INFILTRATION OF THE KIDNEY BY ALPHA-BETA AND GAMMA-DELTA T-CELLS - EFFECT ON PROGRESSION IN IGA NEPHROPATHY

(W)e have studied renal biopsies from three groups of patients to dete rmine if alpha beta T cells or gamma delta T cells are present, and wh ether their presence is correlated with disease progression in IgA nep hropathy (IgAN). Group one comprised thin basement membrane disease bi opsies (non-immunological control, N = 7); group two were patients wit h IgAN and stable renal function one year following biopsy (stable, N = 7); and group three were IgAN patients with rapidly declining renal function after one year (pregressive, N = 7). Immunohistochemical stai ning using monoclonal antibodies (CD3, TcR beta, TcR delta) and molecu lar studies utilizing polymerase chain reaction amplification of cDNA transcribed from biopsy RNA, with primers specific for either the alph a beta TcR or gamma delta TcR, were undertaken. On immunohistochemistr y a significant increase in CD3+ cells in progressive biopsies was see n (vs. control P = 0.002, vs. stable P = 0.002). The progressive biops ies infiltrate consisted of both alpha beta TcR (vs. control P = 0.001 , vs. stable P = 0.003) and gamma delta TcR cells (vs. control P = 0.0 1). The RNA study demonstrated an increase in TcR C alpha transcriptio n in the progressive (vs. control P = 0.003) biopsies. Increased TcR C delta transcription was seen in the progressive group (vs. control P = 0.01, vs. stable P = 0.02). We confirm that the presence of lymphocy tes in IgAN biopsies predicts progressive disease. While alpha beta T cells are found in both stable and progressive disease, the presence o f gamma delta T cells is only associated with progressive IgAN.