Associations of HLA-A, -B and -DRB1 types with oral diseases in Swiss adults

Oral active matrix metalloproteinase-8 immunotest may be less accurate in haemato-oncologic patients

OBJECTIVES

This study examines the associations of active matrix metalloproteinase-8 (aMMP-8) point-of-care immunotest (Periosafe) outcomes with oral health of patients with haemato-oncologic diseases.

METHODS

Adult patients diagnosed with haematological diseases aimed to be treated with haematopoietic stem cell transplantation (HSCT) between 2018 and 2019 were included in the study. Clinical and radiological dental examination were taken immediately prior to transplantation. The presence of oral foci of infections, caries or periodontitis was examined and compared with the outcomes of aMMP-8 immunotest.

RESULTS

Acute oral infection foci were present in 11.9%, chronic in 44.1% and periodontitis in 42.0% of the 143 subjects. aMMP-8 immunotest was positive in 13.3% of all the 143 subjects. Among subjects with periodontitis (n = 60), the aMMP-8 immunotest was also positive in 13.3% of these subjects. However, the subjects with positive aMMP-8 immunotest (n = 19) had more often acute or chronic infection foci and more than one of the examined dental treatment needs compared with subjects with negative immunotest (all p < 0.05). There were no differences in age, sex, hyposalivation, DMFT-index values nor with plasma levels of leukocytes, neutrophils or C-reactive protein between subjects with positive or negative aMMP-8 immunotest.

CONCLUSIONS

aMMP-8 immunotest accuracy might be reduced, in relation to periodontitis, in haemato-oncologic patients.

Human leukocyte antigens are associated with salivary level of active MMP-8

Objectives

This case control study examined the associations of HLA antigens and periodontitis with the salivary level of active MMP‐8 (aMMP‐8).

Materials and Methods

A total of 202 subjects, registered as Swiss bone marrow donors, participated in the study. HLA‐A, ‐B, and ‐C types were determined by serology or PCR. Saliva samples were collected from subjects, followed by a periodontal examination. The salivary level of aMMP‐8 was determined with immunofluorometric assay.

Results

The mean salivary level of aMMP‐8 was directly comparable to the grade of periodontitis and increased from healthy to mild/moderate to severe (125.0 ± 132.1, 200.6 ± 170.2, 290.1 ± 202.3 ng/ml; p < 0.001 between each group, respectively). The only association between the HLA types and the salivary level of aMMP‐8 was observed in subjects with HLA‐A11. Subjects with healthy periodontium and HLA‐A11 had a lower level of aMMP‐8 (49.2 ± 32.5 ng/ml) compared with subjects without HLA‐A11 (123.6 ± 119.2; p = 0.048). Among subjects with periodontitis, a higher level of aMMP‐8 (394.2 ± 255.6 ng/ml) was observed in subjects with HLA‐A11 compared with subjects without HLA‐A11 (201.1 ± 146.1 ng/ml; p < 0.002). This finding was statistically significant also after adjusting for sex, age, smoking, tooth brushing and the number of medications (p < 0.05).

Conclusions

HLA‐A11 is associated with the salivary level of aMMP‐8 which contributes to the subject's immune and inflammatory response in periodontium.

The complex pattern of genetic associations of leprosy with HLA class I and class II alleles can be reduced to four amino acid positions

