A case report of chronic intermedullary inflammation of bone in a child.

Osteolytic lesions refer to the destruction of any part of bone due to a disease process (pertaining to dissolution of bone, especially loss of calcium). Osteomyelitis is the inflammation of the bone caused by an infecting organism. Although bone is normally resilient to bacterial colonization, events such as trauma, surgery, infections, the presence of foreign bodies, and anemia may disrupt bony integrity and lead to the onset of bone infections. Sometimes, osteomyelitis causes no signs and symptoms or the signs and symptoms are hard to distinguish from other problems. This may be true for children, older adults, and people whose immune systems are compromised. Here, we report a case of chronic intermedullary inflammation of bone in a child.

Atypical Clinical Presentation of Xanthogranulomatous Pyelonephritis in a Female Child: A Case Report.

Xanthogranulomatous pyelonephritis (XGPN) is an uncommon chronic obstructive renal suppuration disease. Histopathologically, XGPN manifests as lipid-laden macrophage infiltration in renal microstructure and inflammation of an engorged non-functional kidney. Nephrectomy is the standard therapeutic treatment, and the overall prognosis is good. Here, we report a case of XGPN presented as flank pain in an otherwise healthy child.

Diagnóstico y tratamiento de abscesos hepáticos, a propósito de tres casos

El absceso hepático tiene baja incidencia, pero alta mortalidad. Su diagnóstico suele ser tardío dada la variabilidad de presentaciones clínicas. Presentamos tres casos en mujeres, de los cuales dos se manifestaron con síndrome febril con microbiología no precisada, mientras que el tercero con shock séptico secundario a colangitis, aislándose Escherichia coli. Todos fueron manejados con antibioticoterapia endovenosa empírica y drenaje quirúrgico, uno vía laparoscópica, dos percutáneos y uno asociado a una colangio-pancreatografía retrógrada endoscópica. La elección terapéutica se determina de acuerdo a la presencia de rotura, tamaño y/o loculaciones del absceso, combinando antibioticoterapia con métodos de drenaje quirúrgico mínimamente invasivos. Se contrasta y discute la bibliografía disponible, destacando la necesidad de investigaciones actualizadas en Chile.

Liver abscess has low incidence but high mortality. Its diagnosis is often delayed due to the variability of clinical presentations. We present three cases in women, two of which manifested with a febrile syndrome with unspecified microbiology, while the third presented with septic shock secondary to cholangitis, with Escherichia coli isolated. All cases were managed with empirical intravenous antibiotic therapy and surgical drainage, one through laparoscopy, two through percutaneous methods, and one associated with endoscopic retrograde cholangiopancreatography. The therapeutic approach is determined based on the presence of rupture, size, and/or loculations of the abscess, combining antibiotic therapy with minimally invasive surgical drainage methods. We discuss the available literature, emphasizing the need for updated research in Chile.

Periodontitis Severity Grading Scale and C-Reactive Protein: A Possible Relation.

Background C-reactive protein (CRP) is the first acute-phase protein and is an exceptional investigative marker for local and systemic inflammation. The periodontitis severity grading scale (PSGS) indicates the extent of periodontal inflammation. Therefore, the aim of the study was to explore the correlation between the markers of systemic and periodontal inflammation as assessed by CRP and the PSGS in participants with periodontitis. Materials and methods The present study enrolled 85 systemically healthy participants with periodontitis. PSGS and CRP levels were measured in each participant. Descriptive and inferential statistics were applied for analysis. Results The PSGS scores ranged from 24 to 213, and the CRP levels ranged from 0.5 to 3.23 mg/l. This shows a positive correlation between the periodontal scale and CRP. A nonsignificant (p-value > 0.05) correlation exists between age and CRP score, and a significant association was seen between gender and severity of periodontitis with p-value < 0.02. A highly significant association between gender and CRP score was found with p-value < 0.001. Conclusion The level of serum CRP dramatically increased with the severity of periodontitis. The results of this study point to a highly significant correlation between markers of systemic and periodontal inflammation, as well as a strength of association between the two markers.

Risk factors associated with keloid infections: A five-year retrospective study.

