Activated (IL-2R+) intraglomerular mononuclear cells in crescentic glomerulonephritis

We recently reported evidence for the involvement of local cellular immune activation in the immunopathogenesis of human IgA nephropathy, particularly in cases of IgA disease featuring crescent formation. In the current study, using monoclonal antibodies, we investigated whether mononuclear cells bearing receptors for interleukin 2 (IL-2R+ MNC) were present within glomeruli or associated crescents in biopsies from patients with crescentic glomerulonephritis (greater than 60% crescents, N = 19), IgA disease with crescents (N = 9), or other types of proliferative glomerulonephritis with crescents (10 to 44%, N = 6), compared with normal control kidneys (N = 10). Biopsies were further classified into those showing active (cells, fibrin) (N = 15) or inactive (sclerosed) crescents (N = 19), to determine whether IL-2R+ MNC were particularly associated with active crescent formation. Few leucocytes were found within glomerular tufts of normal kidneys (2.4 +/- 0.7 cells/glomerular cross-section; mean +/- SEM). By contrast, in biopsies from patients with active crescentic glomerulonephritis, total intraglomerular tuft leucocytes were increased to 14.0 +/- 1.7 (P less than 0.01 vs. normal kidneys), largely due to increased numbers of intraglomerular monocytes (10.4 +/- 1.1, P less than 0.01) and T cells (3.7 +/- 0.6, P less than 0.01). Biopsies with active crescents also contained significantly increased numbers of intraglomerular tuft IL-2R+ MNC (4.0 +/- 0.7, 29% of total intraglomerular leucocytes), and there was a strong correlation between the numbers of intraglomerular IL-2R+ MNC and T cells (P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)