Magdalena Żurawek

A coding variant in NLRP1 is associated with autoimmune Addison's disease.

Autoimmune Addisons disease (AAD) is a complex disorder with several susceptibility loci. Variations in the NLRP1 (previously, NALP1) gene have recently been reported to confer risk for vitiligo and associated autoimmune conditions. We hypothesized that polymorphisms in this gene may affect susceptibility to AAD. The aim of this study was to analyze the associations of six NLRP1 single-nucleotide polymorphisms (SNPs) with AAD within a Polish cohort. The study comprised 101 AAD patients and 254 healthy control individuals. Genotyping was performed by polymerase chain reaction followed by restriction fragment length polymorphism and single strand conformation polymorphism methods. The minor allele of the coding SNP rs12150220 appeared significantly more frequently in AAD compared with healthy individuals (OR = 1.5, 95% CI, 1.08-2.08, p = 0.015). The distribution of genotypes also demonstrated significant differences. The frequency of high-risk genotype AA of rs12150220 SNP was significantly increased among AAD subjects versus controls (p = 0.006 and p = 0.036, respectively; significant after Bonferroni correction), yielding an OR of 2.96 (95% CI, 1.34-6.55). Likewise, the heterozygous genotype TA was observed more frequently in the patient group [OR = 3.09 (95% CI, 1.53-6.24), p = 0.001 and p = 0.006 after Bonferroni correction]. In conclusion, this study confirms an association between the coding polymorphism in NLRP1 and AAD.

The tryptophan 620 allele of the lymphoid tyrosine phosphatase (PTPN22) gene predisposes to autoimmune Addison's disease

Objective  Previous studies of the association between autoimmune Addisons disease (AAD) and a nonsynonymous single nucleotide polymorphism (SNP) in the PTPN22 gene (C1858T, pR620W; SNP ID no. rs2476601) have shown conflicting results. We aimed to examine this association using additional cohorts of AAD subjects from the UK and Poland.

PTPN22, PDCD1 and CYP27B1 polymorphisms and susceptibility to type 1 diabetes in Polish patients

Type 1 diabetes (T1DM) is a common autoimmune disease with a complex genetic background. This study was aimed to investigate the association of PTPN22 G(‐1123)C and C1858T, PDCD1 G7146A and CYP27B1 C(‐1260)A polymorphisms with T1DM among Polish subjects. The PTPN22 gene encodes lymphoid tyrosine phosphatase, a potent negative regulator of T cell activation. PDCD1 gene gives rise to an inhibitory cell‐surface receptor, expressed on activated lymphocytes. CYP27B1 encodes 1‐alpha hydroxylase, responsible for conversion of the vitamin D3 precursor into its active form, involved in the immune function. Polymorphic variants of these genes have previously been associated with various autoimmune disorders. The four polymorphisms were genotyped by PCR‐restriction fragment assays in a case–control study comprising 215 T1DM patients and 236 healthy controls. The PTPN22 T1858 allele appeared significantly increased in T1DM compared to the control group (P = 0.004), yielding an OR of 1.73 (95% CI 1.19–2.51). The difference in distribution of C1858T genotypes also demonstrated statistical significance (P = 0.015). The frequencies of PTPN22 G(‐1123)C alleles and genotypes did not differ between T1DM cases and controls, although the haplotype comprising both mutant PTPN22 alleles, C(‐1123) and T1858, was significantly more frequent in affected individuals (P = 0.003). G(‐1123)C and C1858T were in linkage disequilibrium (D′ = 0.98; r2 = 0.61 in T1DM and D′ = 0.97; r2 = 0.41 in controls). No significant differences in the allele and genotype frequencies of PDCD1 and CYP27B1 polymorphisms were found between patients and controls. This study confirms the association of PTPN22 C1858T polymorphism with T1DM, whereas the effects of PTPN22 G(‐1123)C, PDCD1 G7146A and CYP27B1 C(‐1260)A seem unlikely, at least in the Polish population.

Susceptibility loci in lung cancer and COPD: association of IREB2 and FAM13A with pulmonary diseases.

