Suppression of subgingival Actinobacillus actinomycetemcomitans in localized juvenile periodontitis by systemic tetracycline

Abstract The current study assessed the clinical and microbiological effects of systemic antimicrobial therapy alone in Actinobacillus actinomycetemcomitans-infected adolescents with periodontal disease. The study involved 6 localized juvenile periodontitis patients 13–18 years of age, who harbored high numbers of A. actinomycetemcomitans: in subgingival plaque samples. The periodontal lesions were microbiologically monitored by selective culture, and clinically assessed for probing pocket depth and periodontal attachment level 3 months prior to baseline, and at 3, 6, 12, and 24 months posttreatment. Tetracycline-HCl (250 mg/ QID) was prescribed until 1 week after subgingival A. actinomycetemcomitans was no longer detectable or for a maximum of 8 weeks. During 3 months prior to treatment, pocket depth was unchanged, and was then significantly reduced from an average of 7.1 mm to 5.1 mm 12 months after treatment (p - 0.02). The mean change in clinical attachment level was a gain of 1.4 mm between baseline and 12 months (p= 0.02). 3 of the 6 patients were still infected with A. actinomycetemcomitans after 8 weeks of antibiotic therapy and 4 subjects were infected at 12 months. Numbers of A. actinomycetemcomitans were still suppressed in most lesions. There was a strong association between mean numbers of A. actinomycetemcomitans in periodontal pockets and mean change in probing attachment level at any given time point. For 22 available comparisons, derived from all time points, there was a strong association (r= 0.68) between subgingival A. actinomycetemcomitans and change in probing attachment level. 8 of 9 (89%; sensitivity) individual patient time intervals with “disease” (< 1.5 mm gain in probing attachment level) were tested positive (≥ 100 CFUJ, whereas 9 of 13 (69%; specificity) individual patient time intervals with “no disease” (≥ 1.5 mm gain in probing attachment level) were A. actinomycetemcomitans negative (< 100 CPU) (p= 0.007).     

Microbiological and clinical effects of surgical treatment of localized juvenile periodontitis

Since Actinobacillus actinomycetemcomitans appears to be a key etiologic agent in localized juvenile periodontitis, this study determined the effectiveness of different treatment modalities in suppressing A. actinomycetemcomitans in localized juvenile periodontitis lesions. A total of 25 deep periodontal lesions from 7 patients with localized juvenile periodontitis were included in the study. The test periodontal lesions either received scaling and root planing alone, scaling and root planing together with soft tissue curettage, or modified Widman flap surgery. Subgingival A. actinomycetemcomitans were enumerated using selective culturing. Clinical measurements included changes in probing periodontal attachment level, probing periodontal pocket depth, gingival index, plaque index, and digital subtraction of standardized serial radiographs. The microbiological and clinical effects of treatment were monitored over a period of 16 weeks. All periodontal lesions studied demonstrated high numbers of A. actinomycetemcomitans prior to treatment. Scaling and root planing alone did not markedly change the subgingival A. actinomycetemcomitans counts, nor any of the clinical parameters studied. In contrast, soft tissue curettage as well as modified Widman flap surgery suppressed A. actinomycetemcomitans to undetectable levels immediately after therapy in more than 80% of the lesions studied. A total of 5 periodontal lesions exhibited gain of probing periodontal attachment after subgingival curettage or Widman flap treatment; 3 of these sites revealed no detectable A. actinomycetemcomitans, and the remaining 2 sites harbored only low levels of A. actinomycetemcomitans. 5 periodontal lesions which lost probing attachment after treatment all demonstrated high numbers of subgingival A. actinomycetemcomitans. Changes in alveolar bone, assessed by digital subtraction of serial radiographs, correlated with changes in probing periodontal attachment level, confirming the clinical results. The present study revealed a close relationship between post-treatment A. actinomycetemcomitans levels and the clinical response to treatment, which supports the concept that A. actinomycetemcomitans is an important organism in the etiology of localized juvenile periodontitis. This study also showed that a substantial suppression of subgingival A. actinomycetemcomitans cannot be achieved by periodontal scaling and root planing alone, but can be accomplished by surgical removal of periodontal tissues.(ABSTRACT TRUNCATED AT 400 WORDS)     

