PT  - JOURNAL ARTICLE
AU  - Wenli Xia
AU  - Bixia Gao
AU  - Lin Duan
AU  - Yan Li
AU  - Yubing Wen
AU  - Limeng Chen
AU  - Xuemei Li
AU  - Falei Zheng
AU  - Mingxi Li
TI  - Clinical significance of C4d deposition in renal tissues from patients with primary Sjögren’s syndrome—A preliminary study
AID  - 10.1101/562215
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 562215
4099  - http://biorxiv.org/content/early/2019/02/27/562215.short
4100  - http://biorxiv.org/content/early/2019/02/27/562215.full
AB  - Objectives To evaluate renal expression of C4d, a complement component in the classical/mannose binding lectin (MBL) pathway, in patients with primary Sjögren’s syndrome (pSS)-associated renal impairments.Methods We retrospectively reviewed the clinical and pathological data from 39 patients with pSS presenting with renal impairments. C4d was examined in paraffin-embedded biopsy tissues using immunohistochemistry. Glomerular C4d positive was defined when >75% glomeruli were globally stained. Tubulointerstitial C4d (TI-C4d) were scored semi-quantitatively as 0 (absent), 1 (spotty or weak), 2 (patchy) and 3 (diffuse). A TI-C4d score ≥2 was considered TI-C4d positive and included in the TI-C4d+ group and vice versa. Peritubular capillary (PTC) C4d was scored as 0 (absent), 1 (0∼10%, minimal), 2 (10%∼50%, focal), and 3 (>50%, diffuse).Results Glomerular C4d deposition was observed in all 8 patients with pSS-related membranous nephropathy (MN) without obvious C1q deposition. Two of 5 patients with mesangial proliferative glomerulonephritis and 1 of 2 patients with IgA nephropathy had mild mesangial C4d deposition. Sixteen patients (6 glomerular dominant and 10 tubulointerstitial dominant) presented TI-C4d score ≥2. Patients in the TI-C4d+ group exhibited a higher serum creatinine level at the time of renal biopsy (TI-C4d+ 132.5 [89.7, 165.5] vs. TI-C4d- 83.0 [70.7, 102.0] μmol/L, P=0.008). PTC C4d was observed in 12 patients, with each of minimal, focal and diffuse staining being noted in 4 patients.Conclusions The MBL pathway of complement activation was potentially involved in pSS-related MN. Tubulointerstitial C4d might be a pathological marker of severe renal injury in patients with pSS-related renal impairments.