TY - JOUR
T1 - Quantitation of C4 nephritic factor by an enzyme-linked immunosorbent assay
AU - Seino, Jin
AU - Kinoshita, Yasumichi
AU - Sudo, Katsuhiko
AU - Horigome, Ikuo
AU - Sato, Hiroshi
AU - Narita, Mitsuyoshi
AU - Noshiro, Hiroo
AU - Kudo, Kenichi
AU - Fukuda, Kazuo
AU - Saito, Takao
AU - Yoshinaga, Kaoru
N1 - Funding Information:
research grant from the Miyagi Prefecture Kidney Association, Japan,
Funding Information:
This study was supported in part by a research grant (progressive renal lesions) from the Intractable Disease Division, Public Health Bureau, Ministry of Health and Welfare, Japan, and by a
PY - 1990
Y1 - 1990
N2 - We have developed an enzyme-linked immunosorbent assay (ELISA) for the quantitation of C4 nephritic factor (C4NeF). Incubation of the C4NeF-positive serum from patient M.I. with normal human serum (NHS) in the presence of human aggregated IgG (AHG) resulted in the formation of stable C4-C2 complex. No complex was formed in EDTA or under the condition free of AHG. The reaction mixture was filtered through an ACA 22 column, from which the C4-C2 complex was eluted at the first protein peak. When IgG purified from M.I. serum was incubated with NHS and AHG, C4-C2 complex also increased in proportion to dose of the purified M.I. IgG. These results show that C4NeF in M.I. serum stabilizes C4b2a convertase of the classical complement pathway, and is quantified by the ELISA. C4NeF activity was measured, using the ELISA method, in patients with various glomerular diseases, and found elevated in three of 24 patients with membranoproliferative glomerulonephritis (MPGN) type I and slightly but distinctly positive in seven of 24. No C4NeF was detected in two C3 nephritic factor-positive patients with MPGN type II and six with active systemic lupus erythematosus. The new method was more simple and quantitative than C4b2a stabilization assay for C4NeF.
AB - We have developed an enzyme-linked immunosorbent assay (ELISA) for the quantitation of C4 nephritic factor (C4NeF). Incubation of the C4NeF-positive serum from patient M.I. with normal human serum (NHS) in the presence of human aggregated IgG (AHG) resulted in the formation of stable C4-C2 complex. No complex was formed in EDTA or under the condition free of AHG. The reaction mixture was filtered through an ACA 22 column, from which the C4-C2 complex was eluted at the first protein peak. When IgG purified from M.I. serum was incubated with NHS and AHG, C4-C2 complex also increased in proportion to dose of the purified M.I. IgG. These results show that C4NeF in M.I. serum stabilizes C4b2a convertase of the classical complement pathway, and is quantified by the ELISA. C4NeF activity was measured, using the ELISA method, in patients with various glomerular diseases, and found elevated in three of 24 patients with membranoproliferative glomerulonephritis (MPGN) type I and slightly but distinctly positive in seven of 24. No C4NeF was detected in two C3 nephritic factor-positive patients with MPGN type II and six with active systemic lupus erythematosus. The new method was more simple and quantitative than C4b2a stabilization assay for C4NeF.
KW - C3 nephritic factor
KW - C4 nephritic factor
KW - C42a stabilization
KW - ELISA
KW - Membranoproliferative glomerulonephritis
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U2 - 10.1016/0022-1759(90)90468-B
DO - 10.1016/0022-1759(90)90468-B
M3 - Article
C2 - 2324500
AN - SCOPUS:0025332533
VL - 128
SP - 101
EP - 108
JO - Journal of Immunological Methods
JF - Journal of Immunological Methods
SN - 0022-1759
IS - 1
ER -