Probe-specific DNA fingerprinting applied to the epidemiology of localized juvenile periodontitis

Although Actinobacillus actinomycetemcomitans has been recognized as a primary etiological agent in localized juvenile periodontitis, questions remain concerning the source of infection, mode of transmission, and relative virulence of strains. DNA fingerprinting analysis, using a randomly cloned chromosomal DNA fragment as a probe, revealed that previously characterized strains of A. actinomycetemcomitans displayed significant restriction site heterogeneity which could be applied to the typing of clinical isolates of this bacterium such that individual strains or variants could be traced within subjects from localized juvenile periodontitis families. Hybridization data derived from an analysis of bacterial isolates obtained from families participating in an ongoing longitudinal study of the disease showed that a single individual could be infected with more than one strain or variant of A. actinomycetemcomitans and that various members of the same family could harbor different strains or variants of the bacterium. In several cases the clinical isolates were matched to characterized laboratory strains by comparing hybridization patterns generated by digestion of the DNA with several restriction enzymes in independent reactions. Thus, probe-specific DNA fingerprinting of A. actinomycetemcomitans will permit us to determine if particular strains or variants are frequently associated with sites of periodontal destruction. Attention could then be focused on determining the virulence properties of those strains or variants that have in vivo significance.     

Metronidazole in the treatment of localized juvenile periodontitis

Abstract Systemic metronidazole and tetracycline were compared as adjunctive agents in the treatment of localized juvenile periodontitis (LJP). 27 patients with Actinobacillus actinomycetemcomitans-positive (Aa) LJP were treated with scaling and rootplaning, control of oral hygiene and periodontal surgery if indicated. The patients were randomly divided into 3 equal groups: the 1st group had metronidazole 200 mg × 3 × 10 days, the 2nd tetracycline 250 mg × 4 × 12 days, the 3rd group received no medication and served as a control. 6 patients had periodontal surgery. 4 sites with the most advanced bone loss as determined on radiographs were selected in each subject for test sites. Gingival index, gingival bleeding after probing (GB), probing depth (PD), suppuration, and radiographic bone loss were registered, and subgingival Aa was selectively cultured. GB and PD>4 mm were registered in the whole dentition as well. All parameters were monitored at baseline and at 6 and 18 months after treatment. By the end of the study, Aa was suppressed to below detection level at all test sites only in the metronidazole group, at 17/26 sites (4 patients) in the tetracycline group and at 19/26 sites (6 patients) in the control group. Clinically, all groups showed improvement. In conclusion, metronidazole was more effective than tetracycline in the suppression of Aa and the suppression of Aa appeared to produce better clinical results.     

Bacteriological study of juvenile periodontitis in China

The predominant cultivable bacteria associated with juvenile periodontitis (JP) in China were studied for the first time. Subgingival plaque samples were taken on paper points from 23 diseased sites in 15 JP patients and from 7 healthy sites in 7 control subjects. Serially diluted plaque samples were plated on nonselective blood agar and on MGB agar, a selective medium for the isolation of Actinobacillus actinomycetemcomitans. Fifteen or more isolated colonies from each sample (in sequence without selection) were purified for identification. The results indicated that the microflora in healthy sulci of the 7 control subjects was significantly different from that in diseased sites of JP patients. The predominant species in healthy sulci were Streptococcus spp. and Capnocytophaga gingivalis. In JP patients, Eubacterium sp. was found in significantly higher frequency and proportion. Actinobacillus actinomycetemcomitans was not detected in any samples. It appears that this species is not associated with juvenile periodontitis in China.     

