Active thymopoiesis in idiopathic chronic pancreatitis

R. Cianci 1, C. Spada 2, V. Perri 2, G. Cammarota 1, R. Urgesi 2, S. Lolli 1, E. Girardi 3, G. Costamagna 2, F. Pandolfi 1

1 Institute of Internal Medicine and 2 Digestive Endoscopic Unit, Catholic University, Rome (Italy) 3 Epidemiology Unit, National Institute for Infectious Diseases “L. Spallanzani”, Rome (Italy)

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• Immunology

Background/Aims: Cellular immunity has a pivotal role in the pathogenesis of chronic pancreatitis (CP), resulting in pancreas infiltration by T-cells. Studies on systemic immunity are few and contradictory. One study reported a decrease of naive CD45RA+ cells. The presence of naive T cells, detected as recent thymic emigrants (RTEs), is evaluated with a new molecular technique by using real-time PCR to detect the T-cell receptor excision circles (TREC). To elucidate the role of naive T-cells in the pathogenesis of CP, we investigated the percentage of sj-TREC in CP patients.

Patients: Thirty CP patients were studied and compared to 30 sex- and age-matched healthy volunteers.

Methods: Genomic DNA was isolated from peripheral blood mononuclear cells (PBMC) of each patient. RTEs were evaluated by measuring sj-TREC by real-time PCR.

Results: The mean percentage of sj-TREC+ cells present in CP was not significantly different from that of control group (0.02319% vs 0.02338%, respectively).

Conclusion: Our data show that naive TREC+ cells are normally represented in CP. The presence of active thymopoiesis may be the underlying mechanism resulting in continuous production of T-cells, responsible of maintaining the inflammatory process.

Corresponding Author: Franco Pandolfi, MD; e-mail: lab.immunol.2@rm.unicatt.it