Keloid infections reduce patient-reported quality of life greatly. Characteristics and risk factors of keloid infections have not been thoroughly studied. So, a retrospective cohort study was conducted focusing on the potential risk factors, microbiologic cultures and histological findings. Keloid patients consulting for surgical interventions were included in this study. Data were collected from their electronic medical records. 564 patients were recruited with the keloid infection rate being 22.4%. For adult patients, age above 40 years (OR, 2.84; P = .000), disease duration of 12 years or more (OR, 3.03; P = .000), the number of keloids over 3 (OR, 1.59; P = .050) and the presence of family history (OR, 1.91; P = .027) were significantly associated with keloid infections. Suppurative keloids were located mostly in thorax (61.79%). For the under-age subgroup(n = 25), family history was frequently seen in patients with infections. Microbiologic cultures revealed a mixed spectrum of bacteria including Staphylococcus (25%), Actinomyces (30%) and Prevotella (10%). The rate of epidermoid cysts was 19.7% in histological examination. Age > 40 years, disease duration ≥12 years, the number of keloids >3 and the presence of family history are risk factors for keloid infections.

Management of perianal fistulas in Crohn's disease: a 2021 update of the French National Society of Coloproctology consensus.

BACKGROUND: Since our last publication of algorithms for the management of perianal fistulas in patients with Crohn's disease, researchers have proposed a treat to target strategy systematic combotherapy for anal lesions, and indications for stem cell injection. In the absence robust publications, the Société Nationale Française de Coloproctologie (French National Society of Coloproctology [SNFCP]) wished to establish a group consensus using the Delphi method. METHODS: From October 2020 to January 2021, a scientific committee and panel of gastroenterologists and surgeons established answers which were submitted to the members of the SNFCP during a national conference in November 2020. Three questions were clarified and reformulated, and then submitted during a third and final round of consultation of members of the SNFCP. RESULTS: The target was defined as being the response obtained in every domain (symptoms, physical and radiological evaluation) which could be considered satisfactory, without the need to intensify therapeutic management. By consensus, the time required for clinical evaluation of the efficacy of treatment was 6 months. A response on magnetic resonance imaging (MRI) should include the absence of a collection of 10 mm or more in size at 6 months, and a frank decrease or complete disappearance of hyperintensity in T1 and T2 sequences of the main tract at 12 months. Systematic association of an immunosuppressant with tumor necrosis factor inhibitors did not reach the consensus level for adalimumab (50%), but just did for infliximab (70%). The majority of the respondents considered failure of one, or even two lines of different biotherapies to be potential indications for injection of stem cells. CONCLUSIONS: These findings reinforce the importance of composite targets including MRI evaluation, and underscore the need for precise timing of evaluation. Combotherapy is only recommended with infliximab. Injection of stem cells is a second- or third-line option.

Risk factors for periappendiceal adhesions in acute appendicitis: a retrospective comparative study.

PURPOSE: Acute appendicitis usually requires immediate surgical treatment, but appendectomies were difficult for some patients with severe periappendiceal adhesions. We investigated risk factors of intraoperative adhesions to help surgeons make better treatment plans for appendicitis. METHODS: We retrospectively analyzed 186 cases diagnosed with acute appendicitis and underwent surgery in Shandong Provincial Hospital affiliated to Shandong First Medical University between January 2018 and December 2019. According to the degree of intraoperative adhesions, they were divided into mild, moderate and severe groups. Then, we analyzed a number of preoperative factors contributed to adhesions, suppuration and perforation during appendectomy in 186 patients. RESULTS: Contrast to the moderate group (MoG) and the mild group (MiG), the severe degree of adhesions group (SG) had a higher intraoperative perforation and suppuration rate, a greater likelihood of conversion to open and more postoperative complications. Multivariable logistic regression analysis showed that recurrent appendicitis and high neutrophil percentage were independently associated with periappendiceal adhesions. The preoperative ultrasonography (US) revealed periappendiceal fluid and high neutrophil percentage were independently associated with appendix suppuration. A high preoperative neutrophil percentage was independently associated with appendix perforation. CONCLUSIONS: Recurrent appendicitis and preoperative high neutrophil percentage were risk factors of periappendiceal adhesions; preoperative US revealed periappendiceal fluid and high neutrophil percentage were risk factors of appendix suppuration; and a high preoperative neutrophil percentage was a risk factor of appendix perforation.

Bronchiectasis in Childhood.

Bronchiectasis is one of the diagnostic entities in the spectrum of pediatric chronic wet cough, causing significant morbidity and mortality. The pathobiology involves a vicious cycle of repeated infections, airway inflammation, dysregulated immunity, and tissue remodeling, resulting in impaired airway clearance, destruction of structural elements within the bronchial wall causing them to become dilated, and small-airway obstruction. Pediatric pathobiological studies are lacking, although there are recent data on the role of antibiotics in treating and preventing exacerbations. The focus has moved to understanding ways to prevent bronchiectasis and the role of novel drugs in preventing and treating bronchiectasis in children.

