Assessment of adenosine deaminase (ADA) activity and oxidative stress in patients with chronic tonsillitis.

To emphasize the effectiveness of adenosine deaminase (ADA) enzyme, which has important roles in the differentiation of lymphoid cells, and oxidative stress in patients with chronic tonsillitis. Serum and tissue samples were obtained from 25 patients who underwent tonsillectomy due to recurrent episodes of acute tonsillitis. In the control group, which also had 25 subjects, only serum samples were taken as obtaining tissue samples would not have been ethically appropriate. ADA enzyme activity, catalase (CAT), carbonic anhydrase (CA), nitric oxide (NO) and malondialdehyde (MDA) were measured in the serum and tissue samples of patients and control group subjects. The serum values of both groups were compared. In addition, the tissue and serum values of patients were compared. Serum ADA activity and the oxidant enzymes MDA and NO values of the patient group were significantly higher than those of the control group (p < 0.001), the antioxidant enzymes CA and CAT values of the patient group were significantly lower than those of the control group (p < 0.001). In addition, while CA, CAT and NO enzyme levels were found to be significantly higher in the tonsil tissue of the patient group when compared to serum levels (p < 0.05), there was no difference between tissue and serum MDA and ADA activity (p > 0.05). Elevated ADA activity may be effective in the pathogenesis of chronic tonsillitis both by impairing tissue structure and contributing to SOR formation.

Transcriptomic analysis identifies phosphatases as novel targets for adenotonsillar hypertrophy of pediatric obstructive sleep apnea.

RATIONALE: Obstructive sleep apnea (OSA) is a highly prevalent disorder in children, in which enlarged adenotonsillar tissues (AT) play a major pathophysiologic role. Mechanisms leading to the proliferation and hypertrophy of AT in children who subsequently develop OSA remain unknown, and surgical extirpation of AT is associated with potential morbidity and mortality. OBJECTIVES: We hypothesized that a computationally based analysis of gene expression in tonsils from children with OSA and children with recurrent tonsillitis without OSA can identify putative mechanistic pathways associated with tonsillar proliferation and hypertrophy in OSA. METHODS: Palatine tonsils from children with either polysomnographically documented OSA or recurrent infectious tonsillitis were subjected to whole-genome microarray and functional enrichment analyses followed by significance score ranking based on gene interaction networks. The latter enabled identification and confirmation of a candidate list of tonsil-proliferative genes in OSA. MEASUREMENTS AND MAIN RESULTS: In vitro studies using a mixed tonsil cell culture system targeting one of these candidates, phosphoserine phosphatase, revealed that it was more abundantly expressed in tonsils of children with OSA, and that pharmacological inhibition of phosphoserine phosphatase led to marked reductions in T- and B-lymphocyte cell proliferation and increased apoptosis. CONCLUSIONS: A systems biology approach revealed a restricted set of candidate genes potentially underlying the heightened proliferative properties of AT in children with OSA. Furthermore, functional studies confirm a novel role for protein phosphatases in AT hypertrophy, and may provide a promising strategy for discovery of novel, nonsurgical therapeutic targets in pediatric OSA.

Glutathione S-transferase enzyme activity and protein expression in patients with recurrent tonsillitis and idiopathic tonsillar hypertrophy.

OBJECTIVES: The palatine tonsil is a significant part of the secondary immune system. Tonsillitis and idiopathic tonsillar hypertrophy (ITH) are the most common pathologies of this component. Although there are studies on their pathogenesis, there is insufficient study of the role of antioxidant agents. Glutathione S-transferase (GST) isozymes contribute to the antioxidation reactions in the tissue via the glutathione pathway. The purpose in this study was to reveal the levels of the GST enzyme activity and protein expression of GSTP1 and GSTA1 isozymes in patients with tonsillitis and tonsil hypertrophy, and to investigate their role in the pathogenesis of these diseases. MATERIALS AND METHODS: Sixteen patients with recurrent tonsillitis and 5 patients with ITH and were included in the study. Cytosolic extracts were prepared from post-tonsillectomy tissues of both patient groups and GST enzyme activities were measured. RESULTS: The expression of GSTP1 was found to be significantly higher than GSTA1 in tissue samples of patients with ITH and recurrent tonsillitis (P<0.001). Increased GST activity and GSTP1 isozyme expression were shown in patients with recurrent tonsillitis compared to the idiopathic tonsillar hypertrophy study group. There was a positive correlation between the expressions of GSTP1 (P=0.040; r=0.47). CONCLUSION: Increased GST activity and GSTP1 isozymes were demonstrated histologically in the pathogenesis of ITH and recurrent tonsillitis. We believe that the data of changes in antioxidant capacity, obtained from studies with more extensive and larger samples, would support our findings.

