SO058IGG4-RELATED KIDNEY DISEASE : A FRENCH NATIONWIDE RETROSPECTIVE COHORT STUDY. (6th June 2020)

• Record Type: Journal Article
• Authors: Chaba, Anis; Zaidan, Mohamad; Jean Jacques, BOFFA; Alexandre, KARRAS; Vincent, Audard; RENAUD, SNANOUDJ; Thaunat, Olivier; NOUVIER, Mathilde; Arnaud, DEVRESSE; Joly, Dominique; Halimi, Jean Michel; CARTERY, CLAIRE; Daugas, Eric; Peraldi, Marie-Noelle; Mathieu, LEGENDRE; Julie, BELLIERE; Faguer, Stanislas; Dimitri, TITECA; William, HANF; Petitclerc, Thierry; Guillaume, HANOUNA; Chemouny, Jonathan; Nabila, GOUMRI; Simon, DUQUENNOY; Vilaine, Eve
• Is Part Of: Nephrology dialysis transplantation. Volume 35(2020)Supplement 3
• Publication Date: 2020-06-06
• Subjects: Nephrology -- Periodicals; Hemodialysis -- Periodicals; Kidneys -- Transplantation -- Periodicals; Hemodialysis; Kidneys -- Transplantation; Nephrology; Periodicals; 616.61
• DOI: 10.1093/ndt/gfaa139.SO058
• Languages: English
• ISSNs: 0931-0509

Abstract

Abstract: Background and Aims: IgG4 disease is a systemic fibroinflammatory disorder that may affect virtually any organ. IgG4-related kidney disease (IgG4-RKD) is a major manifestation, occurring in almost one third of patient. The present study addresses the diagnosis, management and outcome of French patients with IgG4-RKD. Method: We conducted a retrospective observational study including patients with renal impairment due to IgG4-RKD from 32 centers. Clinical, biological, and imaging data, as well as management modalities and outcome, were retrieved from medical records. Results: 74 patients, 64 males and 10 females, were diagnosed with IgG4-RKD between 1997 and 2019 and were included in the present study. The mean age at diagnosis was 65.2 ± 15-year-old. Renal involvement was present at diagnosis in 63% of cases. Nine (12%) patients had isolated renal involvement, whereas extra-renal involvement included retroperitoneal fibrosis (20%), auto-immune pancreatitis (49%), cholangitis (27%), and lung disease (22%). Renal imaging lesions were observed in 48 (64%) patients, and included renal hypertrophy, patchy lesions and pseudo-tumor solitary renal lesion. PET-CT scan was performed in 47 (65%) patients and showed hypermetabolic renal lesion(s) in 36% of cases. The presence of extra-renal hypermetabolic lesions was observed in 35 cases (74%). 43 %, 25% and 14% of patients presented with AKI, AKI-on-CKD, and isolated CKD, respectively. The mean serum creatinine level at diagnosis was 244 ± 140 µmol/L, corresponding to an eGFR of 69 ± 22ml/min/1.73m. Urinary sediment was most often bland. Mean urine protein-to-creatinine ratio was 1.27 g/g. of note, 26% of patients had more than 1 g/g. 82% of patients underwent a kidney biopsy showing tubulointerstitial involvement in all cases, 12 (16%) had additional glomerular involvement, mainly membranous nephropathy. The major additional laboratory abnormalities included polyclonal hypergammaglobulinemia, and increased serum IgG4 increase in 83% and 86%, respectively. Complement levels were decreased in 27 (37%) patients. Two patients were lost for follow-up and 69 patients were treated with corticosteroid therapy in 66 (89%) patients and 10 received Rituximab as first line therapy. The mean duration of follow-up was 28.8 ± 30 months. During follow-up, 22 (30%) patients relapsed, while 45 (62%) patients had persistent CKD at last follow-up, with a mean eGFR of 47±27 ml/min/1.73m. Seven (9%) patients progressed to ESRD and 7 died. A significant response was achieved in 46 (62%) patients. Patients who received steroids higher than 0.5mg/kg/day had lower serum IgG4 levels (1.8 g/l versus 5.7 g/l, p= 0.007) at last follow up but there was no significant difference observed in terms of renal function between the two groups (45.5 vs 48.8 ml/min/1.73m, p= 0.72). By univariate analysis, predictors of relapse were low C3 or C4 serum level ( p= 0.01), ANCA positivity ( p= 0.02), renal radiological lesions ( p= 0.05). At last follow-up the eGFR was worse in patients with a serum creatinine diagnosis greater than 300 µmol/L (30.25 vs 57 ml/min/1.73m p= 0.0001) and more progressed to ESRD ( p= 0.03). Conclusion: IgG4-RKD has been recently described and may affect middle-aged males. The disease presents as tubulointerstitial nephritis with glomerular involvement in 16% of cases. Disease response to corticosteroid therapy is favorable but is characterized by a high rate of relapses and a significant risk of persistent CKD in the majority of patient. Risk of ESRD and death in almost 20% of patients.