Quantitative studyofmesangial injury withproteinuria induced bymonoclonal antibody 1-22-3

SUMMARY Murine MoAb 1-22-3 hasalready beenreported tobindtothemesangial cell surface andtocause transient proteinuria andmesangial morphological changes characterized by mesangiolysis, subsequent mesangial cell proliferation andmesangial matrix increase byasingle i.v. injection. Inthis study, MoAb-induced glomerulopathy wasquantitatively analysed. No correlation between the severity ofmesangial morphological changes andthedegree ofproteinuria wasdetected (r=0-190). Theminimumdoseinjected toinduce abnormal proteinuria was25pg. Thisdosecorresponded to 1-79 pg/2 kidneys 30minafter MoAbinjection. Thehighest average level ofproteinuria wasobserved inrats injected with500pgofMoAb,andless proteinuria wasobserved inrats injected with10-0, 5-0 and2-0mg.Although theamounts ofkidney-fixing MoAbandthesubsequent deposition ofratC3in thehigh-dose-injected groupwerelarger thaninthe500pginjected group, thenumbers ofinfiltrating inflammatory cells werethesameinbothgroups. No correlations between thedegrees ofsuch mediators andproteinuria wereobserved.