband in February 2001. Pre-transplant donor-specific T- and B-cell cross-match was negative. Immunosuppressive treatment consisted of tacrolimus (TAC), mycophenolate mofetil (MMF), methylprednisolone (MP) and antilymphocyte globulin (ALG). The kidney functioned immediately after kidney transplantation. On post-operative day 9, the level of serum creatinine (S-Cr) rose from 1.1 to 1.5 mg/dL. The allograft biopsy specimen taken on the day revealed moderate accumulations of polymorphonuclear leucocytes in peritubular capillaries (PTCs), dilatation of PTCs and transplant glomerulitis, moderate to severe. Immunofluorescent study of a frozen section of the allograft biopsy specimen showed a strong, diffusely distributed endothelial staining pattern in PTCs for the stable complement split product C4d. Post-transplant donor-specific T- and B-cell cross-matches performed on post-operative day 13 were positive. From the allograft biopsy and the positive post-transplant donor-specific T- and B-cell cross-matching, acute humoral rejection (AHR) associated with the development of antidonor antibodies (ADA) was diagnosed. Plasma exchange (PE) treatment was initiated on day 11. After a total of 13 treatments of PE, donor-specific T- and B-cell cross-matches became negative and the biopsy performed on day 72 revealed mild transplant glomerulopathy without accumulation of polymorphonuclear leucocytes in PTCs or a C4d staining pattern in PTCs of immunofluorescence. The allograft functioned well and the creatinine level was 1.1 mg/dL 7 months post-transplant. This was a case of AHR after renal transplantation associated with the development of ADA, which was triggered by spousal-donor antigens. The presence of widespread C4d deposition in PTCs in renal allograft biopsies played a role in the diagnosis of AHR and the diagnosis was confirmed by positive donor-specific T- and B-cell cross-matches at the time of rejection, which were negative at pre-transplantation. Several treatments of PE were effective for resolving AHR in this case and the effect of PE in the treatment of AHR could be assessed by the degree of peritubular capillaritis (PTCitis) and C4d deposits in PTCs.
Antibodies↗
Post-transplant lymphoproliferative disorders in kidney transplantation: histological and molecular genetic assessment.
We performed histopathological and immunohistochemical studies, in situ hybridization (ISH) for Epstein-Barr virus (EBV) and molecular genetic analysis using the PCR method for the immunoglobulin heavy chain gene in six patients with post-transplant lymphoproliferative disorders (PTLD) to clarify these problems. In two patients, PTLD developed in the graft, and in the remaining four it developed in systemic lymphoid tissues or organs. In terms of morphological classification, lesions in the graft of two patients were polymorphic with features of rejection in the background. In the other four patients, three of them presented monomorphic lesions and the remaining one presented features of reactive lymphoid hyperplasia. All the patients were positive for EBV as determined by ISH. The molecular genetic study could be performed for four patients, the cells in lesions of two patients were found to be monoclonal and those of the remaining two were polyclonal in IgH as determined by PCR. We conclude that PTLD are of two types, namely, intragraft PTLD and extra-graft PTLD. In the cases of intragraft PTLD their diagnosis is relatively difficult, because lesions are mixed with features of rejection. Molecular genetic analysis and detection of EBV by ISH are useful for diagnosis. In contrast, the diagnosis of extra-graft PTLD is easier than that of intragraft PTLD, by basing of the latest classification of malignant lymphoma. Grading of severity of PTLD should be carried out according to the newest system and protocols for treatment based on the grade of the lesion should be established as soon as possible.
Adolescent↗
Glomerular expression of alpha2(IV) and alpha5(IV) chains of type IV collagen in patients with IgA nephropathy.
IgA nephropathy (IgAN) frequently accompanies glomerular basement membrane (GBM) alterations. To clarify the compositional changes of the GBM in IgAN, we examined the glomerular expression of alpha2(IV) and alpha5(IV) chains of type IV collagen in 36 patients with IgAN. Increased expression of the alpha2(IV) chain was observed in the expanded mesangium, and there were segmental sclerotic lesions of glomeruli in which the expression of the alpha5(IV) chain in the GBM was reduced. These lesions were found in 11 out of the 36 patients (30.6%). The patients with these lesions had more proteinuria, lower creatinine clearance and severer histological changes than the patients without them. On the other hand, a partial reduction of alpha5(IV) chain in normal-appearing GBM was observed in 15 out of the 36 patients (41.7%). The patients with this lesion had a longer disease period before biopsy than the patients without it. No other clinical and histological parameters were related to the partial reduction of alpha5(IV) in the GBM. In conclusion, an imbalance of glomerular alpha2(IV) and alpha5(IV) chain expression occurred in IgAN. This may be associated with the morphological changes of glomerular sclerosis and GBM alterations in IgAN. Further studies are required to understand the pathogenesis of the abnormal expression of type IV collagen chains.
Adult↗
[A case of focal xanthogranulomatous pyelonephritis difficult to differentiate from renal cell carcinoma].
A 34-year-old female with left flank pain persisting for 3 months consulted us on 19 Feb, 2001. Ultrasonography (US), computerized tomography (CT), magnetic resonance imaging (MRI) and renal angiography revealed a cystic renal tumor in the upper pole of the left kidney invading the spleen, and paraaortic lymph node swelling. Left radical nephrectomy combined with splenectomy and partial diaphragmectomy was performed under a tentative diagnosis of renal cell carcinoma. However, histopathological findings revealed xanthogranulomatous pyelonephritis (XGP). XGP is a rare, severe, chronic inflammatory disease characterized by accumulation of lipid laden macrophages. XGP is classified as diffuse or focal type. Preoperative diagnosis of focal XGP is difficult because of radiological similarities to renal cell carcinoma. Our case was more difficult to diagnose because she showed few signs of inflammation and had no history of urinary tract infection or stones.
Adult↗