Expression of endothelial and inducible nitric oxide synthase and caspase-3 in tonsillar cancer, chronic tonsillitis and healthy tonsils.

Neoangiogenesis and inhibition of apoptosis are two factors considered as major leading causes of tumorigenesis. NO, synthesized by NOS, plays an important role in tumour growth, dissemination and vascularization. Caspase-3 is an executive enzyme of apoptosis. The presented research work has been focused on the comparative evaluation of localization of the angiogenic and proapoptotic cytokines expressed in tonsillar diseases. The immunohistochemical reaction of eNOS, iNOS and caspase-3 in tonsillar cancer (N = 17), chronic tonsillitis (N = 11) and clinically healthy tonsils (N = 8) was detected. High eNOS occurrence in endothelial cells of highly vascularized regions in tonsillar cancer, variable eNOS expression in the vessels of lamina propria in chronic tonsillitis and high expression in the cytoplasm of endothelial cells of small veins in healthy tonsillar tissue was ascertained. Increased iNOS expression was found in cancer tissue in comparison with the healthy tonsils. Nevertheless, the highest expression of iNOS was found in chronic tonsillitis. Higher expression of caspase-3 was discovered in germinal centres of lymphoid follicles of the chronic tonsillitis tissue. However, the positivity in the interfollicular zone and surface squamous epithelium was weak only. Merely isolated caspase-3-positive cells were found in tonsillar cancer. Very low expression of caspase-3 was detected in the lymphatic follicles of the healthy tonsils. Research results showed high expression of eNOS in the carcinomatous tissue. The eNOS expression in chronic tonsillitis confirms its role in regulating the lymphocyte circulation. Low expression of caspase-3 in malignant epithelial cells of tonsillar cancer shows decreased capability of apoptosis compared to chronic tonsillitis tissue, where apoptosis seems to be rather frequent and concentrated in the germinal centres of lymphatic follicles. The differences in localization of eNOS and caspase-3 expression between benign and malignant processes may be a promising tool for precise morphological distinction of chronic inflammation and tumours.

Alteration of adenoid tissue alkaline and acid phosphatase in children with secretory otitis media.

OBJECTIVE: The role of pharyngeal lymphoid tissue in etiopathogenesis of secretory otitis is not yet defined. The influence of tonsillar and adenoid mass, weight, obstruction of naspharyngeal orrifitium, bacterial reservoire or some immunological events are of scientific interest. Tissue nonspecific alkaline phosphatase (TNAP) and acid phosphatase (ACP) are enzymes detected in lymphoid tissue, TNAP as characteristic of B cells, ACP as a characteristic of macrophages and folucullardentritic cells. These enzymes interfere in cell metabolism by removing 5' phosphate group from nucleotides and proteins. Specific activity and kinetic properties were studied in palatinal tonsils and adenoids of children with secretory otitis (OME) and compared with children with recurrent tonsillitis without ear involvement. METHOD: Adenoid and tonsillar tissue of l7 children with OME and 30 children with recurrent tonsillitis were subjected to biochemical investigation using method of releasing of p-nitrophenol from p-nitrophenylphosphate (pNPP). Kinetic parameters as Michaelis-Menten constant were calculated by non-linear regression estimation method. RESULTS: Specific activity of adenoid alkaline phosphatase was lower in children with OME in relation to children with recurrent tonsillitis (t=5.733507, p<0.01). Specific activity of adenoid acid phosphatase was also lower in children with OME (t=3.655456, p<0.01). pH optimum for both enzymes was the same in these two groups of children. Michaelis-Menten constant for both enzymes was significantly higher in adenoid of children with OME than in children with recurrent tonsillitis suggesting lower enzyme affinity for the substrate. CONCLUSION: Differences in specific activities and kinetic properties of adenoid alkaline and acid phosphatases between children with OME and children with recurrent tonsillitis without OME were verified in this study. The results of the study are not able to explain the alteration of alkaline and acid phosphatase characteristics but could point to some possible and specific role of nasopharyngeal lymphoid tissue in pathogenesis of secretary otitis.

