Peter MacMahon, Presenter: Nothing to Disclose

Dorota Kozlowska, Abstract Co-Author: Nothing to Disclose

Richard O'Kennedy, Abstract Co-Author: Nothing to Disclose

Stephen John Eustace MD, Abstract Co-Author: Nothing to Disclose

To assess the safety, specificity and detectability of antibody conjugated super para-magnetic iron-oxide (SPIO) nanoparticles targeting the CD138 molecule indicative of disease in Multiple Myeloma.

Two established human myeloma cell lines (U-266, RPMI-8226) and a CD138 negative human B-cell line (SU-DHL-4) were cultured using standard techniques. Cells were exposed to 50nm dextran coated SPIO nanoparticles conjugated to the B-B4 antiCD138 antibody (Miltenyi Biotec). In-vitro cell labelling protocols were designed to replicate in-vivo conditions. After repeated washing, cells were resuspended in agarose gel within 70ul PCR tubes at various concentrations (140x106/ml-1x106/ml). The cells were imaged within an in-house designed multi-tube phantom placed in a circularly polarising flex coil using a large bore 1.5T MR scanner. Imaging was performed using clinical T2*, T1, T2 and proton density weighted sequences. Cell binding site and specificity was assessed by immunofluorescent microscopy. Agent cytotoxicity was assessed by MTS assay. Statistical analysis performed using ANOVA.

There was no detectable labelling of CD138 negative B-cells post agent exposure. Immunofluoresence localised the particles to the membrane of myeloma cells. The agent was non-toxic at study doses. On MR imaging there was significant signal change within exposed cell suspensions compared to control (p6cells/cc when exposed to 10μl of agent per 5x106cells. No signal change was detected in the exposed CD138 negative cell suspensions.

Antibody conjugated SPIO particles targeting the CD138 antigen are non-toxic, myeloma cell specific and detectable with a 1.5T scanner. Such a technique may reveal the location of myeloma cells within the living organism by use of whole-body magnetic resonance imaging.

Multiple Myeloma is diagnosed by detecting CD138 within marrow samples. An accurate non-invasive technique may allow earlier diagnosis, more accurate prognosis and improved evaluation of treatment.

MacMahon, P, Kozlowska, D, O'Kennedy, R, Eustace, S, CD138 Targeted Super Paramagnetic Nanoparticles: A Potential Multiple Myeloma Specific MR Contrast Agent.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5007875.html