Leprosy is a chronic disease caused by Mycobacterium leprae. Worldwide, more than 200,000 new patients are affected by leprosy annually, making it the second most common mycobacterial disease after tuberculosis. The MHC/HLA region has been consistently identified as carrying major leprosy susceptibility variants in different populations at times with inconsistent results. To establish the unambiguous molecular identity of classical HLA class I and class II leprosy susceptibility factors, we applied next-generation sequencing to genotype with high-resolution 11 HLA class I and class II genes in 1,155 individuals from a Vietnamese leprosy case-control sample. HLA alleles belonging to an extended haplotype from HLA-A to HLA-DPB1 were associated with risk to leprosy. This susceptibility signal could be reduced to the HLA-DRB1*10:01~ HLA-DQA1*01:05 alleles which were in complete linkage disequilibrium (LD). In addition, haplotypes containing HLA-DRB3~ HLA-DRB1*12:02 and HLA-C*07:06~ HLA-B*44:03~ HLA-DRB1*07:01 alleles were found as two independent protective factors for leprosy. Moreover, we replicated the previously associated HLA-DRB1*15:01 as leprosy risk factor and HLA-DRB1*04:05~HLA-DQA1*03:03 as protective alleles. When we narrowed the analysis to the single amino acid level, we found that the associations of the HLA alleles were largely captured by four independent amino acids at HLA-DRβ1 positions 57 (D) and 13 (F), HLA-B position 63 (E) and HLA-A position 19 (K). Hence, analyses at the amino acid level circumvented the ambiguity caused by strong LD of leprosy susceptibility HLA alleles and identified four distinct leprosy susceptibility factors.

Despite global efforts to eliminate leprosy over the past 25 years, more than 200,000 new cases are reported annually, and leprosy still represents a major public health problem in endemic regions. Leprosy presents a strong link with the host genetic background. The most significant susceptibility factors are located in the MHC region and likely involve classical HLA genes. However, the molecular identity of the HLA class I/II-leprosy risk factor(s) has been a matter of longstanding scientific dispute. By conducting a comprehensive sequenced-based analysis of HLA class I and class II genes, we are able to provide a unifying view of the complex relationship of leprosy susceptibility and HLA alleles. In addition, we show that four amino acid polymorphisms in HLA-DRβ1, HLA-B and HLA-A are sufficient to explain the majority of leprosy-HLA associations which opens the way for select protein-HLA peptide binding studies.

Association between HLA-DRB1* allele polymorphism and caries susceptibility in Han Chinese children and adolescents in the Xinjiang Uygur Autonomous Region

OBJECTIVE

The rate of caries and the mean number of decayed, missing, or filled teeth were reported to be significantly higher in children in the Xinjiang Uygur Autonomous Region than in children in eastern China. Little is known regarding the genetic basis of caries among residents of the Xinjiang Uygur Autonomous Region. This study investigated the association between HLA-DRB1 alleles and caries susceptibility in Han Chinese children and adolescents in the Xinjiang Uygur Autonomous Region.

METHODS

HLA-DRB1 allele frequency was assessed in DNA samples from buccal swabs of 42 patients with caries and 123 healthy control participants using a polymerase chain reaction method with sequence-specific primers. The chi-squared test or Fisher's exact test, followed by Bonferroni correction, was used to calculate differences in allele frequencies between groups.

RESULTS

Compared with the healthy controls, the allele frequency of HLA-DRB1*13 was significantly higher in patients with caries in the Xinjiang Uygur Autonomous Region (35.71% vs. 18.70%). The allele frequency of HLA-DRB1*09 was significantly lower in patients with caries than in healthy controls (4.76% vs. 25.20%).

CONCLUSIONS

HLA-DRB1*13 alleles could confer greater caries susceptibility, whereas HLA-DRB1*09 could be protective against caries pathogenesis, in Han Chinese children in the Xinjiang Uygur Autonomous Region.

Oral disorders in patients with newly diagnosed haematological diseases

OBJECTIVE

This study aimed to examine saliva flow rates and prevalence of dental and periodontal diseases of patients with newly diagnosed severe haematological diseases and compare these findings with age-matched controls of normal population.

METHODS

A total of 149 patients diagnosed with haematological diseases aimed to be treated with haematological stem cell transplantation between 2008 and 2018 and 154 controls were included in the study. A dental examination was performed for patients within a maximum of 6 months after diagnosis. Differences were compared in terms of the stimulated salivary flow rate (SSFR); decayed, missing and filled teeth (DMFT) index; number of teeth; caries prevalence; presence of periodontitis and acute infections.