Opsonic IgG antibody against Actinobacillus actinomycetemcomitans in localized juvenile periodontitis

Actinobacillus actinomycetemcomitans is a gram-negative bacterium frequently recovered from periodontal lesions of patients with localized juvenile periodontitis (LJP). Elevated levels of serum IgG and IgM antibodies to A. actinomycetemcomitans antigens are frequently observed in LJP patients, although the functional properties of such antibodies have not been characterized systematically. In this study, we analyzed serum from LJP subjects infected with A. actinomycetemcomitans with respect to the presence of IgG antibodies expressing opsonic, bactericidal and/or leukotoxin-neutralizing activity against this organism. The IgG fractions obtained from serum of 3 LJP patients with elevated antibody titers to A. actinomycetemcomitans contained opsonic activity against a non-leukotoxic Y4 strain, as well as for a highly leukotoxic JP2 strain. Opsonic activity required the presence of complement. The IgG fractions of pooled normal serum and serum from a fourth LJP subject with minimal ELISA-reactive IgG antibody against this organism lacked detectable opsonic activity. Leukotoxin-neutralizing IgG antibodies, although variably present, did not influence neutrophil killing of the leukotoxic JP2 strain. None of the sera tested contained bactericidal IgG antibodies capable of promoting direct complement-mediated killing of A. actinomycetemcomitans. These results indicate that LJP subjects infected with A. actinomycetemcomitans are capable of producing opsonic IgG antibodies which may facilitate neutrophil-mediated host defense against this periodontopathic organism.     

Analysis of data from clinical studies of localized juvenile periodontitis

Data from 27 subjects with localized juvenile periodontitis were used to compute estimates of the intraclass correlation coefficient for initial periodontal pocket depth measurements and total subgingival Actinobacillus actinomycetemcomitans counts, and for changes from pre- to post-treatment in periodontal pocket depth, probing attachment level and Actinobacillus actinomycetemcomitans counts. The estimates for the clinical parameters were considerably higher than those found in a similar study of adult periodontitis. On the average, the estimates for the intraclass correlation coefficients for Actinobacillus actinomycetemcomitans counts did not differ markedly from the corresponding estimates for the clinical parameters. Although the results of this study indicate that the major component of variability in parameters commonly used in studies of periodontal disease can be attributed to site-specific factors, sites within subjects cannot be considered statistically independent. For the analysis of data arising from studies of periodontal disease, it is recommended that statistical techniques, like the nested mixed effects analysis of variance model be employed, which account for this dependence. These techniques will allow meaningful biological questions concerning site-specific phenomenon to be answered. However, changes in clinical and microbiological parameters, when therapeutic measures are employed on localized juvenile periodontitis patients, are often dramatic enough to allow informal data presentation.     

Quantitative aspects of the subgingival distribution of Actinobacillus actinomycetemcomitans in a patient with localized juvenile periodontitis

Abstract The subgingival microflora in a patient with localized juvenile periodontitis was studied. Of the 97 sites investigated, 28 (29%) showed attachment loss. A correlation was found between the number of Actinobacillus actinomycetemcomitans cells and the clinical attachment level and probing pocket depth. Of the 97 test sites, 70 (73%) were positive for A. actinomycetemcomitans. Of the total number of A. actinomycetemcomitans cells isolated from this patient, more than 99% were found at sites with attachment loss, <1 % being present at sites without attachment loss. The mean percentage of A. actinomycetemcomitans was 21.2% at sites with attachment loss and 0.45% at sites without attachment loss. The distribution of Porphyromonas gingilis showed a symmetrical pattern, being present at the 1st molar and 2nd premolar sites in all quadrants and at the lower incisor sites. This species was absent at multiple sites showing overt attachment loss.     

