187-P ANTI HLA IMMUNIZATION REDUCES ACCESS TO VASCULARIZED COMPOSITE ALLO TRANSPLANTATION FOREXTENSIVELY BURNED PATIENTS. Caroline Suberbielle 1, Patrick Duhamel 2, Philippe Grimbert 3, BenoitAudry 4, Christian Jacquelinet 4, Maryvonnick Carmagnat 1, Chantal Gautreau 1, Dominique Charron 1, LaurentLantieri 5, Mikael Hivelin 5. 1 Laboratoire Regional d’Histocompatibiblite ‘‘Jean Dausset’’, Hopital Saint Louis,Paris, France; 2 Service de Chirurgie Plastique, Hopital d’instruction des armees Percy, Clamart, France;3 Service de Nephrologie et Transplantation, CHU Henri Mondor, Creteil, France; 4 Agence de la Biomedecine,Agence de la Biomedecine, Saint Denis, France; 5 Service de Chirurgie Plastique et Reconstructrice, Hopitaleuropeen Georges Pompidou, Paris, France.

Aim: Vascularized composite allotransplantations (VCA) provide therapeutic options for functional oresthetic damage beyond conventional surgical reconstruction. The objectives of this study were to evaluatethe immunological characteristics of patients treated for third degree burns who could benefited from recon-structive transplantation by VCA and to determine their access to transplantation.

Methods: Serum samples of all the 29 patients treated in a single center from 2007 to 2010 for extensiveburns were collected. Fifteen patients received skin allografts, 8 cryopreserved skin allografts (CPSA) and 7glycerolized preserved skin allografts (GPSA). Anti HLA Ab and C1q binding Ab were detected by LABScreensingle-antigen, (One Lambda, Canoga Park, CA), MFI cut offs were respectively 500 and 300 over background.Then cPRA representing the percentage of potential donors expected to present unacceptable mismatches wascalculated.

Results: Among the patients, 97% had anti HLA Ab, 45% had C1q fixing Ab, 62% were considered hyperim-munized with a cPRA above 85%. The average cPRA score of the 1055 patients on the waiting list for kidneytransplantation at the same time in the same region was 27.2% ± 37.3 whereas it was 64.7%± 40.8 for burnedpatients. The risk of being hyper immunized was 3.3 times higher for burned patients than for those on thewaiting list for kidney transplantation. Multivariate analysis (stepwise backward before multiple linearregression) identified the use of CPSA (p=0.0043) and the number of previous pregnancies (p=0.0074) to beindependent predictive factors for cPRA with an adjusted coefficient of determination (R2) of 0.37 (p =0.0024).

Conclusions: Anti-HLA alloimunization is potentially a major obstacle to VCA in extensively burnedpatients. To improve access to transplantation, glycerolized preserved skin allografts should be preferred tocryopreserved skin allograft for burned patients suffering extensive facial and hand injuries when possible.

188-P A PRELIMINARY STUDY OF NEUTROPHILS CD177 GENOTYPE AND HNA-2a EXPRESSION IN GUANGDONGPOPULATION. Xin Ye, Xiuzhang Xu, Wenjie Xia, Haoqian Ding, Yangkai Chen. Guangzhou Blood Center,Institute of Clinical Blood Transfusion, Guangzhou, China.

Aim: To study the genotype of CD177 and the expression and distribution of HNA-2a on neutrophils inGuangdong population.

Methods: PCR-SBT and flow cytometry were respectively employed to analyze the CD177 genotype andHNA-2a phenotype of 83 blood donors, and several factors (SNPs, age and gender) that may affect the expres-sion of HNA-2a were analyzed by T-test and ANOVA. A P-value of less than 0.05 was considered to besignificant.

Results: The CD177 genotype of 83 samples were mainly 42C / C and 42C / G ,40 cases (48.19%) and 37cases (44.58%) respectively. The 42G / G genotype was very less in Guangdong population, only 6 cases(7.23%). The HNA-2a expression of all 83 blood donors were more than 5%(mean ± SD :61.37 ± 17.87%),including the expression of HNA-2a was slightly greater in females (65.60 ± 18.45) than in males(58.98 ± 17.25), but with increasing of women age the expression of HNA-2a was no significantly different.It is noteworthy that G42C polymorphism (CD177) can affect the expression of HNA-2a. The expression ofHNA-2a in 42C / C genotype (64.94 ± 17.62) was significantly higher than 42C / G (59.14 ± 18.00) and 42G/ G (51.37 ± 14.93) genotype; and the MFI of HNA-2a in 42C / C and 42G / G genotype was significantly dif-ferent (5.16 ± 1.56 vs.3.93 ± 0.84, p < 0.05).

Conclusions: CD177 genotype has its own characteristics in Guangdong population. And the expression ofHNA-2a is affected by many factors and show significant individual differences. In addition, the SNPs (G42C)of CD177 gene may also affect the expression of HNA-2a.

Abstracts / Human Immunology 74 (2013) 51–173 173