Kidney Week

Abstract: FR-PO183

IgG4-Related Kidney Disease (IgG4-RKD) a Large Single-Institution Study

Session Information

• CKD: Epidemiology, Risk Factors, Prevention - II
  October 26, 2018 | Location: Exhibit Hall, San Diego Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: CKD (Non-Dialysis)

• 1901 CKD (Non-Dialysis): Epidemiology, Risk Factors, and Prevention

Authors

• Buglioni, Alessia, Mayo Clinic , Rochester, Minnesota, United States

Alessia Buglioni,

• Alexander, Mariam P., Mayo Clinic , Rochester, Minnesota, United States

Mariam P. Alexander,

• Herrera hernandez, Loren Paola, Mayo Clinic , Rochester, Minnesota, United States

Loren Paola Herrera hernandez,

• Fidler, Mary E., Mayo Clinic , Rochester, Minnesota, United States

Mary E. Fidler,

• Nasr, Samih H., Mayo Clinic , Rochester, Minnesota, United States

Samih H. Nasr,

• Sethi, Sanjeev, Mayo Clinic , Rochester, Minnesota, United States

Sanjeev Sethi,

• Said, Samar M., Mayo Clinic , Rochester, Minnesota, United States

Samar M. Said,

• Grande, Joseph P., Mayo Clinic , Rochester, Minnesota, United States

Joseph P. Grande,

• Hogan, Marie C., Mayo Clinic , Rochester, Minnesota, United States

Marie C. Hogan,

• Cornell, Lynn D., Mayo Clinic , Rochester, Minnesota, United States

Lynn D. Cornell,

Background

IgG4-related disease (IgG4-RD) is an immune-mediated condition that can involve any organ, often by mass-forming inflammatory lesions. The kidney is usually affected in a pattern of tubulointerstitial nephritis (TIN); membranous glomerulonephritis (MGN) is another recognized pattern.

Methods

A retrospective biopsy (bx) - and nephrectomy-based study from a single institution with clinicopathological correlation was performed in cases of IgG4-RKD diagnosed between 1/2001 and 5/2018.

Results

101 patients (80 M, 21 F) were identified with IgG4-RKD on bx (n= 96) or nephrectomy (n= 5), with a histologic pattern of TIN (94%) and/or MGN (15%). Race/ethnicity included white non-Hispanic (65%), African-American (11%), Asian (11%), Hispanic (11%), and American Indian (3%). The mean age was 62 years (range 20-84). Mean creatinine (SCr) at bx was 3.4 mg/dl (median 2.6 mg/dl, range 0.9-11.0 mg/dl). The primary indication for bx or nephrectomy was acute or chronic renal failure (68%), proteinuria (9%), or abnormal imaging (23%). Overall, 39% had renal masses. Extra-renal involvement was present in 85%. Serum IgG and/or IgG4 was increased in 88%. 29% had positive antinuclear antibody. Serum complement (C3 and/or C4) was decreased in 63%.

Plasma cell-rich TIN was present in all cases of TIN and 93% showed an increase in IgG4+ plasma cells (focal >10 cells/40x field). Interstitial fibrosis was severe in 65% of cases, moderate in 15%, mild in 20%. 15% had MGN; of those with MGN, 71% also had a component of TIN. None showed granulomatous inflammation. 70% showed tubular basement membrane immune complex deposits by IF or EM.
Follow-up was available in 49 patients (49%), with a mean length of 17 months. 98% were treated with immunosuppression (prednisone in 64%, rituximab in 6%, both 10% and other in 19%). 80% of patients with elevated SCr responded to therapy.

Conclusion

In our study, the most common manifestation of IgG4-RKD is TIN with functional impairment rather than mass lesions. MGN is not uncommon. Clinical features of IgG4-KRD included a higher prevalence of hypocomplementemia. Notably, 15% of patients have renal-limited disease. Immunosuppressive therapy improves renal function in the majority of patients.