Antigenic components of Actinobacillus actinomycetemcomitans lipopolysaccharide recognized by sera from patients with localized juvenile periodontitis

The dominant antigen of Actinobacillus actinomycetemcomitans recognized by high-titer sera from patients with localized juvenile periodontitis is the serotype antigen located in the O-side chains of lipopolysaccharide. Whether such sera contain antibodies reactive with other epitopes in lipopolysaccharide, as is the case for patients with rapidly progressive periodontitis, remains unknown. We prepared and characterized by gas liquid chromatography lipopolysaccharide, lipid A, core carbohydrate with no or few O-side chains (core) and high-molecular-mass carbohydrate-rich in O-side chains (oligosaccharide) from A. actinomyce-temcomitans ATCC 43718 (serotype b, Y4). Using enzyme-linked immunosorbent assay (ELISA), sera from 36 patients with localized juvenile periodontitis were surveyed using whole-cell sonicate as plate antigen. The seven highest titer sera were selected for further study. Specific IgG antibody binding was observed to intact lipopolysaccharide and to all the lipopolysaccharide fractions. The mean titers were highest for intact lipopolysaccharide (138.8 ELISA units), and lipid A (122 ELISA units), followed by the core fraction (81 ELISA units) and the oligosaccharide fraction (69.5 ELISA units). ELISA inhibition revealed that the core fraction at a concentration of 10 micrograms/test well inhibited antibody binding to A. actinomycetemcomitans lipopolysaccharide by a mean value of 56.7%. To further characterize antibody binding to the core fraction, ELISA inhibition was performed using as inhibitor the core carbohydrate fraction of the Re mutant of Salmonella minnesota, which is known to contain only alpha-keto-3-deoxyoctonate residues and phosphate. This fraction at 10 micrograms/test well inhibited binding of antibodies from 6 of 7 test sera with a mean value of 49.2%. Thus, sera from patients with localized juvenile periodontitis contain antibodies that bind to the O-side chains of lipopolysaccharide, as has been previously reported, but they also contain antibodies that bind to lipid A and to lipopolysaccharide core polysaccharide epitopes, specifically to alpha-keto-3-deoxyoctonate moieties. The humoral immune response to A. actinomycetemcomitans in patients with localized juvenile periodontitis is more complex than previously reported and is very similar to that of patients with rapidly progressive periodontitis.     

Collagenase activity in gingival crevicular fluid of patients with juvenile periodontitis

The nature and origin of collagenases in gingival crevicular fluid of juvenile periodontitis patients was investigated. Gingival crevicular fluid collected from deep untreated periodontal pockets of juvenile periodontitis patients was found to contain only vertebrate collagenase (EC 3.4.24.7) activity that cleaved soluble type-I and -III collagens into 3/4 and 1/4 length fragments, as analyzed by SDS-polyacrylamide gel electrophoresis. Type II collagen was degraded at a markedly slower rate. This substrate specificity is indicative of collagenases produced by fibroblasts, epithelial cells and macrophages. We have previously found that collagenase in gingival crevicular fluid of adult periodontics patients appears to be mainly derived from polymorphonuclear leukocytes (PMN). The reasons for the apparent difference in collagenase source between the groups were investigated. We examined whether the pathogen characteristic for juvenile periodontitis, Actinobacillus actinomycetemcomitans, can release collagenase from normal human PMNs. All 10 A. actinomycetemcomitans strains tested, freshly isolated from the subgingival plaque of juvenile periodontitis patients, caused release of collagenase from PMNs in vitro. These results suggest that the lack of normally functioning PMNs in the periodontium of juvenile periodontitis patients may result in a colonization of bacteria that activate the resident periodontal cells to produce increased amounts of collagenase.     