RESULTS

The mean SSFR of the patient group was significantly lower (1.1 ml/min ± 0.7 ml/min) than the mean SSFR of the controls (1.3 ml/min ± 0.5 ml/min; p = 0.004). The number of caries lesions was significantly higher in the patient group (mean ± SD, 1.1 ± 1.9) than in the control group (mean ± SD, 0.4 ± 1.2; p < 0.001). There were fewer teeth and a higher DMFT index in the patient group compared to the control group, but the differences were not significant. Acute symptomatic infections were observed in eight (5.4%) patients and in none of the controls (p < 0.01).

CONCLUSIONS AND CLINICAL RELEVANCE

Oral examinations in patients with newly diagnosed severe haematological disease demonstrated a higher prevalence of caries, acute infections and lower mean SSFR compared with the controls. These findings support the recommendations for early dental examination at the time of diagnosis.

Dissociations of oral foci of infections with infectious complications and survival after haematopoietic stem cell transplantation

Introduction

Haematopoietic stem cell transplantation (HSCT) recipients are at increased risk for severe infections. This study examined the associations of common oral infections with survival and infectious complications in HSCT recipients.

Materials and methods

All autologous and allogeneic HSCT recipients transplanted in the University Hospital of Basel, Switzerland, between 2008 and 2016 and referred to oral infection control pre-HSCT were included in this retrospective case-control study. All patients had a clinical and a panoramic radiological dental examination taken immediately prior to HSCT. Presence of acute or chronic oral foci of infections, decayed, missing or filled tooth index (DMFT) and radiological attachment loss (RAL) were examined. Survival and infections of the subjects were followed up for 6 months post-HSCT.

Results

Altogether 341 allogeneic and 125 autologous HSCT recipients were included in the study. Within 6 months post-HSCT, 47 (14%) of the allogeneic and 4 (3%) of the autologous recipients died. Oral foci of infections (acute or chronic), DMFT or periodontitis pre-HSCT were not associated with survival 6 months post-HSCT. Oral foci of infections were also not associated with hospital treated infectious diseases or blood culture positive bacteremia during the 6 month follow-up period. Untreated oral foci of infections were not associated with survival or severe infectious complications within 6 months post-HSCT.

Conclusion

The results of this study suggest that radical dental interventions to chronic oral infections could be postponed until post-HSCT.

Host genetics role in the pathogenesis of periodontal disease and caries

BACKGROUND

This study aimed to produce the latest summary of the evidence for association of host genetic variants contributing to both periodontal diseases and caries.

MATERIALS AND METHODS

Two systematic searches of the literature were conducted in Ovid Medline, Embase, LILACS and Cochrane Library for large candidate gene studies (CGS), systematic reviews and genome-wide association studies reporting data on host genetic variants and presence of periodontal disease and caries.

RESULTS

A total of 124 studies were included in the review (59 for the periodontitis outcome and 65 for the caries outcome), from an initial search of 15,487 titles. Gene variants associated with periodontitis were categorized based on strength of evidence and then compared with gene variants associated with caries. Several gene variants showed moderate to strong evidence of association with periodontitis, although none of them had also been associated with the caries trait.

CONCLUSIONS

Despite some potential aetiopathogenic similarities between periodontitis and caries, no genetic variants to date have clearly been associated with both diseases. Further studies or comparisons across studies with large sample size and clear phenotype definition could shed light into possible shared genetic risk factors for caries and periodontitis.

Associations of oral fluid MMP-8 with periodontitis in Swiss adult subjects

OBJECTIVE

MMP-8 is a prominent collagenase in periodontal disease. This cross-sectional study examined whether MMP-8 levels in saliva and gingival crevicular fluid (GCF) are associated with periodontitis in a Swiss population.

