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Biomedical subjects

Ronald Jaffe

Publications and source records attributed to Ronald Jaffe.

26 records · Page 2Linked to original sources
PubMed2003

Chronic rejection of small bowel grafts: pediatric and adult study of risk factors and morphologic progression.

One hundred and seventy-two patients underwent small bowel transplantation at Children's Hospital of Pittsburgh and University of Pittsburgh Medical Center between May 1990 and August 2001. Thirty-four patients had complete or partial resection of their primary graft and in 15, histologic features of chronic rejection were present in the resected small bowel. This is a descriptive and correlative study of the demographic, perioperative, and histologic features associated with progression to intestinal graft failure. Variable features associated with an increased risk of chronic rejection included acute rejection within the 1st month, increased number and higher grade of acute rejection episodes, isolated small bowel grafts rather than small bowel-liver grafts, older recipient age, non-Caucasian race, and Caucasian to non-Caucasian transplant. The mucosal biopsies showed predictive changes many months before the grafts were excised. The mucosal biopsy diagnosis of chronic vascular rejection can be difficult because the affected vessels, the distal branches of the mesenteric arteries, and the larger arteries of the subserosa and submucosa are not routinely sampled. The possibility of underlying arteriopathy, however, can be inferred in some instances from the presence of secondary mucosal changes in the small bowel biopsies though the "early" changes lack specificity. It is the progression of biopsy findings over time that is predictive of outcome. It is important to recognize the persistence of "late" mucosal changes of chronic rejection so that patients are not subjected to increased immune suppression when it is unlikely to be of significant benefit.

Adolescent↗
PubMed2003

Minimal evidence of transdifferentiation from recipient bone marrow to parenchymal cells in regenerating and long-surviving human allografts.

Liver, small intestine, and heart allografts in residence for 4 days to 16 years were analyzed by simultaneous XY fluorescent in situ hybridization to search for evidence of the recently described process of transdifferentiation of recipient bone marrow stem cells to allograft parenchymal cells. These studies were carried out in an effort to find conditions associated with maximal levels of engraftment or expansion of the recipient parenchymal cells. Despite prolonged survival up to 16 years, regeneration after severe preservation injury or use of split livers, only rare, isolated and tentatively identified recipient hepatocytes were detected in liver allografts. In intestinal allografts, despite survival of up to 8 years and extensive mucosal regeneration because of severe damage from acute rejection, there was no crypt replacement by recipient epithelial cells. In cardiac allografts, no recipient myocytes were detected despite recipient survival for 2-3 days and 3-4 weeks after myocardial infarcts at 5 and 8 years after transplantation. Parenchymal cell transdifferentiation from recipient bone marrow stem cells was rare to nonexistent in severely injured, regenerating, and long-surviving allografts. The rare isolated recipient parenchymal cells tentatively identified did not appear to behave as stem cells: they did not form clusters and did not increase with time after transplantation. Because of the extremely low frequency, interpretation was difficult. Regardless of these results, a more vigorous search for conditions that promote transdifferentiation is warranted.

Adolescent↗
PubMed2002

A primary immunodeficiency disorder associated with absence of lymphoid germinal centers.

In this article we describe three infants who suffered from a disorder characterized by splenomegaly, anemia, and severe infections beginning during the first months of life. Immunologic studies revealed agammaglobulinemia. However, normal numbers of lymphocytes and lymphocyte subsets were present in peripheral blood, and lymphocyte proliferation in responses to mitogenic stimulation in vitro was normal. Histologic and immunohistologic studies performed in one of the patients revealed lack of secondary follicles and follicular dendritic cells in lymphoid tissues and absence of plasma cells in the intestinal lamina propria. Similar findings have been observed in the hyper-IgM syndrome. However, these patients can be distinguished from currently recognized genetic variants of hyper-IgM syndrome on the basis of their clinical and histologic features, together with information obtained from DNA sequence analysis. Thus, their condition is likely to represent a novel form of primary immune deficiency with features of hyper-IgM syndrome.

Agammaglobulinemia↗
PubMed2002

Pheochromocytoma in von hippel-lindau disease: distinct histopathologic phenotype compared to pheochromocytoma in multiple endocrine neoplasia type 2.

