Prevalence of periodontopathic bacteria in aggressive periodontitis patients in a Chilean population

BACKGROUND: Actinobacillus actinomycetemcomitans is considered a major etiologic agent of aggressive periodontitis (AgP). Other periodontopathic bacteria such as Porphyromonas gingivalis are also suspected of participating in aggressive periodontitis although the evidence to support this is controversial. The aim of the present study was to determine the prevalence of eight periodontopathic bacteria in Chilean patients with AgP. METHODS: Subgingival plaque samples were collected from 36 aggressive, 30 localized, and six generalized periodontitis patients. Samples from 17 advanced chronic periodontitis (CP) patients were taken as controls. Samples collected from the four deepest periodontal pockets in each patient were pooled in prereduced transport fluid (RTF) and cultured. Periodontal bacteria were primarily identified by colony morphology under stereoscopic microscope and rapid biochemical tests. The identity of some bacterial isolates was confirmed by colony polymerase chain reaction (PCR). RESULTS: AgP showed a significatively higher prevalence of C. rectus than CP (P = 0.036). The only statistical difference found was for C. rectus. Patients with AgP showed a higher, but not statistically significant, prevalence of P. gingivalis, E. corrodens, P. micros, and Capnocytophaga sp. A similar prevalence in both groups of patients was observed for F. nucleatum and P. intermedia/nigrescens, and A. actinomycetemcomitans was less prevalent in AgP than CP patients. In localized AgP, P. intermedia/nigrescens, E. corrodens, F. nucleatum, and P. micros were the more prevalent pathogens in contrast to generalized AgP patients who harbored A. actinomycetemcomitans, P. gingivalis, and Capnocytophaga sp. as the most prevalent bacteria. CONCLUSIONS: C. rectus, P. gingivalis, E. corrodens, P. micros, and Capnocytophaga sp. were the most predominant periodontopathic bacteria of AgP in this Chilean population, but the only statistical difference found here between AgP and CP was for C. rectus, suggesting that the differences in clinical appearance may be caused by factors other than the microbiological composition of the subgingival plaque of these patients. In this study, the prevalence of A. actinomycetemcomitans was much lower than that of P. gingivalis.     

Identification of periodontopathic bacteria in gingival tissue of Japanese periodontitis patients

INTRODUCTION: The identification of invading periodontopathic bacteria in tissues is important to determine their role in the pathogenesis of periodontal disease. The objective of this study was to identify periodontopathic bacteria in diseased gingival tissue of periodontitis patients. METHODS: Subgingival plaque and gingival tissue were collected from 32 generalized chronic periodontitis (CP), 16 generalized aggressive periodontitis (GAgP) and eight localized aggressive periodontitis (LAgP) patients. Detection frequencies and quantities of Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans and Tannerella forsythensis were investigated by polymerase chain reaction. The prevalences of Streptococcus oralis and Streptococcus sobrinus were also examined and the distribution of A. actinomycetemcomitans serotypes was observed. RESULTS: P. gingivalis and T. forsythensis were detected in approximately 70% of tissue samples and 50% of plaque samples in the three periodontitis groups. Prevalence of A. actinomycetemcomitans in tissue samples was higher in the LAgP (63%) group than in either the CP (16%) or the GAgP (38%) group. A. actinomycetemcomitans serotype c was detected in 50% of LAgP patients. Detection frequencies of S. oralis and S. sobrinus were markedly low in both plaque and tissue samples from all three periodontitis groups. Amounts of P. gingivalis, A. actinomycetemcomitans and T. forsythensis in the tissue samples were not different among the three periodontitis groups. CONCLUSION: P. gingivalis, A. actinomycetemcomitans and T. forsythensis can localize in diseased gingival tissue and may be involved in periodontal tissue destruction. Serotype c is the predominant serotype of A. actinomycetemcomitans in Japanese LAgP patients.     

