flow cytometry. Patients were divided into patients with andwithout SAD. The B cell compartment in patients with SADshowed reduced percentages of class-switchedmemory B cellsin 8 of 11 patients (range: 1-4%) in comparison to age-matchedcontrols (range: 8-19%). Three of 13 patients without SAD hadlow percentages (range: 3-5%) of class-switched memory Bcells. These findings mirror experimental observations ofdecreased switched memory B cells in the presence ofpersistent IgG antibodies.

doi:10.1016/j.clim.2008.03.196

F.85. Differences After Heterologous T CellDependent Costimulation in B Cells from CommonVariable Immunodeficiency (CVID) Patients andHealthy ControlsAlejandra Vélez-Ortega, Luisa Cardona, Marcela Moncada,José Franco. University of Antioquia, Medellin, Colombia

CVID is a primary immunodeficiency syndrome in whichabnormalities have been reported suggesting impaired Bcell activation, terminal differentiation and memorygeneration. To investigate the mechanisms leading toCVID, we have begun to evaluate the response of patients'B cells to heterologous T-cell dependent costimulationfrom normal individuals. Purified T cells from 12 healthydonors were stimulated with PMA and Ionomycin or incombination with PHA and rhIL-2 to induce expression ofCD40L or ICOS, respectively. Next, stimulated T cells wereused to stimulate purified B cells from 8 CVID patients or4 controls, under heterologous conditions for 2 days andthe expression of several cell surface markers wasdetermined on CD19+ cells by flow cytometry. The Bcells from controls became activated and increased theexpression of CD25, CD69 and CD86; anti-HLA (class I andII) blocking antibodies showed that the activation was notdue to an allogenic effect but to the result of T-celldependent costimulation. All patients had a higherpercentage of CD69+ B cells than controls and their Bcells (most of which were CD27neg ex vivo) were inducedto express CD27 after culture, similar to the controls. Incontrast, the numbers of HLA-DR+ B cells in five CVIDpatients remained significantly lower than controls. Nostatistical differences were found for the expression ofCD25, CD80 and CD86. Our results suggest that costimula-tion of B cells from CVID patients with T cells fromnormal individuals could show differences relevant to thepathogenesis of this syndrome.

doi:10.1016/j.clim.2008.03.197

F.86. Abnormalities in Peripheral Blood B Cells inPatients with Hyperimmunoglobulinemia ESyndrome (HIES)José Franco, Marcela Moncada, Alejandra Vélez-Ortega,Julio Orrego. University of Antioquia, Medellin, Colombia

HIES is a compound primary immunodeficiency character-ized by chronic eczema, candidiasis, skin abscesses, respira-tory tract infections and pneumatoceles, high serum IgE andeosinophilia. HIES can be inherited as an autosomal orrecessive trait due tomutations in STAT3 or Tyk2, respectively.Reduced CD27+ memory B cells have been demonstrated inseveral primary immunodeficiencies along with expansions ofimmature B cells, suggesting defective B cell maturation;therefore we investigated possible B cell abnormalities inHIES. Seven HIES patients with a median age of 15 years(interval of 12-28), with NIH scores over 37 points (5 of themwith proved STAT3 mutations) as well as 3 adult controls werestudied. Expression of CD10, CD19, CD21, CD22, CD27, IgD,CD72, Igk/Igl chains and BAFF Rc were studied on CD19+ Bcells. Compared to normal controls, all patients had severelydecreased CD27+ B cells (39.91±10.83 N=3 vs 6.560±0.9755N=7, p=0.0010), that affected non-switched (IgD+CD27+) andswitched (IgD-CD27+) memory B cells. CD10+ B cells wereslightly increased in HIES patients with respect to controls butdifferences were not significant. No abnormalities were foundin the expression of CD21, CD72 and BAFFR. However, thenumber of CD72- B cells were significantly decreased in HIESpatients when compared to controls. Our results suggest thatHIES patients have abnormalities in the repertoire of B cells inperipheral blood which could indicate defective tolerancecheckpoints; in addition, low expression of regulatorymolecules such as CD72 could potentially indicate abnormalregulatory signaling.

doi:10.1016/j.clim.2008.03.198

F.87. Screening of Patients Suspected of Having aPrimary Immunodeficiency Disorder: StatisticalPerformance of Criteria Employed for Their InitialIdentificationLuis Enriquez,1 GomezRuben Gómez,2 Victor Rodriguez,1

Pablo Patiño,1 Julio Orrego,1 José Franco.1 1Facultad deMedicina y Sede de Investigación Universitaria, Medellin,Colombia; 2Universidad de Antioquia, Medellin, Colombia

The initial identification of patients suspected of having aprimary immunodeficiency (PID) relies largely on applicationof proper algorithms. We investigated the usefulness of thecriteria currently used to identify these patients, comparingthe performance of the criteria used by the Jeffrey ModellFoundation against our own. Medical records evaluated andmatched for the “warning signs” from both sources wereused to calculate sensitivity (S), specificity (E), positive(PPV) and negative (NPV) predictive values, and the like-lihood ratio (LR). From 203 patients initially identified ashaving Abnormal Recurrent Infection Syndrome (ARIS) aftertheir first visit, 90 were a PID. In the JMF “warning signs”,“need for IV antibiotics to clear infections” and “2 or moredeep-seated infections” exhibited the highest sensitivity. Incontrast, highest sensitivity for our criteria were with“unusual prolongation of infections or inadequate treatmentresponse” and “family history of ARIS, neonatal deaths dueto infections and/or haematological malignancies”. Specifi-city was N80% for most criteria from both sources, still the LR

S71Abstracts