sensitivity and specificity. Using this screening platform todetect IgE of a mouse model sensitized with penicillin revealsthat high levels of penicillin specific IgE were found in thepenicillin sensitized animals but not in OVA sensitized oruntreated control animals. Penicillin-specific Tcells producerelatively higher levels of IL-4 and IL-5 in the penicillinsensitized group, indicating a Th2-cytokine dominatedresponse of T-cell dependent IgE production against peni-cillin. This observation and the development of suchconvenient platform to measure penicillin specific IgE maybenefit further study of penicillin allergy.

doi:10.1016/j.clim.2008.03.432

Su.82. Evidence for Genetic Regulation of Fc AlphaReceptor (CD89) Expression: Study of Soluble CD89in Plasma of IgA Nephropathy Patients andHealthy ControlsMirjana Hahn-Zoric,1 Mai Vuong,2 Sigrid Lundberg,3 LarsWramner,4 Jarl Ahlmen,5 Lars Å Hanson,1 Iva Gunnarsson,2

Stefan Jacobson,6 Leonid Padyukov.2 1SahlgrenskaUniversity Hospital and the Sahlgrenska Academy atGöteborg University, Göteborg, Sweden; 2KarolinskaInstitute, Stockholm, Sweden; 3Karolinska Hospital,Stockholm, Sweden; 4Sahlgrenska University Hospital,Göteborg, Sweden; 5Skaraborg Hospital, Skövde, Sweden;6Danderyd Hospital, Stockholm, Sweden

Background: It has been recently shown that Fc alphareceptor (FcαRI or CD89) is involved in IgA complexformation in circulation. CD89-IgA complexes were sug-gested to be implicated in development of IgA nephro-pathy (IgAN), which is relatively common disease in theWestern world. We have developed an ELISA method fordetection of soluble CD89 bound to IgA in human serum/plasma. Aim of this study was to test genetic variations inFCAR gene in relation to expression of soluble IgAreceptor (sCD89) in plasma of IgAN patients and healthycontrols. Material and methods: In a cohort of 219 IgANpatients and 113 healthy controls we performed genotypingfor 5 single nucleotide polymorphisms (SNPs) from FCARgene using TaqMan allelic discrimination assay anddetected sCD89-IgA complex in plasma in a sandwichELISA with monoclonal anti-CD89 antibody (A3) and poly-clonal anti-IgA antibodies. Results: We found significantdifference between the levels of sCD89 complex in plasmaof female IgAN patients and controls (p=0.02, Mann-Whitney Test) with lower levels in the controls, whilethere was no significant difference in sCD89 levels betweenthe male patients and the controls. When sCD89 complexlevels were correlated with FCAR genotypes in combinedgroup it appeared that one SNP (rs11084377) associatedwith lower production of sCD89 in G dominant model(p=0.04, Mann-Whitney Test). This marker is at closeproximity to alternative exon 2 in the FCAR gene structure,which is the part of the common domain for Ig superfamilyproteins. However, no association with the disease wasfound with any of the investigated SNPs. Conclusion: Ourdata suggest a genetic component in regulation ofproduction or expression of sCD89, which may relate to

splicing mechanisms. We also found a gender effect inexpression of sCD89 in IgAN.

doi:10.1016/j.clim.2008.03.433

Su.83. High Throughput Sample Preparation in 96Well Plates for Flow Cytometry AnalysisCarlos Aparicio, Julie Wilkinson, Ileana Munoz-Antoni,Enrique Rabellino. Beckman Coulter, Miami, FL

The importance and use of flow cytometry analysis forcell-based assays in drug screening, diagnostics, andbiologic development continues to grow. However, thetransfer of these assays to large clinical trials and highthroughput test settings has been curtailed due, in part, tolaborious and time consuming sample preparation proce-dures. This study focuses on the use of the Biomek series ofautomated liquid handlers to prepare flow cytometrysamples in 96 well plates to facilitate automation ofsample preparation and analysis in high throughput testsettings. Automation of the assay also improves reprodu-cibility and facilitates standardizations and evaluation ofcomparative studies conducted at different testing sites.Fundamental steps such as transfer of antibody solutions,samples (whole blood and cell lines), red cell lysingreagents to plates and cell washing were independentlycharacterized for accuracy, reproducibility, mean fluores-cence intensity, cell recovery, and wash efficiency. Overallperformance for the automated processes was assessed bycomparing results to those of manual procedures of cellsurface staining of major cell sub-populations (CD45, CD3,CD4, and CD8) and intra-cellular staining for interferon-gamma(IFN-g) and interleukin 2 (IL-2). This evaluationshowed statistically identical results for manual andautomated processes. In addition, the automation enableda significant reduction of “hands-on” sample preparationwhile increasing overall sample throughput.

doi:10.1016/j.clim.2008.03.434

Su.84. A Time Course Analysis of the Protection ofPulmonary Arterial Hypertension by Splenocytes inAthymic RatsLijuan (Jenny) Wang,1 Rasa Tamosiuniene,1 Xinguo Jiang,1

Mark Nicolls. 2 1Stanford University, Stanford, CA; 2VA PaloAlto Health Care System, Palo Alto, CA

Severe pulmonary arterial hypertension (SPH) is afrequently lethal condition. Pathologically, SPH is character-ized by a proliferation of endothelial cells and expansion ofthe adventitial and vascular smooth muscles in pulmonaryarteries. A rat model was previously established to studySPH, in which athymic nude rats (rnu/rnu) that lack T cellsdevelop SPH after the treatment with a single injection ofvascular endothelial growth factor (VEGF) receptor SU5416(20 mg/kg) intraperitoneally (Taraseviciene-Stewart et al,Am J Respir Crit Care Med 175:1280-1289, 2007). The SPHthat developed in these rats was prevented by injectingsplenocytes from euthymic rats (rnu/+) 7 days prior to (i.e.,

S151Abstracts