Quantitative analysis of periodontal pathogens in aggressive periodontitis patients in a Japanese population

The aim of the present study was to clarify the relationship between the relative/absolute numbers of periodontal bacteria and different types of periodontitis. Fifteen patients with localized aggressive periodontitis (LAgP), 25 patients with generalized aggressive periodontitis (GAgP) and 28 patients with chronic periodontitis (CP) were included in this study. Saliva and subgingival plaque samples were collected from all subjects for microbiological analysis. The prevalence and proportions of Actinobacillus actinomycetemcomitans, Tannerella forsythensis, Porphyromonas gingivalis and Treponema denticola were determined by conventional PCR and real-time PCR. The prevalence of A. actinomycetemcomitans in saliva was significantly higher in LAgP patients (46.7%) and GAgP patients (40.0%) than that in CP patients (14.3%). The mean proportion of A. actinomycetemcomitans in LAgP patients (4.42%) was significantly higher than that in GAgP patients (0.59%) and CP patients (0.37%) in saliva. In subgingival plaque, LAgP patients showed a significantly higher mean proportion of T. forsythensis (19.8%) than CP patients (7.45%). In conclusion, A. actinomycetemcomitans was the more predominant periodontopathic bacteria in LAgP than in GAgP and CP. The increased proportion of T. forsythensis might relate to LAgP, in addition to A. actinomycetemcomitans. These results indicate that real-time PCR analysis is useful for the evaluation of the bacterial profiles in different types of periodontitis.     

Herpes viruses and periodontopathic bacteria in early-onset periodontitis

OBJECTIVES: This study examined the occurrence of human herpes viruses and suspected periodontopathic bacteria in early-onset periodontitis patients who experienced progressive disease in at least 2 periodontal sites during the maintenance phase of therapy. MATERIAL AND METHODS: In each of 16 individuals (9 male and 7 female; mean age 33.1+/-2.6 years), subgingival plaque samples were collected from 2 deteriorating and 2 stable periodontitis sites. A nested polymerase chain reaction method determined the presence of human cytomegalovirus (HCMV), Epstein-Barr virus type 1 (EBV-1) and herpes simplex virus (HSV). A 16s rRNA polymerase chain reaction method identified Porphyromonas gingivalis, Dialister pneumosintes, Bacteroides forsythus and Actinobacillus actinomycetemcomitans. RESULTS: HCMV was detected in 59.4% of active and in 12.5% of stable sites (p<0.001), EBV-1 in 43.8% of active and in 12.5 % of stable sites (p=0.01), HSV in 34.5% of active and in 9.4% of stable sites (p=0.03), and co-infection with any of the 3 test herpesviruses in 43.8% of active and in 3.1% of stable sites (p<0.001). P. gingivalis was detected in 71.9% of active and in 37.5% of stable sites (p=0.01), D. pneumosintes in 62.5% of active and in 18.8% of stable sites (p=0.04), co-infection with P. gingivalis and D. pneumosintes in 50% of active and in 0% of stable sites (p<0.001), and co-infection with any 3 or 4 of the test bacteria in 40.6% of active and in 0% of stable sites (p=0.001). All periodontitis sites showing herpesvirus co-infection and all but one site showing P. gingivalis and D. pneumosintes co-infection revealed bleeding upon probing. CONCLUSIONS: HCMV, EBV-1, HSV and herpesvirus co-infection, as well as P. gingivalis, D. pneumosintes and P. gingivalis-D. pneumosintes co-infection were statistically associated with active periodontitis. Herpesviruses are immunosuppressive and may set the stage for overgrowth of subgingival P. gingivalis, D. pneumosintes and other periodontopathic bacteria. Understanding the significance of herpesviruses in human periodontitis may allow for improved diagnosis, more specific therapy and, ultimately, disease prevention.     

Herpesviruses and periodontopathic bacteria in Trisomy 21 periodontitis

BACKGROUND: Little is known about the etiology and pathogenesis of periodontal disease in Trisomy 21 patients. This study determined the occurrence of herpesviruses and putative periodontopathic bacteria in Trisomy 21 periodontitis. METHODS: Nineteen Trisomy 21 patients (17 to 37 years of age) contributed subgingival samples from molar and bicuspid teeth presenting interproximal periodontitis lesions (probing depths, 5 to 8 mm) and from shallow periodontal sites (probing depths, 1 to 3 mm). Samples were obtained at baseline, and at 1 and 4 weeks after subgingival debridement by means of hand instruments and ultrasonic scalers. Epstein-Barr virus type 1 and 2 (EBV-1 and EBV-2), human cytomegalovirus (HCMV), and herpes simplex virus (HSV) were identified by sensitive and specific nested polymerase chain reaction. Putative periodontopathic bacteria were identified by means of non-selective and selective culture. RESULTS: Of 19 Trisomy 21 periodontitis lesions, 6 (32%) were positive for EBV-1, 5 (26%) were positive for HCMV, 3 (16%) were positive for HSV, and 2 (11%) showed viral co-infection. Of 19 shallow periodontal sites, only one revealed HCMV. Prevotella intermedia, Bacteroides forsythus, and Capnocytophaga species were detected in higher proportions in deep than in shallow periodontal pockets (P = 0.02). Subgingival debridement did not reduce genomic herpesvirus presence but caused a decrease in proportions of Porphyromonas gingivalis and Capnocytophaga species. CONCLUSIONS: Periodontal herpesvirus-bacteria coinfections may play important roles in the pathogenesis of destructive periodontal disease in Trisomy 21 patients. Herpesviruses may reduce the periodontal defense and promote growth of subgingival bacteria capable of causing periodontal breakdown.     

