Clinical outcomes and risk factors of hepatitis B virus recurrence in patients who received prophylaxis with entecavir and hepatitis B immunoglobulin following liver transplantation

INTRODUCTION

Although entecavir (ETV) and hepatitis B immunoglobulin (HBIG) have widely been used for prophylaxis of hepatitis B virus (HBV) recurrence following liver transplantation (OLT), there have been few studies about clinical outcomes and risk factors of HBV recurrence.

MATERIALS AND METHODS

This study retrospectively assessed clinical outcomes and identified risk factors of post-transplant HBV recurrence in 154 patients who received prophylaxis with both ETV and HBIG after OLT.

RESULTS

The median follow-up duration was 28.0 months (range, 1.0-57.8). Post-transplant HBV recurrence occurred in 5 patients (3.2%) without any ETV-resistant mutants. The overall rates of HBV recurrence at 1, 2, and 4 years were 0.6%, 1.6%, and 6.2%, respectively. We found that recurrent hepatocellular carcinoma (HCC) was an independent risk factor of HBV recurrence (hazard ratio = 13.5, 95% confidence interval, 2.4-74.4; P = .006).

CONCLUSIONS

Prophylaxis with a combination of ETV and HBIG resulted in a low HBV recurrence rate following OLT without any emergence of ETV-resistant mutants. Recurrent HCC was an independent risk factor of HBV recurrence in patients who received prophylaxis with both ETV and HBIG for prophylaxis following OLT.

Fate and transport of radiocesium, radiostrontium and radiocobalt on urban building materials

Kinetics of (137)Cs, (60)Co and (85)Sr sorption on powdered building materials in aqueous suspensions at 20 °C for interaction times of 1, 7, 14 and 28 days were studied. The (137)Cs distribution coefficient (Kd) values for all building materials except limestone practically did not change during 28 days of sorption. The Kd ((85)Sr) was several orders of magnitude lower than for (60)Co. The highest values were observed for asphalt and granite. An effective method to study the radionuclide distribution in depth of building materials using layer-by-layer sanding was developed. Using the developed method, the (137)Cs, (60)Co and (85)Sr distribution with depth of selected building materials at different air humidity, time and temperature was studied. Relative humidity (RH) was found to influence significantly the (85)Sr depth distribution in the case of granite (unlike (137)Cs and (60)Co). While (85)Sr penetrated to 0.5 mm in depth of granite at RH 30%, at RH 87% the depth of (85)Sr penetration to granite reached up to 7 mm.

Clinical characteristics of patients with tuberculosis-destroyed lung

SETTING

Multicentre study.

OBJECTIVE

To define the clinical characteristics of patients with tuberculosis (TB) destroyed lung due to past TB.

DESIGN

We reviewed patients with TB-destroyed lung between May 2005 and June 2011.

RESULTS

A total of 595 patients from 21 hospitals were enrolled. The mean age was 65.63 ± 0.47 (mean ± standard error); 60.5% were male. The mean number of lobes involved was 2.59 ± 0.05. Pleural thickening was observed in 54.1% of the patients. Mean forced vital capacity (FVC), forced expiratory volume in 1 s (FEV(1)), FEV(1)/FVC, bronchodilator response and number of exacerbations per year were respectively 2.06 ± 0.03 l (61.26% ± 0.79), 1.16 ± 0.02 l (49.05% ± 0.84), 58.03% ± 0.70, 5.70% ± 0.34, and 0.40 ± 0.04. The number of lobes involved was significantly correlated with FVC and FEV(1), and with the number of exacerbations per year. Use of long-acting muscarinic antagonists or long-acting beta-2 agonists plus inhaled corticosteroids resulted in bronchodilatory effects. Multivariable regression analysis showed that age, initial FEV(1) (%) and number of exacerbations during follow-up were independent factors affecting change in FEV(1).

CONCLUSION

Decreased lung function with exacerbation, and progressive decline of FEV(1) were observed in patients with TB-destroyed lung.

GenoType® MTBDRplus assay detection of drug-resistant tuberculosis in routine practice in Korea

SETTING

Korea is an intermediate-burden country with high rates of tuberculosis (TB) drug resistance.

OBJECTIVE

To evaluate the performance of the GenoType® MTBDRplus (MTBDR) assay in diagnosing drug-resistant TB in routine practice in Korea.