The potential inflammatory role of arginase and iNOS in children with chronic adenotonsillar hypertrophy.

OBJECTIVE: Nitric oxide (NO) induced tissue damage has been implicated in the pathogenesis of several diseases. Although recurrent/chronic tonsillitis and hypertrophy are still the most frequent surgical procedures carried out on children in order to cure these pathologies, etiopathogenetic mechanisms underlying these entities are still unknown. We aimed to investigate the potential inflammatory role of NO regulatory enzymes, arginase and inducible nitric oxide synthase (iNOS), in children with adenotonsillar hypertrophy. MATERIALS AND METHODS: The study consisted of 22 children with chronic adenotonsillar hypertrophy and 30 control subjects with similar age and sex. All the patients and/or their parents had complaints of snoring, mouth breathing and pausing of breathe during sleep at least 6 months. All patients underwent an adenotonsillectomy operation under general anesthesia with curettage and cold dissection methods. Venous blood samples were taken pre-operatively and 4 weeks post-operatively. iNOS activity was based on the diazotization of sulfanilic acid by nitric oxide at acid pH and subsequent coupling to N-(1-naphthtyl)-ethylenediamine. Arginase activity was measured by the spectrophotometric method. RESULTS: The mean pre-operative and post-operative arginase activities in patient group were 4283.7 +/- 1823.7 and 2754.5 +/- 889.3 IU/L, respectively. In the control group, mean arginase activity was 2254.7 +/- 903 IU/L. When pre-, post-operative and control arginase values were compared with each other, the mean activity in pre-operative activity was significantly different from the post-operative and control values (p < 0.001). In the patient group, the mean levels of pre- and post-operative iNOS were 2.84 +/- 1.16 and 1.99 +/- 0.78 IU/ml, respectively. The difference was statistically significant (p = 0.007). Similarly, post-operative and control values were not significantly different (p > 0.05). CONCLUSION: The results of the present study supports that L-arginine:NO pathway may be key the participant in the pathogenesis of chronic adenotonsillar disease; arginase and iNOS activities are altered in children with adenotonsillar hypertrophy and this alteration improves after tonsillectomy.

[Antioxidants enzymes activity and concentration of lipid peroxidation products in chronic tonsillitis before and after surgery]. / Aktywnosc enzymów antyoksydacyjnych i poziom produktów peroksydacji lipidów w przebiegu przewleklego zapalenia migdalków podniebiennych przed operacja i po operacji.

INTRODUCTION: Chronic tonsillitis is one of the most often disease in otolaryngological practice. Free radicals release during chronic inflammation process are responsible for tissue destruction. The aim of the study was to estimate the free radicals production and the activity of antioxidative enzymes during chronic tonsillitis before and after surgery. MATERIAL AND METHODS: The study was performed in group of 60 patients and 32 healthy persons as a control group. We analized the activity of enzymes in blood and serum from the patients before the operation and on 7 day, 4 week and 6 months after the operation. RESULTS: The obtained results shows a lower activity of superoxide dismutase before the operation. After the surgery the activity of the enzyme increased to values observed in control group. The catalase and glutathione peroxidase activity were higher during chronic inflammation, and after the operation the activity decreased, but it was still higher then in control group. Concentration of lipid peroxides products (malondialdehyde) in erythrocytes and serum were higher before the surgery. Then the concentration decreased to values observed in healthy subjects. CONCLUSIONS: The measuring and monitoring the activity of antioxidative enzymes and the concentration of lipid peroxidation products (malondialdehyde) could be useful in proper diagnosis of chronic tonsillitis and in adequately early qualification for surgery.

Proteolytic processing of the streptococcal IgG endopeptidase IdeS modulates the functional properties of the enzyme and results in reduced immunorecognition.

The important human gram positive bacterial pathogen Streptococcus pyogenes employs various virulence factors to promote inflammation and to facilitate invasive disease progression. In this study we explored the relation of the secreted streptococcal cysteine proteases IdeS and SpeB, and neutrophil (PMN) proteases. We found that SpeB is resistant to proteolytic attack in an inflammatory environment, emphasizing the importance of SpeB for streptococcal pathogenicity, while PMN enzymes and SpeB itself process the IgG degrading endopeptidase IdeS. Processing occurs as NH2-terminal cleavage of IdeS resulting in reduced immunorecognition of the protease by specific antibodies. While the endopeptidase retains IgG cleaving activity, its ability to suppress the generation of reactive oxygen species is abolished. We suggest that the cleavage of NH2-terminal peptides by SpeB and/or neutrophil proteases is a mechanism evolved to prevent early inactivation of this important streptococcal virulence factor, albeit at the cost of impaired functionality.

