Urinary myeloid IgA Fc alpha receptor (CD89) and transglutaminase-2 as new biomarkers for active IgA nephropathy and henoch-Schönlein purpura nephritis.

Abstract

BACKGROUND:

IgA nephropathy (IgAN) and Henoch-Schönlein purpura nephritis (HSPN) are glomerular diseases that share a common and central pathogenic mechanism. The formation of immune complexes containing IgA1, myeloid IgA Fc alpha receptor (FcαRI/CD89) and transglutaminase-2 (TG2) is observed in both conditions. Therefore, urinary CD89 and TG2 could be potential biomarkers to identify active IgAN/HSPN.

METHODS:

In this multicenter study, 160 patients with IgAN or HSPN were enrolled. Urinary concentrations of CD89 and TG2, as well as some other biochemical parameters, were measured.

RESULTS:

Urinary CD89 and TG2 were lower in patients with active IgAN/HSPN compared to IgAN/HSPN patients in complete remission (P < 0.001). The CD89xTG2 formula had a high ability to discriminate active from inactive IgAN/HSPN in both situations: CD89xTG2/proteinuria ratio (AUC: 0.84, P < 0.001, sensitivity: 76%, specificity: 74%) and CD89xTG2/urinary creatinine ratio (AUC: 0.82, P < 0.001, sensitivity: 75%, specificity: 74%). Significant correlations between urinary CD89 and TG2 (r = 0.711, P < 0.001), proteinuria and urinary CD89 (r = - 0.585, P < 0.001), and proteinuria and urinary TG2 (r = - 0.620, P < 0.001) were observed.

CONCLUSIONS:

Determination of CD89 and TG2 in urine samples can be useful to identify patients with active IgAN/HSPN.

• Authors: Rafael N Moresco, Marijn M Speeckaert, Slawomir C Zmonarski, Magdalena Krajewska, Ewa Komuda-Leszek, Agnieszka Perkowska-Ptasinska, Loreto Gesualdo, Maria T Rocchetti, Sigurd E Delanghe, Raymond Vanholder, Wim Van Biesen, Joris R Delanghe
• Journal: BBA clinical (BBA Clin) Vol. 5 Pg. 79-84 (Jun 2016) ISSN: 2214-6474 [Print] Netherlands
• PMID: 27051593 (Publication Type: Journal Article)