CYTOKINE PROFILE IN COELIAC DISEASE: A LASER CAPTURE MICRODISSECTION APPROACH Background and Aim: Different approaches have been used to study the pattern of cytokines in celiac disease (CD), which have led sometimes to contradictory results. Laser capture microdissection (LCM) is a powerful tool for the isolation of specific cell populations from stained sections. The aim of this study was to characterize the pattern of cytokines within the tissue compartments of the small intestinal mucosa of CD patients, dissected by LCM. Methods: Frozen section of jejunal biopsies were obtained from 7 untreated patients and 7 controls. Epithelium and lamina propria were isolated separately by LCM, and the cytokine messenger RNA (mRNA) levels for IFN-?, IL-21, IL-15, IL-10 and TGF-?, were determined by using real-time reverse transcription PCR. Results: The mRNA levels of all the cytokines analyzed were significantly higher, in both compartments, in untreated CD than from controls. Active celiac disease was characterized by higher expression of IFN-g and IL-21 mRNA in lamina propria than in epithelium and by higher expression of IL-15 mRNA in epithelium than in lamina propria. Furthermore, same levels of IL-10 and TGF-b mRNA expression was seen in both compartments of untreated CD biopsies. Finally no differential mRNA expression was observed for cytokines, in controls between the two compartments. Conclusion: Our results suggest that an imbalance in the relative amounts of cytokine mRNAs production, between epithelium and lamina propria, is an important feature of active CD. Particularly, the epithelium seems mostly produce cytokines involved in the innate immunity whereas lamina propria may produce cytokines involved in the adaptive immune response. Finally, both compartment produce cytokines involved in the suppressive activity. This work underlines the importance of LCM as a valuable tool to determine potential inflammatory components in epithelial and lamina propria cells that may enhance understanding to CD pathogenesis.