ABSTRACT
PURPOSE: To investigate the incidence and prognostic factors of ocular sequelae in Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) cases arising between 2016 and 2018 in Japan, and compare the findings with those presented in the previous 2005-2007 survey. DESIGN: Retrospective, national trend survey. METHODS: Dermatologic case report forms (CRFs) (d-CRFs) were sent to 257 institutions that treated at least 1 SJS/TEN case, and 508 CRFs were collected from 160 institutions. Ophthalmologic CRFs (o-CRFs) regarding patient demographic data, onset date, ocular findings (first appearance, day of worst severity, and final follow-up), topical treatment (betamethasone), outcome (survival or death), and ocular sequelae (visual disturbance, eye dryness) were sent to the ophthalmologists in those 160 institutions. The results of this survey were then compared with that of the previous 2005-2007 survey. RESULTS: A total of 240 cases (SJS/TEN: 132/108) were included. The incidence of ocular sequelae incidence was 14.0%, a significant decrease from the 39.2% in the previous survey (SJS/TEN: 87/48). In 197 (82.1%) of the cases, systemic treatment was initiated within 3 days after admission, an increase compared to the previous survey (ie, treatment initiated in 82 [60.7%] of 135 cases). Of the 85 cases with an Acute Ocular Severity Score of 2 and 3, 62 (72.9%) received corticosteroid pulse therapy and 73 (85.9%) received 0.1% betamethasone therapy; an increase compared to the 60.0% and 70.8%, respectively, in the previous survey. Ocular-sequelae-associated risk factors included Acute Ocular Severity Score (P < .001) and specific year in the survey (P < .001). CONCLUSIONS: The ophthalmologic prognosis of SJS/TEN has dramatically improved via early diagnosis, rapid assessment of acute ocular severity, and early treatment.
ABSTRACT
BACKGROUND: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are life-threatening, severe mucocutaneous adverse reactions. Severity prediction at early onset is urgently required for treatment. However, previous prediction scores have been based on data of blood tests. OBJECTIVE: This study aimed to present a novel score that predicts mortality in patients with SJS/TEN in the early stages based on only clinical information. METHODS: We retrospectively evaluated 382 patients with SJS/TEN in a development study. A clinical risk score for TEN (CRISTEN) was created according to the association of potential risk factors with death. We calculated the sum of these risk factors using CRISTEN, and this was validated in a multinational survey of 416 patients and was compared with previous scoring systems. RESULTS: The significant risk factors for death in SJS/TEN comprised 10 items, including patients' age of ≥65 years, ≥10% body surface area involvement, the use of antibiotics as culprit drugs, the use of systemic corticosteroid therapy before the onset, and mucosal damage affecting the ocular, buccal, and genital mucosa. Renal impairment, diabetes, cardiovascular disease, malignant neoplasm, and bacterial infection were included as underlying diseases. The CRISTEN model showed good discrimination (area under the curve [AUC] = 0.884) and calibration. In the validation study, the AUC was 0.827, which was statistically comparable to those of previous systems. CONCLUSION: A scoring system based on only clinical information was developed to predict mortality in SJS/TEN and was validated in an independent multinational study. CRISTEN may predict individual survival probabilities and direct the management and therapy of patients with SJS/TEN.
ABSTRACT
BACKGROUND: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are life-threatening severe cutaneous adverse reactions (SCARs). Sepsis has been shown to be the main cause of death in SJS/TEN. The European SCAR study reported that 14.8 % of SJS/TEN patients were receiving systemic steroid therapy for their underlying condition prior to onset. However, it remained unclear whether this factor affected the mortality rate. OBJECTIVE: This study was performed to identify risk factors for sepsis in SJS/TEN patients. In addition, we compared patients who had and had not received systemic steroid therapy for their underlying condition. METHODS: A primary survey regarding the numbers of SJS/TEN patients between 2016 and 2018 was sent to 1205 institutions in Japan. A secondary survey seeking more detailed information was sent to institutions reporting SJS/TEN patients. We analyzed 315 SJS patients and 174 TEN patients using a logistic regression model, Wilcoxon's rank-sum test, χ2 test, and Fisher's exact test. RESULTS: Significant risk factors for sepsis included TEN, diabetes, and intensive care unit (ICU) admission. The mortality rate was significantly higher among patients with sepsis. Patients who had received systemic steroid therapy had a lower incidence of fever, and showed a higher mortality rate. CONCLUSION: Based on a nationwide epidemiological survey of SJS/TEN in Japan, we identified risk factors for sepsis and found that patients who had received steroid therapy for their underlying condition had a lower incidence of fever and a higher mortality rate.
