Oral Presentations - Federation of Clinical Immunology Societies

S50 Abstracts
F.103 Differences in Telomerase Expression by the
CD1a+ Cells in Langerhans Cell Histiocytosis Reflects
the Diverse Clinical Presentation of the Disease
Cristiana Costa, PhD Student, Leiden University Medical
Center, Department of Pediatrics, Leiden, The Netherlands,
Maarten Egeler, MD PhD, Leiden University Medical Center,
Leiden, The Netherlands, Manja Hoogeboom, Leiden
University Medical Center, Leiden, The Netherlands, Ramses
Forsyth, N. Goormaghtigh Institute of Pathology, University
Hospital Gent, Gent, Karoly Szuhai, PhD, Leiden University
Medical Center, Leiden, The Netherlands, Marieke Niesters,
Leiden University Medical Center, Department of Pediatrics,
Leiden, The Netherlands, Ronald de Krijger, Erasmus
Medical Center, Department of Pathology, Rotterdam,
Abdellatif Tati, Service de Pneumonologie, Hospital Saint
Louis, Paris, Pancras Hogendoorn, Leiden University Medical
Center, Department of Pathology, Leiden, The Netherlands,
Nicola Annels, PhD, Leiden University Medical Center,
Department of Pediatrics, Leiden, The Netherlands
Langerhans cell histiocytosis (LCH) is a disease characterised
by an uncontrolled clonal proliferation of Langerhans
cells, whose aetiology is still unclear. The clonal nature of
LCH could support the hypothesis that it is a neoplastic
disease with unlimited growth potential. One requirement
for unlimited proliferation is the maintenance of telomere
length. In a group of 70 patients we investigated whether a
telomere maintenance mechanism is active by LCH cells.
Results showed that LCH cells from all restricted skin LCH
lesions (6/6) expressed telomerase as assessed by human
telomere reverse transcriptase (hTERT) immunohistochemistry,
whereas LCH cells from the majority of bone lesions
analysed did not (26/34). Interestingly, in contrast to solitary
bone lesions, LCH cells from lesions of multisystem patients
always expressed telomerase (11/11), regardless of the
lesional site. In situ telomeric repeat amplification protocol
(TRAP) assay performed on different lesional sites showed
that telomerase was active. In addition, the telomere length
of LCH cells from a hTERT positive skin multisystem lesion
was long and homogeneous when compared to the LCH cells
from hTERT negative bone single system LCH lesions, which
were heterogeneous in length. No evidence for an alternative
lengthening of telomeres mechanism was found in
hTERT negative lesions. The difference in telomerase
expression and telomere length in the different lesional
sites and in biopsies from patients with solitary versus
multisystem disease appears to be reflective of the diverse
clinical presentation and course of LCH. The results from this
study have important implications for understanding the
nature of this disease.
doi:10.1016/j.clim.2007.03.316
F.104 Multiplex Capabilities for Serological
Immunoassays Using Luminex xMAP ® Technology
Harold Baker, Senior Scientist, Luminex Corporation,
Austin, TX
The Luminex xMAP technology incorporates fluorescently
encoded microspheres (xMAP microspheres) to perform
multiplexed bioassays in conjunction with advanced digital
signal processing and proprietary identification techniques.
The advantage of the multiplexing technology is the
capability to measure several antigens within one sample.
The combination of multiple results and reduced sample
volume increases the efficiency for testing and sample
consumption. Another advantage is that the serological
assays can be multiplexed with other immunoassays. Five
specific antigens were coupled to xMAP microspheres
representing several individual regions. BSA coated microspheres
were prepared to function as internal assay controls
for non-specific reactivity. A total of five regions were used
with each antigen to develop a 30-plex assay. The xMAP
serological assay format we used was a 60 minute, no wash
assay. Diluted patient serum, 10 ƒÝL, was combined with the
microsphere mixture, 50 ƒÝL, and incubated 30 min. Diluted
PE conjugated antibody, 150 ƒÝL, was added and incubated
30 min before being analyzed with the Luminex system.
Equivalent results were obtained with the replicate antigen
coated regions. Analytical sensitivity was defined by the
maximum dilution before an appreciable decrement in MFI
response was observed. This was observed to be at a dilution
of 1:1000 representing the use of 0.01 ƒÝL serum for the
measurement of antibodies in the serum sample. These
results demonstrate that the Luminex xMAP technology can
be used to develop multiplex assays such as those required
for serological assessment of autoimmune diseases.
doi:10.1016/j.clim.2007.03.319
F.105 Immunofluorometrical Exploring of FSH
Levels in the Serum of Patients with Histologically
Verified Macrocellular Lung Cancer
Ivan Milosevic, Primary Care Physician, Dispensary 2, ZZZZR,
Kragujevac
It is already known in that the cells of macrocellular lung
cancer can produce gonadotropins. By following the levels of
FSH as one of gonadotropins, in the serum of macrocellular
lung cancer patients, we could make certain statistical
conclusions how significant these levels would be in eventual
future early diagnostic procedures, besides already existing
tumor markers and other methods. This work would connect
the Oncology, Endocrinology and Immunology fields, containing
very interesting immunofluorometrical procedures,
hormonal theories and statistical estimates. As an immunological
part in this theoretical model, it is represented
through figure, time-resolved fluoroimmunoassay for quantitative
detection of FSH. By following of FSH levels in the
serum of microcellular lung cancer patients and making
determinate statistical conclusions about its importance,
that procedure could be eventually used as one of early or
advanced diagnostic methods concerning mentioned disease.
What would we get with that? The histological verification is
very slow and painful, when the macrocellular lung cancer is
in the question. This histological type gives the metastases
rapidly and it needs to be diagnosed in the fastest possible
way in order to be prevented by adequate reaction and
therapy. At the same time the biopsy as a very invasive
method would be avoided. When the tumor markers are in