Autoimmune systemic lupus erythematosus (SLE) nephritis is characterized by the influx of mononuclear inflammatory cell infiltrates within the glomeruli and renal interstitium. To evaluate the possibility that intrarenal T cells result from the expansion of lymphocytes using limited T-cell receptor (TCR) genes, we analyzed the TCR Vbeta gene expression among infiltrating lymphocytes in renal tissue compared with simultaneous peripheral blood lymphocytes of four children with new-onset SLE nephritis. The TCR Vbeta gene expression in peripheral blood T cells from patients with SLE nephritis, when compared with normal controls, showed no preferential expansion or deletion of select Vbeta gene families. In contrast, when paired peripheral blood and renal tissue were analyzed, intrarenal lymphocytes in SLE nephritis demonstrated evidence of expansion of select Vbeta gene families. Sequence analysis of the V(D)J joining regions of the TCRbeta with the expanded families demonstrated a striking oligoclonality. These observations suggest that infiltrating T cells within renal tissue may use TCR Vbeta genes targeted toward nephritogenic antigens.