Tumor del estroma gastrointestinal y trasplante renal / Gastrointestinal stromal tumor and renal transplant

El tumor estromal gastrointestinal (GIST) representa alrededor del 1% de todos los tumores digestivos y su aparición en pacientes trasplantados renales es infrecuente. Aproximadamente el 95% muestra tinción positiva para c-kit/CD117. DOG1 es un anticuerpo recientemente descrito que se sobre-expresa en los GIST, incluso en c-kit/ CD117 negativos. El diagnóstico preciso de GIST resulta imperativo, debido a la disponibilidad y la creciente eficacia de los inhibidores de la tirosina quinasa en estos tumores, incluso en el subgrupo c-kit/ CD117 negativo. Se presenta el caso de una mujer trasplantada renal inicialmente con GIST en intestino delgado y débil positividad para CD117 tratada con cirugía y recidiva tumoral a los tres años, pérdida de la expresión CD117 y tinción positiva para DOG1. Recibió tratamiento exitoso con imatimib sin presentar recaída tumoral durante un seguimiento de cinco años.

Gastrointestinal stromal tumor (GIST) accounts for nearly 1% of all gastrointestinal tumors. Its association with renal transplantation is not frequent. Approximately 95% of GIST show staining for CD177. DOG1 is a recently described monoclonal antibody that shows positivity even in the absence of CD177 staining. The diagnosis of GIST should be pursued because of the availability of very effective treatments with tyrosine-kinase inhibitors. Herein, we describe the case of a woman with renal transplant who presented a small bowel GIST and weak positivity for CD177, treated initially with surgery. Tumor recurrence was documented 3 years later and histopatology showed loss of CD177 staining and positivity for DOG1. She was treated with imatimib without further recurrence after five years of follow up.

Serine protease [TPS]: a diagnostic and prognostic marker in pediatric patients with acute non-lymphoblastic leukemia

The Serine protease, TPS [tryptase], is a specific marker for mast cells and mast cell-associated disorders. However, substantial amounts of TPS are also expressed in neoplastic myeloid, non-mast cell lineage. The aim of this study is determination and quantitation of TPS expression in patients with acute non-lymphoblastic leukemia [ANLL]; to evaluate its prognostic value and its relevance as a genetic marker for detection of minimal residual blast cells. Reverse transcriptase-polymerase chain reaction [RT-PCR] was used to detect levels of TPS from 30 newly diagnosed ANLL children and 10 normal children served as controls. TPS levels for positive cases were reevaluated after induction chemotherapy; after onset of relapse or by the end of the study. Our results showed that the gene transcripts were detected in 56.7% of patients but were not expressed by normal controls. The highest frequency of TPS was recorded in patients with M4 showing significantly higher levels compared to other FAB [French-American-British Classification] subtypes. TPS levels were directly correlated to TLC, absolute blast counts in peripheral blood, levels of CD34 and CD117. After induction chemotherapy, levels of TPS decreased significantly in those who achieved complete remission while it increased significantly in relapsed patients, with a risk estimate of relapse six times higher in positive cases than TPS negative patients. 84.6% of the patients negative for TPS achieved complete remission with better disease free survival. In conclusion, TPS is expressed in a group of patients with ANLL thus serves as a disease related marker; it could be used as a prognostic indicator in evaluating remission status and early relapse as its elevated levels are associated with high risk of relapse; again, it is useful in predicting disease outcome