RT Journal Article
SR Electronic
T1 C3 concentrations can be normal in patients with C3 glomerulopathy secondary to C3 nephritic factor
JF Journal of Clinical Pathology
JO J Clin Pathol
FD BMJ Publishing Group Ltd and Association of Clinical Pathologists
SP 503
OP 506
DO 10.1136/jcp-2023-209319
VO 77
IS 7
A1 Anderson, Hamish
A1 Van Voorthuizen, Mark
A1 O'Donnell, John
A1 Beck, Sarah
YR 2024
UL http://jcp.bmj.com/content/77/7/503.abstract
AB C3 glomerulopathy (C3G) is a rare kidney disease caused by the glomerular deposition of C3 fragments secondary to alternative pathway complement dysregulation. C3 nephritic factors (C3Nef) are the most common acquired cause, and their detection has treatment and prognostic implications. Although C3 concentration can be normal in the presence of C3Nef, many laboratories will only perform C3Nef testing when C3 is low. We performed a retrospective study of all positive C3Nef results from the authors’ laboratory since 2015 and found that two of the four patients with positive C3Nef and biopsy-confirmed C3G had normal C3 concentrations. This may be in part due to limitations in commercial C3 testing methods which use anti-C3c antisera directed against both C3 breakdown products and native C3. A normal C3 concentration should not preclude C3Nef testing in the appropriate clinical context.