Drug resistance and virulence characteristics of of Staphylococcus aureus isolated from skin sites of suppurative infections in Inner Mongolia / 中华皮肤科杂志

Objective:To analyze drug resistance, virulence and molecular epidemiological characteristics of Staphylococcus aureus ( S. aureus) isolated from skin sites of suppurative infections, and to provide an experimental basis for clinical anti-infective therapies. Methods:Swab samples from suppurative skin lesions and nasal secretions were collected from inpatients in Department of Dermatology, the Affiliated Hospital of Inner Mongolia Medical University from May 2020 to December 2020, and subjected to bacterial isolation and culture. Suspected S. aureus colonies were identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Drug sensitivity test was conducted by using the broth microdilution method. Virulence genes of S. aureus were amplified by PCR, and real-time fluorescence-based quantitative PCR was performed to determine the relative expression of 4 virulence genes including tsst-1, pvl, hla and clfA in S. aureus strains from different sources. S. aureus strains were genotyped by multilocus sequence typing. Drug resistance rates and detection rates of virulence genes were compared by using chi-square test or Fisher′s exact test, and measurement data among groups were compared by using t test or Mann-Whitney U test. Results:A total of 85 strains of S. aureus were isolated from 210 inpatients, including 54 isolates from skin sites of suppurative infections (case group) and 31 isolates from the nasal cavity (control group) . Drug sensitivity test showed that 14 strains of methicillin-resistant S. aureus (MRSA) were identified among 85 strains of S. aureus. The resistance rate to penicillin was the highest (90.59%, 77/85) in the 85 S. aureus strains; the resistance rates to clindamycin and erythromycin were 60.00% (51/85) and 61.18% (52/85) respectively; no strains showed resistance to rifampicin, vancomycin or linezolid. PCR showed that the detection rate of the pvl gene was 33.33% (18/54) in the case group, which was significantly higher than that in the control group (12.90%, 4/31; χ2= 4.28, P= 0.038) . Real-time fluorescence-based quantitative PCR showed that the relative expression level of the clfA gene was significantly higher in the control group (3.87[2.30, 5.94]) than in the case group (1.63[0.95, 2.62], P= 0.007) . A total of 17 ST types were identified among the 85 strains of S. aureus, and the dominant types were ST398-methicillin-susceptible S. aureus (20/71) and ST22-MRSA (9/14) . The detection rate of the virulence gene pvl was significantly higher in the ST22-MRSA strain (14/14) than in the non-ST22 MRSA strains (0, P < 0.001) . Conclusions:S. aureus strains isolated from the skin sites of suppurative infections were highly resistant to penicillin, clindamycin and erythromycin, so these antibiotics should not be used as the first-choice empiric treatment. The occurrence of cutaneous S. aureus infections may be associated with the virulence gene pvl, and the nasal colonization of S. aureus may be associated with the clfA gene.

Diagnostic Key Points and Surgical Management of Necrotizing Fasciitis: A Retrospective Study.

Necrotizing fasciitis (NF) is a fatal disease with a high mortality rate that can be easily misdiagnosed. The aim of this study was to improve the diagnostic rate of NF and overall survival. We conducted a single-center, retrospective, noncontrolled study involving 36 patients who were admitted to our department between December 2017 and October 2019, and summarized the diagnostic key points and timing of surgical treatment. All patients were diagnosed at our department and underwent multiple courses of treatment. The records included information regarding underlying diseases, bacterial culture results, laboratory risk indicator for necrotizing fasciitis (LRINEC) score, number of procedures, and type of antibiotics. All 36 cases of NF were cured and showed good patient condition on follow-up; the mean number of surgeries was three, and the mean duration of hospitalization was 37 days (range, 21-83 days). The LRINEC scores of 16 patients were ≥8 points. Seventeen patients with underlying diabetic disease had higher inflammatory index scores than those without diabetes. The LRINEC scores of patients with (n = 17) and without (n = 19) DM were 7.40 ± 2.99 and 3.80 ± 2.39, respectively (P < .01). Cases of NF that were treated with early incision and surgical abscess drainage required fewer surgeries and a shorter length of hospitalization. Thus, surgeons should be more aware of NF and aim to make an early and accurate diagnosis using various approaches. Complete surgical debridement plays an essential role in NF treatment, and diabetes mellitus is a significant adverse factor that exacerbates the severity of NF. Negative-pressure techniques are useful in cases involving nonanaerobic infections and cause minimal complications.