Subject(s)
Sepsis , Stevens-Johnson Syndrome , Cross-Sectional Studies , Humans , Japan/epidemiology , Retrospective Studies , Risk Factors , Sepsis/complications , Sepsis/drug therapy , Sepsis/epidemiology , Steroids/adverse effects , Stevens-Johnson Syndrome/drug therapy , Stevens-Johnson Syndrome/epidemiology , Stevens-Johnson Syndrome/etiologyABSTRACT
BACKGROUND: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are life-threatening severe cutaneous adverse reactions (SCARs). The first national epidemiological survey of SJS/TEN was carried out in 2008. We conducted a new survey to identify changes from the previous survey. OBJECTIVE: The present survey aimed to estimate the number of SJS/TEN patients in Japan between 2016 and 2018 (primary survey) and to clarify clinical epidemiological profiles (secondary survey). METHODS: A primary survey asking for numbers of SJS/TEN patients during the study period was sent to 1205 institutions nationwide. A secondary survey was sent to institutions reporting SJS/TEN patients, seeking detailed information. RESULTS: Yearly prevalence per million was 2.5 for SJS and 1 for TEN. The secondary survey allowed analysis of 315 SJS cases and 174 TEN cases from 160 institutions. Mean age was 53.9 years in SJS, and 61.8 years in TEN. Mortality rate was 4.1 % for SJS and 29.9 % for TEN. In TEN, mean age and mortality rates had increased from the previous survey. The ratio of expected to observed mortality calculated by SCORTEN score was lowest with high-dose steroid therapy (0.40), followed by steroid pulse therapy (0.52). CONCLUSION: The present findings suggest that the mortality rate of TEN has increased because of increases in mean ages of patients and patients with malignant neoplasm as underlying disease. When comparing the ratio of expected mortality to actual mortality, high-dose steroid therapy achieved the greatest reduction in mortality.
Subject(s)
Glucocorticoids/administration & dosage , Stevens-Johnson Syndrome/epidemiology , Adult , Aged , Aged, 80 and over , Dose-Response Relationship, Drug , Female , Humans , Japan/epidemiology , Male , Middle Aged , Mortality , Prevalence , Retrospective Studies , Severity of Illness Index , Stevens-Johnson Syndrome/diagnosis , Stevens-Johnson Syndrome/drug therapy , Stevens-Johnson Syndrome/etiology , Treatment OutcomeSubject(s)
Drug Hypersensitivity Syndrome/genetics , HLA-A11 Antigen/genetics , Stevens-Johnson Syndrome/genetics , Sulfonamides/adverse effects , Adult , Female , Genetic Predisposition to Disease , HLA-A11 Antigen/metabolism , Humans , Japan , Male , Middle Aged , Molecular Docking Simulation , Skin/drug effects , Sulfamethoxazole/adverse effects , Sulfamethoxazole/metabolism , Sulfanilamide/adverse effects , Sulfanilamide/metabolism , Sulfasalazine/adverse effects , Sulfasalazine/metabolism , Sulfonamides/metabolismABSTRACT
The clinical classification of cutaneous adverse reactions by drugs should be clearly distinguished to avoid conceptual confusion and inconsistency. Although dermatologists appear to have established a roughly common consensus for cutaneous adverse reactions, some types are more rigorously defined than other, possibly misleading classifications. To assess the consensus on the clinical classifications, we investigated the concordance rate of diagnosis by Japanese experts through a snap visual inspection of various clinical pictures exhibiting erythema multiforme and maculopapular eruption types of cutaneous adverse reactions. The experts were shown images on a screen and were then asked to decide whether to classify cases as maculopapular eruption or erythema multiforme type, and the concordance rates were calculated. Overall, the mean concordance rate was 71.6% (standard deviation, 17.3%), and only 33.8% of cases had a 90% or more concordance rate. Our study shows that the determinations of erythema multiforme and maculopapular eruption types by the existing classification criteria were confusing even among experts, which prompted us to standardize the terminology. We propose clinically defining erythema multiforme type as generalized macules mainly of 1 cm or more with a tendency of elevation and coalescence, and maculopapular eruption type as generalized erythema other than erythema multiforme type. Currently, the clinical definitions of cutaneous adverse reactions are poorly described, which may be problematic upon analyzing large volumes of data. Our proposal for a new terminology will enhance the accuracy and consistency of information for the correct analysis of cutaneous adverse reactions.
