Page 73 - Livre électronique du Congrès National de Pneumologie 2018

C020 BTLA GENE POLYMORPHISMS ARE ASSOCIATED WITH LUNG CANCER IN

TUNISIAN PATIENTS
EXPRESSION MOLÉCULAIRE DES INTERACTIONS CELLULAIRES ET DE LEURS
MODES DE COMMUNICATION DANS LE POUMON,

Khadhraoui CH, Kaabachi W, Belhaj R, Hamzaoui K, Hamzaoui A.

UR/12-SP15, MEDICAL FACULTY OF TUNIS, TUNIS EL MANAR UNIVERSITY, TUNIS, TUNISIA. DEPARTMENT
OF PEDIATRIC RESPIRATORY DISEASES, HOSPITAL A. MAMI, PAV

Introduction :
B and T lymphocyte attenuator (BTLA) is an immune-inhibitory receptor that negatively regulates the lymphocyte
activation. Polymorphisms that encoding BTLA gene was essentially investigated in autoimmune diseases. However,
a few numbers of studies have been devoted to the relationship between BTLA gene variations and cancers risk. The
aim of this study is to evaluate the association of the BTLA gene with the lung cancer risk, in the Tunisian population.
Methods :

In this case–control study, three BTLA single-nucleotide polymorphisms (SNPs): rs1982809 A>G, rs9288952 G>A,
rs9288953 C>T were genotyped with use of TaqMan probes in 169 lung cancer patients and in 270 controls.

Results :
The rs1982809 A>G was significantly associated with increased risk of lung cancer compared to controls (OR 1.50,
95%CI 1.00 – 2.25, p= 0.047). However, no significant differences in rs9288952 G>A and rs9288953 C>T genotypes
between patients and controls was observed (p>0.05). Moreover, a higher significant frequency of rs1982809 AG
genotype was observed in oldest age patients compared to healthy controls (p= 0.03). When patients were stratified
by histologic types, the rs1982809 AG genotype was a risk factor for adenocarcinoma patients (OR =1.92).
Furthermore, our analysis revealed a statistical association between BTLA polymorphisms with tumor size and lymph
node status. For the rs9288952 G>A, frequencies of AG genotype was higher in T4 –T3 cases than in T2 cases (p =
0.047). In the rs1982809 A>G, the AG genotype was significantly more frequent in patients with large tumor size (T4)
than in controls (p=0.01) and was a risk factor for patients with lymphatic invasion (OR =3.14).

Conclusion:
We found that the genetic variants of rs1982809A>G in BTLA is associated with increased lung adenocarcinoma risk
in the Tunisian population. Our study is the first to indicate a significant association between BTLA SNPs and
susceptibility to lung cancer, which may contribute to the pathogenesis of the disease.

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