Noriko Sugita

The Fcγ Receptor Genotype as a Risk Factor for Generalized Early-Onset Periodontitis in Japanese Patients

BACKGROUND Genetic polymorphisms of immunoglobulin G (IgG) Fc receptors (FcγR) were recently shown to be associated with recurrence rates of adult periodontitis (AP). The purpose of this study was to evaluate whether FcγR polymorphisms are also associated with generalized early-onset periodontitis (G-EOP) in Japanese patients. METHODS Thirty-eight Japanese patients with G-EOP and 83 Japanese patients with AP were identified according to established clinical criteria, including measurements of probing depth, clinical attachment level, and alveolar bone level. FcγR genotypes for 3 bi-allelic polymorphisms were determined in these G-EOP and AP patients and 104 race-matched healthy controls by means of allele-specific polymerase chain reactions. RESULTS There was a significant difference in the distribution of FcγRIIIb genotypes between G-EOP patients and healthy controls (P = 0.02). Additionally, a significant over-representation of FcγRIIIb-NA2 allele was observed in G-EOP patients as compared to AP patients and controls (P = 0.02, P = 0.009, respectively). Moreover, we found a strong association between GEOP and the composite genotype comprising FcγRIIIb-NA2 and FcγRIIIa-158F (G-EOP versus controls: odds ratio 2.4, 95% CI 1.0-6.0, X2 = 4.13, P = 0.04). CONCLUSIONS This study indicates that the FcγRIIIb-NA2 allele and possibly FcγRIIIa-158F could be associated with susceptibility to G-EOP in Japanese patients. J Periodontol 2000;71:1425-1432.

A novel PCR-based method for direct Fcγ receptor IIIa (CD16) allotyping

Abstract Leukocyte IgG receptors (FcγR) are important immune-response modulating molecules. FcγRIIIa is expressed on macrophages, NK-cells and γδ-T cells and exhibits a genetically determined, functional polymorphism at nucleotide 559. This allelic difference predicts either a phenylalanine (F158) or valine (V158) at amino acid 158 in the membrane-proximal extracellular domain, and has been shown to be associated with autoimmune and infectious diseases. Published methods to determine FcγRIIIa genotypes are cumbersome. Therefore, we developed a novel, rapid and reliable PCR-based method to determine FcγRIIIa genotypes. Comparison of genotyping results with direct FcγRIIIa sequencing of 60 blood donors showed 100% accuracy of this new method. Since genotype frequencies of FcγR polymorphisms depend strongly on race and ethnicity, we compared FcγRIIIa genotype frequencies of 176 Caucasian Dutch and 104 Japanese blood donors. Interestingly, these frequencies were not significantly different (P>0.1), in contrast to the FcγRIIa and FcγRIIIb genotype frequencies (P

The Fcγ Receptor Genotype as a Severity Factor for Chronic Periodontitis in Japanese Patients

BACKGROUND Functional polymorphisms of immunoglobulin G (IgG) Fc receptors (FcγR) have been shown to be associated with generalized aggressive periodontitis (GAgP) or recurrence of chronic periodontitis (CP) in Japanese patients. The purpose of this study was to evaluate whether FcγR polymorphisms are also associated with severity of CP. METHODS Fifty Japanese non-smoking patients with severe CP and 39 Japanese non-smoking patients with moderate CP were identified according to established clinical criteria, including measurements of probing depth (PD), clinical attachment level (CAL), and alveolar bone loss (BL). FcγR genotypes for 3 bi-allelic polymorphisms (FcγRIIa-R/H131, FcγRIIIa-158V/F, FcγRIIIb-NA1/NA2) were determined in these CP patients and 64 race-matched, non-smoking healthy controls by means of allele-specific polymerase chain reactions. RESULTS There was a significant over-representation of FcγRIIIa-158V allele in severe CP patients compared to moderate CP patients (odds ratio 2.03, 95% confidence interval [CI] 1.03-4.01, χ 2 = 4.86, P = 0.028). In addition, we found a strong association between CP severity and FcγR composite genotype comprising FcγRIIIa-158V plus FcγRIIIb-NA2 (severe CP versus moderate CP: odds ratio 4.69, 95% CI 1.52-15.10, χ 2 = 9.35, P = 0.002; severe CP versus healthy controls: odds ratio 4.10, 95% CI 1.62-10.59, χ 2 = 11.13, P = 0.0009). Moreover, CP patients positive for the composite genotype exhibited more severe signs of periodontitis than composite genotype-negative individuals (positive versus negative; mean PD: 3.8 mm versus 3.2 mm, P = 0.005; mean CAL: 4.5 mm versus 3.7 mm, P = 0.005; mean % BL: 37.6% versus 29.9%, P = 0.008). CONCLUSION Our results document the FcγRIIIa-158V allele and possibly FcγRIIIb-NA2 to be associated with severity of CP in Japanese patients. J Periodontol 2001;72:1324-1331.

