Association of polycystic ovarian syndrome with human leukocyte antigen polymorphism in Korean women

Distribution of HLA DRB1 and DQB1 alleles and DRB1-DQB1 haplotypes among Bahraini women with polycystic ovary syndrome

OBJECTIVE

This study investigated the association between HLA-DRB1 and -DQB1 alleles and DRB1-DQB1 haplotypes, and polycystic ovary syndrome (PCOS) in Bahraini women.

DESIGN

Case-control, retrospective study.

METHODS

Study subjects comprised 80 women with PCOS, and 169 age- and ethnically-matched control women. DRB1 and DQB1 genotyping was done by PCR-SSP.

RESULTS

Of the 13 DRB1 alleles and 5 DQB1 alleles identified, DRB1*10 (14.3% vs. 4.4%) and DRB1*14 (8.7% vs. 1.1%), along with DQB1*05 (35.0% vs. 23.9%), were the most frequent alleles in cases, while DRB1*11 (15.3% vs. 6.8%) was the frequent allele found in controls. The association of PCOS with DRB1*10 (Pc<0.001), DRB1*14 (Pc<0.001), DQB1*05 (Pc=0.040), but not DRB1*11 (Pc=0.076) persisted after correcting for multiple comparisons. DRB1-DQB1 haplotype analysis identified nine common shared haplotypes in women with PCOS and control women, with a frequency exceeding 1%. Significantly higher frequency of DRB1*10-DQB1*05 (12.4% vs. 3.1%) and DRB1*14-DQB1*03 (5.6% vs. 1.0%), and reduced frequency of DRB1*11-DQB1*03 (4.1% vs. 14.1%) haplotypes were seen in women with PCOS vs. control women, thus assigning PCOS-susceptible and -protective nature to these haplotypes, respectively. This association persisted after controlling for multiple comparisons.

CONCLUSION

Our results confirm an association of HLA-DRB1 and -DQB1 alleles and haplotypes with PCOS susceptibility in Bahraini Arabs, further underscoring the immunological/inflammatory nature of this disorder.

High prevalence of chronic thyroiditis in patients with polycystic ovary syndrome

OBJECTIVE

A higher prevalence (26.9% versus 8.3% of controls) of autoimmune thyroiditis (AIT) in polycystic ovary syndrome (PCOS) has been reported in one study to date. We aimed to evaluate the prevalence of clinical, subclinical, potential thyroid autoimmune diseases and other organ-specific autoimmunity in a group of Italian patients with PCOS.

STUDY DESIGN

113 consecutive patients referred to our endocrinology unit as outpatients over 18 months, and diagnosed with PCOS according to the Rotterdam criteria, were included in the study, and 100 age-matched healthy women were enrolled as controls. Each patient was evaluated for family and personal history of autoimmune and non-autoimmune diseases and tested for autoantibodies against thyroperoxidase, thyroglobulin, parietal cells, intrinsic factor, adrenal-cortex, 21-hydroxylase, steroid-producing cells, 17-alpha-hydroxylase, side-chain cleavage enzyme, islet-cells, glutamic-acid decarboxylase, nuclei and mitochondria. All patients had serum TSH, FT4 and FT3 tested and patients with thyroid autoantibodies and/or abnormal TSH levels had an ultrasound thyroid scan. An oral glucose tolerance test and measurements of serum anti-Mullerian hormone (AMH) and inhibin B levels were carried out.

RESULTS

AIT was present in 30/113 (27%) patients compared with 8% of controls (p<0.001). Subclinical hypothyroidism was detected in 13/30 (43%) patients with AIT; the remaining patients had normal thyroid function. The prevalence of non-thyroid autoantibodies in PCOS patients was not different from controls. AMH concentration was higher in PCOS patients compared to controls, but there was no difference between AIT and non-AIT groups.

CONCLUSIONS

The prevalence of AIT in patients with PCOS was significantly higher than in controls. No other autoimmune diseases were associated with PCOS. This observation suggests that PCOS patients should be screened for AIT.

HLA and Disease Associations in Koreans

The human leukocyte antigen (HLA), the major histocompatibility complex (MHC) in humans has been known to reside on chromosome 6 and encodes cell-surface antigen-presenting proteins and many other proteins related to immune system function. The HLA is highly polymorphic and the most genetically variable coding loci in humans. In addition to a critical role in transplantation medicine, HLA and disease associations have been widely studied across the populations world-wide and are found to be important in prediction of disease susceptibility, resistance and of evolutionary maintenance of genetic diversity. Because recently developed molecular based HLA typing has several advantages like improved specimen stability and increased resolution of HLA types, the association between HLA alleles and a given disease could be more accurately quantified. Here, in this review, we have collected HLA association data on some autoimmune diseases, infectious diseases, cancers, drug responsiveness and other diseases with unknown etiology in Koreans and attempt to summarize some remarkable HLA alleles related with specific diseases.