T-cell-receptor gene usage of Actinobacillus actinomycetemcomitans-reactive periodontal CD4+ T cells from localized juvenile periodontitis patients and human peripheral blood leukocyte-reconstituted NOD/SCID mice

We investigated the variable Valpha and Vbeta gene usage of Actinobacillus actinomycetemcomitans-reactive periodontal CD4+ T cell receptors (TCR) from: (i) four A. actinomycetemcomitans-infected localized juvenile periodontitis (LJP) patients, (ii) four groups of A. actinomycetemcomitans-inoculated NOD/SCID mice engrafted with individual LJP-derived HuPBL and (iii) HuPBL samples of four LJP patients and two healthy control subjects, by quantitative PCR analyses. The results show that: (i) the majority of the TCR genes (82.5% of Valpha and 91.1% of Vbeta) used by periodontal CD4+ T cells in A. actinomycetemcomitans-inoculated HuPBL-engrafted NOD/SCID mice overlap with those used by local periodontal T cells in LJP patients, (ii) although A. actinomycetemcomitans-reactive periodontal CD4+ TCR repertoire is relatively widespread, there are a few dominant genes shared by the LJP patients, suggesting a limited number of antigens or epitopes commonly recognized and (iii) A. actinomycetemcomitans likely lacks superantigenic characteristics. These results suggest A. actinomycetemcomitans-associated human CD4+ T cell repertoire established in HuPBL-NOD/SCID mice provides a useful approach to study specific aspects of immune-parasite interactions in the periodontium.     

The description of a unique population with a very high prevelance of localized juvenile periodontitis

Abstract. The reported prevalence of localized juvenile periodontitis (LJP) amongst teenagers and young adults varies greatly. The etiology of LJP has been related to Actnobacillus actinomy cetemcomitans Aa$ and it has also been suggested that there may be a transmission of Aa within families resulting in the familial distribution of the disease. This study describes the high prevalence of LJP in adolescents, 12–20 years of age, from a group of nuclear families living and functioning in a closed, closely knit community. The survey was carried out on a population of teenagers that had attended the same school and their siblings. All students attending that school and their siblings were examined. They were given a periodontal examination and a questionnaire relating to their demographic details and their personal oral hygiene habits. The periodontal examination was limited to the incisors and first molar teeth. Plaque index (PII), gingival index (GI), the presence or absence of bleeding on probing (BOP), probing pocket depth (PPD) and recession ere measured. All patients having at least two of the examined sites with probing pocket depth ≥5 mm or one site ≥6 mm were considered as possible sufferers from LJP and had a full mouth periapieal radiographic survey carried out using a paralleling technique to confirm the diagnosis. At the sites with probing pocket depth ≥5 mm, a Shei ruler was used to measure the $$ of the root coronal to the alveolar bone. A cut off point of ≥20mm was used as a measure of true bone loss confirming the clinical diagnosis of LJP 86 individuals from 30 families comprised the population of interest There were 44 males and 42 females with a mean age of 14.7±2.3. Of the 86 individuals examined, 33 individuals from 15 families were diagnosed as having LJP (38.4%). None of the individuals examined showed any evidence of the generalized form of juvenile periodontitis. The mean age of the LJP patients was 15±23 yrs. with a 1:1.75 male to female ratio. Except for 2 pairs of families with genetic tics, no familial connections could be traced between the different nuclear families affected by LJP despite repeated and intensive questioning. There were no significant differences in the PII and the GI between the groups while the LJP group had significantly higher BOP. PPD and PAL than the non-LJP group. These finding strongly suggest an environmental influence in the etiologu of the disease.     