DESIGN

The MTBDR assay was performed on 428 samples, and the results were retrospectively compared with the results of conventional drug susceptibility testing (DST). The interval between treatment and diagnosis of drug resistance was also compared.

RESULTS

The sensitivity, specificity and positive and negative predictive values of the MTBDR assay were respectively 96.6%, 98.9%, 93.4% and 99.5% for the detection of rifampicin (RMP) resistance; 93.8%, 98.3%, 92.7% and 98.6% for isoniazid (INH) resistance; and 91.1%, 99.2%, 99.4% and 98.7% for multidrug-resistant TB (MDR-TB). The median interval between the start of anti-tuberculosis chemotherapy and the reporting of results was 88.9 days for conventional DST and 19.8 days for MTBDR using clinical specimens.

CONCLUSION

The specificity of the MTBDR assay in detecting MDR-TB was very high, although the sensitivity in detecting INH resistance and MDR-TB was not optimal (<95%). Although the turnaround time in detecting drug resistance was dramatically reduced with MTBDR compared to conventional DST, more effort is needed to shorten the turnaround time.

Lymph node ratio is an independent prognostic factor in patients with rectal cancer treated with preoperative chemoradiotherapy and curative resection

PURPOSE

To evaluate the prognostic effect of lymph node ratio (LNR) in patients with locally advanced rectal cancer who were treated with curative resection after preoperative chemoradiotherapy (CRT).

METHODS

Between October 2001 and December 2007, 519 patients who had undergone curative resection of primary rectal cancer after preoperative CRT were enrolled. Of these, 154 patients were positive for lymph node (LN) metastasis and were divided into three groups according to the LNR (≤ 0.15 [n=80], 0.16-0.3 [n=44], >0.3 [n=30]) to evaluate the prognostic effect on overall survival (OS) and disease-free survival (DFS).

RESULTS

LNR (≤ 0.15, 0.16-0.3, and >0.3) was significantly associated with 5-year OS (90.3%, 75.1%, and 45.1%; p<0.001) and DFS (66.7%, 55.8%, and 21.9%; p<0.001) rates. In a multivariate analysis, LNR (≤ 0.15, 0.16-0.3, and >0.3) was a significant independent prognostic factor for OS (hazard ratios [HRs], 1, 3.609, and 8.197; p<0.001) and DFS (HRs, 1, 1.699, and 3.960; p<0.001). LNR had a prognostic impact on OS and DFS in patients with <12 harvested LNs, as well as in those with ≥ 12 harvested LNs (p<0.05).

CONCLUSION

LNR was a significant independent prognostic predictor for OS and DFS in patients with locally advanced rectal cancer who were treated with curative resection after preoperative CRT.

Increased striatal dopamine transporter density in moderately severe old restless legs syndrome patients

BACKGROUND AND PURPOSE

Dopamine dysregulation in restless legs syndrome (RLS) may be varied by the severity of RLS, which could contribute to the conflicting results from previous functional neuroimaging studies on the central dopaminergic neurotransmission of RLS. The aim of this study was to observe whether reduced striatal dopaminergic neurotransmission is associated with moderate to moderately severe RLS.

METHODS

Thirteen elderly patients with RLS and 12 normal elderly controls were enrolled in the study. All the subjects were dopaminergic-drug naïve and twelve patients with RLS had the severity of moderate to moderately severe degree based on the International Restless Legs Syndrome Study Group (IRLSSG) Severity Scale. We compared dopamine transporter density (DAT) availability and D2 receptor density in the striatum between patients with RLS and controls using [(123)I]2β-carbomethoxy-3β-(4-iodophenyl)tropane single-photon emission computed tomography (SPECT) and [(123)I]iodobenzamide SPECT.

RESULTS

Dopamine transporter density of patients with RLS was increased in the caudate (P = 0.037), posterior putamen (P = 0.041), and entire striatum (P = 0.046) compared with that of normal controls. DAT density was higher in the anterior putamen of patients with RLS than controls, although statistically not significant (P = 0.079). There was no difference in the D2 receptor density between patients with RLS and normal controls in the whole striatum or any of subregions.

CONCLUSIONS

Dysregulation rather than simple upregulation or downregulation of central dopaminergic neurotransmission may underlie the pathogenesis of RLS, and decreased dopaminergic neurotransmission may cause moderate to moderately severe RLS in the elderly.

