Biomedical subjects

T Niehues

Publications and source records attributed to T Niehues.

4 recordsLinked to original sources

PubMed1996

Treatment of pediatric malignant thymoma: long-term remission in a 14-year-old boy with EBV-associated thymic carcinoma by aggressive, combined modality treatment.

Malignant thymoma, including thymic carcinoma, is extremely uncommon in the pediatric population. It is known to have a very poor outcome. We report on a 14-year-old boy with Epstein-Barr virus (EBV)-associated thymic carcinoma. Sections of the original tumor were analyzed for EBV by in situ hybridization to confirm the histological diagnosis of a lymphoepithelioma-like subtype. High copy numbers of EBV RNA were detected in the tumor tissue, suggesting an etiological role of EBV in our case. Intensive treatment resulted in long-term remission over 12 years. In order to facilitate the difficult management of the rare child with malignant thymoma, a literature search was initiated. Forty well-documented pediatric cases of malignant thymoma were found in the literature. Histological characteristics, clinical features, and therapeutic regimens were reviewed. Having the very limited experience with malignant thymoma in childhood in mind, it is concluded that its aggressiveness makes the most intensive treatment necessary. Long-term remission can be achieved by application of radical surgery, high-dose irradiation, and multiagent chemotherapy. The combination of cisplatinum, etoposide, and ifosfamide seems to be promising.

Adolescent↗

PubMed1996

Severe combined immunodeficiency (SCID) associated neutropenia: a lesson from monozygotic twins.

A case of severe combined immunodeficiency (SCID) in monozygotic twin sisters was detected at 3 months of age with neutropenia in one twin and a normal differential count in the other. The neutropenic twin, suffering from severe skin ulcers, was successfully treated with granulocyte colony stimulating factor (G-CSF). Discordant occurrence of neutropenia in identical twins shows that there may be a non-genetic cause for the neutropenia in SCID. Suppression of myelopoiesis was probably induced by activated maternal T cells. The neutropenia in this case may thus be classified as SCID associated neutropenia, as opposed to reticular dysgenesis, in which the neutropenia is G-CSF refractory and is most probably caused by a genetic stem cell defect. A response to G-CSF in a neutropenic child with SCID can be clinically beneficial and might help to distinguish between G-CSF unresponsive reticular dysgenesis and G-CSF responsive SCID associated neutropenia.

Diseases in Twins↗

PubMed1994

Unique phenotype and distinct TCR V beta repertoire in human peripheral blood alpha beta TCR+, CD4-, and CD8- double negative T cells.

TCR-alpha beta+ CD4- CD8- double-negative (DN) T cells represent a small, poorly defined T cell subset in human peripheral blood that has been postulated to be potentially autoreactive. To define some of the characteristics of this subset of T cells, DN cells and CD4+ and CD8+ single-positive (SP) cells were purified from the peripheral blood of six unrelated individuals by a combination of positive selection and depletion using mAb conjugated to immunomagnetic beads. Purified DN cells were found to be enriched in cells expressing HLA-DR and the NK cell marker, CD56, when compared to the SP population. Furthermore, in contrast to SP cells that express the adhesion marker CD44, DN cells were found to express very little, if any, CD44. When the V beta TCR repertoires of DN and SP (CD4+ and CD8+) cells, determined by quantitative (q) PCR, were compared all three populations were found to be considerably different. Furthermore, several V beta segments (V beta 11 and V beta 19) were consistently expressed at higher levels on DN cells than on SP cells. The TCR repertoires of both DN and SP cells were frequently characterized by dominance of one or more V beta segments that could in some instances be shown to be restricted to the CD45RO+ ("memory") population. However, differences in TCR repertoire between DN and SP cells were observed even when CD45RO+ cells were removed before qPCR analysis. These studies suggest that the TCR repertoires of DN and SP cells are determined by different selection mechanisms and that DN and SP cells are directed against different Ag.

CD4 Antigens↗

PubMed1994

Marked gamma delta T-cell decrease in peripheral blood of patients with primary biliary cirrhosis (PBC).

PBC is a cholestatic liver disease of unknown etiology with autoimmune features that is often associated with other autoimmune diseases. We analyzed peripheral blood T-cell subsets in patients groups with PBC (n = 11), non-PBC hepatobiliary disease (n = 11) and an age and sex matched control group (n = 11) by two color FACS-analysis. Seven out of eleven PBC patients exhibited markedly lowered and nearly undetectable levels of gamma delta T-cells (< 0.8%). None of the individuals in the non-PBC hepatobiliary disease (HBD) group or the normal control group had gamma delta values below 1%. The other four individuals in the PBC group had gamma delta values within the normal range. Overall, the PBC group had a statistically significant, lowered mean percentage of gamma delta T-cells (1.50%) as compared to the hepatobiliary disease group (3.76%) and the control group (4.22%, p = 0.01). The percentages of CD4+ and CD8+ and alpha beta TCR+ CD4-CD8- double negative cells in PBC patients did not differ from the control group. PBC patients with normal gamma delta cell counts did not differ from the PBC group with low gamma delta values in autoantibody titers, liver tests or treatment of the disease. As a possible cause for the observed decrease of gamma delta T-cells three sera of PBC patients with low gamma delta T-cell counts were screened by single color, indirect immunofluorescence for antibodies to gamma delta T-cell enriched lymphocytes, but no differences to control sera were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