CD4

The disease's origin is a peripheral CD4+ T-lymphocyte, although rarer CD8+/CD4- cases have been observed.

The CD4- and CD8-p56lck complexes are also widely accepted as the initiators of T-cell activation leading to the recruitment and activation of a second tyrosine kinase ZAP-70 and other substrates.

Histopathologic examination of the pancreas reveals a characteristic lymphoplasmacytic infiltrate of CD4- or CD8-positive lymphocytes and IgG4-positive plasma cells, and exhibits interstitial fibrosis and acinar cell atrophy in later stages.