Subject(s)
Dermatology/standards , Drug Eruptions/classification , Erythema Multiforme/diagnosis , Exanthema/diagnosis , Terminology as Topic , Drug Eruptions/diagnosis , Erythema Multiforme/chemically induced , Exanthema/chemically induced , Female , Humans , MaleABSTRACT
The effect of alcohol intake on varicose veins (VV) has not been determined by its consumption level. The aim of this study was to investigate the association between alcohol intake and VV in an elderly general population. Using a cross-sectional approach, the Shimane CoHRE Study data, comprising a total of 1060 participants, were analyzed. By multivariate regression analysis adjusted with basic characteristics, past work history, lifestyle-related factors and medical history, compared with non-drinkers, mild drinkers (<20.0 g/day) showed a significantly lower adjusted odds ratio (aOR) of VV (aOR = 0.64, P = 0.036). In a similar way, regular drinkers (1-5 days/week) showed a significantly lower aOR of VV when compared with occasional drinkers (aOR = 0.57, P = 0.032). VV and alcohol intake showed J-curve relationships. In a stratified analysis by alcohol consumption levels, the association of smoking and VV were also observed in moderate to heavy drinkers and habitual drinkers. These findings can provide better understanding of pathophysiological mechanism and be used for evidence-based patient education.
Subject(s)
Alcohol Drinking/adverse effects , Smoking/adverse effects , Varicose Veins/epidemiology , Aged , Cross-Sectional Studies , Female , Humans , Incidence , Japan/epidemiology , Life Style , Male , Middle Aged , Patient Education as Topic , Risk Factors , Saphenous Vein/diagnostic imaging , Ultrasonography , Varicose Veins/etiology , Varicose Veins/prevention & controlABSTRACT
Drug-induced hypersensitivity syndrome (DIHS), also referred to as drug reaction with eosinophilia and systemic symptoms (DRESS), is a multi-organ systemic drug reaction characterized by hematological abnormalities and reactivation of human herpesvirus-6 (HHV-6). DIHS/DRESS is typically associated with a limited number of drugs, such as the anticonvulsants. Our group has treated 12 patients for DIHS/DRESS due to lamotrigine (LTG), but their presentation differed from that of patients with DIHS/DRESS caused by other drugs. The aim of the present study was to identify significant differences between DIHS/DRESS caused by LTG versus other drugs. We retrospectively reviewed data of 12 patients with DIHS/DRESS caused by LTG and 32 patients with DIHS/DRESS due to other drugs. The increase in alanine aminotransferase level was significantly milder in the LTG group than the DIHS/DRESS group due to other drugs. The percentage of atypical lymphocytes in the blood during DIHS/DRESS was lower in the LTG group. Serum levels of lactate dehydrogenase and thymus and activation-regulated chemokine were also lower in the LTG group. There were fewer DIHS/DRESS patients with HHV-6 reactivation in the LTG group than in the group treated with other drugs. Lymphocyte transformation after DIHS/DRESS onset was faster in the LTG group. The two groups did not differ with respect to the interval from first drug intake to rash, white blood cell count, blood eosinophilia or DRESS score. There were no significant histopathological differences between the two groups. The features of LTG-associated DIHS/DRESS and DIHS/DRESS due to other drugs differ.