Serum immunoglobulin G responses to various Actinobacillus actinomycetemcomitans serotypesinayoung ethnographically heterogeneous periodontitis patient group

Sera from young patients with periodontal diseases have been shown to often contain highly elevated antibody levels to Actinobacillus actinomycetemcomitans. in particular serotype b. Such responses were reportedly predominated by antibodies of the immunoglobulin G2 (IgG2) subclass. The aim of this study was to investigate an ethnically diverse group of 14 early-onset periodontitis and 15 rapidly progressive periodontitis patients for the occurrence of elevated antibody titers against the five known A. actinomycetemcomitans serotypes, and to compare the patient's IgG subclass response profiles. Enzyme-linked immunosorbent assays were used to measure both total IgG and subclass specific IgG titers. Twenty-four subjects had markedly elevated total IgG levels against at least one serotype. The frequencies of high responses against serotypes a, b, c, d and e were 7, 11, 6, 4, and 4, respectively. Elevated antibody responses were predominated by IgG2, regardless of the serotype to which the response was directed. The serotype specificity of the host responses was further investigated by competitive binding studies with serotype-specific monoclonal antibodies. Twelve sera were found to contain antibodies capable to strongly inhibit the binding of monoclonal antibodies against a single serotype; four other sera had antibodies against epitopes of two, and one serum against those of three serotypes. The findings document broad serotype diversity in an ethnically heterogeneous group of patients and indicate that strong antibody responses to A. actinomycetemcomitans are predominated by IgG2 regardless of the serotype of the infective agent.     

Long‐term follow‐up of successful orthodontic‐periodontal treatment of localized aggressive periodontitis: a case report

This report describes a case of localized aggressive periodontitis (localized juvenile periodontitis) that was jointly treated with conventional periodontal therapy, selective extractions to eliminate localized areas of vertical bone loss, and orthodontic therapy. A 20‐year follow‐up is described in this report. The success of periodontal treatment in a case such as this depends on making an accurate diagnosis, providing periodontal treatment to control the disease, and providing regular periodontal maintenance during and after orthodontic treatment.     

A case of localized juvenile periodontitis: treatment and 3 years follow-up with superimposable radiographs

Abstract A 17-year-old male patient with localized juvenile periodontitis was treated by subgingival instrumentation with full thickness flap on the lower molars, combined with a 3-week course of systemic tetracycline, and a programme of supervised oral hygiene. The treatment was rapidly followed by dramatic clinical and microbiological improvement. However, despite good oral hygiene, gingival inflammation recurred at regular intervals. It was necessary to maintain the clinical results by periodic subgingival instrumentation with an ultrasonic sealer. Healing of alveolar bone was monitored in the lower 1st molar regions over 3 years by using superimposable radiographs. Quantitative analysis of bone density performed with a high-resolution digitalisation technique showed a considerable improvement 1 year after therapy. However, continuous remodelling, probably related to variations in inflammation, occurred during the 3 postoperative years.     

A retrospective radiographic study of alveolar bone loss in the primary dentition in patients with localized juvenile periodontitis

Lately, it has been questioned whether localized juvenile periodontitis (LJP) is restricted to the permanent dentition, or if it sometimes might have a prepubertal onset, involving the primary dentition. To clarify this question, 17 patients with LJP, together with 17 non-LJP matched controls, were retrospectively examined for radiographic signs of alveolar bone destruction in their primary dentitions. All LJP subjects but one showed localized marginal bone loss, whereas no bone loss was observed among the controls. The results suggest that at least some cases of LJP start in the primary dentition prior to the involvement of the permanent teeth.     

Diacylglycerol in peripheral blood neutrophils from patients with localized juvenile periodontitis

Neutrophils from patients with localized juvenile periodontitis (LJP) show several functional abnormalities. Recently, it has become increasingly apparent that the reason for these changes lies in part at the post receptor level of cellular metabolism. In this study we have analyzed intracellular diacylglycerol (DAG), a second messenger and an endogenous activator of protein kinase C, in un-stimulated and agonist-stimulated neutrophils. from five LJP patients showing a chemotaxis defect and matched normal individuals. No difference was observed in the basal cellular DAG between the two groups. In neutrophils from LJP patients the DAG levels increased by 67% and 111% from the basal level following stimulation with N-formyl-methionyl-leucyl-phenylalanine (FMLP) and unopsonized zymosan particles, respectively, while in control cells the mean increases were 36% and 65%, respectively. Incubation with serum-opsonized zymosan particles produced an identical rise in DAG in both groups. These data indicate that the stimulation of receptors for FMLP and unopsonized zymosan may produce an enhanced accumulation of DAG in neutrophils from LJP patients. In addition to DAG mass analysis, we determined the effect of R59022, a DAG-kinase inhibitor, on zymosan-stimulated luminol-amplified chemiluminescence (CL) of neutrophils. In control cells R59022 significantly enhanced unopsonized zymosan induced CL, but it had no effect on cells from LJP patients, suggesting a possible change in the regulation of DAG-kinase in LJP.     