Prevalence of human herpesviruses in patients with aggressive periodontitis

BACKGROUND: Recent studies have demonstrated that various human viruses, especially cytomegalovirus (HCMV) and Epstein-Barr virus type-1 (EBV-1), seem to play a part in the pathogenesis of human periodontitis. The aim of this investigation was to evaluate the subgingival presence of HCMV and EBV in patients with aggressive periodontitis (AgP) and healthy subjects and to examine the effect of treatment on the incidence of these viruses 3 months following surgery. METHODS: A polymerase chain reaction (PCR) method determined the presence of HCMV and EBV-1. Subgingival plaque samples from 17 consecutive AgP patients and 16 healthy controls were collected. The following indices were measured: plaque index (PI), gingival index (GI), probing depths (PD), and clinical attachment loss (CAL). Clinical parameters were assessed pretherapy and at 3 months following surgical and antimicrobial therapy. RESULTS: HCMV was detected in 64.7% of AgP patients but not detected in healthy subjects (P < 0.001) and EBV-1 in 70.6% of AgP patients and 6.3% of the healthy controls (P < 0.001). HCMV and EBV-1 coinfection was detected in 41.7% of AgP patients. A statistically significant decrease was found in all clinical parameters 3 months after treatment. There was a statistically significant decrease in HCMV and EBV-1 following therapy (P < 0.001; no HCMV; 1 patient with EBV-1). CONCLUSIONS: These findings indicate that subgingival presence of EBV-1 HCMV is strongly associated with aggressive periodontitis, and coinfection with HCMV and EBV-1 appears to be particularly deleterious to periodontal health.     

Suspected periodontopathic bacteria associated with brokenmouth periodontitis in sheep

Sheep from a broken-mouth periodontitis-affected farm were classified into three groups according to degree of severity of periodontal destruction. Subgingival plaque samples were collected from 10 animals in each group, as well as from 10 sheep from a periodontitis-free farm, and were plated anaerobically onto a variety of selective and non-selective media. Results show that several different suspected periodontopathic microorganisms commonly associated with human periodontitis are also present in the plaque of sheep. Black-pigmented Bacteroides were associated with the severely-affected category but there were no significant differences between less severely-affected groups and healthy animals. This suggests either that sampling may not have coincided with periods of activity in these sheep or that other bacteria may be involved in the initiation of the disease. Type II Fusobacterium nucleatum was associated with all disease categories when compared to healthy animals.     

Relationship of periodontopathic bacteria with early-onset periodontitis in Down's syndrome

BACKGROUND: Down's syndrome (DS) patients often develop severe early-onset marginal periodontitis in early adulthood; however, there is little information available on the microbiology of DS periodontitis. METHODS: Subgingival plaque specimens were taken from 67 DS young adults and 41 age-matched systemically healthy individuals with mental disabilities (MD). The prevalence of 10 possible periodontopathic bacterial species, Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Bacteroides forsythus, Treponema denticola, Prevotella intermedia, Prevotella nigrescens, Capnocytophaga ochracea, Capnocytophaga sputigena, Campylobacter rectus, and Eikenella corrodens, were investigated in their subgingival plaque samples using a polymerase chain reaction method. The detection of P. gingivalis fimA genotypes was also performed in P. gingivalis-positive samples. RESULTS: Although DS subjects generally develop an earlier and more extensive periodontal breakdown than those with MD, no significant differences were observed in the bacterial profiles. The profiles of subjects with periodontitis were significant in DS, but not in MD. The prevalence of P. gingivalis, B. forsythus, and P. intermedia were significant in the DS periodontitis group, compared to DS gingivitis group. Moreover, the occurrence of P. gingivalis with the type II fimA gene was significantly related to periodontitis in both DS and MD, with odds ratios of 6.32 and 12.03, respectively. CONCLUSIONS: These results suggest that early-onset periodontitis in DS is mainly due to the more susceptible host for the causative microbial agents including P. gingivalis with type II fimA.     

