Presence of monocytes in systemic lupus erythematosus-associated glomerulonephritis: marker study and significance.

: The presence and significance of monocytes in the glomerular lesions of 13 renal specimens obtained from ten patients with systemic lupus erythematosus-associated nephritis were studied. The monocytes were identified by the presence of intracytoplasmic lysozyme, as demonstrated by immunoperoxidase staining on paraffin-embedded tissue. Eight specimens obtained from six patients displayed monocytes. These were found most often associated with mesangial hypercellularity, and their appearance fluctuated with it. There was a positive correlation between the number of lysozyme-positive cells and the amount of proteinuria. We conclude that monocytes contribute to the endocapillary hypercellularity and affect protein filtration in lupus nephritis.