• collapsing focal segmental glomerulosclerosis
• rituximab
• steroid dependent nephrotic syndrome
• steroid resistant nephrotic syndrome

• Child
• Collapsing glomerulopathy
• Long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency
• Nephrotic syndrome

To compare the clinico-pathological features of collapsing glomerulopathy (CG) at a tertiary hospital in Saudi Arabia with the world literature.

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.

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.

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.

• Adolescent
• Adult
• Aged
• Aged, 80 and over
• Child
• Child, Preschool
• Female
• Glomerulosclerosis, Focal Segmental/pathology
• Humans
• Male
• Middle Aged
• Prognosis
• Saudi Arabia
• Young Adult

Focal segmental glomerulosclerosis (FSGS) is characterized by focal and segmental obliteration of glomerular capillary tufts with increased matrix. FSGS is classified as collapsing, tip, cellular, perihilar and not otherwise specified variants according to the location and character of the sclerotic lesion. Primary or idiopathic FSGS is considered to be related to podocyte injury, and the pathogenesis of podocyte injury has been actively investigated. Several circulating factors affecting podocyte permeability barrier have been proposed, but not proven to cause FSGS. FSGS may also be caused by genetic alterations. These genes are mainly those regulating slit diaphragm structure, actin cytoskeleton of podocytes, and foot process structure. The mode of inheritance and age of onset are different according to the gene involved. Recently, the role of parietal epithelial cells (PECs) has been highlighted. Podocytes and PECs have common mesenchymal progenitors, therefore, PECs could be a source of podocyte repopulation after podocyte injury. Activated PECs migrate along adhesion to the glomerular tuft and may also contribute to the progression of sclerosis. Markers of activated PECs, including CD44, could be used to distinguish FSGS from minimal change disease. The pathogenesis of FSGS is very complex; however, understanding basic mechanisms of podocyte injury is important not only for basic research, but also for daily diagnostic pathology practice.

• Focal segmental glomerulosclerosis
• Parietal epithelial cells
• Permeability factors
• Podocytopathy

• End stage renal disease
• Idiopathic collapsing glomerulopathy
• Podocyte
• Proteinuria

Collapsing glomerulopathy (CG) is a distinct clinicopathologic entity associated with various infections, medications and acute ischemia. There have been few scattered reports of CG from India. This study aimed at evaluating the clinicopathologic features of idiopathic CG in Indian patients with comparison between adult-onset and childhood CG. This study included all cases of idiopathic CG diagnosed over a period of 4 years (2006-2009). Appropriate clinical details and laboratory findings were retrieved. Renal biopsies were reviewed and detailed pathologic features assessed. Statistical analysis was performed to compare various features between adult-onset and childhood CG. Over these 4 years, 30 cases of idiopathic CG were diagnosed. Of these, 11 were children. Childhood CG cases had longer duration of symptoms and lower serum urea and creatinine levels compared with adult patients. In renal histology, tubular atrophy and interstitial fibrosis was frequent in our cases. Pediatric cases of CG showed a higher proportion of segmental glomerulosclerosis. On clinical follow-up, nine of the 30 patients progressed to end-stage renal disease and these included two pediatric patients. Idiopathic CG is a significant cause of renal dysfunction in both pediatric and adult patients. Childhood and adult-onset CG differ in few clinicopathologic features. Early and accurate diagnosis of CG is imperative for appropriate management of these patients.

• Collapsing
• glomerulopathy
• histology
• idiopathic
• prognosis

• Children
• Pakistan
• focal segmental glomerulosclerosis
• nephrotic syndrome
• variants

Collapsing focal segmental glomerulosclerosis (cFSGS), also known as collapsing glomerulopathy is currently classified under the rubric of FSGS. However, its defining morphological features are in stark contrast to those observed in most other variants of FSGS. During the early stage of the disease, the lesion is characterized pathologically by an implosive segmental and/or global collapse of the glomerular capillary tufts, marked hypertrophy and hyperplasia of podocytes, and severe tubulointerstitial disease. With advancement of the disease, segmental and/or global glomerulosclerosis is also observed in association with the collapsing lesions. The etiology of this enigmatic disorder is still elusive, but a growing list of diseases/conditions is being reported in association with this morphological pattern of renal parenchymal injury. The pathogenesis of cFSGS involves discreet epithelial cell injury leading to cell cycle dysregulation and a proliferative cellular phenotype. From the clinical perspective, cFSGS is notorious for its propensity to affect black people, a high incidence and severity of nephrotic syndrome, marked resistance to empirical therapy, and rapid progression to end-stage renal disease. The lesion has also been reported in transplanted kidneys either as recurrent or de novo disease, frequently leading to graft loss. Most cases have been reported in western countries, but the lesion is also being increasingly recognized in the tropical regions. The recent increase in reporting of cFSGS partly reflects a true increase in the incidence and partly a detection bias. There is no specific treatment for the disorder at present. Newer insights into the pathogenesis may lead to the development of targeted and specific therapy in near future. There is an urgent need to increase awareness of the lesion among pathologists and nephrologists, especially those from developing countries, to ensure accurate diagnosis and appropriate managment. With the accumulation of more and more data, it is hoped that the prevailing confusion about the nosological identity of the lesion will also be resolved in a more logical way.

• Collapsing focal segmental glomerulosclerosis
• End-stage renal disease
• Etiology
• Pathology
• Renal biopsy
• Prognosis

• Adolescent
• Adult
• Female
• Glomerulosclerosis, Focal Segmental/complications
• Glomerulosclerosis, Focal Segmental/epidemiology
• Glomerulosclerosis, Focal Segmental/pathology
• Humans
• Kidney Failure, Chronic/etiology
• Male
• Nephrotic Syndrome/etiology
• Pakistan/epidemiology
• Retrospective Studies