Subject(s)
Anticonvulsants/adverse effects , Drug Hypersensitivity Syndrome/etiology , Lamotrigine/adverse effects , Adult , Drug Hypersensitivity Syndrome/blood , Epilepsy/drug therapy , Female , Humans , Leukocyte Count , Male , Middle Aged , Retrospective StudiesABSTRACT
OBJECTIVES: To clarify the surgical methods and the clinical results of subfascial endoscopic perforator surgery in Japan. METHODS: This study included 1287 limbs of 1091 patients who underwent subfascial endoscopic perforator surgery in 14 hospitals. Simultaneous saphenous vein treatment was performed in 1079 limbs (83.8%), and 118 limbs (9.2%) had deep venous lesions. The venous clinical severity score was calculated before and 6 to 12 months after surgery. The ulcer healing rate and ulcer recurrence rate were calculated cumulatively. RESULTS: Preoperative venous clinical severity score was significantly decreased from 10.0 ± 6.6 to 3.1 ± 3.4 ( P < .0001) postoperatively. The primary ulcer healing rate was 96.2% (332/345 C6 limbs) at an average follow-up of 47.7 months, and the ulcer recurrence rate was 12.0% (49/393 C5, C6 limbs) at the average follow-up of 46.0 months after the ulcer healed. CONCLUSION: These results indicate that subfascial endoscopic perforator surgery is an alternative to improve the long-lasting disease severity and/or clinical outcome.
Subject(s)
Endoscopy/methods , Endovascular Procedures/methods , Saphenous Vein/surgery , Varicose Ulcer/surgery , Adolescent , Adult , Aged , Aged, 80 and over , Female , Follow-Up Studies , Humans , Male , Middle AgedABSTRACT
BACKGROUND: In severe drug eruptions, precise evaluation of disease severity at an early stage is needed to start appropriate treatment. It is not always easy to diagnose these conditions at their early stage. In addition, there are no reported prognostic biomarkers of disease severity in drug eruptions. The aim of this study was to test whether the thymus and activation-regulated chemokine (TARC) level in serum at an early stage of a drug eruption can serve as a prognostic biomarker of systemic inflammation. METHODS: Study participants included 76 patients who received a diagnosis of a drug eruption, one of the following: drug rash with eosinophilia and systemic symptoms/drug-induced hypersensitivity syndrome, maculopapular exanthema, and erythema multiforme. Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) was eliminated in this study because scoring system for evaluating the severity was established. Correlation coefficients between serum TARC levels and indicators of systemic inflammation, including the neutrophil-to-lymphocyte ratio, Glasgow prognostic score, modified systemic inflammatory response syndrome (mSIRS) score, and C-reactive protein in serum were evaluated. RESULTS: Serum TARC levels positively correlated with the neutrophil-to-lymphocyte ratio, Glasgow prognostic score, mSIRS score, C-reactive protein, albumin, white blood cell count, body temperature, and pulse rate. TARC levels negatively correlated with systolic blood pressure. Among these parameters, the mSIRS score showed strong correlation (correlation coefficient: 0.68). CONCLUSIONS: Serum TARC levels correlate well with indicators of systemic inflammation and of disease severity among patients with a drug eruption except SJS/TEN. Serum TARC may be a prognostic biomarker of severity of inflammation in drug eruptions.
Subject(s)
Chemokine CCL17/blood , Drug Eruptions/blood , Systemic Inflammatory Response Syndrome/blood , Adolescent , Adult , Aged , Aged, 80 and over , Biomarkers/blood , Blood Pressure , C-Reactive Protein/metabolism , Child , Drug Eruptions/pathology , Drug Eruptions/physiopathology , Female , Humans , Leukocyte Count , Male , Middle Aged , Systemic Inflammatory Response Syndrome/pathology , Systemic Inflammatory Response Syndrome/physiopathologyABSTRACT
To investigate the trends of antimicrobial resistance in pathogens isolated from skin and soft-tissue infections (SSTI) at dermatology departments in Japan, a Japanese surveillance committee conducted the first nationwide survey in 2013. Three main organisms were collected from SSTI at 30 dermatology departments in medical centers and 10 dermatology clinics. A total of 860 strains - 579 of Staphylococcus aureus, 240 of coagulase-negative Staphylococci, and 41 of Streptococcus pyogenes - were collected and shipped to a central laboratory for antimicrobial susceptibility testing. The patient profiles were also studied. Among all 579 strains of S. aureus, 141 (24.4%) were methicillin-resistant (MRSA). Among 97 Staphylococcus epidermidis strains, 54 (55.7%) were methicillin-resistant (MRSE). MRSA and MRSE were more frequently isolated from inpatients than from outpatients. Furthermore, these methicillin-resistant strains were also isolated more frequently from patients with histories of taking antibiotics within 4 weeks and hospitalization within 1 year compared to those without. However, there were no significant differences in MIC values and susceptibility patterns of the MRSA strains between patients with a history of hospitalization within 1 year and those without. Therefore, most of the isolated MRSA cases at dermatology departments are not healthcare-acquired, but community-acquired MRSA. S. pyogenes strains were susceptible to most antibiotics except macrolides. The information in this study is not only important in terms of local public health but will also contribute to an understanding of epidemic clones of pathogens from SSTI.