Chronic obstructive lung disease-related health care utilisation in Korean adults with obstructive lung disease

OBJECTIVES

The numbers of nationwide epidemiological surveys about chronic obstructive pulmonary disease (COPD) prevalence and prospective cohort studies for health care utilisation are limited. We investigated COPD-related health care utilisation in adults with obstructive lung disease in the second Korean National Health and Nutritional Survey (KNHANES II) in 2001 using Korean national medical insurance claim data.

METHODS

Among people aged >40 years, obstructive lung disease (OLD) is defined according to Global Initiative for Chronic Obstructive Lung Disease criteria. Data from a total of 1942 subjects were linked with Korean national medical insurance claims data, and we investigated their COPD-related out-patient visits from 2002 to 2005.

RESULTS

Among the 1942 subjects, 256 (13.2%) had airflow obstruction. COPD-related out-patient visits were reported for 8.2% of patients without airway obstruction, 18.1% of those with mild airway obstruction, and 33.9% of those with moderate to very severe airway obstruction. Multivariate analysis revealed that previous COPD diagnosis by a physician (OR 2.54; P = 0.02) and lower socio-economic status (OR 0.45; P = 0.02) were independent predictors of COPD-related out-patient visits in subjects with OLD.

CONCLUSIONS

Of the subjects with airway obstruction, those with poor financial status utilised COPD-related health care services less frequently, and those previously diagnosed as having COPD by a physician utilised the services more frequently.

Relative bioavailability of two 5-mg montelukast sodium chewable tablets: a single dose, randomized, open-label, 2-period crossover comparison in healthy korean adult male volunteers

Montelukast sodium, cysteinyl leukotriene receptor 1 specific antagonist, has been marketed in Korea for the treatment of bronchial asthma and allergic rhinitis. The aim of this study was to compare the pharmacokinetics and relative bioavailability of a test and reference formulation of montelukast 5-mg chewable tablets in healthy Korean male volunteers to meet KFDA regulatory criteria for marketing of the new generic formulation. This study was designed as a single-dose, 2-treatment, and 2-period crossover trial with 32 healthy volunteers. Each subject was randomly assigned to receive the test (Dong-Kook Montelukast Sodium Chewable Tablet 5 mg®) or reference (Singulair Chewable Tablet 5 mg®) formulation. The tablet was chewed 20 times, and then swallowed with 240 mL of water. Plasma concentrations of montelukast up to 24 h after the dose were determined using a validated UPLC-MS/MS method, and the bioequivalence between the 2 formulations was assessed by statistical analysis of mean ratios of log-transformed AUC0-24 h and Cmax. No period or sequence effects were detected. The AUC0-24 h was 1 835 ng·h/mL for the test formulation, and 1 930 ng·h/mL for the reference formulation. The respective values of AUC0-∞ were 1 917 and 2 015 ng·h/mL. The Cmax of the test and reference products (247 and 283 ng/mL, respectively) reached at 2.25 and 2.72 h, respectively. Then, they gradually decreased with the mean terminal t1/2 of 5.25 and 5.30 h for the test and reference products, respectively. The 90% CIs for the ratio of log-transformed AUC0-24 h and Cmax for the test and reference formulations were 0.92-0.99 and 0.83-0.91, respectively. No adverse events were reported in this study. This single dose study found that the test and reference products met the regulatory criteria for bioequivalence in these fasting healthy Korean male volunteers.

Co-morbid diabetes in patients with Crohn's disease predicts a greater need for surgical intervention

BACKGROUND

The prevalence of diabetes is increasing rapidly. Given its pro-inflammatory nature, comorbid diabetes may affect the course of Crohn's disease (CD).

AIM

To determine whether comorbid diabetes influences the natural history of CD.

METHODS

We compared a cohort with CD and comorbid diabetes to a nondiabetic control population and calculated the period prevalence of surgical intervention over a 5-year period. Unadjusted and adjusted odds-ratios were calculated regarding the need for surgical intervention using univariate and multivariate logistic regression.