Pheochromocytomas are rare neuroendocrine tumors that arise from chromaffin tissue. In a small subset of patients, pheochromocytomas occur as a manifestation of von Hippel- Lindau (VHL) disease. The histology of VHL-associated pheochromocytomas has not been reported in detail. In this article, we describe histopathologic features of 14 pheochromocytomas in eight patients with VHL disease and demonstrate that VHL-associated pheochromocytomas have a distinct histologic phenotype as compared with pheochromocytomas in patients with multiple endocrine neoplasia type 2 (MEN 2). VHL tumors are characterized by a thick vascular tumor capsule; myxoid and hyalinized stroma; round, small to medium tumor cells intermixed with small vessels; predominantly amphophilic and clear cytoplasm; absence of cytoplasmic hyaline globules; and lack of nuclear atypia or mitoses. In contrast to MEN 2, there is no extratumoral adrenomedullary hyperplasia in the VHL adrenal gland. Our findings of a distinct histologic phenotype of VHL pheochromocytoma may further help in subdividing patients who clinically present with multiple, bilateral pheochromocytomas.

Adrenal Gland Neoplasms↗
PubMedDate not supplied

Pediatric intestinal transplantation: the resected allograft.

We reviewed the clinical and pathologic finding of 22 resected allografts from 19 of the 83 children who underwent a variety of small intestinal transplant procedures in the years 1990-2000 at the Children's Hospital of Pittsburgh. Resections were compared with prior mucosal biopsies because resections allow for evaluation of the entire bowel thickness, including the feeding vessels, and obviate the problems of limited sampling. Partial resections that were done soon after the transplant, or soon after additional surgery, were for surgical problems such as leaks, adhesions, and volvulus. None had biopsy features suggestive of rejection or infection. Partial resections done late (6 months or more) after transplantation were more likely to be related to allograft immune biology; two had a sclerosing peritonitis that was confined to the allograft, and one had an obstructing carcinoma arising in the allograft mucosa. One patient had a localized stricture, demonstrated to be due to graft vascular disease at partial resection, and this patient went on to have the allograft removed a year later for chronic rejection. Early complete allograft enterectomies were for refractory acute cellular rejection, 1-2 months following transplant. One was removed for pancreatitis and liver failure from operative complications. Late allograft enterectomies were generally for chronic rejection, some with residual acute rejection, but there were also a number of patients who had multiple superimposed conditions such as cytomegalovirus, Epstein-Barr virus, and post-transplant lymphoproliferative disorder in various combinations. One had idiopathic scarring and developed an adynamic bowel that remains unexplained. Examination of the resected specimens allows for dissection of the multiple contributions to graft failure, especially the vascular disease that can rarely be seen on mucosal biopsy. An unexpected finding was the impressive hypertrophy of neural elements, nerves, and ganglion cells in many of the patients, the significance of which requires further investigation.

Adolescent↗
PubMedDate not supplied

Macrophage activation and hemophagocytic syndrome in langerhans cell histiocytosis: report of 30 cases.

Macrophage activation and secondary hemophagocytic syndrome are rarely reported in association with Langerhans cell histiocytosis (LCH). The authors reviewed their pathology files for cases of LCH in which evidence of macrophage activation coexisted and report 30 such cases indicating that the association is not that rare and may even be underdiagnosed unless specifically sought. Available clinical data were collected and correlated with pathological findings. Of the 30 cases of LCH with varying degrees of macrophage activation, 29 had multisystem disease. The cases were graded from I to V on the basis of evidence for, and severity of, macrophage activation; cases in category I had evidence of fully developed hemophagocytic syndrome whereas those in category V had limited evidence of macrophage activation. There were seven cases with fully developed hemophagocytic syndrome (category I) and an additional five with hemophagocytosis and some but not all of the features of hemophagocytic syndrome (category II). Most of these 12 cases were young children with high-risk LCH and poor prognosis; 4 are known to have died. Coexisting hemophagocytic syndrome in these cases of LCH may have contributed to their poor prognosis. The association of LCH with macrophage activation, though more than coincidental, is of unknown pathogenesis, but the role of T lymphocytes and cytokines is prominent in both disorders and is presumed to link the two.

Adolescent↗