Collapsing glomerulopathy with patchy acute cortical necrosis secondary to postpartum hemorrhage

Collapsing glomerulopathy with patchy acute cortical necrosis secondary to postpartum hemorrhage Sir, Collapsing glomerulopathy (CG) represents a distinct pattern of renal response to injury characterized by segmental to global collapse of capillaries in association with hyperplasia and hypertrophy of the visceral epithelial cells (VECs) associated with marked tubulointerstitial damage [1]. The reporting of CG in the literature has increased with the growing awareness among the nephrologists and pathologists of its association with disorders other than human immunodefi-ciency virus-1 infection [1–3]. Currently, it is classified as a variant of focal segmental glomerulosclerosis (FSGS) [3]. However, more recently, some authors have suggested that this relationship with FSGS may not last longer, and sooner or later it may be classified as a separate nosologic entity [2, 3]. With increasing awareness, the vascular lesions and thromboembolic phenomenon with consequent ischaemia have also emerged as important etiopathogenetic mechanisms in the development of CG in both the native and the transplanted kidneys [4–7]. More recently, the direct causal relationship between patchy infarction and de novo CG in transplanted kidneys has been reported [8]. However, no such link with acute cortical necrosis (ACN) secondary to post-partum haemorrhage (PPH) and hypovolaemic shock in native kidneys of young patients with no vascul-opathy has been reported till date. We herein report two cases of CG involving the glomeruli in the vicinity of patchy ACN found on biopsies from native kidneys in two patients. Both patients were young females, 17 and 26 years, respectively, and presented with acute renal failure (ARF) following PPH. No history of drug intake or past medical illness of note was elicited. Ultrasound findings were not typical of ACN. Urine analysis was non-contributory. Relevant viral and autoimmune serology was negative. Both patients required dialysis initially, but one is off dialysis and maintaining serum creatinine at 221 lmol/L 8 months post-biopsy, whereas the other is on haemodialysis, waiting for kidney transplantation 10 months after diagnosis. Renal biopsies in both cases showed patchy infarction. In addition, both biopsies showed variable numbers of glo-meruli in the vicinity of infarction, with segmental to global collapse of capillaries associated with hyperplasia and hy-pertrophy of VECs (Figure 1). There was moderate mixed inflammatory cell infiltration in the interstitium. However, no vasculopathy or thrombotic lesions were noted. Immu-nofluorescence was performed on snap-frozen tissue and showed segmental positivity of immunoglobulin M (IgM) and C3 in areas of collapsed tufts of viable glomeruli, whereas IgG, IgA …