Abstract: FR-PO741

Collapsing FSGS: Vascular Injury as a Cause of Secondary Collapsing Glomerulopathy?

Session Information

Category: Glomerular

  • 1004 Clinical/Diagnostic Renal Pathology and Lab Medicine

Authors

  • Gougeon, Francois, UNC-Chapel Hill Nephropathology, Chapel Hill, North Carolina, United States
  • Singh, Harsharan Kaur, University of North Carolina School of Medicine , Chapel Hill, North Carolina, United States
  • Jennette, J. Charles, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
  • Nickeleit, Volker, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
Background

Collapsing glomerulopathy (CG) has been associated with various diseases such as infections, diabetes mellitus or auto-immune diseases. In renal allografts CG has occasionally been linked to perfusion abnormalities. At present a systematic review of CG and concurrent other renal diseases is lacking

Methods

We searched our database for a biopsy diagnosis of CG in native and transplant kidneys between 01/2011 and 01/2016. Among 7641 cases 4.4% (322) showed CG in an initial index biopsy. Tip variant FSGS 51/7641 (0.7%) served as one control cohort. Cases were grouped as: 1) “pure”: no other significant kidney disease, 2) presumptive “secondary”: with concurrent other significant renal diseases

Results

CG was more often secondary than the tip-variant (152/322, 47% vs. 14/51, 28%; p<0.01; table 1). In the study set three disease categories were significantly more often diagnosed in secondary CG: severe arterionephrosclerosis (AS; 25%), membranous glomerulopathy (MGN, 15%) and thrombotic microangiopathies (TMA, 9%; all p<0.01). In comparison secondary tip variant FSGS showed tightest associations with MGN and no association with TMA. In transplants, 21/30 (70%) of CG cases were classified as secondary: 7/21 had prominent vascular sclerosis and 4/21 antibody mediated rejection with microvascular injury

Conclusion

In conclusion: CG but not tip-variant FSGS is commonly associated with concurrent renal diseases. Secondary CG is significantly linked to vascular injury (AS, TMA, rejection with capillaritis). These findings further understanding of CG and pending future studies can streamline diagnostic decision making

 CGTip lesionTotal cohort
Total
Total "pure
Total "secondary"
322517319
170 (52.8%)37 (72.5%)N/A
152 (47.2%)14 (27.5%) p=<0.01N/A
Associations in "secondary" cohort
Severe arteriosclerosis38/152 (25.0%)2/14 (14.3%)757 (10.3%)
p<0.01
Membranous glomerulopathy22/152 (14.5%)5/14 (35.7%)
p<0.05
623 (8.5%)
p<0.01
Lupus nephropathy20/152 (13.2%)1/14 (7.1%)663 (9.1%)
Diabetic nephropathy20/152 (13.2%)1/14 (7.1%)951 (13.0%)
Thrombotic microangiopathy14/152 (9.2%)0187 (2.6%)
p<0.01
Combined severe arteriosclerosis and diabetic nephropathy12/152 (7.9%)0372 (5.1%)
IgA nephropathy (proliferative)4/152 (2.6%)0320 (4.4%)
ANCA-associated glomerulonephritis3/152 (2.0%)0406 (5.5%)
Other19/152 (12.5 %)5/14 (35.7%)N/A

Table 1: Total biopsy cohort and tip lesion compared to secondary CG cases (natives). All statistics refer to comparison with the CG cohort.