Preceding T-Cell-Mediated Rejection Is Associated with the Development of Chronic Active Antibody-Mediated Rejection by de Novo Donor-Specific Antibody.

AIM: Chronic active antibody-mediated rejection (CAABMR) is an important cause of late-stage renal allograft loss. Early inflammatory events such as acute rejection and infection after transplantation are considered to be the risk factors of de novo donor-specific antibody (dnDSA) production. In this study, we investigated the relationship between pre-disposing T-cell-mediated rejection and dnDSA-positive CAABMR. METHODS: We recruited 365 patients who underwent ABO-compatible renal transplantation at our hospital. Among them, 16 patients diagnosed as having dnDSA-positive CAABMR were designated as a CAABMR group, and 38 randomly selected patients were designated as a control group. All biopsies from 1 month after transplantation were included in the study. The presence or absence of borderline changes (BLCs), acute T-cell-mediated rejection (ATMR), microvascular inflammation (MVI), and C4d positive on peritubular capillaries (C4d-P) was examined. RESULTS: In the CAABMR group, BLC/ATMR was found in 12 cases (75%), and the mean duration until appearance of BLC/ATMR was 282.7 ± 328.7 days. C4d-P was found in 11 cases (68.8%), and the mean duration until its appearance was 1,432 ± 1,307 days. MVI was found in all cases, and the mean duration until its appearance was 1,333 ± 1,126 days. The mean duration until diagnosis of CAABMR was 2,268 ± 1,191 days. In the control group, BLC/ATMR was found in 13 cases (34.2%), and the mean duration until the appearance of BLC/ATMR was 173.1 ± 170.4 days. C4d-P was found in 2 cases (5.3%), and the durations until its appearance were 748 and 1,881 days. No cases of MVI were found in the control group. The frequency of BLC/ATMR was significantly higher in the CAABMR group (p < 0.01). CONCLUSION: Preceding BLC/ATMR is associated with the development of CAABMR with dnDSA.

[Thymoma with Hemorrhage and Necrosis Presenting with Fever and Chest Pain;Report of a Case].

A 53-year-old man was admitted to our hospital for treatment of fever and chest pain. Chest computed tomography showed an anterior mediastinal cystic tumor 39×57 mm in size surrounded by fat with edema and left pleural effusion. After one course of antibiotic administration, the edema of fat surrounding the tumor disappeared and the patient underwent scheduled tumor resection with thymectomy through a median sternotomy. Postoperative pathological examination revealed a thymoma of type AB according to the World Health Organization (WHO) classification associated with hemorrhage and necrosis. Cases of thymoma with hemorrhage or necrosis may lead to atypical presentations such as fever, acute chest pain, pleural effusion, and spontaneous regression. Clinicians should be aware of these unusual presentations of chest pain and fever due to thymoma, and consider the possibility of a differential diagnosis of an anterior mediastinal tumor.

Validity and reproducibility of Ki-67 assessment in gastrointestinal stromal tumors and leiomyosarcomas.

With the aim of standardizing Ki-67 immunohistochemistry, we assessed interobserver and interlaboratory variability of the Ki-67 labeling index and Ki-67 score among eight general pathologists for 24 gastrointestinal stromal tumors (GISTs) and 12 leiomyosarcomas, which were predominantly of the gastrointestinal (GI) tract, mesentery and retroperitoneum, based on a review of a tissue microarrays subjected to immunohistochemistry with antibodies for Ki-67. For Ki-67 immunostaining of mesenchymal tumors of the GI tract, including GISTs, differences were seen in the scores given by regional hospitals. Conversely, for two categories of the Ki-67 labeling index, namely <10% and ≥10%, concordance of the Ki-67 score between microscopic observation and image analysis, and between the observers, was good, but it was not good for the other four categories of the index for <5%, 5-9%, 10-29%, and ≥30%. The concordance of the Ki-67 scores between the observers in two categories was higher using the Ki-67 pre-stained tissue microarrays (TMAs) within each participating institute than that using the Ki-67 stained TMAs between the participating institutes. The reproducibility of a 10% cut-off value for the Ki-67 labeling index to predict the prognosis of GISTs was relatively high, but there is an urgent need to standardize the staining technique.

Unusual basal ganglia lesions in a diabetic uraemic patient proven to be demyelination: first pathological observation.