Analysis of Vitamin D and Fcγ Receptor Polymorphisms in Japanese Patients with Generalized Early-onset Periodontitis

Early-onset periodontitis (EOP) is considered to have a genetic basis which has not been clearly defined. Genetic polymorphisms of the vitamin D receptor (VDR-B-b) and the immunoglobulin-Fcγ receptor IIIb (FcγRIIIb-NA1-NA2) are associated with bone metabolism and infectious diseases, respectively. The purpose of this study was to investigate the associations of EOP with VDR and FcγRIIIb polymorphisms. Subjects were comprised of those with generalized EOP (G-EOP, n = 42), adult periodontitis (AP, n = 52), and healthy control (HC, n = 55). VDR and FcγRIIIb genotypes were determined by allele-specific polymerase chain-reactions. Our results indicated that frequencies of the VDR-B non-carrier and the FcγRIIIb-NA2 carrier were lower in the G-EOP compared with the AP and HC groups. Furthermore, we found a strong association between G-EOP and the VDR-FcγRIIIb composite genotype (G-EOP vs. AP - OR = 5.09, p = 0.009; G-EOP vs. HC - OR = 5.93, p = 0.004). In conclusion, no correlation was found between the VDR genotype and G-EOP. However, the VDR and FcγRIIIb genotype combination may be associated with susceptibility to G-EOP.

Increased Frequency of FcγRIIIb-NA1 Allele in Periodontitis-resistant Subjects in an Elderly Japanese Population

Many elderly people show minimum periodontal tissue destruction, which might be partly due to genetic advantages in host immune response against periodontopathic bacteria. The human IgG Fc receptor IIIb on neutrophils bears a NA1-NA2 polymorphism. The FcγRIIIb-NA1 displays a more efficient interaction with IgGl- and IgG3-opsonized bacteria, compared with the FcγRIIIb-NA2. We investigated a 70-year-old Japanese population (n = 599) to determine whether the FcγRIIIb polymorphism was associated with resistance to periodontitis. Among subjects with≥ 20 teeth present, periodontitis-resistant (n = 46) and periodontitis-susceptible groups (n = 73) were selected based on the percentage of sites with ≥ 4 mm probing attachment loss in the entire dentition. The FcγRIIIb-NA1 allotype was overrepresented in the periodontitis-resistant group, compared with the periodontitis-susceptible group (χ2 = 4.89, p = 0.03, odds ratio = 1.87, 95% CI, 1.07 to 3.28). This suggests that FcγRIIIb-NA1 may be associated with resistance to periodontitis.

FcγRIIB gene polymorphisms in Japanese periodontitis patients

Human type II low-affinity receptor for immunoglobulin G (FcγRII) constitutes a clustered gene family consisting of FcγRIIA, IIB and IIC genes. FcγRIIB is unique in its ability to transmit inhibitory signals in B cells via immunoreceptor tyrosine-based inhibitory motif (ITIM). B-cell activation and subsequent elevated production of IgG are the immunopathological features of inflammatory disease such as periodontitis. To determine whether an association with periodontitis susceptibility exists, genetic polymorphisms of FcγRIIB were examined in Japanese patients with aggressive periodontitis (AGP) and chronic periodontitis (CP), and in the race-matched healthy controls (HCs). A significant difference was observed in the distribution of FcγRIIB−232I/T allele (exon 5) between the AGP and HC groups, with enrichment of the 232T in the AGP group (P=0.006). In addition, the FcγRIIB-nt 646−184A/G allele (intron 4) distribution was significantly different between the CP and HC groups, with enrichment of the nt 646−184A in the CP group (P=0.011). These results document the association of FcγRIIB gene polymorphisms with susceptibility to periodontitis in the Japanese.

ACTIVATION OF TRANSCRIPTION FACTORS AND IL-8 EXPRESSION IN NEUTROPHILS STIMULATED WITH LIPOPOLYSACCHARIDE FROM PORPHYROMONAS GINGIVALIS

DNA binding activity of NF-κB and AP-1 were examined in neutrophils stimulated with LPS purified from P. gingivalis, a major pathogenic bacteria of periodontitis lesion. Porphyromonas gingivalis LPS enhanced the activity reaching a peak at a concentration of 500 ng/ml in the absence of serum. The NF-κB activation stimulated with 10 ng/ml of P. gingivalis LPS was suppressed approximately 44% by treatment of neutrophils with anti-CD14 antibody under the presence of serum. Increase in the steady-state IL-8 mRNA level was concomitantly observed by stimulation of neutrophils with 500 ng/ml of P. gingivalis LPS under the absence of serum. These results indicate that P. gingivalis LPS activates NF-κB and AP-1 in both serum-dependent and -independent manners, followed by increased IL-8 transcription in neutrophils, and suggested a role for P. gingivalis LPS in IL-8 synthesis by neutrophils in inflamed gingiva and GCF.

