Collapsing glomerulopathy, the Saudi Arabian scenario. A study of 31 cases and a review of literature

Abstract

To compare the clinico-pathological features of collapsing glomerulopathy (CG) at a tertiary hospital in Saudi Arabia with the world literature. Methods: In a retrospective study, all biopsy-diagnosed cases of CG between 2004-2015 were identified and analyzed, at King Khalid University Hospital, King Saud University, Riyadh. The clinico-pathological findings along with prognosis were reviewed and compared with the reported literature. Results: Thirty-one CG patients were identified, most were adult males. All the CG cases were idiopathic, all Arabs, none HIV positive, none of African descent, and none with a history of drug abuse. The number of glomeruli with collapsing lesions per biopsy ranged from 1 to 9. Other types of FSGS lesions (not otherwise specified and perihilar) were also noted. There was extensive podocyte effacement. Upon treatment, remission (complete/partial) was noted in almost half the patients; around one fourth did not respond to treatment; and one fourth progressed to end stage kidney disease (ESKD). The median time taken to develop ESKD from the time of biopsy diagnosis was 23 months. Conclusion: The clinico-pathological and prognostic correlates of CG in Saudi Arabia are comparable with that of the world literature. The management protocol at our center is the same as that practiced in different parts of the world, and the prognosis is overall poor.

Figure 1

Light microscopy photomicrograph of a A) renal biopsy in a case of collapsing glomerulopathy shows segmental collapse of the glomerular tuft (arrow) with hyperplasia and hypertrophy of the overlying epithelial cells. Another tuft showing NOS (not otherwise specified) type of segmental sclerosis with adhesion to the Bowman’s capsule is also noted (arrowhead). (Periodic Acid Schiff stain; original magnification x400.) B) renal biopsy in a case of collapsing glomerulopathy, shows a small focus of segmental collapse of the glomerular tuft (arrowhead) with mild hyperplasia of the overlying epithelial cells. (Periodic Acid Schiff stain; original magnification x400.) C) renal biopsy in another case of collapsing glomerulopathy, shows segmental glomerular tuft collapse (arrowhead) with mild hyperplasia of the overlying epithelial cells (arrow) and some resorption protein droplets. (Periodic Acid Schiff stain; original magnification x400.) D) renal biopsy in a case of collapsing glomerulopathy, shows several cystically dilated tubules (arrows). The intervening glomeruli in this image show mild glomerulomegaly. (Periodic Acid Schiff stain; original magnification x100.)

Figure 2

Electron micrographs from renal biopsies diagnosed with collapsing glomerulopathy are shown. All the images exhibit different degrees of collapse in the capillary loops (arrows) with diffuse effacement of the epithelial cell foot processes and microvilli formation. Hypertrophy of the epithelial cell (arrowheads) is also seen in images (Uranyl acetate and lead citrate; original magnification A) x5000, B) x5000, C) x800 and D) x6000)