Subject(s)
Anti-Bacterial Agents/pharmacology , Drug Resistance, Bacterial , Soft Tissue Infections/microbiology , Staphylococcal Skin Infections/microbiology , Staphylococcus aureus/drug effects , Streptococcal Infections/microbiology , Streptococcus pyogenes/drug effects , Cross-Sectional Studies , Dermatology , Hospitalization/statistics & numerical data , Humans , Japan/epidemiology , Methicillin-Resistant Staphylococcus aureus/drug effects , Microbial Sensitivity Tests , Soft Tissue Infections/epidemiology , Staphylococcal Skin Infections/epidemiology , Streptococcal Infections/epidemiologyABSTRACT
BACKGROUND: This study aims to evaluate the relationship between serum thymus and activation-regulated chemokine (TARC) levels with various clinicopathological conditions in patients with drug eruptions. The value of TARC in diagnosing drug-induced hypersensitivity syndrome (DIHS) was also examined. METHODS: Study participants included 84 patients who presented with generalized eruptions suspected to be drug-related, including DIHS, Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN), maculopapular exanthema (MPE), erythema multiforme (EM), erythroderma, and toxicoderma. The correlation coefficients between serum TARC levels and clinical parameters in peripheral blood samples were calculated. RESULTS: Serum TARC levels in patients with DIHS were higher than those found in patients with SJS/TEN, MPE, EM, and toxicoderma. TARC levels had 100% sensitivity and 92.3% specificity in diagnosing DIHS, with a threshold value of 13,900 pg/mL. Serum TARC levels positively correlated with age, white blood cell (WBC) count, neutrophil count, eosinophil count, monocyte count, atypical lymphocyte (Aty-ly) count, serum blood urea nitrogen (BUN) levels, and creatinine (Cr) levels. It negatively correlated with serum total protein (TP), albumin (Alb), and estimated glomerular filtration rate (eGFR). Among these clinical parameters, blood eosinophil counts were most strongly correlated with serum TARC levels, with a correlation coefficient of 0.53. CONCLUSIONS: Serum TARC levels are well correlated with blood eosinophil counts in patients with generalized drug eruptions, indicating that Th2-type immune reactions underlie TARC production. Serum TARC measurements also have potent diagnostic value for DIHS, with high sensitivity and specificity.
Subject(s)
Chemokine CCL17/blood , Drug Eruptions/blood , Eosinophils , Adolescent , Adult , Aged , Aged, 80 and over , Albumins/immunology , Albumins/metabolism , Child , Child, Preschool , Creatinine/blood , Creatinine/immunology , Drug Eruptions/immunology , Female , Humans , Leukocyte Count , Male , Middle Aged , Th2 Cells/immunology , Th2 Cells/metabolismABSTRACT
BACKGROUND: Varicose veins (VVs) cluster in families, but the familial risk of VVs has not been determined among adoptees. The aim was to estimate whether the familial transmission of VVs is related to disease in biological and/or adoptive parents. STUDY DESIGN: The Swedish Multi-Generation Register and the Swedish Patient Register were used to follow all Swedish-born adoptees (born 1932 through 2004) that could be linked to both their biological and their adoptive parents (n = 80,214; 50% females). The risk of VVs was estimated in adoptees with at least 1 biological parent with VVs, but no adoptive parent with VVs (n = 187) compared with adoptees without a biological or adoptive parent with VVs (n = 1,758). The risk of VVs was also determined in adoptees with at least 1 adoptive parent, but no biological parent with VVs (n = 87), and in adoptees with both biological and adoptive parents affected (n = 21). RESULTS: Adoptees from an affected biological parent, but no adoptive parent, were more likely to have VVs than adoptees from an unaffected biological or adoptive parent (standard incidence ratio [SIR] = 2.21; 95% CI, 1.91-2.55). The familial SIR for adoptees with both an affected biological parent and an adoptive parent was 4.58 (95% CI, 2.83-7.01). Adoptees with an affected adoptive parent but no biological parent were not at increased risk of VVs (SIR = 1.15; 95% CI, 0.92-1.42). CONCLUSIONS: These novel findings suggest that genetic factors make a strong contribution to the familial transmission of VVs from parents to offspring, although familial environmental factors might contribute.