A 64-year-old man suffering from diabetes mellitus and chronic renal failure was admitted to our hospital because of consciousness disturbance and parkinsonism. Cranial MRI showed very characteristic features involving the bilateral basal ganglia. Subsequent postmortem examinations demonstrated demyelination in the affected areas. These myelin destruction patterns were quite similar to those of central pontine myelinolysis. However, rapid correction of hyponatraemia was ruled out in this patient. Therefore, a new demyelinating brain disease associated with diabetes mellitus and chronic renal failure was suggested.

[Black esophagus due to acute necrotizing esophagitis: four case reports].

We describe four patients with acute esophageal necrosis who were admitted to hospital due to upper gastrointestinal bleeding. "Black esophagus" is endoscopically defined as diffuse dark pigmentation of the esophageal wall. The underlying conditions were ketoacidosis in three of the patients and diabetes mellitus in two. Three patients responded well to empirical supportive therapy and one patient died of coexisting illness rather than the esophageal status. Acute esophageal necrosis is a rare entity that should be considered in the differential diagnosis of upper gastrointestinal bleeding.

Transplantation-associated thrombotic microangiopathy after steroid pulse therapy for polyserositis related to graft-versus-host disease.

Transplantation-associated thrombotic microangiopathy (TA-TMA) is a rare but devastating syndrome that occurs in allogeneic hematopoietic stem cell transplant recipients, and is associated with a variety of transplantation-related factors, including conditioning regimens, immunosuppressive agents, graft-versus-host disease (GVHD) and opportunistic infections. TA-TMA has an unfavorable prognosis and responds poorly to conventional treatment including plasma exchange (PE). We present a case of a 37-year-old man with membranous nephropathy (MN) and polyserositis caused by GVHD after hematopoietic stem cell transplantation. He developed TA-TMA after steroid pulse therapy for polyserositis. We treated the patient with PE and mycophenolate mofetil (MMF) after which the TA-TMA successfully improved and the MN underwent complete remission. The present case suggests that corticosteroids with severe GVHD might increase the risk of TA-TMA, and that PE in combination with MMF may be a valuable therapy to improve the prognosis.

Use of tissue microarrays and immunohistochemistry to standardize the diagnosis of gastrointestinal stromal tumors.

We assessed the concordance among seven general pathologists with respect to histologic diagnosis and interpretation of c-kit proto-oncogene (KIT) and platelet-derived growth factor receptor alpha (PDGFRA) immunostaining of 36 cases of primary spindle-cell tumor, predominantly of the gastrointestinal tract, mesentery, and retroperitoneum, based on review of a tissue microarray (TMA) subjected to immunohistochemistry with antibodies to KIT/CD117, PDGFRA, vimentin, desmin, smooth muscle action, CD34, and S-100 protein. Tumors included 20 molecularly analyzed gastrointestinal stromal tumors (GISTs), 4 leiomyosarcomas, 4 schwannomas, 4 desmoid-type fibromatoses, and 4 solitary fibrous tumors. The mean overall concordance with original diagnosis for each histologic type was 91.1%, with a mean kappa value of 0.91. With respect to PDGFRA immunostaining, the four GISTs with PDGFRA mutation were interpreted as cytoplasm positive, but the 16 GISTs with c-kit mutation were interpreted as weak or positive. These results indicate that the overall concordance with original diagnosis in mesenchymal tumors with the use of immunohistochemical panels is high, despite the use of TMAs. To some extent, PDGFRA immunophenotyping may be useful in GISTs with PDGFRA mutation, but it was not highly reproducible or specific. Therefore, in KIT-negative or weakly positive GISTs, mutation analysis will be required.

Remission of membranoproliferative glomerulonephritis associated with a noncirrhotic portosystemic shunt after percutaneous transhepatic portal vein embolization.

We present a case of a 75-year-old man with nephrotic syndrome and renal insufficiency caused by immune complex-mediated secondary membranoproliferative glomerulonephritis. He developed hepatic encephalopathy. A congenital portosystemic shunt was identified, indicating a diagnosis of membranoproliferative glomerulonephritis with noncirrhotic portosystemic shunt. Proteinuria resolved after shunt ratio reduction by percutaneous transhepatic portal vein embolization. Renal function and histopathological findings improved without immunosuppressive therapy. This case emphasizes the role of a high shunt ratio and reduced hepatic clearance of circulating immune complexes in such nephropathy. Membranoproliferative glomerulonephritis with a shunt may cause refractory nephrotic syndrome, but embolization is effective.