Genome-wide association studies have identified loci at 15q25 (IREB2) and 4q22 (FAM13A), associated with lung cancer (LC) and chronic obstructive pulmonary disease (COPD). The aim of our research was to determine the association of IREB2 and FAM13A SNPs with LC and severe/very severe COPD patients. We examined IREB2 variants (rs2568494, rs2656069, rs10851906, rs13180) and FAM13A (rs1903003, rs7671167, rs2869967) among 1.141 participants (468 LC, 149 COPD, 524 smoking controls). The frequency of the minor IREB2 rs2568494 AA genotype, was higher in LC vs controls (P = 0.0081, OR = 1.682). The FAM13A rs2869967 was associated with COPD (minor CC genotype: P = 0.0007, OR = 2.414). The rs1903003, rs7671167 FAM13A variants confer a protective effect on COPD (both P < 0.002, OR < 0.405). Haplotype-based tests identified an association of the IREB2 AAAT haplotype with LC (P = 0.0021, OR = 1.513) and FAM13A TTC with COPD (P = 0.0013, OR = 1.822). Cumulative genetic risk score analyses (CGRS), derived by adding risk alleles, revealed that the risk for COPD increased with the growing number of the FAM13A risk alleles. OR (95% CI) for carriers of ≥5 risk alleles reached 2.998 (1.8 to 4.97) compared to the controls. This study confirms that the IREB2 variants contribute to an increased risk of LC, whereas FAM13A predisposes to increased susceptibility to COPD.

Polymorphic variants of the IL2RA gene and susceptibility to type 1 diabetes in the Polish population.

Polymorphic variants of the IL2RA gene, which encodes high-affinity alpha subunit (CD25) of the interleukin-2 receptor, were recently found to affect the risk of several autoimmune disorders. This study was aimed to investigate the association of selected IL2RA polymorphisms (rs11594656, rs3118470, rs2104286 and rs7093069) with type 1 diabetes (T1D) in a Polish cohort comprising 445 patients and 671 healthy control subjects. The minor A allele at rs11594656 was found significantly less frequently among T1D subjects, compared with the control group [P = 0.011; odds ratio (OR) = 0.77; 95% confidence interval (CI) = 0.629-0.942]. In contrast, the minor C allele at rs3118470 appeared to be significantly associated with the occurrence of T1D (P = 0.003; OR = 1.30; 95% CI = 1.094-1.550). Two other IL2RA single nucleotide polymorphisms (SNPs) did not show significant differences among investigated groups. In conclusion, the study confirms the association of the IL2RA locus with T1D in the Polish population.

FKBP5 polymorphism is associated with insulin resistance in children and adolescents with obesity

OBJECTIVE Since metabolic syndrome shares several clinical features with hypercortisolism, it was hypothesised that genes altering individual glucocorticoid (GC) sensitivity might be implicated in pathogenesis of obesity and its adverse outcomes. FKBP5 gene encodes a chaperon protein in the GC receptor (GR) complex, which modulates steroid action upon target genes. Its functional variant, rs1360780, may enhance FKBP5 gene transcription, affect GR signalling and thereby influence the hypothalamo-pituitary-adrenal axis. We investigated the association of rs1360780 with obesity and metabolic characteristics in 250 obese children and adolescents (mean age 12.3±3.6years, BMI ≥95th percentile). METHODS Anthropometric measurements, body composition, biochemical and hormonal results were analysed. Genotyping of rs1360780 was compared with 568 lean controls. RESULTS Impaired fasting glucose was present in 8.8%, glucose intolerance in 10.4%, diabetes in 2.8% and dyslipidemia in 28.8% obese individuals. Hypertension was diagnosed in 34 out of 143 patients. No difference was found in FKBP5 polymorphism distribution between subjects with obesity and controls (p>0.05). Stratification by rs1360780 revealed no differences in body mass and composition. However, carriers of the minor allele displayed enhanced insulin resistance (p=0.009) and elevated serum triglyceride (p=0.006), whereas cholesterol, HbA1c, and oral glucose challenge results were similar for all genotypes. Morning ACTH and cortisol did not differ but evening cortisol was higher in minor allele carriers (p=0.039), although this association was lost in logistic regression analysis. CONCLUSION This study does not support the association of FKBP5 with obesity but demonstrates plausible implication of its variant in susceptibility to obesity-related insulin resistance and hypertriglyceridemia.