Profiling biomarkers in gingival crevicular fluid using multiplex bead immunoassay.

OBJECTIVE Biomarkers in gingival crevicular fluid (GCF) have been investigated; however, measurements were limited by the small sample volume available. The aim of this study was to determine the levels of 40 different cytokines and chemokines in GCF samples. DESIGN Eleven patients with generalised chronic periodontitis participating in a supportive periodontal therapy programme with remaining probing pocket depths (PDs) of >5mm were enrolled. One healthy and two diseased sites were sampled in each subject. Forty biomarkers in GCF were examined using a multiplex bead immunoassay. Porphyromonas gingivalis from the diseased sites was quantified by real-time polymerase chain reaction. RESULTS Twenty-six biomarkers were detected in the GCF samples using the multiplex bead immunoassay. The levels of nine biomarkers were significantly different between the diseased and healthy sites after adjustment with Bonferronis correction. The level of 26 biomarkers in diseased sites was compared between bleeding on probing (BOP)-positive and BOP-negative sites. Interleukin (IL)-1β and interferon-inducible protein (IP)-10 levels were significantly higher in BOP-positive diseased sites than BOP-negative diseased sites after adjustment for multiple comparisons (IL-1β, p=0.0007, IP-10; p=0.0009). In addition, the levels of IL-1β in GCF were found to be strongly correlated with the P. gingivalis ratio (r=0.646, p=0.0012). CONCLUSION IL-1β levels in GCF correlate with the PDs, BOP and the presence of P. gingivalis in subgingival plaque. Multiplex bead assays can be useful in GCF studies. These findings can help in identifying new diagnostic methods in the diagnosis of periodontal disease.

Effective in vitro clearance of Porphyromonas gingivalis by Fcα receptor I (CD89) on gingival crevicular neutrophils

ABSTRACT Porphyromonas gingivalis has been implicated as a causative pathogen in periodontitis. Immunotherapeutic approaches have recently been suggested to aid in the clearance of P. gingivalis from disease sites. Because antibody-Fc receptor (FcR) interactions play a role in the effector functions of polymorphonuclear neutrophils (PMN), we evaluated which FcR on PMN from gingival crevicular fluid (GCF) serves as an optimal target molecule for FcR-directed immunotherapy. GCF PMN and peripheral blood (PB) PMN from adult periodontitis patients were analyzed for their immunoglobulin G (IgG) and IgA FcR (FcγR and FcαR, respectively) expression and function by studying IgG- and IgA-mediated elimination of P. gingivalis. GCF PMN exhibited higher FcαRI and FcγRI levels and lower FcγRIIa and FcγRIIIb levels than PB PMN. Functional studies revealed that GCF PMN exhibited less of a capacity to phagocytose and kill IgG1-opsonized P. gingivalisthan PB PMN. IgA1-mediated phagocytosis and killing capacity was, however, comparable between GCF PMN and PB PMN. In summary, these in vitro results document that FcαRI represents a candidate target for FcR-directed immunotherapy for the clearance of P. gingivalis.

Peroxisome proliferator-activated receptor (PPAR) γ polymorphism, vitamin D, bone mineral density and periodontitis in postmenopausal women

OBJECTIVES PPARg regulates bone metabolism and inflammation. Our previous study suggested PPARg Pro12Ala polymorphism to represent a susceptibility factor for periodontitis in pregnant Japanese women. Several recent papers have drawn attention to a possible link between low bone mineral density (BMD) and periodontitis in postmenopausal women. Since the pathogenesis for both involve bone remodeling, they might share common risk factors such as gene polymorphisms and vitamin D level. The present study investigated possible associations between the PPARgPro12Ala polymorphism, periodontitis, BMD and serum 25(OH)D in postmenopausal Japanese women. MATERIALS AND METHODS PPARgPro12Ala genotypes of 359 women were determined by PCR-RFLP. BMD and periodontal parameters of each woman were measured. Serum 25(OH)D levels were determined by radioimmunoassay. RESULTS PPARgPro12Ala polymorphism was not associated with periodontitis or BMD as an independent factor. Serum 25(OH)D was significantly higher in Ala allele carriers compared to non-carriers. Only in the Ala allele carriers, positive correlations were found between mean clinical attachment level and BMD, between BMD and 25(OH)D, and between percentage of sites with probing depth ≥ 4 mm and 25(OH)D. CONCLUSIONS PPARgPro12Ala polymorphism was not independently associated with periodontitis or BMD. However, the polymorphism might be a modulator of the relationship between the two conditions in postmenopausal Japanese women.