Original scientific paper

https://doi.org/10.11613/BM.2019.030707

Classical pathway activity C3c, C4 and C1-inhibitor protein reference intervals determination in EDTA plasma

Benjamin Lopez ; Department of Immunology, Lille University Hospital, Lille, France; Lille Inflammation Research International Center, University of Lille, Lille, France
Nicolas Bertier ; Department of Immunology, Lille University Hospital, Lille, France
Emmanuel Ledoult ; Department of Immunology, Lille University Hospital, Lille, France; Department of Internal Medicine and Clinical Immunology, Lille University Hospital, Lille, France
Romane Joudinaud ; Department of Immunology, Lille University Hospital, Lille, France
Mehdi Maanaoui ; Department of Immunology, Lille University Hospital, Lille, France; Department of Nephrology, Lille University Hospital, Lille, France
Victoria Majerus ; Department of Immunology, Lille University Hospital, Lille, France
Emmanuelle Moitrot ; Department of Immunology, Lille University Hospital, Lille, France
Anne-Sophie Deleplancque ; Department of Immunology, Lille University Hospital, Lille, France
Stéphanie Rogeau ; Department of Immunology, Lille University Hospital, Lille, France; Lille Inflammation Research International Center, University of Lille, Lille, France
David Launay ; Lille Inflammation Research International Center, University of Lille, Lille, France; Department of Internal Medicine and Clinical Immunology, Lille University Hospital, Lille, France; National Reference Center for Angioedema (CREAK), Grenoble, France
Guillaume Lefèvre ; Department of Immunology, Lille University Hospital, Lille, France; Lille Inflammation Research International Center, University of Lille, Lille, France; Department of Internal Medicine and Clinical Immunology, Lille University Hospital, Lille, France
Myriam Labalette ; Department of Immunology, Lille University Hospital, Lille, France; Lille Inflammation Research International Center, University of Lille, Lille, France
Sylvain Dubucquoi ; Department of Immunology, Lille University Hospital, Lille, France; Lille Inflammation Research International Center, University of Lille, Lille, France

Abstract

Introduction: Reference intervals (RIs) for complement assays in EDTA plasma samples have not previously been published. The objectives of the
present study were to validate and/or determine RIs for classical pathway (CP50) activity and C3c, C4 and C1 inhibitor protein (C1INH) assays and to
assess the need for age-specific RIs in EDTA plasma.
Materials and methods: We retrospectively evaluated a cohort of 387 patients attending our university hospital and known to be free of complement-
modifying diseases. The need for age partitioning was assessed and RIs were calculated according to the CLSI protocol.
Results: No need for age partitioning was evidenced for CP50 activity, C3c and C4 concentrations and RIs (90% CI) were calculated from the pooled
data: 35.4 (33.1-37.2) to 76.3 (73.7-83.6) U/mL for CP50 activity, 0.80 (0.75-0.87) to 1.64 (1.59-1.72) g/L for C3c, and 0.12 (0.10-0.14) to 0.38 (0.36-
0.40) g/L for C4. Our results highlight a positive association between age and C1INH concentrations. We derived 3 age partitions (6 months to 30
years, 30-50 and > 50 years) and the related RIs: 0.20 (0.18-0.21) to 0.38 (0.36-0.40) g/L, 0.22 (0.20-0.24) to 0.39 (0.36-0.41) g/L and 0.25 (0.22-0.27)
to 0.41 (0.40-0.43) g/L, respectively).
Conclusions: The newly determined RIs for CP50 activity were higher than those provided by the manufacturer for EDTA plasma samples, whereas
those for C3c and C4 RIs were similar to the values provided for serum samples. The C1INH concentration and activity were found to be associated
with age and age-specific RIs are mandatory for this analyte.

Keywords

reference values; complement C3c; complement C4; classical complement pathway; complement C1 inhibitor protein

Hrčak ID:

226453

URI

https://hrcak.srce.hr/226453

Publication date:

15.10.2019.

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