title: Polyclonal gammopathy after BKV infection in HSCT recipient: a novel trigger for plasma cells replication?
abstract: BACKGROUND
  BK polyomavirus infects most of the general population. However, its clinical manifestations are almost exclusively seen in immunocompromised patients, particularly in kidney and hematopoietic stem cell transplantation recipients.
  
  
  METHODS
  A 15-y-old female suffering from common B-cell acute lymphoblastic leukaemia underwent hematopoietic stem cell transplantation. The patient had reactivation of BKPyV infection and developed an haemorrhagic cystitis. Three months after transplant, BKPyV viremia and viruria increased and she developed a severe nephropathy associated to a polyclonal gammopathy with high levels of isolated IgM.
  
  
  CONCLUSIONS
  This case report describes a rare and unexpected polyclonal gammopathy developed during a polyomavirus-associated nephropathy confirmed by immunohistochemical and laboratory analyses.
authors.affiliation: Bone Marrow Transplant Unit, Institute for Maternal and Child Health IRCCS Burlo Garofolo, Via dell'Istria 65/1, 34134, Trieste, Italy. natalia.maximova@burlo.trieste.it.
authors.forename: Natalia
authors.initials: N
authors.lastname: Maximova
authors.affiliation: Pediatric Hemato-Oncology Department, Institute for Maternal and Child Health IRCCS Burlo Garofolo, Trieste, Italy. pizzol.antonio@gmail.com.
authors.forename: Antonio
authors.initials: A
authors.lastname: Pizzol
authors.affiliation: Department of Pathology, Ospedale Beato Papa Giovanni XXIII, Bergamo, Italy. asonzogni@hpg23.it.
authors.forename: Aurelio
authors.initials: A
authors.lastname: Sonzogni
authors.affiliation: Department of Radiology, Institute for Maternal and Child Health IRCCS Burlo Garofolo, Trieste, Italy. massimo.gregori@burlo.trieste.it.
authors.forename: Massimo
authors.initials: M
authors.lastname: Gregori
authors.affiliation: Laboratory Department, A.O.U. Ospedali Riuniti, Trieste, Italy. marilena.granzotto@gmail.com.
authors.forename: Marilena
authors.initials: M
authors.lastname: Granzotto
authors.affiliation: Pediatric Hemato-Oncology Department, Institute for Maternal and Child Health IRCCS Burlo Garofolo, Trieste, Italy. paolo.tamaro@burlo.trieste.it.
authors.forename: Paolo
authors.initials: P
authors.lastname: Tamaro
mesh_terms: D000293:Adolescent; D000914:Antibodies, Viral / Q000276:immunology*; D001739:BK Virus / Q000276:immunology / Q000502:physiology*; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects*; D006801:Humans; D007674:Kidney Diseases / Q000209:etiology* / Q000276:immunology / Q000821:virology; D015448:Leukemia, B-Cell / Q000150:complications / Q000628:therapy*; D010950:Plasma Cells / Q000166:cytology* / Q000276:immunology; D027601:Polyomavirus Infections / Q000209:etiology / Q000276:immunology* / Q000821:virology; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000150:complications / Q000628:therapy*
chemical_list: D000914:Antibodies, Viral