Issue Highlights-January 2013

Stabilization media increases recovery in paucicellular cerebrospinal fluid specimens submitted for flow cytometry testing

BACKGROUND

Flow cytometric immunophenotpying (FCI) of cerebrospinal fluid (CSF) and other paucicellular fluids has been demonstrated to have increased sensitivity in detection of lymphoma and leukemia when compared to cytomorphology [(1) de Graaf et al., Cytometry Part B 2011, 80B:271-281; (2) Szamosi et al., CLSI Document H56-A-Body Fluid Analysis for Cellular Composition; Approved Guideline, Wayne, PA: Clinical and Laboratory Standards Institute, 2006; (3) Kraan et al., Flow Cytometric Immunophenotyping of Cerebrospinal Fluid. Current Protocols in Cytometry, Hoboken, NJ: Wiley, 2008]. However, low cellularity has been an historical problem with these samples. Several studies indicate that immediate addition of a stabilization media (e.g., RPMI with fetal calf serum (FCS)) to CSF improves the cell yield for FCI [(1) de Graaf et al.]. Such stabilization medias can, however, significantly increase cost.

METHODS

We compared FCI results in CSF stabilized with RPMI 1640 (without additional additives) to results obtained using non-stabilized CSF. Samples were processed according to published CLSI guidelines [(2) Szamosi et al.].

RESULTS

About 98/105 (93%) CSF specimens stabilized with RPMI had adequate numbers of viable cells (>100) for performing FCI. About 65/217 (30%) CSF specimens without stabilization had adequate numbers of viable cells for analysis (70% either quantity not sufficient (QNS) or specimen viability below analytical limits).

CONCLUSIONS

Utilizing RMPI without FCS as a stabilization media results in increased cell yield and improved FCI results. We have found FCS is not required to achieve high quality results in FCI of paucicellular CSF specimens.