[1666] Production of Control Slides for BK Virus Immunostaining/In-Situ Hybridization Using Voided Urine; a Practical Solution for the Renal Pathologist

Yasmin Elshenawy, James Ferris, Johanna Preiszner, Parmjeet S Randhawa, George A Youngberg. East Tennessee State University, Johnson City, TN; University of Pittsburgh, Pittsburgh, PA

Background: Maintaining BK virus control material is a common and frustrating problem. BK virus can cause severe tubulointerstitial nephritis leading to graft loss. Detection and confirmation of BK virus in kidney biopsies using immunohistochemical stains (IHC) or in-situ hybridization (ISH) is essential for optimal patient care. The scarcity of BK virus control material is in part attributable to the limited amount of tissue in a renal needle biopsy and to the limited availability of commercial controls.
Design: We implemented a new method to generate positive controls using a voided urine specimen from a patient with BK viremia, previously diagnosed by serum PCR testing. A single voided random urine sample was centrifuged down to pellets, washed with phosphate buffered saline (PBS), combined and re-suspended in PBS to create 5 ml. of a concentrated cell suspension. The pellet was mixed 1:1 with HistoGel, fixed in formalin and finally processed into paraffin-embedded cell blocks. Freshly cut slides were stained with a mouse anti-BK virus large T antigen monoclonal antibody. In addition, five randomly selected cell blocks were submitted for ISH, using a standard technique.
Results: The cellularity of the single voided random urine sample provided us with a generous amount of centrifuged cellular material (50 blocks). Approximately ten positive cells were present per section. The positive cells depicted a brown nuclear stain visible on light microscopy.

The same results were obtained using the ISH procedure.
Conclusions: The urine-derived cell block method has proven to be helpful in our laboratory for the production of control tissue sections for BK virus IHC. It has been in successful use since 2009. While tissue from renal biopsies represents a more conventional resource for control sections, any positive biopsy used as a control is soon cut through, so a reliable source of control material cannot be maintained. Retrieving cytologic material from urine can be a readily accessible, non-invasive source of positively staining cells for IHC and ISH control purposes. This methodology can be easily implemented in most renal pathology practices.
Category: Kidney (does not include tumors)

Wednesday, March 21, 2012 1:00 PM

Poster Session VI # 295, Wednesday Afternoon


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