Screening for associated autoimmune disorders in Polish patients with Addison's disease

Autoimmune Addison's disease (AAD) is the main reason of primary adrenal failure. More than a half of patients display additional autoimmune conditions, which represent a considerable clinical concern. This study aimed to investigate the prevalence of concomitant autoimmune disorders in 85 Polish AAD patients (61 females, 24 males). Mean age at AAD onset was 34.6 ± 12.6 years, significantly earlier in males (P < 0.001). Sixty-nine patients presented positive serum antibodies to 21-hydroxylase and shorter AAD duration than those with negative results (P = 0.027). Seventy-three subjects suffered from coexisting autoimmune disorders. Serum autoantibodies against thyreoperoxidase, thyroglobulin, TSH receptor, glutamic acid decarboxylase, insulin, tyrosine phosphatase-like protein IA2, parietal cell H(+)/K(+)-ATPase, intrinsic factor and tissue transglutaminase were detectable in 71.8, 41.2, 4.7, 21.0, 4.9, 2.5, 49.4, 12.0 and 3.5% of patients, respectively. Antinuclear antibodies were found in 12.5%. Thyroid autoimmunity was most common (46 subjects with lymphocytic thyroiditis, 19 with Graves' disease), followed by atrophic gastritis (29.4%), pernicious anaemia (11.8%), hypergonadotropic hypogonadism (8.2%), vitiligo (8.2%), type 1 diabetes (7.1%), celiac disease (3.5%) and alopecia (2.4%). Gender differences were observed only for thyroid autoimmunity. Current study confirms particular tendency of AAD patients to develop other autoimmune disorders. Active search for concomitant conditions is warranted to prevent serious complications.

Chromogranin A as a useful neuroendocrine marker in patients with autoimmune Addison's disease

BACKGROUND

Antiparietal cells antibodies (APC-Ab) are commonly found in patients with autoimmune Addison's disease (AAD), usually pointing to autoimmune atrophic gastritis and pernicious anemia. The autoaggression to the gastric proton pumpmay result in a long-term hypergastrinemia, which predisposes to enterochromaffin-like cell hyper/dysplasia and gastric carcinoids.

AIM

We evaluated the clinical utility of assessing serum chromogranin A levels in patients with AAD.

MATERIAL AND METHODS

Serum chromogranin A, gastrin, and gastric APC-Ab levels were determined in 40 patients with AAD using commercially available kits.

RESULTS

Serum chromogranin A and gastrin levels were found to be elevated in 27.5 and 22.5% of patients with AAD, respectively. The Addison's patients with elevated APC-Ab had significantly higher chromogranin A and gastrin levels, as compared to individuals with normal APC-Ab (chromogranin A: 128.00+/-123.08 vs 57.68+/-36.50 ng/ml, p=0.0036; gastrin: 141.38+/-191.43 vs 49.50+/-75.36 muU/ml, p=0.003). Additionally, the patients with AAD and coexisting elevated serum APC-Ab, contrary to those with normal levels, showed a significant correlation between the chromogranin A and gastrin concentrations (r=0.52, p=0.0092 vs r=0.211, p=0.43). Serum chromogranin A appeared also significantly correlated with APC-Ab levels (r=0.431, p=0.005).

CONCLUSIONS

In patients with autoimmune Addison's disease hyperchromograninemia and hypergastrinemia occur with a prevalence of 27.5 and 22.5%, respectively. Addison's patients with coexisting elevated gastric APC-Ab, particularly with elevated gastrin levels, are at risk of enterochromaffin-like cells hyper/dysplasia. Serum chromogranin A assessment may complement histology for the early diagnosis of gastric carcinoid in these patients.

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

Autoimmune Addison's 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.

Association of the CYP27B1 C(-1260)A polymorphism with autoimmune Addison's disease

Autoimmune Addison's disease (AAD) is a complex endocrine disorder with several susceptibility loci. This study was aimed to investigate the associations of CYP27B1 C(-1260)A and PDCD1 G7146A polymorphisms with AAD in a Polish cohort, comprising 101 AAD patients and 251 healthy controls. CYP27B1 encodes 1alpha-hydroxylase, responsible for conversion of the vitamin D (3) precursor into its active form, involved in the immune function. PDCD1 gene gives rise to an inhibitory immune receptor, expressed on activated lymphocytes. Polymorphic variants of these genes had previously been associated with various autoimmune disorders. Genotyping was performed by PCR-RFLP method. The CYP27B1 C(-1260) allele appeared significantly more frequent in AAD compared to controls ( P=0.020), yielding an OR of 1.53 (95% CI 1.07-2.19). The distribution of C(-1260)A genotypes also demonstrated significant difference ( P=0.003). Stratification according to the presence of concomitant autoimmune disorders revealed an association of the C(-1260) allele with the polyendocrine cases of AAD ( P=0.031), while no significance was found for the isolated ADD compared with healthy controls ( P=0.253). Overall, the association between AAD and C(-1260)A was confirmed in a meta-analysis of 325 AAD patients and 952 controls from three different European populations. Under a fixed-effect model, C(-1260) allele and CC genotype were associated with AAD susceptibility with a pooled OR of 1.44 (95% CI 1.18-1.75) and 1.88 (95% CI 1.42-2.36), respectively. No differences were observed for the PDCD1 G7146A between affected subjects and controls (p>0.05). In conclusion, this study confirms the association of the CYP27B1 C(-1260)A polymorphism with AAD, whereas the contribution of PDCD1 G7146A seems less likely.

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 Addison's 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.

DESIGN

DNA samples were obtained from UK and Polish AAD subjects (n = 251 and 87, respectively) and ethnically matched healthy controls (n = 429 and 236, respectively). Genotyping for the C1858T PTPN22 marker was performed by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) assay. Meta-analysis of the results, together with those from three other populations, was performed using RevMan v5.0 software.

RESULTS

In 251 UK AAD subjects the frequency of the PTPN22 1858T allele was 12.2% compared to 7.8% in healthy UK controls; P = 0.008. Similarly, in 87 Polish AAD subjects the PTPN22 1858T allele was found in 19.5% of alleles compared to 11.7% in healthy Polish subjects; P = 0.010. A meta-analysis, combining these result with published data for three other populations, involving 797 AAD subjects and 2032 controls in total, showed that the 1858T allele was associated with AAD susceptibility with a pooled odds ratio (OR) of 1.44 [95% confidence interval (CI) 1.21-1.72; P = 5.6 x 10(-5)], under a fixed-effects model.

CONCLUSION

This study confirms the association between the PTPN22 1858T allele and AAD in an expanded UK cohort and in the previously unstudied Polish population. This meta-analysis allows for the first time a reliable estimate of the strength of effect of this autoimmune disease susceptibility allele across different European Caucasian populations.