Preemptive Retransplantation for BK Virus Nephropathy: Successful Outcome Despite Active Viremia

BK virus nephropathy (BKVN) is now recognized as a major cause of renal allograft loss. Recent reports suggest that retransplantation in patients with graft loss due to BKVN is safe after return to dialysis. Since early transplantation is associated with improved outcomes, it would be advantageous if this procedure could be performed prior to ultimate graft loss. However, little data are available regarding the safety of this approach during active viremia. In this report, we describe successful preemptive retransplantation with simultaneous allograft nephrectomy in two patients with active BKVN and viremia at the time of surgery. With 21- and 12-month follow-up, respectively, both patients have stable allograft function and no evidence for active viral replication. We conclude that preemptive retransplantation can be considered in patients with failing allografts due to BKVN.     

Multiple assay characterization of murine monoclonal antimelanoma antibodies

Selected murine monoclonal antimelanoma antibodies have been extensively evaluated using multiple radioimmunoassay methods, immunoprecipitation and immunohistochemistry. Use of this approach has permitted more complete definition of the specificity of these reagents and provided information regarding the nature and distribution of the respective tumor associated antigens (TAA). Several patterns of reactivity were identified. Some of the reagents were highly reactive with melanomas but also with a variety of tissues of nonmelanoma origin. Others were less highly reactive but of greater specificity for melanoma. Finally, certain of the reagents were poorly reactive in the assays utilized or demonstrated assay-dependent reactivity. None of the included monoclonal antibodies appeared to detect TAA restricted in distribution solely to melanoma.     

Polypoid tumor of the esophagus

Five cases of an uncommon esophageal tumor consisting of a mucosal squamous cell carcinoma that surrounds a polypoid mass of spindle cells were examined. The spindle cell component was composed of elongated cells with blunt nuclei, admixed with multinucleated giant cells. Reticulin fibers enveloped individual cells, and abundant collagen was present. Thirteen to 69 mitotic figures occurred per 10 high-power fields. Electron microscopy showed dilated cisternae of rough endoplasmic reticulum and peripheral intermediate filaments within the cytoplasm. Intermediate-type junctions (zonulae adherens) and subplasmalemmal linear densities connected some cells. No tonofibrillar bundles or desmosomes (maculae adherens) were present. Immunoperoxidase stains detected no keratin in the spindle cells. Alpha-1-antichymotrypsin and alpha-1-antitrypsin were in the spindle cells in five of five and three of five cases, respectively. The absence of desmosomes, tonofibrillar bundles, and keratin and the presence of alpha-1-antitrypsin and alpha-1-antichymotrypsin favor fibrohistiocytic differentiation of the spindle cell component.     

Lymphoblastic lymphoma with the phenotype of common acute lymphoblastic leukemia

Immunologic phenotyping of lymphoblastic lymphomas has shown that most of these are tumors of T-cell origin. In this report, we describe two patients with biopsy-proven lymphoblastic lymphoma whose tumors had no T-cell markers when tested by immunoperoxidase with a large panel of monoclonal antibodies. However, the tumor cells did express the common ALL antigen (CALLA), Ia antigen, and a 24,000 dalton ALL-associated antigen defined by monoclonal antibody DU-ALL-1. The tumor cells also lacked surface immunoglobulin. Although this phenotype is that seen in most cases of acute lymphoblastic leukemia, the patients were never leukemic at any time during their clinical course. Our results support the overall similarity between lymphoblastic lymphoma and acute lymphoblastic leukemia. Further, they suggest that it may be possible to identify prognostically significant immunologic subtypes of lymphoblastic lymphoma.