The spectrum of kidney biopsy findings in patients with morbid obesity Hae-Yoon Grace Choung, Andrew S. Bomback, M. Barry Stokes, Dominick Santoriello, Eric S. Campenot, Ibrahim Batal, Glen S. Markowitz, Vivette D. D’Agati  Kidney International  Volume 95, Issue 3, Pages 647-654 (March 2019) DOI: 10.1016/j.kint.2018.11.026 Copyright © 2019 International Society of Nephrology Terms and Conditions

Kidney International 2019 95, 647-654DOI: (10.1016/j.kint.2018.11.026) Copyright © 2019 International Society of Nephrology Terms and Conditions

Figure 1 Examples of biopsy findings in morbidly obese patients. (a) Obesity-related glomerulopathy (ORG) alone showing typical glomerulomegaly and perihilar focal segmental sclerosis with focal tubular atrophy and interstitial fibrosis (periodic acid–Schiff [PAS], original magnification ×200). (b) ORG alone with marked glomerular hypertrophy. The glomerular capillary luminal diameters appear increased and the glomerular basement membranes are unremarkable (PAS, original magnification ×400). (c) ORG alone showing a discrete perihilar lesion of sclerosis and hyalinosis involving the vascular pole of a hypertrophied glomerulus (PAS, original magnification ×400). (d) Acute postinfectious glomerulonephritis with no evidence of ORG. The glomerulus is engorged with infiltrating neutrophils but the glomerular size is not visibly increased (hematoxylin and eosin, original magnification ×400). (e) ORG alone has relatively preserved foot processes with effacement involving less than 20% of the total glomerular capillary surface area (electron micrograph, original magnification ×6000). (f) Antineutrophil cytoplasmic antibody–associated pauci-immune glomerulonephritis with no evidence of ORG. The glomerulus displays segmental fibrinoid necrosis with the rupture of the glomerular basement membrane and a segmental cellular crescent, but the glomerular size is not visibly increased (Jones methenamine silver, original magnification ×400). To optimize viewing of this image, please see the online version of this article at www.kidney-international.org. Kidney International 2019 95, 647-654DOI: (10.1016/j.kint.2018.11.026) Copyright © 2019 International Society of Nephrology Terms and Conditions

Figure 2 Elucidating the presence or absence of concomitant obesity-related glomerulopathy in biopsies with other renal lesions. (a) Minimal change disease with no evidence of obesity-related glomerulopathy (ORG): the glomerulus appears normal in size and cellularity (hematoxylin and eosin, original magnification ×400). (b) Minimal change disease with no evidence of ORG: the same case as in part (a) has diffuse foot process effacement with no evidence of glomerular basement membrane deposits (electron micrograph, original magnification ×6000). (c) Minimal change disease with ORG (glomerulomegaly alone): the glomerulus is enlarged with a normocellular tuft. The biopsy showed similar diffuse glomerulomegaly but no lesions of segmental sclerosis (Jones methenamine silver, original magnification ×400). (d) Minimal change disease with ORG: the same biopsy as in part (c) has marked diffuse foot process effacement with microvillous transformation of the podocytes (electron micrograph, original magnification ×8000). (e) Diabetic nephropathy with ORG: in addition to the nodules of diabetic glomerulosclerosis, this enlarged glomerulus contains a perihilar lesion of segmental sclerosis and hyalinosis. Such perihilar lesions were identified involving 8 of 12 glomeruli sampled by light microscopy (periodic acid–Schiff [PAS], original magnification ×400). (f) Diabetic nephropathy with ORG: the same case as in part (e) shows a similar perihilar lesion of segmental sclerosis and hyalinosis and capsular adhesion superimposed on changes of nodular diabetic glomerulosclerosis (PAS, original magnification ×400). To optimize viewing of this image, please see the online version of this article at www.kidney-international.org. Kidney International 2019 95, 647-654DOI: (10.1016/j.kint.2018.11.026) Copyright © 2019 International Society of Nephrology Terms and Conditions