Mucosal molecular pattern of tissue transglutaminase and interferon gamma in celiac disease with and without serological markers

Mucosal molecular pattern of tissue transglutaminase and interferon gamma in celiac disease with and without serological markers. R.Mallamaci1,M.Svelto1 F. Giorgio2, E.Ierardi2. 1Bioscience, Biotechnology and Biopharmaceutical Department, University of Bari, 2Section of Gastroenterology, Department of Emergency and Organ Transplantation, University of Bari In seropositive celiac disease (CD) an increased mRNA coding for tissue transglutaminase (tTG) and Interferon gamma (IFNγ) has been found. Seronegative celiac disorder is still a diagnostic challange, where mucosal immune-complexes anti-tTG immunoglobulins (A/tTG) have been found. Therefore, we assayed tTG and IFNγ mRNA in the mucosa of patients with a clinical suspicion of seronegative CD (SSCD) based on the values of intraepithelial CD3 lymphocytes (IELs) by a comparison with seropositive disorder. Distal duodenum specimens from 67 patients with SSCD were retrieved and re-evaluated for immunohistochemically proven CD3 IELs. Five sections 10 micron were used for the extraction and assay of tTG and IFNγ coding mRNA levels using reverse transcriptase real time polymerase chain reaction (RT-PCR). Samples from 15 seropositive CD patients and 15 healthy subjects were used as positive and negative controls. Results were expressed as fold-change. tTG mRNA levels were (mean±SD): CD=9.8±2.6, SSCD=10.04±4.7 and controls=1.04±0.2 (CD= SSCD > controls; Student-Neumann-Keuls test and Bonferroni’s correction). IFNγ mRNA levels were: CD=13.4±3.6, SSCD =7.28±3.6 and controls=1.04±0.4 (CD> SSCD >controls). Our results suggest that tTG and IFNγ mRNA is increased in both seropositive and suspected seronegative patients with CD, showing CD3 IELs count at stage Marsh 1 (> 25/100 enterocytes) when compared to controls, thus suggesting the possibility of a “grey zone” inhabited by patients that should be closely followed up in gluten-related disorders..