Subject(s)
Varicose Veins/epidemiology , Varicose Veins/genetics , Adoption , Adult , Case-Control Studies , Female , Genetic Predisposition to Disease , Humans , Incidence , Male , Middle Aged , Parents , Risk Factors , Socioeconomic Factors , Sweden/epidemiology , Varicose Veins/therapyABSTRACT
PURPOSE: The infiltration of macrophages in skeletal muscle during exhaustive exercise promotes inflammation, myofiber lesion, and muscle injury. Although neutrophils upregulate macrophage infiltration in skeletal muscles during exercise, the role of neutrophils in promoting muscle injury after exhaustive exercise remains unclear. In this study, we investigated the effects of preexercise neutrophil depletion with antineutrophil antibody treatment on muscle injury, inflammation, and macrophage infiltration after exhaustive exercise. METHODS: Male C57BL/6J mice were randomly assigned to four groups, namely, sedentary with control antibody (n = 10), sedentary with antineutrophil antibody (n = 10), exhaustive exercise with control antibody (n = 10), and exhaustive exercise with antineutrophil antibody (n = 10). The mice were given intraperitoneal injection of the antineutrophil antibody (anti-Ly-6G, clone 1A8) or the control antibody (anti-Ly-6G, clone 2A3), and remained inactive or performed exhaustive exercise on a treadmill 48 h after the injection. Twenty-four hours after the exhaustive exercise, the gastrocnemius muscles were removed for histological and polymerase chain reaction (PCR) analyses. Infiltration of neutrophils and macrophages was evaluated with Ly-6G and F4/80 immunohistochemistry staining procedures. Muscle fiber injury was detected based on the number of IgG staining fiber. The mRNA expression levels of proinflammatory cytokines and chemokines were evaluated with real-time reverse transcription PCR. RESULTS: Exhaustive exercise increased neutrophil infiltration into the gastrocnemius muscle substantially by 3.1-fold and caused muscle injury, but these effects were markedly suppressed by preexercise treatment with antineutrophil antibody (neutrophil infiltration, 0.42-fold, and muscle injury, 0.18-fold). Treatment with antineutrophil antibody also decreased macrophage infiltration (0.44-fold) and mRNA expression of tumor necrosis factor-α (0.55-fold) and interleukin-6 (0.51-fold) in the skeletal muscle after exhaustive exercise. CONCLUSION: These results suggest that neutrophils contribute to exacerbating muscle injury by regulating inflammation through the induction of macrophage infiltration.
Subject(s)
Macrophages/physiology , Muscle, Skeletal/injuries , Neutrophils/physiology , Physical Conditioning, Animal/physiology , Animals , Inflammation/physiopathology , Interleukin-6/metabolism , Male , Mice, Inbred C57BL , Muscle, Skeletal/metabolism , Muscle, Skeletal/physiology , RNA, Messenger/metabolism , Random Allocation , Tumor Necrosis Factor-alpha/metabolismABSTRACT
Exhaustive exercise promotes muscle injury, including myofiber lesions; however, its exact mechanism has not yet been elucidated. In this study, we tested the hypothesis that macrophage depletion by pretreatment with clodronate liposomes alters muscle injury and inflammation following exhaustive exercise. Male C57BL/6J mice were divided into four groups: rest plus control liposome (n=8), rest plus clodronate liposome (n=8), exhaustive exercise plus control liposome (n=8), and exhaustive exercise plus clodronate liposome (n=8). Mice were treated with clodronate liposome or control liposome for 48 h before undergoing exhaustive exercise on a treadmill. Twenty-four hours after exhaustive exercise, the gastrocnemius muscles were removed for histological and PCR analyses. Exhaustive exercise increased the number of macrophages in the muscle; however, clodronate liposome treatment reduced this infiltration. Although exhaustive exercise resulted in an increase in injured myofibers, clodronate liposome treatment following exhaustive exercise reduced the injured myofibers. Clodronate liposome treatment also decreased the mRNA expression levels of inflammatory cytokines (TNF-α, IL-1ß, and IL-6) in the skeletal muscle after exhaustive exercise. These results suggest that macrophages play a critical role in increasing muscle injury by regulating inflammation.