Detection of periodontopathic bacteria and an oxidative stress marker in saliva from periodontitis patients

We assessed the salivary levels of periodontopathic bacteria and 8-hydroxydeoxyguanosine (8-OHdG) in patients with periodontitis. The salivary levels of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Tannerella forsythia (formerly Bacteroides forsythus) were assessed using real-time polymerase chain reaction. The 8-OHdG levels were determined using an enzyme-linked immunosorbent assay. The salivary levels of 8-OHdG, P. gingivalis, and T. forsythia in the periodontitis patients were significantly higher than those in healthy subjects. By contrast, the A. actinomycetemcomitans level in healthy subjects was higher than that in periodontitis patients. 8-OHdG was significantly correlated with P. gingivalis. Statistically significant decreases in the levels of P. gingivalis, probing depth, bleeding on probing, and 8-OHdG were observed after initial periodontal treatment. These results suggest that the 8-OHdG levels in saliva reflect the load of periodontal pathogens. 8-OHdG could be a useful biomarker for assessing periodontal status accurately, and for evaluating the efficacy of periodontal treatment.     

侵袭性牙周炎病原微生物的检测

目的检测侵袭性牙周炎（AgP）患者和牙周健康者龈下菌斑中的7种病原微生物,旨在寻找AgP的主要致病微生物.方法应用以16S rRNA为基础的聚合酶链反应（PCR）技术,检测55例AgP患者和17名健康对照者龈下菌斑中的7种牙周病原微生物：伴放线放线杆菌（Aa）,牙龈卟啉单胞菌（Pg）,福赛坦氏菌（Tf）,牙密螺旋体（Td）,直肠弯曲杆菌（Cr）,中间普氏菌（Pi）,变黑普氏菌（Pn）.结果55例AgP患者中仅有1例检测出Aa,而在健康对照者中未检出该菌.Pg、Tf、Td和Cr在AgP组的检出率分别为81.8%、83.6%、80.0%和81.8%,显著高于健康对照者（17.6%、11.8%、5.9%、29.4%）,差异有统计学意义（P＜0.01）.结论Pd、Tf、Td和Cr 4种微生物在AgP患者中有较高的检出率,提示它们的共同定植可能在AgP中起重要作用.     

Relationship between herpesviruses and adult periodontitis and periodontopathic bacteria.

BACKGROUND: Various mammalian viruses and specific bacteria seem to play important roles in the pathogenesis of human periodontitis. This study examined the relationship between subgingival herpesviruses and periodontal disease and potential periodontopathic bacteria in 140 adults exhibiting either periodontitis or gingivitis. METHODS: A nested-polymerase chain reaction (PCR) method determined the presence of Epstein-Barr virus type 1 and type 2 (EBV-1, EBV-2), human cytomegalovirus (HCMV), and herpes simplex virus (HSV) and a 16S rRNA PCR detection method identified Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Bacteroides forsythus, Prevotella intermedia, Prevotella nigrescens, and Treponema denticola. RESULTS: Using a logistic analysis, EBV-1 showed significant positive association with P. gingivalis (odds ratio [OR] 3.37), and with coinfections of P. gingivalis and P. intermedia (OR 4.03); P. gingivalis and B. forsythus (OR 3.84); P. gingivalis and T. denticola (OR 4.17); P. gingivalis, B. forsythus, and T. denticola (OR 4.06); and P. gingivalis, P. nigrescens, and T. denticola (OR 3.29). EBV-1 also showed positive association with severe periodontitis (OR 5.09), with increasing age (OR 1.03), and with periodontal probing depth at the sample sites (OR 1.77). HCMV was positively associated with coinfections of P. gingivalis and P. nigrescens (OR 3.23); P. gingivalis, B. forsythus, and P. nigrescens (OR 3.23); and P. gingivalis, P. nigrescens, and T. denticola (OR 2.59); with severe periodontitis (OR 4.65); and with age (OR 1.03). Patients with mixed viral infections revealed significant associations with P. gingivalis (OR 2.27), and with coinfections of P. gingivalis and B. forsythus (OR 2.06); P. gingivalis and P. nigrescens (OR 2.91); P. gingivalis, B. forsythus, and P. nigrescens (OR 2.91); and P. gingivalis, P. nigrescens, and T. denticola (OR 2.70) with the clinical diagnosis of slight (OR 3.73), moderate (OR 3.82), or severe periodontitis (OR 4.36), and with probing depth at the sample sites (OR 1.39). HSV and EBV-2 showed no significant associations with any of the variables tested. CONCLUSIONS: The results indicate that subgingival EBV-1, HCMV, and viral coinfections are associated with the subgingival presence of some periodontal pathogens and periodontitis. Herpesviruses may exert periodontopathic potential by decreasing the host resistance against subgingival colonization and multiplication of periodontal pathogens.     