Monaldi cavernostomy for lung aspergillosis: A case report.

Pulmonary aspergillosis in patients with respiratory failure can severely affect the pulmonary functional status and may aggravate it through pulmonary suppuration, by recruitment of new parenchyma and hemoptysis, which can sometimes be massive, with lethal risk by flooding the bronchus. The treatment consists of a combination of medical therapy, surgery and interventional radiology. In small lesions, less than 2-3 cm, medical therapy methods may be sufficient; however, in invasive forms (larger than 3 cm) surgical resection is necessary. Surgical resection is the ideal treatment; nevertheless, when lung function does not allow it, action must be taken to eliminate the favorable conditions of the infection. In such cases, whenever the lung cavity is peripheral, a cavernostomy may be performed. Four cases of lung cavernous lesions colonized with aspergillus, in which the need for a therapeutic gesture was imposed by repeated small to medium hemoptysis and by the progression of respiratory failure, were evaluated, one of which is presented in the current study. Cavernostomy closure can be realized either surgically with muscle flap or spontaneously by scarring, after closure of the bronchial fistulas by epithelization and granulation. There were no recurrences of hemoptysis or suppurative phenomena. There was one death, a patient with severe respiratory failure caused by superinfection with nonspecific germs. However, in the case presented in this study, the patient recovered following cavernostomy, which seems to be an effective and safe method for cases in which lung resection is not feasible.

Is bleeding on probing a reliable clinical indicator of peri-implant diseases?

Bleeding on probing (BOP) is regarded as an indispensable diagnostic tool for evaluating periodontal disease activity; however, its role in peri-implant disease is more intricate. Much of the confusion about the interpretation originates from drawing parallels between periodontal and peri-implant conditions. BOP can originate from two forms of probing in implants: traumatic or pathologic induction. This, in addition to the dichotomous scale of BOP can complicate diagnosis. The objective of this commentary is to discuss the following: 1) the value of BOP as a diagnostic tool for peri-implant diseases; 2) the reasons it should be distinct from value for diagnosing periodontal and peri-implant diseases; and 3) the current best evidence on how to implement it in daily clinical practice. A comprehensive bleeding index is proposed for evaluating and monitoring peri-implant conditions. BOP should be used in addition to other parameters such as visual signs of inflammation, probing depth, and progressive bone loss before a peri-implant diagnosis is established.

Unusual intracranial suppuration: illustrative cases.

BACKGROUND: Intracranial suppuration (ICS) is a rare complication that can arise from various disease processes and is composed of brain abscess, extradural empyema, and subdural empyema. Although significant progress has been achieved with antibiotics, neuroimaging, and neurosurgical technique, ICS remains a serious neurosurgical emergency. An uncommon presentation of ICS is sterile ICS, which has yet to be fully elucidated by clinicians. The authors present 2 cases of unusual sterile ICS: a sterile subdural empyema and a sterile brain abscess. OBSERVATIONS: Both patients underwent surgical treatment consisting of craniotomy to evacuate the pus collection. The blood cultures from both the patients, the collected empyema, and the thick capsule from the brain abscess were sterile. However, the necrotic brain tissue surrounding the abscess contained inflammatory cells. The authors' review of the literature emphasizes the rarity of sterile ICS and substantiates the necessity for additional studies to explore this field. LESSONS: Sterile ICS is a disease entity that warrants further investigation to determine appropriate treatment to improve patient outcomes. This study highlights the paucity of data available regarding sterile ICS and supports the need for future studies to uncover the etiology of sterile ICS to better guide management of this condition.

Clinical signs, symptoms, perceptions, and impact on quality of life in patients suffering from peri-implant diseases: a university-representative cross-sectional study.

