title: Microvascular inflammation and acute tubular necrosis are major histologic features of hantavirus nephropathy.
abstract: Hantavirus nephropathy (HVN) is an uncommon etiology of acute renal failure due to hantavirus infection. Pathological features suggestive of HVN historically reported are medullary interstitial hemorrhages in a background of acute interstitial nephritis (AIN). However, interstitial hemorrhages may be lacking because of medullary sampling error. This emphasizes that other pathological criteria may be of interest. We performed a retrospective clinicopathological study of 17 serologically proven HVN cases with renal biopsy from 2 nephrology centers in northern France. Histologic analysis was completed by immunohistochemistry with anti-CD3, anti-CD68, and anti-CD34 antibodies. Three control groups were not related to hantavirus infection: acute tubular necrosis (ATN) of ischemic or toxic etiology and AIN were used for comparison. Renal biopsy analysis showed that almost all HVN cases with medullary sampling (9/10) displayed interstitial hemorrhages, whereas focal hemorrhages were detected in 2 of the 7 "cortex-only" specimens. ATN was common, as it was present in 15 (88.2%) of 17 HVN cases. By contrast, interstitial inflammation was scarce with no inflammation or only slight inflammation, representing 15 (88.2%) of 17 cases. Moreover, HVN showed inflammation of renal microvessels with cortical peritubular capillaritis and medullary vasa recta inflammation; peritubular capillaritis was significantly higher in HVN after comparison with ischemic and toxic ATN controls (P = .0001 and P = .003, respectively), but not with AIN controls. Immunohistochemical studies highlighted the involvement of T cells and macrophages in renal microvascular inflammation related to HVN. Our study showed that microvascular inflammation, especially cortical peritubular capillaritis, and ATN are important histologic features of HVN.
authors: Department of Pathology, CHRU Lille, 59037 Lille, France; Université Lille Nord de France, 59000 Lille, France. Electronic address: viviane.gnemmi@chru-lille.fr.
authors: Viviane
authors: V
authors: Gnemmi
authors: Department of Pathology, Hopital Saint-Louis, 75475 Paris Cedex 10, France.
authors: Jérôme
authors: J
authors: Verine
authors: Department of Nephrology, Centre Hospitalier de Valenciennes, 59300 Valenciennes, France.
authors: Laurence
authors: L
authors: Vrigneaud
authors: Université Lille Nord de France, 59000 Lille, France; Department of Nephrology, Hôpital Huriez, CHRU Lille, rue Michel Polonovski, 59037 Lille, France.
authors: François
authors: F
authors: Glowacki
authors: Department of Nephrology, Centre Hospitalier de Bethune, Rue Delbecque, 62660 Beuvry Bethune, France.
authors: Anderson
authors: A
authors: Ratsimbazafy
authors: Department of Pathology, CHRU Lille, 59037 Lille, France; Université Lille Nord de France, 59000 Lille, France.
authors: Marie-Christine
authors: MC
authors: Copin
authors: Université Lille Nord de France, 59000 Lille, France; Department of Virology, CHRU Lille, 59037 Lille, France.
authors: Anny
authors: A
authors: Dewilde
authors: Department of Pathology, Hôpital Tenon, 75020 Paris, France.
authors: David
authors: D
authors: Buob
mesh_terms: D058186:Acute Kidney Injury / Q000821:virology*; D000328:Adult; D005260:Female; D018778:Hantavirus Infections / Q000473:pathology*; D006801:Humans; D007249:Inflammation / Q000473:pathology / Q000821:virology; D007668:Kidney / Q000098:blood supply / Q000473:pathology*; D007683:Kidney Tubular Necrosis, Acute / Q000473:pathology / Q000821:virology*; D008297:Male; D055806:Microvessels / Q000473:pathology* / Q000821:virology; D008875:Middle Aged; D009395:Nephritis, Interstitial / Q000473:pathology / Q000821:virology*; D012189:Retrospective Studies
keywords: Acute interstitial nephritis; Acute tubular necrosis; Hantavirus nephropathy; Microvascular inflammation; Peritubular capillaritis