Quantitative measurement of beta lactamase in tonsils of children with recurrent tonsillitis.

Tonsils were obtained from 50 children suffering from recurrent tonsillitis. The tonsils' core material was cultured for aerobic and anaerobic microorganisms. Beta lactamase production was assayed in all isolates and beta lactamase activity was measured in the contents of each tonsil. Mixed aerobic and anaerobic flora was obtained in all patients, yielding an average of 7.9 isolates (4.4 anaerobes and 3.5 aerobes) per specimen. Beta lactamase production was noted in 58 isolates recovered from 39 tonsils (78%). These were all 21 isolates of S. aureus and 10 B. fragilis, 18 of 45 B. melaninogenicus (40%), 7 of 14 B. oralis (50%), and 2 of 13 H. influenzae type B (15%). Beta lactamase activity was detected in 33 of the 39 (85%) tonsils which harbored beta lactamase-producing bacteria, and in none of the 11 tonsils which had no beta lactamase-producing bacteria. Our findings indicate the polymicrobial nature of deep tonsillar flora in children with recurrent tonsillitis, and demonstrate the presence of detectable beta lactamase activity in the tonsillar tissue in most of the tonsils which harbored beta lactamase-producing organism.

Divalent cation-activated-ATPase and ecto 5'-nucleotidase activities in chronic tonsillitis.

The activities of two ectoenzymes,Mg(2+)-ATPase (ATPase) and 5'-nucleotidase (5'-NT) from tonsillar mononuclear cells (TMC) and peripheral blood mononuclear cells (PBMC) were investigated in idiopathic tonsillar hyperplasia and recurrent tonsillitis. The ATPase activity of TMC was significantly higher in recurrent tonsillitis than in idiopathic tonsillar hyperplasia, whereas no difference was demonstrated in ATPase activity of PBMC. The activity of 5'-NT was similar in both investigated groups. However, ATPase and 5'-NT activities were significantly higher in TMC compared to PBMC. Such results suggest a possible role of ATPase in the activation of TMC during the course of chronic tonsillitis and indicate a difference in the function of TMC and PBMC.

A study of free radicals and scavenging enzyme in tonsillitis.

The present study is a comparison of malonaldialdehyde (MDA) level and superoxide dismutase (SOD) activity between controls and in tonsillitis patients of different degree before (pre) and after (post) surgery (tonsillectomy). The SOD activity increases in pretonsillectomy cases according to severity of disease and there is a rise in MDA level whereas after tonsillectomy although the increase in SOD is marginal but MDA declines sharply as compared to pretonsillectomy patients indicating that the SOD exerts its protective effect after surgery.

Comparative status of oxidative damage and antioxidant enzymes in chronic tonsillitis patients.

Comparative study of two modalities i.e. antioxidant therapy (by vitamin E) and tonsillectomy was done in chronic tonsillitis patients, the study included 80 cases. It was found that both modalities were affective than tonsillectomy. Thus the use of antioxidant may be a promising alternative for the tonsillectomy.

[Changes in transaminase before and after tonsillectomy].

Almost all patients who undergo palatine tonsillectomy for chronic tonsillitis and/or tonsillar hypertrophy manifest postoperative changes in their condition and laboratory data. In some patients, high preoperative transaminase levels decrease postoperatively. I studied 17 patients who had abnormal serum transaminase levels 10 days before tonsillectomy. Before tonsillectomy, serum glutamate oxaloacetate transaminase (GOT) levels were abnormal in half and serum glutamate pyruvate transaminase (GPT) were abnormal in all. Before operation, laboratory values of serum GPT were higher than those of serum GOT in all 17 patients. After tonsillectomy, the abnormal GOT levels in all patients gradually improved to the normal range before the 11th postoperative day and GPT levels did so before the 25th day. Measurement of intracellular transaminase activity of the palatine tonsil suggested that the migration of intracellular transaminase from tonsillar cells to serum would not elevate the serum transaminase level. Postoperative changes in serum transaminase and serum cholinesterase were different from the recovery process observed in fatty liver. The high transaminase level observed in patients with tonsillectomy is suspected to be due to other organs, rather than continuous inflammation of the palatine tonsil.

