title: Cryoglobulinemia and glomerular rhomboid inclusions in a child with acute kidney injury.
abstract: Cryoglobulinemia is rarely reported in children, and kidney failure secondary to cryoglobulinemia is even more uncommon. We report the case of a 7-year-old boy with cryoglobulins and a systemic illness, including persistent fever, arthralgias, rash, hypocomplementemia, and acute kidney injury associated with nephritic urine sediment. An extensive workup showed no infectious, neoplastic, or rheumatological cause of his kidney injury. The kidney biopsy specimen showed membranoproliferative glomerulonephritis type 1 with electron microscopic evidence of rhomboid crystalloid inclusions. These inclusions have rarely been reported in adult patients with cryoglobulinemia. The patient underwent spontaneous remission, including full recovery of kidney function, and required no immune suppression. The patient's course is consistent with cryoglobulinemia-associated kidney injury, which supports the inclusion of essential cryoglobulinemia in the differential diagnosis of pediatric patients with hypocomplementemic glomerulonephritis.
authors.affiliation: Department of Internal Medicine and Pediatrics, Divisions of Nephrology, The University of Iowa Hospitals and Clinics, Iowa City, IA 52242-1081, USA. carla-nester@uiowa.edu
authors.forename: Carla M
authors.initials: CM
authors.lastname: Nester
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Benner
authors.forename: Mathieu
authors.initials: M
authors.lastname: Latour
authors.forename: Volker
authors.initials: V
authors.lastname: Nickeleit
authors.forename: Harvey
authors.initials: H
authors.lastname: Hamrick
authors.forename: William
authors.initials: W
authors.lastname: Primack
mesh_terms: D058186:Acute Kidney Injury / Q000097:blood / Q000209:etiology* / Q000473:pathology; D001706:Biopsy; D002648:Child; D003165:Complement System Proteins / Q000378:metabolism; D003449:Cryoglobulinemia / Q000097:blood / Q000150:complications* / Q000473:pathology; D003937:Diagnosis, Differential; D015432:Glomerulonephritis, Membranoproliferative / Q000097:blood / Q000150:complications / Q000473:pathology; D006801:Humans; D007678:Kidney Glomerulus / Q000648:ultrastructure*; D008297:Male; D008854:Microscopy, Electron
chemical_list: D003165:Complement System Proteins