Genetically determined lymphopenia and autoimmune manifestations.

Hypomorphic defects of V(D)J recombination in humans lead to
residual T cell development. In these lymphopenic conditions,
homeostatic lymphocyte proliferation occurs, and key
mechanisms that normally maintain host tolerance are altered,
allowing peripheral expansion of oligoclonal and autoreactive T
cells. Recently described murine models support this notion.
This review describes human and murine situations, in which
genetically determined T and B cell lymphopenia is associated
with autoimmune manifestations.