Increased adhesion of peripheral blood neutrophils from patients with localized juvenile periodontitis

Adhesion of peripheral blood neutrophils from 5 patients with localized juvenile periodontitis (LJP) and age- and gender-matched healthy controls was measured using a semi-automated 96-well microtiter plate assay method. Both unstimulated and formyl-methionyl-leucyl-phenylalanine (FMLP, 10–1000 nM)-stimulated neutrophils from LJP patients showed in general higher adhesion than did their controls. After 15–60 min incubation with 100 and 1000 nM FMLP the numbers of adherent cells were significantly (p<0.05), 2.1–2.6-fold higher in LJP patients than in controls. Neutrophils from these LJP patients showed also enhanced respiratory burst activity in response to unopsonized zymosan stimulation. To test whether a decrease in intracellular diacylglycerol (DAG) kinase activity could account for the increased neutrophil adhesion of LJP patients normal neutrophils were treated with R59949 (10 μM), a DAG-kinase inhibitor. Both unstimulated and FMLP-stimulated normal neutrophiis showed significantly (p<0.05) enhanced adhesion after R59949-treatment. Taken together, our data indicate that neutrophils from the 5 LJP patients investigated here exhibit 2 parallel hyperactivities, namely increased adhesion and enhanced production of reactive oxygen species. Furthermore, our present and previous (Hurttia et al, J Periodont Res 1997; 32: 401-407) results suggest that the observed neutrophil functional abnormalities in some LJP patients may be associated with decreased cellular DAG-kinase activity. It is proposed that the hyperadherent and -active neutrophils may promote the development of LJP by causing tissue damage in the periodontium.     

Increased adhesion of peripheral blood neutrophils from patients with localized juvenile periodontitis

Adhesion of peripheral blood neutrophils from 5 patients with localized juvenile periodontitis (LJP) and age- and gender-matched healthy controls was measured using a semi-automated 96-well microtiter plate assay method. Both unstimulated and formyl-methionyl-leucyl-phenylalanine (FMLP, 10-1000 nM)-stimulated neutrophils from LJP patients showed in general higher adhesion than did their controls. After 15-60 min incubation with 100 and 1000 nM FMLP the numbers of adherent cells were significantly (p<0.05), 2.1-2.6-fold higher in LJP patients than in controls. Neutrophils from these LJP patients showed also enhanced respiratory burst activity in response to unopsonized zymosan stimulation. To test whether a decrease in intracellular diacylglycerol (DAG) kinase activity could account for the increased neutrophil adhesion of LJP patients normal neutrophils were treated with R59949 (10 μm), a DAG-kinase inhibitor. Both unstimulated and FMLP-stimulated normal neutrophils showed significantly (p<0.05) enhanced adhesion after R59949-treatment. Taken together, our data indicate that neutrophils from the 5 LJP patients investigated here exhibit 2 parallel hyperactivities, namely increased adhesion and enhanced production of reactive oxygen species. Furthermore, our present and previous (Hurttia et al., J Periodont Res 1997; 32 : 401-407) results suggest that the observed neutrophil functional abnormalities in some LJP patients may be associated with decreased cellular DAG-kinase activity. It is proposed that the hyperadherent and -active neutrophils may promote the development of LJP by causing tissue damage in the periodontium.