OBJECTIVES: To study the symptoms and perception reported by patients with peri-implant diseases, as well as their signs and their potential impact on the oral health quality of life. MATERIAL AND METHODS: Two hundred and forty randomly selected patients were invited to participate. As part of the history assessment, the patient OHIP-14Sp was evaluated together with, for each implant, the patient perception regarding the peri-implant health status and the history of pain, spontaneous discomfort, bleeding, suppuration, swelling, and discomfort during brushing. As part of the clinical examination, the following potential signs of peri-implant diseases were collected: probing pocket depth (PPD), mucosal dehiscence (MD), extent of BoP, presence of SoP, and visual signs of redness and swelling. Those parameters were analyzed in relation to the actual peri-implant health diagnosis. RESULTS: Ninety-nine patients with a total of 458 dental implants were studied. Even in case of peri-implantitis, 88.9% of the implants were perceived by the patients as healthy. The total OHIP-14Sp sum score did not differ in relation to the peri-implant health diagnosis. Increased reports of spontaneous discomfort, bleeding, swelling, and discomfort during brushing were observed in presence of disease. However, only a minor proportion of implants with peri-implant diseases presented symptoms. PPD ≥ 6 mm was more frequent in diseased than in healthy implants (p < .01), while PPD ≥ 8 in pre-peri-implantitis/peri-implantitis than in healthy/mucositis implants (p < .01). Implants with peri-implantitis showed higher MD than implants without peri-implantitis (p < .01). CONCLUSION: Peri-implant diseases are in most cases asymptomatic and not perceived by the patients. Despite being unable to accurately discriminate between peri-implant mucositis and peri-implantitis, PPD and MD resulted as the only two clinical signs associated with pre-peri-implantitis/peri-implantitis.

Choque séptico con disfunción multiorgánica en paciente con pericarditis supurada y bacteriemia por Staphylococcus aureus meticilino sensible. Reporte de caso / Septic shock with multi-organ dysfunction in a patient with suppurative pericarditis and bacteraemia due to sensitive methicillin staphylococcus. Case report

RESUMEN Choque séptico con disfunción multiorgánica tiene una tasa de mortalidad mayor de 50%. Se presenta el caso de un varón que cursó con choque séptico con disfunción multiorgánica, secundario a bacteriemia por Staphylococcus aureus meticilino sensible, con foco de partida dérmico - partes blandas, quien presentó lesiones alveolo nodulares, pericarditis supurativa, lesiones embolicas a nivel dérmico, ocular y renal; recibió soporte en la unidad de cuidados intensivos, tratamiento antibiótico con oxacilina más vancomicina, pericardiectomia subtotal y drenaje pleural. Salió de alta estable para continuar tratamiento. Presentamos este caso para destacar la gravedad de la bacteriemia por Staphylococcus aureus meticilino sensible, con compromiso multiorgánico y así poder tomar medidas terapéuticas agresivas para disminuir la morbilidad y mortalidad por el mismo.

SUMMARY Septic Septic shock with multi organ dysfunction is associated with a mortality above 50%. We present here the case of a young male patient who presented with septic shock and multi organ dysfunctions secondary to methicillinsusceptible Staphylococcus aureus from a skin and soft tissue infection presenting with alveolar-nodular pulmonary lesions, purulent pericarditis and septic embolic lesions on the skin, eyes and kidneys. The patient was admitted to the ICU receiving antibiotic coverage with oxacillin and vancomycin, subtotal pericardiectomy and pleural drainage, and was discharged clinically stable. We present this case to draw attention to the severity of S. aureus bacteremia to initiate prompt aggressive therapeutic measures to ameliorate associated morbidity and mortality.

Assessment of basal implants in compromised ridges.

AIM: The aim of the present study was to evaluate clinically, radiographically, and functionally the outcomes of immediately loaded basal implants when placed in patients with compromised bone/alveolar ridges. MATERIALS AND METHODS: A total of 18 systemically healthy (9 male and 9 female) subjects with compromised bone with poor quantity or quality were included in the study. A total number of 57 implants was placed, out of which 26 implants were placed in maxilla and 31 implants in mandible. There were 6 patients in which single implants were placed and in rest of the 12 patients, multiple implants were placed, out of which full mouth rehabilitation was done in one patient. In 10 patients, implants were placed immediately in fresh extraction socket and in 7 patients, implants were placed in healed edentulous site. In all the patients, loading was done immediately within 72 h of implant placement. All patients were evaluated for primary and secondary stability, pain, periimplant bone levels using IOPA with grid and CBCT, bleeding, suppuration, sulcular bleeding index, prosthetic complications, and patient satisfaction at specified time intervals. RESULT: All the values obtained during the study were expressed in the form of mean, standard deviation, and standard error of the mean. The parameters were compared between groups using Paired t-test for intragroup comparison at a similar time, i.e., baseline, 1 month, and 3 months. The data collected was comprehensively analyzed using SPSS software. All implants were successful, with no incidence of infection, nil mobility at the end of the study period of 6 months. CONCLUSION: Thus, it can be concluded from the present study, that Basal implants can play a vital role in the rehabilitation of patients, where compromised quality and/or quantity of bone is present and additional augmentation procedures would be required for the placement of conventional root form implants.