RESULTS

A total of 240 patients were identified, 16 of whom were diabetics (6.7%). The period prevalence of CD-specific surgery in the diabetic cases was 75.0% and in the nondiabetic controls, 31.7%. The diabetic patients were more obese than the controls (44% vs. 10%; P < 0.0001) and older than the controls (47.4 years vs. 38.6; P < 0.01). There was no difference in the frequency of biologic therapy use, immunomodulator use, smoking, perianal disease, ileal involvement or corticosteroid use between the diabetics and controls. Univariate analysis revealed that diabetes (OR 6.46 [95% CI 2.01-20.8]), smoking (OR 2.46 [95% CI 1.24-4.90]), ileal disease (OR 2.21 [95% CI 1.15-4.24]) and obesity (OR 2.22 [95% CI 1.04-4.77]) were risk factors for needing surgery. After adjustment for covariates, the OR for surgical intervention in diabetics was 5.4 (95% CI 1.65-17.64).

CONCLUSION

Co-morbid diabetes in patients with Crohn's disease predicts a greater need for surgical intervention.

Non-tuberculous mycobacterial diseases presenting as solitary pulmonary nodules

SETTING

South Korea, 2005-2007.

BACKGROUND

Non-tuberculous mycobacterial diseases presenting as solitary pulmonary nodules (NTM-SPN) are rare and may be misdiagnosed as tuberculoma.

DESIGN

Eleven NTM-SPN patients were enrolled retrospectively and compared with two groups each of 33 patients with upper lobe cavitary (UC) and nodular bronchiectatic (NB) type NTM diseases, respectively.

RESULTS

The patients' median age was 52 years. Compared with UC-type disease, NTM-SPN patients showed female (n = 9) and never smoker (n = 8) predominance and fewer comorbidities (n = 0; P < 0.05 for each). Mycobacterium avium (n = 9) was predominant in NTM-SPN patients, followed by M. intracellulare (n = 2), whereas M. intracellulare was most frequently isolated from patients with both UC- and NB-type NTM (P < 0.05). The nodules were a median of 2.3 cm in diameter (range 1.6-6.3 cm) and were distributed evenly in all lobes. In all patients, percutaneous needle aspiration/biopsy was performed with a median 71 days of diagnostic delay. Ten patients successfully completed treatment, and one showed spontaneous reduction of nodule size without treatment. Reverse blot hybridisation assays of six DNA samples identified four subjects with M.avium-intracellulare complex (MAC), in line with conventional test data.

CONCLUSION

NTM-SPN was caused exclusively by MAC. Although clinical outcome was favourable, confirmatory diagnosis was delayed. Molecular methods are needed for early diagnosis of NTM-SPN.

Characterization of filamentous bacteriophage PE226 infecting Ralstonia solanacearum strains

AIMS

The aim of this study was to isolate and characterize new bacteriophages that infect a wide range of plant pathogenic Ralstonia solanacearum strains.

METHODS AND RESULTS

Fifteen bacteriophages were isolated from pepper, tomato and tobacco plant rhizospheres infected with R. solanacearum. A host specificity analysis of the isolated phages using nine strains of R. solanacearum indicated great phage diversity in a single soil. Two phages, PE226 and TM227, showed clear plaques on all nine bacterial hosts tested and were virtually identical in morphology and genome. PE226, an Inovirus, is a long, flexible, filamentous phage carrying a circular (+) sense single-strand DNA genome of 5475 nucleotides. DNA sequences of PE226 exhibited nine open reading frames (ORF) that were not highly similar to those of other phages infecting R. solanacearum. The genome organization of PE226 was partially similar to that of p12J of Ralstonia pickettii. One ORF of PE226 showed identity to the zot gene encoding zonula occludens toxin of Vibrio cholera. Orf7 of PE226 was also present in the genome of R. solanacearum strain SL341. However, SL341, a highly virulent strain in tomato, was still sensitive to phage PE226.

CONCLUSIONS

A new, flexible, filamentous phage PE226 infected wide range of R. solanacearum strains and carried unique circular single-strand DNA genome with an ORF encoding Zot-like protein.

SIGNIFICANCE AND IMPACT OF THE STUDY

PE226 may be a new type of temperate phage, based on its lytic nature on a wide range of hosts and the presence of a zot homologue in a host bacterial genome.