Prevalence of Aggregatibacter actinomycetemcomitans in Sudanese patients with aggressive periodontitis: a case-control study

Elamin A, Albandar JM, Poulsen K, Ali RW, Bakken V. Prevalence ofAggregatibacter actinomycetemcomitansin Sudanese patients with aggressive periodontitis: a case–control study. J Periodont Res 2011; 46: 285–291.©2011 John Wiley & Sons A/S Background and Objective: Aggregatibacter actinomycetemcomitans is considered a possible etiological agent for aggressive periodontitis. The aim of this study was to determine the prevalence of the JP2 clone and non‐JP2 genotypes of A. actinomycetemcomitans in the subgingival plaque of patients with aggressive periodontitis and controls among Sudanese high‐school students. Material and Methods: In a previous study we examined a large representative sample of students attending high schools in Khartoum, Sudan. In this population, 17 patients with aggressive periodontitis and 17 controls (14–19 years of age) consented to participate in the present study. The subjects underwent a clinical periodontal examination, and subgingival dental plaque samples were collected using paper points. The presence of the A. actinomycetemcomitans JP2 clone and non‐JP2 genotypes were assessed using loop‐mediated isothermal amplification (LAMP) and the PCR. Results: The JP2 clone of A. actinomycetemcomitans was not detected in the subgingival plaque of either the cases or the controls. Non‐JP2 types of A. actinomycetemcomitans were detected in the subgingival plaque of 12 (70.6%) patients with aggressive periodontitis and from only one (5.9%) control subject, showing a significantly higher frequency of detection in cases than in controls (p = 0.0001). The odds ratio for the detection of A. actinomycetemcomitans in the subgingival plaque of the patients with aggressive periodontitis was 38.4 (95% confidence interval: 4.0–373.0; p = 0.002). The PCR and LAMP methods showed identical results pertaining to the identification of non‐JP2 types of A. actinomycetemcomitans. Conclusions: The JP2 clone of A. actinomycetemcomitans was not detected in the subgingival plaque of high school subjects in Sudan. The detection of non‐JP2 types of A. actinomycetemcomitans may be a useful marker of increased risk for development of aggressive periodontitis in young subjects.     

Prevalence of Actinobacillus actinomycetemcomitans serotypes in Japanese patients with periodontitis

Oral Actinobacillus actinomycetemcomitans strains are serologically classified into 5 distinct groups, a to e. We examined the distribution of A. actinomycetemcomitans serotypes in Japanese patients with periodontitis. A total of 157 A. actinomycetemcomitans clinical isolates from diseased sites of 39 patients with periodontitis were serotyped by using serotype-specific rabbit antisera against. A. actinomycetemcomitans serotypes a, b, c, d and e strains. In the immunodiffusion assay, autoclaved extracts of 42, 6, 39, 9 and 41 A. actinomycetemcomitans clinical isolates reacted with serotypes a, b, c, d and e antisera, respectively. Although 37 patients were infected with a serotype strain, 2 patients harbored 2 different serotype strains, b/e and b/untypeable. To establish a correlation between serotype and genotype of A. actinomycetemcomitans clinical isolates from 2 patients who had different serotype strains, we used arbitrarily primed polymerase chain reaction (AP-PCR) to fingerprint clinical isolates of different serotypes. The AP-PCR genotype among 4 clinical isolates (b/e and b/untypeable) were identical to that of A. actinomycetecomitans Y4 (serotype b), indicating the presence of multiple A. actinomycetemcomitans serotypes which are genetically homogenous in the periodontally diseased sites of patients with periodontitis.     