[Enzyme histochemical characteristics of prostaglandin synthetase, adenylate cyclase and cAMP in a focus of inflammation in chronic tonsillitis]. / Gistofermentokhimicheskaia kharakteristika prostaglandinsintetazy, adenilattsiklazy i tsAMF v ochage vospaleniia pri khronicheskom tonzillite.

Upon enzyme histochemical evaluation of palatine tonsils removed from 80 patients with chronic tonsillitis it was established that there is a close correlation between activity of prostaglandin synthetase (PG-synthetase), adenylate cyclase (AC), cellular cAMP, pattern of inflammation and the size of streptococcal foci. Enhanced enzymatic activity, elevated content of lymphoid and connective tissue cAMP are associated with minor interstitial streptococcal foci, being a frequent finding in mild inflammation. Low cellular cAMP in high PG-synthetase and AC activity occurs in mild inflammation and large-sized interstitial streptococcal foci. When both enzymatic activity and cellular cAMP are low, torpid inflammation indicates lack of tissue response to microbial invasion resulting in emergence of interstitial streptococcal colonies. In view of the essential role of mediator effects in the inflammation focus, high activity of tonsil PG-synthetase should be considered a major indicator of activated chronic tonsillitis.

[Variations of salivary dismutase superoxide in tonsillar infection]. / Variaciones de la superóxido dismutasa salivar en la infección amigdalar.

The antioxidant effect of superoxido dismutase in saliva was measured in children bearing of tonsillar hypertrophy, recidivant tonsillitis or peritonsillar abscess. These levels were compared to those detected on tonsillar tissue obtained from tonsillectomy (p < 0.001). Although salivary SOD concentration in children with tonsillar infection was higher than hypertrophy, there was not a significative correlation to tonsillar value of the enzyme (R2 = 0.2276), so we can not accept a predictive value for salivary SOD of tonsillar suffering and, eventually, of tonsillectomy.

[Beta-lactamase-producing bacteria in recurrent childhood tonsillitis]. / Bacterias productoras de betalactamasa en amigdalitis recurrente infantil.

Beta-lactamase production by the normal pharyngeal flora could account for the failure of penicillin treatment in patients with recurrent tonsillitis. We studied the microbial flora of tonsils from 22 healthy children (control group) and from 40 children with recurrent tonsillitis who were treated with penicillin. Cultures were made before treatment and repeated 15 days after the first culture. Streptococcus pyogenes was recovered in 25% of the patients in the recurrent tonsillitis group. Beta-lactamase producing bacteria were recovered in 100% of children with tonsillitis and in 86.4% of the healthy children. We found a 65% failure rate of penicillin therapy in recurrent tonsillitis. Our results suggest that beta-lactamase production by pharyngeal organisms does not fully explain the failure of penicillin therapy for recurrent tonsillitis.

[Oxidative profile of tonsil infection. Study of antioxidant enzymes in tonsil and blood]. / Perfil oxidativo de la infección amigdalar. Estudio de las enzimas antioxidantes en amígdala y sangre.

In order to investigate the effect of oxidative damage due to free radicals on ENT infectious diseases, levels of superoxide dismutase (SOD), glutathione-peroxidase (GPx) and reductase (GRt) and the total antioxidant status (TAS) were measured by spectrophotometry on tonsillar tissue obtained from tonsillectomy in 538 patients, who were divided in three groups according to their surgical indication: tonsillar hypertrophy (n = 235), recurrent tonsillitis (n = 280) or peritonsillar abscess (n = 23). SOD concentration were also measured on adenoid tissue and middle ear exudate in 75 patients from the first two groups. Erythrocyte and tonsillar SOD levels were significantly greater in the abscess group, and lower in the hypertrophic one. These differences were similar for GPx and TAS. For GRt, its level in abscess were lower than in the other two groups in a statistically significant way. There were strong correlations between erythrocyte and tonsillar SOD, tonsillar SOD and GPx, tonsillar SOD and TAS, and tonsillar GPx and TAS. SOD concentrations from adenoid tissue and middle ear exudate did not affect its blood level. So, we can conclude that tonsillar oxidative damage is determined by the frequency or the severity of local infections, and it can be evaluated by measuring the SOD concentration in the tonsillar tissue or in the peripheral blood. So, it can be considered a good marker of tonsillar damage.

