1. ASSOCIATIONS BETWEEN ANXA11 RS C/T, BTNL2 RS G/A, HLA CLASS I AND II POLYMORPHISMS AND SARCOIDOSIS EVOLUTION
Manuel Vaz1, Bruno Lima2, Natália Melo1, Patrícia Mota1,3 ,António Morais1,3
1Pulmonology Department, University Hospital São João, EPE, Porto; 2Oficina de Bioestatística, Ermesinde, Portugal; 3Faculty of Medicine, University of Porto, Portugal;
METHODS
Aim
Analysis of associations between ANXA11 rs , BTNL2 rs , HLA class I/II polymorphisms, the potential interaction effect among them and sarcoidosis outcome.
138 patients included (37.2±12.1 years, 56.5% women). Evidence of disease after 2 years was considered chronic sarcoidosis. Samples were genotyped for ANXA11 rs C/T and BTNL2 rs G/A using rt-PCR and for HLA by PCR-SSP. Differences between groups were evaluated through X2-test (or Fisher exact test) in univariate analysis and logistic regression in multivariate analysis. RR or OR and 95% confidence intervals were calculated.
RESULTS
Table 1. Clinical and demographic characteristics of the Sarcoidosis patients
Chronicity (72)
Resolution (66)
Characteristic: na %
Female gender 34
47.2% 44
66.7%
Ageb
40.25 ±13.07
33.91 ±9.97
Radiological staging at diagnosis
Stage 0 2
2.8%
0.0%
Stage I 16
22.2% 28
42.4%
Stage II 32
48.5%
Stage III 5
6.9%
7.6%
Stage IV 15
20.8% 1
1.5%
With Extratoraxic envolvement 39
54.2% 22
33.3%
With Eritema Nodosum
7.5% 25
38.5%
without information
a Values expressed as number of sarcoidosis patients, except where otherwise indicated.
b Values expressed as mean ± SD
Table 2. HLA allele association with sarcoidosis evolution
chronicity
resolution
Allele RR
95%CI
p value
A*11
7 (4.9%)a
13 (9.8%)a
0.65
0.35 – 1.2
0.11
B*14
5 (3.5%)a
12 (9.1%)a
0.55
0.26 – 1.15
0.05
B*18
DRB1*01
8 (5.6%)a
16 (12.1%)a
0.62
0.35 – 1.11
DRB1*03
28 (21.2%)a
0.35
0.18 – 0.69
< 0.001
DRB1*07
23 (16.0%)a
1.31
1.0 – 1.72
0.09
DRB1*12
9 (6.3%)a
2 (1.5%)a
1.61
1.19 – 2.17
0.04
DQB1*02
28 (19.4%)a
39 (29.5%)a
0.75
0.55 – 1.02
Total (2n)
144
132
a allele frequencies; RR - Relative Risk; CI - Confidence Interval; n - number of patients
Comparisons of HLA allele frequencies between chronicity and resolution were performed by X2-test;
Table 3. Annexin A11 rs C/T SNP association with sarcoidosis evolution
chronicity
resolution   
Allele RR
95%CI
p value
rs C
95 (66.0%)a
88 (66.7%)a
0.9
rs T
49 (34.0%)a
44 (33.3%)a
Total (2n)
144
132
Genotype CC
34 (47.2%)
30 (45.5%) CT
37 (37.5%)
28 (42.4%) TT
11 (15.3%)
8 (12.1%)
Total (n) 72 66
a allele frequencies; RR - Relative Risk; CI - Confidence Interval; n - number of patients
Comparisons of the allele frequencies of annexin A11 variants between chronicity and resolution were performed by X2-test; comparisons of the genotype frequencies were performed by X2-test for trend normalized to the CC homozygote’s (odds ratio set to 1).
Table 5. Logistic regression model of association of DRB1*03 with sarcoidosis evolution to chronicity
Variables in the model: OR
95%CI
p-value pc
ANXA-T
0.77
0.36 – 1.61
0.48 ns
BTNL2-A
0.66
0.23 – 1.92
0.45
DRB1*03
0.13
0.05 – 0.35
<0.0001
<0.01
OR Odds Ratio; CI - Confidence Interval; pc correct p-value for multiple comparisons; ns statistically not significant
Table 6. Logistic regression model of association of DRB1*03 with sarcoidosis (without patients with EN) evolution to chronicity adjusted for ANXA and BTNL2
Variables in the model: OR
95%CI
p-value
ANXA-T
0.92
0.41 – 2.08
0.84
BTNL2-A
0.52
0.15 – 1.76
0.29
DRB1*03
0.25
0.08 – 0.78
0.02
OR Odds Ratio; CI - Confidence Interval; ns statistically not significant
Table 4. BTNL2 rs G/A SNP association with sarcoidosis evolution
chronicity
resolution
   
Allele    RR
95%CI
p value
rs G
56 (38.9%)a
41 (31.1%)a 1
0.17
rs A
88 (61.1%)a
91 (68.9%)a
0.85
0.68 – 1.07
Total (2n)
144
132
Genotype GG
14 (19.4%)
6 (9.1%)
0.2 AG
28 (38.9%)
29 (43.9%)
0.41 AA
30 (41.7%)
31 (47.0%)
Total (n) 72 66
a allele frequencies; RR - Relative Risk; CI - Confidence Interval; n - number of patients
Comparisons of the allele frequencies of BTNL2 variants between chronicity and resolution were performed by X2-test; comparisons of the genotype frequencies were performed by X2-test for trend normalized to the GG homozygote’s (odds ratio set to 1).
We define logistic regression models to access the association of the identify HLA alleles and sarcoidosis evolution to chronicity adjusting for the SNPs ANXA and BTNL2 (table 5). In these models only positive DRB1*03 is a statistically significant protective to chronicity after correction for multiple comparisons. No interaction terms were found statistically significant in any logistic regression analysis.
CONCLUSIONS
In this cohort, when tested possible associations between ANXA 11, BTNL2 and HLA polymorphisms with sarcoidosis evolution only DRB1*03 allele show a statistically significant association with Sarcoidosis evolution.