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Hypocomplementaemia caused by C3 nephritic factors (C3 NeF): clinical findings and the coincidence of C3 NeF type II with anti-C1q autoantibodies

Melander Skattum, Lillemor LU ; Mårtensson, Ulla LU and Sjoholm, A G (1997) In Journal of Internal Medicine 242(6). p.455-464
Abstract
OBJECTIVES: The main purposes were to document manifestations associated with prolonged or clinically unexplained C3 deficiency and to approximate how often hypocomplementaemia of this kind is caused by C3 nephritic factors (C3 NeF), i.e. autoantibodies to alternative pathway C3 convertases. We also wished to distinguish between C3 NeF types I and II and to assess coincident autoantibody responses to the collagen-like region of C1q (C1qCLR). SETTING: The investigation was based on serum samples referred to a specialized laboratory for complement analysis in the course of several years. SUBJECTS: Twenty-five persons with C3 concentrations lower than 0.43 g L-1, a third of the normal, were included in the study. RESULTS: Analysis using three... (More)
OBJECTIVES: The main purposes were to document manifestations associated with prolonged or clinically unexplained C3 deficiency and to approximate how often hypocomplementaemia of this kind is caused by C3 nephritic factors (C3 NeF), i.e. autoantibodies to alternative pathway C3 convertases. We also wished to distinguish between C3 NeF types I and II and to assess coincident autoantibody responses to the collagen-like region of C1q (C1qCLR). SETTING: The investigation was based on serum samples referred to a specialized laboratory for complement analysis in the course of several years. SUBJECTS: Twenty-five persons with C3 concentrations lower than 0.43 g L-1, a third of the normal, were included in the study. RESULTS: Analysis using three methods provided evidence of C3 NeF in 20 persons with equal frequencies of C3 NeF types I and II. We also gave evidence of antibody specificity differences for the two types of C3 NeF. Six patients with C3 NeF type II showed antibodies to C1qCLR. Membranoproliferative glomerulonephritis was the predominant diagnosis and two patients had partial lipodystrophy reflecting the well-known association between these diseases and C3 NeF. Anaphylactoid purpura, systemic lupus erythematosus, and severe infection, mainly meningococcal disease, were also observed. CONCLUSIONS: The study group was probably fairly representative of C3 deficiency syndromes as encountered in clinical practice. The findings emphasize the heterogeneity of C3 NeF, and that acquired C3 deficiency syndromes caused by C3 NeF should perhaps be considered more often in diagnostic work. (Less)
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author
; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
autoimmunity, complement 3 nephritic factors, glomerulonephritis, meningococcal infections
in
Journal of Internal Medicine
volume
242
issue
6
pages
455 - 464
publisher
Wiley-Blackwell
external identifiers
  • pmid:9437406
  • scopus:0031455761
ISSN
1365-2796
DOI
10.1111/j.1365-2796.1997.tb00018.x
language
English
LU publication?
yes
id
18c97efd-57e0-4238-8e86-8aa8bbf9c250 (old id 1111919)
date added to LUP
2016-04-01 17:01:28
date last changed
2022-01-28 23:50:11
@article{18c97efd-57e0-4238-8e86-8aa8bbf9c250,
  abstract     = {{OBJECTIVES: The main purposes were to document manifestations associated with prolonged or clinically unexplained C3 deficiency and to approximate how often hypocomplementaemia of this kind is caused by C3 nephritic factors (C3 NeF), i.e. autoantibodies to alternative pathway C3 convertases. We also wished to distinguish between C3 NeF types I and II and to assess coincident autoantibody responses to the collagen-like region of C1q (C1qCLR). SETTING: The investigation was based on serum samples referred to a specialized laboratory for complement analysis in the course of several years. SUBJECTS: Twenty-five persons with C3 concentrations lower than 0.43 g L-1, a third of the normal, were included in the study. RESULTS: Analysis using three methods provided evidence of C3 NeF in 20 persons with equal frequencies of C3 NeF types I and II. We also gave evidence of antibody specificity differences for the two types of C3 NeF. Six patients with C3 NeF type II showed antibodies to C1qCLR. Membranoproliferative glomerulonephritis was the predominant diagnosis and two patients had partial lipodystrophy reflecting the well-known association between these diseases and C3 NeF. Anaphylactoid purpura, systemic lupus erythematosus, and severe infection, mainly meningococcal disease, were also observed. CONCLUSIONS: The study group was probably fairly representative of C3 deficiency syndromes as encountered in clinical practice. The findings emphasize the heterogeneity of C3 NeF, and that acquired C3 deficiency syndromes caused by C3 NeF should perhaps be considered more often in diagnostic work.}},
  author       = {{Melander Skattum, Lillemor and Mårtensson, Ulla and Sjoholm, A G}},
  issn         = {{1365-2796}},
  keywords     = {{autoimmunity; complement 3 nephritic factors; glomerulonephritis; meningococcal infections}},
  language     = {{eng}},
  number       = {{6}},
  pages        = {{455--464}},
  publisher    = {{Wiley-Blackwell}},
  series       = {{Journal of Internal Medicine}},
  title        = {{Hypocomplementaemia caused by C3 nephritic factors (C3 NeF): clinical findings and the coincidence of C3 NeF type II with anti-C1q autoantibodies}},
  url          = {{http://dx.doi.org/10.1111/j.1365-2796.1997.tb00018.x}},
  doi          = {{10.1111/j.1365-2796.1997.tb00018.x}},
  volume       = {{242}},
  year         = {{1997}},
}