Human leukocyte antigen class II alleles and dental caries in a child population.

PURPOSE: The purpose of this study was to investigate a possible relationship between human leukocyte antigens (HLAs) DRB1 and DQB1, dental caries, and colonization by mutans streptococci (MS) in children. METHODS: Sixty children were clinically examined for caries in accordance with World Health Organization criteria and methods. Thereafter, subjects were assigned into 2 groups: (1) high-caries children (dft and DMFT > or = 5); and (2) caries-free children (dft and DMFT = 0). Fresh saliva samples were collected and testedfor mutans streptococci, after which the subjects were placed into 2 groups, having either high (> or =10(5) colony-forming units [CFU]/mL saliva) or low (< 10(5) CFU/mL saliva) numbers of micro-organisms in saliva. The polymerase chain reaction/sequence specific primer method was used to determine HLA DNA typing from fresh blood samples. RESULTS: There was no significant difference between the frequency of HLA alleles in high-caries and caries-free subjects. Although chi-square test suggested an association for HLA-DRB1*01 and HLA-DQB1*03 with the salivary numbers of MS (P = .026 and P = .009, respectively), these could not be confirmed by logistic regression analysis (P = .188 and P = .101, respectively). CONCLUSIONS: The results obtained fail to establish an association between human leukocyte antigen alleles DRB1 and DQB1 and salivary numbers of MS in the selected child population.

Vitamin D receptor gene polymorphisms are not associated with alopecia areata.

BACKGROUND: It has been demonstrated that the vitamin D receptor (VDR) is strongly expressed in key structures of hair follicles, and a lack of VDR leads to alopecia. We investigated whether there was any association between VDR gene polymorphisms (BsmI, ApaI, and TaqI) and alopecia areata (AA). METHODS: Thirty-two patients with AA and 27 healthy control subjects were genotyped using polymerase chain reaction and restriction fragment length polymorphism analysis. RESULTS: In the patient group, the B and b allele frequencies were 53.1% and 46.9%, A and a allele frequencies were 70.3% and 29.7%, and T and t allele frequencies were 62.5% and 37.5%, respectively. In the control group, the corresponding values were 51.9% and 48.1%, 63.0% and 37.0%, and 77.8% and 22.2%, respectively. In the patient group, the BB, Bb, and bb genotype frequencies were 25.0%, 56.2%, and 18.8%, AA, Aa, and aa genotype frequencies were 43.8%, 53.1%, and 3.1%, and TT, Tt, and tt genotype frequencies were 37.5%, 50.0%, and 12.5%, respectively. In the control group, the corresponding values were 11.1%, 81.5%, and 7.4%, 29.6%, 66.7%, and 3.7%, and 63.0%, 29.6%, and 7.4%, respectively. None of the allele or genotype frequencies showed statistically significant differences between the patient and control groups. CONCLUSION: These findings suggest that there is no relationship between VDR gene polymorphisms and AA.

HLA-DR B1 and DQ B1 polymorphisms in patients with coronary artery ectasia.

OBJECTIVES: The purpose of our study was to evaluate the significance of polymorphisms in HLA class II genes in coronary artery ectasia (CAE) patients. METHODS AND RESULTS: Twenty-six patients with CAE without associated cardiac defects were enrolled in the study. CAE was defined as luminal dilation of 1.5- to 2.0-fold of normal limits. Ninety-five healthy subjects who were donors for different organ transplantations, were chosen as control group. Physical examination, electrocardiography and chest X-ray were completely normal in these cases. Both the patients and the control group were screened and compared for their HLA class II genotypes. HLA-DR B1*13, DR16, DQ2 and DQ5 genotypes were significantly more frequent in the patient group. When the known risk factors of coronary heart disease were compared in the patients carrying these genotypes with the non-carrying group, no significant differences were encountered. CONCLUSIONS: HLA-DR B1*13, DR16, DQ2 and DQ5 may be associated with the pathogenesis and increase the risk of CAE.

Lack of association between Vitamin D receptor FokI polymorphism and alopecia areata.

Vitamin D receptor (VDR) is expressed in the hair follicle and the lack of it leads to alopecia. In this study, we investigated whether there was a relationship between VDR FokI gene polymorphism and alopecia areata (AA). This is the first study investigating the relationship between VDR gene polymorphism and AA. Twenty-five patients with the extensive forms of AA (alopecia totalis; AT, alopecia universalis; AU and AT/AU) and 27 healthy control subjects were genotyped. Their genotypes were determined by a polymerase chain reaction (PCR) and restriction fragment length polymorphism analysis. The genotypes were classified as FF (absence of the FokI site) and ff (presence of the FokI site). Allele frequencies for F and f alleles were 76.0% and 24.0% in the alopecic group and 72.2% and 27.7% in the control group (p > 0.05). The frequencies for the FF, Ff and ff genotypes were 56.0%, 40.0% and 4.0% in the patient group, and 48.1%, 48.1% and 3.7% in the control group, respectively. No statistically significant differences were observed in the frequencies of the VDR FokI genotype between the patient and the control groups. However, to conclude that there is no relationship between VDR gene polymorphism and AA, the VDR FokI polymorphism should be further studied in other populations, larger groups, and the distribution of other VDR polymorphisms such as BsmI, Tru9I, ApaI, TaqI and polyA.

Association of HLA class I antigens and HLA class II alleles with vitiligo in a Turkish population.

As is the case with many other autoimmune diseases, there is an association between vitiligo and HLA complex. HLA subtypes vary with racial/ethnic background. The purpose of this study was to determine which HLA class I antigens and HLA class II alleles are associated with Turkish vitiligo patients. Forty-one patients with vitiligo and 61 healthy control subjects were typed for HLA class II alleles. Thirty-three out of 41 patients with vitiligo and 100 healthy transplant donors were typed for HLA class I antigens. HLA DNA typing was performed by polymerase chain reaction/sequence specific primer method for class II. HLA typing for class I was performed by serological method. The frequency of HLA DRB1*03 was 0.6340 in patients compared to 0.2950 in controls (P = 0.0014). The frequency of HLA DRB1*04 was found to be 0.6830 in patients compared to 0.2950 in controls (P = 0.00026). The allele HLA DRB1*07 was present in 0.390 of patients compared to 0.0820 of the controls (P = 0.0004). A preventive antigen for the manifestation of vitiligo has not been identified in this study. Our findings suggest that DRB1*03, DRB1*04 and DRB1*07 alleles are genetic markers for general susceptibility to vitiligo in a Turkish population.