Association of the G-protein and α2-adrenergic receptor gene and plasma norepinephrine level with clonidine improvement of the effects of diuretics in patients with cirrhosis with refractory ascites: a randomised clinical trial

OBJECTIVE

Clonidine is an α(2)-adrenoceptor agonist which, by coupling with G-protein, has been proposed as an alternative treatment for refractory ascites of patients with cirrhosis for several years. Genetic polymorphisms of β-adrenoceptor and angiotensin II type 1 receptor blockers have been reported to affect drug response in patients with cirrhosis. This study evaluated the clonidine-diuretic response rate, favourable predictors and genetic components of the clonidine-diuretic response in patients with cirrhosis with refractory ascites.

METHODS

270 patients with cirrhosis with refractory ascites were randomised equally into two treatment groups to receive diuretics alone or the clonidine-diuretics association. The primary end point was clonidine-diuretic response rate. Secondary end points were mean daily dose of diuretics, times of paracentesis, ascites-related readmission and 1-year survival rate.

RESULTS

Good clonidine responders had better natriuresis and diuresis as well as a significant decrease in abdominal circumference, plasma renin, aldosterone and norepinephrine levels. The overall clonidine-diuretics response rate was 55-60%. In patients with cirrhosis, the prevalence of ARDA(2)C WD/DD and GNB3 CT/TT genotypes was 71% and 77%, respectively. Among the responders, 71% of patients with cirrhosis had the ARDA(2)C WD/DD genotype and 67% has the GNB3 CT/TT genotype. Besides higher baseline norepinephrine levels, the presence of both ARDA(2)C WD/DD and GNB3 CT/TT genotypes showed a positive predictive value of 82% and a negative predictive value of 79% for good clonidine response.

CONCLUSIONS

These results suggest that neurohormonal and genetic testing may be used as predictive factors for the additive effects of clonidine on the diuresis and natriuresis effects of diuretics in patients with cirrhosis with refractory ascites.

Changes in the organ procurement system in South Korea: effects on brain-dead donor numbers

In Korea, the Organ Transplantation Act came into effect in 2000, establishing the Korean Network for Organ Sharing (KONOS) with centralized authority for organ procurement as well as for approval of donors and recipients to ensure fair organ allocation. However, the number of brain-dead donors decreased sharply, and the organ allocation system proved inefficient. The government revised the Organ Transplantation Act in August 2002, introducing an incentive system. If a transplantation hospital formed a Committee for Brain Death Evaluation and a Hospital Organ Procurement Organization, it could receive a kidney from a brain dead-donor as an incentive to foster organ procurement regardless of the KONOS wait list. The government also launched a pilot brain-dead donor registry program to strengthen Hospital Organ Procurement Organization activity. If local hospitals collaborated with specialized hospitals in organ procurement, local hospitals obtained financial incentives. But because the organ shortage problem has not been resolved, the government has proposed four initiatives: first, broadening the incentive system, which makes it possible to give each specialized hospital a choice of one of eight organs from each donor as an incentive; second, development of an Independent Organ Procurement Organization; third introduction of an opt-out system; and last, improvement of the Committee for Brain Death Evaluation system. It is uncertain which initiatives will be adopted, but changes in organ procurement systems are nonetheless considered a key to solve the organ shortage problem in Korea.

An outbreak of highly pathogenic avian influenza at a public animal exhibit in seoul, Korea, during 2008

This study describes the first recorded outbreak of HPAI in the city of Seoul, in captive birds held in an exhibition for public viewing at a local district office. The index cases were two pheasants, which had been introduced into the exhibit on 24 April, 4 days prior to death, from a store in a local market in Gyeonggi-do. Ducks and chickens from an HPAI outbreak farm, subsequently confirmed on 4 May, had also been held in this store. This outbreak highlights the potential role of local markets in AIV transmission. This outbreak led to considerable public health concern in Korea, however, no human cases were reported. The non-commercial poultry sector needs to be considered in national plans for preparedness and response.

Combined use of QuantiFERON-TB Gold assay and chest computed tomography in a tuberculosis outbreak

OBJECTIVE

To evaluate the value of the QuantiFERON-TB Gold (QFT-G) assay and chest computed tomography (CT), in addition to the conventional use of the tuberculin skin test (TST) and chest radiography (CXR), in a contact investigation of a tuberculosis (TB) outbreak.