Prevalence of juvenile periodontitis in a circumpubertal population

A cross-sectional radiographic screening was performed on bite-wing pairs (BW) from 1872 10-12 year old schoolchildren in the Greater Worcester, Massachusetts area to assess the prevalence of juvenile periodontitis (JP). The 3-stage screening process entailed: (1) visual identification of possible cases based upon a visual assessment of BW for interproximal crestal bone levels greater than or equal to 2 mm from the cemento-enamel junction (CEJ) on greater than or equal to 1 permanent first molar; (2) identification of probable cases based upon BW from possible cases measured with a transparent ruler calibrated in millimeters; (3) finally, clinical confirmation of JP in consenting probable cases. A total of 1038 subjects were eligible to be included in the study (greater than or equal to 3 mesial sites readable). Of the 1038 eligible subjects, 117 possible and 103 probable cases were identified in stage 1 and stage 2, respectively. A total of 99 probable cases could be contacted and 43 were examined clinically. Two cases of JP were confirmed clinically in stage 3, yielding a prevalence rate of 4.6/1000. Specifically, this report defines a rate of JP in 10-12 year-old schoolchildren for the first time. In addition, these results indicate that BW can be used to identify children with JP from large data sets. However, further studies including complete clinical and radiographic examinations are necessary to determine whether this method is adequate for large epidemiologic studies.     

Prevalence of aggressive periodontitis in school attendees in Uganda

AIM: The prevalence and severity of early onset periodontitis (EOP) among students attending secondary schools in two regions of Uganda was studied. MATERIAL AND METHODS: 690 students (393 males and 297 females) aged 12-25 years (mean 17 years), representing a range of tribal groups, were recruited from six schools in the peri-urban Central and rural Western regions of Uganda. The study subjects were clinically examined in field conditions by a single calibrated examiner to measure gingival recession and probing depth at six sites per tooth, with subsequent calculation of clinical periodontal attachment level for each site. Subjects exhibiting >or= 4 mm of clinical periodontal attachment loss at approximal surfaces of one or more teeth were classified with EOP. A structured written questionnaire obtained demographic characteristics of the study subjects. RESULTS: 199 (28.8%) study subjects showed clinical features of EOP, of which 16 (2.3%) subjects exhibited generalized EOP, 29 (4.2%) localized EOP, and 154 (22.3%) incidental EOP. The percentage of EOP-affected males was significantly higher than females (33.8% vs. 22.2%, P < 0.001). EOP prevalence tended to increase with increasing age, but no association was found between EOP prevalence and socioeconomic status or residency in urban vs. rural areas of Uganda. Molars and mandibular incisors generally demonstrated the highest occurrence of >or= 4 mm attachment loss. Clinical periodontal attachment loss of >or= 5 mm was mainly seen at first molars and incisors, suggesting that these two tooth types are first affected with attachment loss. Approximal tooth surfaces showed greater probing depth and attachment loss than buccal and lingual surfaces. Gingival recession was most prevalent at mandibular anterior teeth, whereas gingival margin coronal to CEJ was most frequently observed at second molars and maxillary incisors. CONCLUSION: A relatively high prevalence of EOP (28.8%) was found in young Ugandan school attendees, with 6.5% of these showing severe disease. EOP in Uganda was significantly more prevalent in males than females, and most frequently characterized by approximal involvement of molars and mandibular incisors. Etiologic and predisposing factors associated with the high occurrence of EOP in Uganda, as well as therapeutic and preventive measures of the disease in this population, remain to be delineated.     

Interleukin-4 gene polymorphisms in Japanese and Caucasian patients with aggressive periodontitis

OBJECTIVES: Recently, interleukin (IL) 4 gene polymorphisms have been analyzed in association with periodontitis. Genetic differences between Caucasian and Japanese patients with periodontitis have previously been detected. The aim of the present study was to analyze IL-4 genotypes in Caucasian and Japanese patients with aggressive periodontitis (AgP). MATERIAL AND METHODS: One hundred and twenty-four subjects were included in the study, 31 Japanese and 30 Caucasian patients with generalized AgP, plus 30 Japanese and 33 Caucasian healthy controls. IL-4 polymorphisms were determined by polymerase chain reaction. A logistic regression was used to investigate the possible association of the genotypes with the disease in both populations. Odds ratio (OR) estimates were analyzed for allele frequencies. RESULTS: No significant association of IL-4 polymorphisms with the risk of AgP was determined in either population. However, the allele frequencies showed different results between populations. The carriage of the polymorphism in intron 2 was higher in Caucasian patients compared with controls (OR: 2.0, 95% confidence interval: [1.0;4.2]. Furthermore, the frequency of the IL-4 promoter/intron 2 composite genotype (PP+/IP+) in patients and controls, respectively, was found to be approximately 25% and 60% higher in the Japanese population than in the Caucasian population. CONCLUSION: There was no evidence of an association of IL-4 genotypes and AgP in either population, although the frequencies of the IL-4 genotypes in the Japanese and the Caucasians were different.