[Contamination of surgical wound during tracheal resection depending on the mode of mechanical ventilation]. / Kontaminatsiya operatsionnoi rany v zavisimosti ot varianta IVL pri rezektsii trakhei.

OBJECTIVE: To analyze contamination of surgical wound during tracheal resection depending on the mode of mechanical ventilation. MATERIAL AND METHODS: There were 976 patients. Circular tracheal resection was made in 396 of these patients. RESULTS: Overall postoperative morbidity was 15.7%, mortality - 0.8%. Bacteriological examination of surgical wound was performed before tracheotomy and after formation of anastomosis depending on the method of mechanical ventilation. Surgical field was sterile before tracheotomy in all cases, contamination was confirmed after tracheotomy in all patients. Minimal contamination was observed in case of apneic oxygenation (100 times less than volumetric mechanical ventilation or high frequency mechanical ventilation). In all cases, several species of pathogenic microorganisms were identified. The number of species was also minimal in case of hypnotic mechanical ventilation. CONCLUSION: Contamination does not directly affect the development of local purulent-inflammatory process. However, this factor should not be ignored and compliance with all preventive measures is required.

Acute mastoiditis in children: contemporary opportunities and challenges.

BACKGROUND: Mastoiditis is the most common intra-temporal complication of acute otitis media. Despite potentially lethal sequelae, optimal management remains poorly defined. METHOD: A retrospective case review was conducted of children diagnosed with mastoiditis at a tertiary referral centre, in North East England, between 2010 and 2017. RESULTS: Fifty-one cases were identified, 49 without cholesteatoma. Median patient age was 42 months (2 months to 18 years) and median hospital stay was 4 days (range, 0-27 days). There was no incidence trend over time. Imaging was conducted in 15 out of 49 cases. Surgery was performed in 29 out of 49 cases, most commonly mastoidectomy with (9 out of 29) or without (9 out of 29) grommets. Complications included sigmoid sinus thrombosis (3 out of 49) and extradural abscess (2 out of 51), amongst others; no fatalities occurred. CONCLUSION: A detailed contemporary description of paediatric mastoiditis presentation and management is presented. The findings broadly mirror those published by other UK centres, but suggest a higher rate of identified disease complications and surgical interventions.

Insight into innate immune response in "Yusho": The impact of natural killer cell and regulatory T cell on inflammatory prone diathesis of Yusho patients.

BACKGROUND: In 1968 in western Japan, polychlorinated biphenyl-contaminated "Kanemi rice oil" was used in cooking, causing food poisoning in many people. More than 50 years have passed since the Yusho incident, and although inflammatory disorders such as suppuration have been observed in Yusho patients, the etiology of this inflammation susceptibility remains obscure. OBJECTIVES: To investigate the mechanisms of susceptibility to inflammation in Yusho patients, peripheral immune cell fractions and concentrations of inflammatory cytokines were evaluated in blood samples collected from both Yusho patients and age-matched healthy subjects undergoing medical examination in Nagasaki. METHODS: To exclude diagnostic uncertainty, serum levels of polychlorinated biphenyl (PCB), polychlorinated quarterphenyl (PCQ), and polychlorinated dibenzofuran (PCDF) were measured. Immune cell (e.g. natural killer and regulatory T cell) populations were analyzed by flow cytometry. Serum cytokines involved in immune cell activation were measured by ELISA. RESULTS: The relative proportion of natural killer cells was higher in Yusho patients than in healthy subjects, while the proportion of regulatory T cells did not differ between groups. Serum concentrations of IL-36 and IFN-γ were significantly lower in Yusho patients than in healthy subjects. Conversely, serum cytotoxic T lymphocyte-associated antigen-4 (CTLA-4), which is a cytokine related to activated NK cells, was higher in Yusho patients than in healthy subjects and was positively correlated with PCDF blood levels. CONCLUSION: Increased numbers of NK cells in Yusho patients suggests that the innate immune response has been activated in Yusho patients. The seemingly paradoxical results for CTLA-4 and IFN-γ may reflect counterbalancing mechanisms preventing excessive NK cell activation. This dysregulation of innate immunity might contribute to the inflammation observed in Yusho patients.