DESIGN

In a contact investigation of a TB outbreak in a high school, TST and CXR were performed on all 1044 employees and students. QFT-G was performed on TST-positive subjects, and CT on QFT-G-positive subjects and students with TST > or =20 mm.

RESULTS

TST was positive in 388 subjects (37.2%), while QFT-G was positive in 7.6% (30/394). CXR showed abnormal findings suggestive of TB in 10 (1.0%) subjects, all of whom were TST-positive and six of whom were QFT-G-positive. Findings suggestive of active TB were noted in 17 (32.7%) of 52 subjects by CT. Collectively, among 21 (1.1%) TB patients, all were TST-positive, 12 (57.1%) were QFT-G-positive and active TB was diagnosed by CT, and not by CXR, in 11 subjects.

CONCLUSION

Compared to the conventional approach, the additional use of QFT-G in TST-positive subjects and chest CT in subgroups with a high probability of infection was found to be more effective in the differentiation between active TB, latent TB and non-infected subjects in a contact investigation.

Clinical course and lung function change of idiopathic nonspecific interstitial pneumonia

Most studies of idiopathic nonspecific interstitial pneumonia (NSIP) have primarily studied mortality. In order to clarify the detailed outcome and prognostic markers in idiopathic NSIP, the clinical course with initial radiological and clinical features was analysed. The clinical course of 83 patients who were classified with idiopathic NSIP (72 fibrotic, 11 cellular; 27 males and 56 females; mean+/-sd age 54.4+/-10.1 yrs) was retrospectively analysed. In fibrotic NSIP, 16 (22%) patients died of NSIP-related causes with a median (range) follow-up of 53 (0.3-181) months. Despite the favourable survival (5-yr 74%), patients with fibrotic NSIP were frequently hospitalised with recurrence rate of 36%. Reduced forced vital capacity at 12 months was a predictor of mortality. On follow-up, lung function was improved or stable in approximately 80% of the patients. The extent of consolidation and ground-glass opacity on initial high-resolution computed tomography correlated significantly with serial changes of lung function, and the presence of honeycombing was a predictor of poor prognosis. During follow-up, eight (10%) patients developed collagen vascular disease. In conclusion, the overall prognosis of fibrotic nonspecific interstitial pneumonia was good; however, there were significant recurrences despite initial improvement and a subset of the patients did not respond to therapy. Some patients developed collagen vascular diseases at a later date.

Impacts of peripheral obestatin on colonic motility and secretion in conscious fed rats

Obestatin, a novel putative 23-amino acid peptide, was found to be derived from a mammalian preproghrelin gene by using a bioinformatics approach. Although the effects of obestatin on food intake and upper gut motility remain controversial, no studies have been carried out to explore its influence on lower gut motility and secretion. We investigated the impacts of intravenous (IV) injection of obestatin on rat colonic motor and secretory functions. Colonic transit time, fecal pellet output, and fecal content were measured in freely fed, conscious rats, which were chronically implanted with IV and colonic catheters. To test the validity of this animal model, human/rat corticotropin-releasing factor (h/rCRF) served as a stimulatory inducer of colonic motility and secretion. IV injection of obestatin (45, 100, and 300 nmol/kg) did not affect the colonic transit time, whereas IV injection of h/rCRF (30 nmol/kg) effectively accelerated colonic transit time. IV obestatin, in every dose we tested, also did not modify fecal pellet output, frequency of watery diarrhea, total fecal weight, fecal dried solid weight, or fecal fluid weight in the first hour after injection. On the other hand, IV injection of h/rCRF significantly enhanced fecal pellet output, as well as increased the frequency of watery diarrhea, total fecal weight, fecal dried solid weight, and fecal fluid weight during the first hour after injection compared with IV saline controls. In conclusion, peripheral obestatin administration has no impact on colonic motility and secretion in conscious fed rats.