N-acetyl-ß-hexosaminidase in chronic tonsillitis and tonsillar hypertrophy.

BACKGROUND: The concentration and specific activity of N-acetyl-ß-hexosaminidase (HEX) in palatine tonsils with chronic tonsillitis and tonsillar hypertrophy give insight in tonsillar tissue remodeling and constitute a potential marker for diagnosis and treatment of chronic tonsillitis and tonsillar hypertrophy. AIM: Determining the concentration and specific activity of N-acetyl-ß-hexosaminidase in palatine tonsils with hypertrophy and chronic tonsillitis. METHODS: HEX activity was analyzed by the method of Marciniak et al. with p-nitrophenyl N-acetyl-ß-glucosaminepyranoside as a substrate. RESULTS: The concentration and specific activity of HEX in palatine tonsils in patients with tonsillar hypertrophy and chronic tonsillitis both in childhood and adulthood significantly increase in comparison to healthy individuals. CONCLUSIONS: Our data demonstrate the presence of HEX in palatine tonsils and indicate on significant increase of its concentration and specific activity. Based on content and specific HEX activity we suggest that tonsils with hypertrophy and chronic tonsillitis should be treated as identical unit irrespectively of age.

Circulating phospholipase-A2 activity in obstructive sleep apnea and recurrent tonsillitis.

OBJECTIVE: Phospholipase A2 (PLA2) plays a major part in growth regulation, differentiation and inflammation. It has been proposed as an evaluating marker for infection and inflammation. The aim of this study was to investigate activity of serum type II secretory PLA2 (sPLA2 IIa) in obstructive sleep apnea (OSA) and recurrent infective tonsillitis (RT) in children. METHODS: Activity of serum sPLA2 IIa was determined in children who underwent tonsillectomy, including OSA in 126 cases and RT in 60. Serum enzyme activities were measured using the standard assay with Diheptanoyl Thio-Phosphatidylcholin as substrate. RESULTS: The sPLA2 IIa activity of serum was significantly higher in RT than in OSA (P<0.01). Serum sPLA2 IIa activity in the RT patients was positively correlated with BMI (r=0.26; P=0.02), which was not apparent in OSA (r=0.14; P=0.09). CONCLUSION: This study suggests that serum sPLA2 IIa activity may be considered as a supportive diagnostic marker in suspected or clinically unclear cases of RT children.

Paraoxonase and arylesterase activity and total oxidative/anti-oxidative status in patients with chronic adenotonsillitis.

OBJECTIVES: The aim of this study was to investigate serum paraoxonase, arylesterase activities along with determination of oxidative status via measurement of total oxidant status (TOS), total antioxidant status (TAS) and oxidative stress index (OSI) in children with recurrent adenotonsillitis during pre- and post-adenotonsillectomy period and to compare results with data from healthy subjects. METHODS: We performed a prospective controlled trial on adenoidectomy and/or tonsillectomy patients. A total of 47 subjects, including 22 patients with recurrent adenotonsillitis and 25 healthy controls were enrolled in this study. Peripheral venous blood samples were taken from patients before adenotonsillectomy and a second sample was obtained in first month postoperatively. In the control group, blood samples from healthy volunteers were collected for one time only. Serum paraoxonase, arylesterase activities, TOS, TAS and OSI levels were measured. RESULTS: Paraoxonase, arylesterase activity, TAS and TOS levels were significantly higher in preoperative group compared to control group (P<0.001, P=0.003, 0.003 and 0.005, respectively). However, OSI level was similar in preoperative group compared to control group (P=0.25). In the post-operative group, paraoxonase, arylesterase activities, TAS and OSI levels were lower as compared to preoperative group but differences were statistically insignificant (P=0.483, 0.265, 0.149 and 0.090, respectively). TOS level in post-operative group was significantly lower than the preoperative group (P<0.001). In the post-operative group, paraoxonase and arylesterase activities were significantly higher as compared to control group (P=0.004 and 0.02, respectively). TOS and OSI levels were significantly lower in post-operative group compared to control group (P=0.001 and 0.02, respectively). However, TAS was similar between post-operative and control groups (P=0.464). CONCLUSIONS: Based on data obtained from this study, we may state that paraoxonase, arylesterase activities with TAS, TOS and OSI levels of patients with chronic adenotonsillitis shows alterations due to oxidant/antioxidant imbalance induced by frequent infections.