1 research outputs found
Properdin in C3 glomerulopathy
24 p.-3 fig.-3 tab.Properdin (P) stabilizes the alternative pathway (AP) convertases, being the only
known positive regulator of complement system. In addition, P is a pattern recognition
molecule able to initiate directly the AP on non-self surfaces. Although P deficiencies
are long time known to be associated with Neisseria infections and P is often found
deposited at sites of AP activation and tissue injury, the potential role of P in the
pathogenesis of complement dysregulation associated disorders has not been
extensively studied. Serum P levels were measured in 49 patients with histological and
clinical evidence of C3 glomerulopathy (C3G). Patients were divided in two groups
according to the presence or absence of C3 nephritic factor (C3NeF), an autoantibody
that stabilizes the AP C3 convertase. The presence of this autoantibody results in a
significant reduction in circulating C3 (p<0.001) and C5 levels (p<0.05), but does not
alter factor B, P and sC5b-9 levels. Interestingly, in our cohort, serum P levels were low
in 17 of the 32 C3NeF-negative patients. This group exhibited significant reduction of
C3 (p<0.001) and C5 (p<0.001), and increase of sC5b-9 (p<0.001) plasma levels,
compared to the control group. Besides, P consumption was significantly correlated
with C3 (r= 0.798, p 0.0001), C5 (r= 0.806, p<0.0001), sC5b-9 (r = -0.683, p 0.043) and
a higher degree of proteinuria (r= -0.862, p 0.013). These results further illustrate the
heterogeneity among C3G patients and suggest that P serum levels could be a reliable
clinical biomarker to identify patients with underlying surface AP C5 convertase
dysregulation.This work was performed with the support of grants from the Spanish Ministerio de Economía y Competitividad (SAF2012-38636), Comunidad de Madrid (S2010/BMD-2316) and CIBERER (ACCI-2014).Peer reviewe