Percentage of {gamma}{delta} T cells in panniculitis by paraffin immunohistochemical analysis.

Cutaneous T-cell lymphomas with panniculitis-like histologic features have different clinical courses depending on whether they are composed of alphabeta T cells or gammadelta T cells, necessitating their distinction for proper prognostication. However, unlike alphabeta T cells, gammadelta T cells cannot be reliably detected in formalin-fixed, paraffin-embedded sections. We demonstrated that a commercially available antibody can detect gammadelta T cells and examined 2 cases of flow cytometry-proven gammadelta T-cell lymphomas and 15 control cases of nonneoplastic panniculitis.

Gamma c-signaling cytokines induce a regulatory T cell phenotype in malignant CD4+ T lymphocytes.

In this study, we demonstrate that malignant mature CD4(+) T lymphocytes derived from cutaneous T cell lymphomas (CTCL) variably display some aspects of the T regulatory phenotype. Whereas seven cell lines representing a spectrum of primary cutaneous T cell lymphoproliferative disorders expressed CD25 and TGF-beta, the expression of FOXP3 and, to a lesser degree, IL-10 was restricted to two CTCL cell lines that are dependent on exogenous IL-2. IL-2, IL-15, and IL-21, all of which signals through receptors containing the common gamma chain, induced expression of IL-10 in the IL-2-dependent cell lines as well as primary leukemic CTCL cells.

Interlobular bile duct loss in pediatric cholestatic disease is associated with aberrant cytokeratin 7 expression by hepatocytes.

The objective of this study was to determine whether aberrant hepatic expression of cytokeratin 7 (CK7) and/or other putative stem cell markers is seen in pediatric cholestatic diseases. Eighteen liver biopsies and 14 liver explants from pediatric patients with extrahepatic biliary atresia (EHBA), Alagille syndrome (AGS), primary sclerosing cholangitis (PSC), inborn errors of bile acid synthesis, and progressive familial intrahepatic cholestasis (PFIC) were examined along with 5 histologically normal control liver biopsies. Immumohistochemical stains (CK7, CD56, and OV6) were performed on paraffin-embedded tissue.

Immunohistochemical analysis of hSNF5/INI1 in pediatric CNS neoplasms.

Atypical teratoid/rhabdoid tumor (AT/RT) may be misdiagnosed as primitive neuroectodermal tumor/medulloblastoma (PNET) and occasionally as other tumors. Molecular genetic analysis of AT/RT demonstrates deletion and mutation of the hSNF5/INI1 gene in most cases, with decreased or absent expression at the RNA or protein level. Immunohistochemistry with an antibody to INI1 was performed to determine whether this would be a sensitive and specific means of assessing INI1 loss in pediatric brain tumors.

Immunohistochemical detection of Aspergillus species in pediatric tissue samples.

Definitive diagnosis of invasive aspergillosis often requires tissue samples for histologic evidence of fungal infection and culture confirmation of Aspergillus species. However, the culture frequently fails to isolate Aspergillus species. Alternative approaches to confirm Aspergillus infection use polymerase chain reaction, in situ hybridization, and immunohistochemical analysis on paraffin-embedded sections.