SUBJECTS AND METHODS

A total of 258 subjects (107 m, 151 f, mean age: 43.5 yr; range: 21-58 yr) acquired from the Swiss bone marrow donor registry participated in the study. Saliva and GCF samples were collected from subjects followed by a thorough dental and periodontal examination. MMP-8 levels were determined with immunofluorometric assay. Associations of MMP-8 levels with periodontal diagnosis, probing pocket depth (PPD) and bleeding on probing were statistically analysed with Pearson chi-square test, Spearman's rho and logistic regression analysis.

RESULTS

MMP-8 in GCF correlated with MMP-8 in saliva (p < .001). Periodontitis was more common (p < .001) among subjects with high levels of MMP-8 in saliva and/or GCF compared with subjects with low levels of MMP-8. Higher MMP-8 levels in GCF and saliva were associated with any periodontal diagnosis (mild, moderate or severe), greater PPD, and bleeding on probing (p < .05). When age, gender, smoking, body mass index, number of medications and decayed, missing and filled teeth were adjusted for, all observed associations remained statistically significant. The area under curve of receiver-operating characteristic was 0.67 for saliva and 0.71 for GCF.

CONCLUSION

Elevated MMP-8 levels both in saliva and GCF are associated with periodontitis in a normal adult population.

A haplotypic variant at the IRGM locus and rs11747270 are related to the susceptibility for chronic periodontitis

OBJECTIVE AND DESIGN

Immunity-regulated GTPase M (IRGM) plays a critical role in the defense against intracellular bacteria by regulating autophagy formation. This direct genetic association study aimed to determine whether variants at the IRGM genetic locus are associated with chronic periodontitis.

MATERIALS AND SUBJECTS

Using PCR and melting curve analysis 390 periodontitis patients and 770 healthy controls have been genotyped regarding six polymorphisms in the IRGM gene (rs13361189, rs10065172, rs4958847, rs1000113, rs11747270, rs931058).

RESULTS

Frequency distribution of alleles and genotypes for the six polymorphisms were not significantly different between the periodontitis and the control group. Also following stratification according to gender and smoking no significant linkage was found for any of the IRGM variants with periodontitis. Analysis of a subsample of patients revealed a significant association for rs11747270 with severe periodontitis (p = 0.003). Pairwise linkage analysis revealed one block composed of rs13361189, rs10065172, rs4958847, rs1000113 and 11747270 with strong or even complete linkage disequilibrium (r ² > 0.9). Four haplotypes showed a frequency of > 1%, among which the haplotype C-T-A-T-G was significantly associated with chronic periodontitis (p = 0.0051; OR 4.66, 95% CI 1.41-15.42).

CONCLUSIONS

One rare haplotype of the IRGM locus is significantly associated with chronic periodontitis in a German cohort.

HLA Haplotypes and Genotypes Frequencies in Brazilian Chronic Periodontitis Patients

Human leukocyte antigens (HLA) have a pivotal role in immune response and may be involved in antigen recognition of periodontal pathogens. However, the associations of HLA with chronic periodontitis (CP) have not been previously studied in the Brazilian population. In an attempt to clarify the issue of genetic predisposition to CP, we examined the distribution of HLA alleles, genotypes, and haplotypes in patients from Southern Brazil. One hundred and eight CP patients and 151 healthy and unrelated controls with age-, gender-, and ethnicity-matched were HLA investigated by polymerase chain reaction with sequence specific oligonucleotides. To exclude smoking as a predisposing factor, statistical analyses were performed in the total sample and in nonsmoking individuals. The significant results showed a positive association of the A∗ 02/HLA-B∗ 40 haplotype with CP (total samples: 4.2% versus 0%, Pc = 0.03; nonsmokers: 4.3% versus 0%, Pc = 0.23) and a lower frequency of HLA-B∗ 15/HLA-DRB1∗ 11 haplotype in CP compared to controls (total samples: 0.0% versus 4.3%, Pc = 0.04; nonsmokers: 0 versus 5.1%, P = 1.0). In conclusion, the HLA-A∗ 02/B∗ 40 haplotype may contribute to the development of CP, while HLA-B∗ 15/DRB1∗ 11 haplotype might indicate resistance to disease among Brazilians.