Interleukin-2 and subunit alpha of its soluble receptor in autoimmune Addison's disease – An association study and expression analysis

Abstract Autoimmune Addisons disease (AAD) results from T cell-mediated destruction of the adrenal cortex, commonly accompanied by autoantibodies to 21-hydroxylase (21OH). In order to gain insight into the obscure aetiology of this disease, we investigated the roles of the IL2 and IL2RA genes, encoding interleukin-2 and subunit alpha of its receptor (IL2Ra), respectively. The association of AAD with IL2 and IL2RA polymorphisms (rs6822844, rs2069762, rs3136534, rs11594656, rs3118470 and rs2104286) was tested in 223 patients and 672 healthy controls. Functional studies consisted of gene expression analysis in cultured PBMCs exposed to 21OH and evaluation of serum interleukin by ELISA assays. The frequency of the minor C allele of rs3136534 was significantly decreased in AAD subjects compared to controls (OR 0.71; 95%CI 0.561–0.887; p = 0.003). Only AAD cells responded to 21OH with an elevated IL2 and IL2RA mRNA synthesis (p = 0.004 and p = 0.009 versus controls, respectively), paralleled by increased supernatant levels of both cytokines (p = 0.031 and p = 0.001 versus controls). IL2 mRNA level in 21OH-stimulated AAD PBMCs correlated negatively with age (p = 0.036) and positively with serum antibodies to 21OH (p = 0.006). Carriers of the rs2104286 AA genotype demonstrated higher IL2RA mRNA (p = 0.022) and soluble IL2Ra secretion (p = 0.029) upon 21OH stimulation. Serum interleukin-2 in AAD subjects was significantly higher compared to controls (4.61 ± 4.3 versus 1.71 ± 3.2 pg/mL, p < 0.001), whereas sIL2Ra levels remained similar in both groups (p = 0.885). In conclusion, the study reveals an association between AAD and IL2 locus. It confirms specific 21OH-directed reactivity of the peripheral AAD lymphocytes, which display increased synthesis of interleukin-2 and sIL2Ra.

Adrenal hypoplasia congenita – an uncommon reason of primary adrenal insufficiency

Adrenal hypoplasia congenita (AHC) is a rare inherited condition characterised by primary adrenal failure and hypogonadotropic hypogonadism. Most cases arise from mutations in the NR0B1 gene (Xp21.3), which encodes an orphan nuclear receptor DAX-1. A 20-year-old patient was recently diagnosed with AHC. Adrenal failure had been recognized and treated since his infancy. During adolescence, gradual decrease in growth velocity and low body mass were noted. Lack of puberty and skeletal immaturity were observed. Serum DHEA-S and testosterone were undetectable. Low gonadotropin levels failed to rise after stimulation. Neither dysfunction of the somatotropic nor pituitary-thyroid axis was found and no hypothalamo-pituitary pathology was visible on MRI. Androgen replacement therapy induced the development of secondary sexual characteristics, remarkably improved patients growth and advanced his bone age. NR0B1 mutation screening revealed nucleotide transversion C>A, resulting in premature stop codon (Y399X). Same mutation was previously identified in a Scottish family, however, phenotypic differences suggest the role of additional factors modifying the disease course. Although it does not change therapeutic strategy, accurate molecular diagnosis allows genetic counselling in family members. Autoimmunity remains the major cause of adrenal failure; however, other rare conditions should always be considered.

Polymorphisms in the interferon‐induced helicase (IFIH1) locus and susceptibility to Addison's disease

The interferon‐induced helicase C domain‐containing protein 1 (IFIH1) gene encodes a sensor for double‐stranded RNA that initiates antiviral activity against enteroviruses. Previous investigations have indicated a role for IFIH1 in autoimmunity, as common and rare polymorphisms in this gene have been associated with type 1 diabetes. We hypothesized that polymorphisms in the IFIH1 locus may play a role in the pathogenesis of autoimmune Addisons disease (AAD).