title: Plasma cell infiltrates in polyomavirus nephropathy.
abstract: Polyomavirus (PV) associated nephropathy (PVAN) has become an important cause of allograft dysfunction. We studied plasma cells (PCs) - which have not yet been characterized - present in the cellular infiltrate of 20 PVAN cases using immunohistochemistry and morphometry. The results were correlated with morphological, clinical and anti-BK virus serological findings. PC-rich cellular infiltrates occurred in 50% of cases (>15% PCs in the cellular infiltrate) and in these IgM producing PCs were commonly seen (70%): IgM PC predominance in 50% of cases and a comparable number of IgM and IgG PCs in 20% of cases. We found a significant correlation not just between the absolute numbers (P < 0.034) and the percentage values of IgM PCs (P < 0.004 in relation to all cells) and the serum IgM-Ab anti-BKV activity, but also between the ratio of IgG/IgM PCs and the ratio of serum IgG/IgM-Ab activities (P < 0.0001). We showed that IgM PC counts in biopsies correlate with titers of circulating anti-BK virus IgM antibodies. Every case except one was C4d negative in peritubular capillaries (PTC). As IgG PCs characterize PC-rich rejection cases, we suggest that in the presence of IgM PCs in PC-rich infiltrate with PTC C4d negativity, a search for possible PVAN infection should be initiated.
authors.affiliation: Department of Pathology, University of Szeged, Szeged, Hungary.
authors.forename: Eva
authors.initials: E
authors.lastname: Kemény
authors.forename: Hans H
authors.initials: HH
authors.lastname: Hirsch
authors.forename: József
authors.initials: J
authors.lastname: Eller
authors.forename: Ursula
authors.initials: U
authors.lastname: Dürmüller
authors.forename: Helmut
authors.initials: H
authors.lastname: Hopfer
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Mihatsch
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001706:Biopsy; D002196:Capillaries / Q000378:metabolism; D002648:Child; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism; D007075:Immunoglobulin M / Q000378:metabolism; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D008875:Middle Aged; D010950:Plasma Cells / Q000166:cytology* / Q000821:virology; D011120:Polyomavirus / Q000378:metabolism*; D027601:Polyomavirus Infections / Q000097:blood*
chemical_list: D007074:Immunoglobulin G; D007075:Immunoglobulin M