Table 2 Summary of results of experiments addressed to determine the nature of electron dense structures associated with glomerular membranes in nephritic kidneys that are targeted by autoantibodies in vivo

Constituents	Healthy glomeruli	Structures characterised in glomerular membrane-associated electron dense structures				Interpretation of EDS composition
Constituents	Healthy glomeruli	Nephritic glomeruli (NZB×NZW)F1	Present in membranes outside EDS	Human lupus nephritis	References	Interpretation of EDS composition
DNA	Not detected	Dense pattern confined to EDS	Negative	Dense pattern in EDS	14 26 42	Presence of DNA, histones and transcription factors indicates accumulation of nucleosomes in EDS associated with membranes
Histones	Not detected	Dense pattern confined to EDS	Negative	Dense pattern in EDS	14 26 42
Transcription factors*	Not detected	Presence confined to EDS	Negative	Present in EDS	14 26
Laminin	Normal membrane constituent	Surrounding EDS†	Normal pattern	Not analysed	14	Laminin and collagen are not part of EDS
Collagen	Normal membrane constituent	Surrounding EDS	Not analysed	Not analysed	14	Laminin and collagen are not part of EDS
α-Actinin	In podocytes and mesangial cells	Present in membranes, interstitium and in EDS	Random pattern in the extracellular space	Not analysed	13	α-Actinin is extracellular in nephritic glomeruli

*To demonstrate the presence of transcription factor in EDS, antibodies to Tata-box binding protein (TBP) have been used, as this factor is constitutively bound to nucleosomes; †as an example of this, see fig 1D,E.