Pulmonary tuberculosis with acute respiratory failure

The aim of the present study was to evaluate the clinical characteristics, prognoses and predictors of mortality of patients with pulmonary tuberculosis (TB) with acute respiratory failure (ARF), and to investigate the adjunctive use of corticosteroids in such cases. TB patients with ARF requiring mechanical ventilation (n = 90) were enrolled retrospectively during 1989-2006. The patients were divided into two groups: tuberculous pneumonia (TBP; n = 66), and miliary TB (MTB; n = 24). The TBP patients were older than the MTB patients (mean age 68.0 versus 54.5 yrs), and the mean+/-SD interval from hospital admission to start of anti-TB treatment was longer for the TBP than for the MTB group (5.0+/-7.0 versus 2.8+/-2.5 days). However, there was no difference in in-hospital mortality rate between the two groups (68.2 versus 58.3%). In the TBP patients, multivariate analysis showed that advanced age and shock unrelated to sepsis were associated with poor outcomes. Even though corticosteroid use was a predictor of survival in TBP patients, it was difficult to conclusively determine the efficacy of corticosteroids in TBP with ARF because of the retrospective study design. The present study reveals the need for randomised controlled trials to clarify the role of corticosteroids as adjunctive therapy in the management of tuberculous pneumonia with acute respiratory failure.

Incidence of tuberculosis among health care workers at a private university hospital in South Korea

SETTING

A private university hospital in South Korea.

OBJECTIVE

To investigate the incidence of tuberculosis (TB) among health care workers (HCWs) employed at a university hospital in South Korea.

DESIGN

The occurrence of TB cases among HCWs over a 6-year period (2001-2006) was reviewed. The prevalence of TB was compared with that of the general population using a prevalence ratio (PR) adjusted by age and sex.

RESULTS

The study involved 8433 people. TB developed in 61 HCWs (0.72%). The prevalence ratio among all HCWs was 1.05 (95%CI 0.80-1.35). In occupational subgroups, the PRs for doctors, nurses and employees in other departments were respectively 0.58 (95%CI 0.30-1.01), 1.81 (95%CI 1.21-2.59) and 0.95 (95% CI 0.58-1.46). For nurses working in TB-related departments, the relative risk of developing TB was 3.4 times higher (95%CI 1.52-8.25) than for employees in other departments (P=0.005). The PR for nurses working in TB-related department was 5.1 (95%CI 3.23-8.42).

CONCLUSION

Among HCWs, nurses working in TB-related departments were at increased risk of developing TB. This suggests that some TB develops via in-hospital infection.

Impact of short-term exposure to fluoroquinolones on ofloxacin resistance in HIV-negative patients with tuberculosis

SETTING

Seoul, Korea, a country with an intermediate tuberculosis (TB) burden and low prevalence of human immunodeficiency virus (HIV) infection.

OBJECTIVES

To determine the frequency of ofloxacin (OFX) resistance in Mycobacterium tuberculosis, and to assess whether short-term use of fluoroquinolones (FQNs) induces ofloxacin-resistant M. tuberculosis.

DESIGN

The subject cohort consisted of 2788 patients with culture-confirmed TB with drug susceptibility testing data; only four were HIV-positive. The patients were divided into two groups: those who were or were not recently exposed to FQNs.

RESULTS

Of the 2788 isolates, the rates of OFX resistance were 1.1% and 8.5% in initially treated and retreated patients, respectively (P < 0.05). Of the 94 OFX-resistant isolates, 83 (88.3%) were multidrug-resistant (MDR). There was no difference in rates of OFX resistance throughout the study period, or between the FQN-exposed (1/39, 2.6%) and control groups (93/2749, 3.4%). The median duration of FQN treatment was 7 days (range 1-47 days). One OFX-resistant isolate in the FQN-exposed group was MDR.

CONCLUSION

The rate of OFX-resistant M. tuberculosis was low and stationary throughout the study period in Korea. Most OFX resistance was accompanied by MDR, and the frequency of OFX-resistant M. tuberculosis was low in subjects taking short-term FQNs.

4-1 BB stimulation inhibits allergen-specific immunoglobulin E production and airway hyper-reactivity but partially suppresses bronchial eosinophilic inflammation in a mouse asthma model

BACKGROUND

4-1 BB, a member of the tumour necrosis factor receptor superfamily, functions as a co-stimulatory molecule. Recently, stimulation of the 4-1 BB pathway was shown to suppress antigen-specific CD4(+) T cell and subsequent T cell-dependent humoral immune responses.

OBJECTIVE

We examined the effect of agonistic anti-4-1 BB monoclonal antibody (mAb) treatment on allergic asthma, in which allergen-specific type 2 helper T cells (Th2) have been shown to play an important role.

METHODS

BALB/c mice were systemically sensitized with intraperitoneal injections of ovalbumin (OVA) and alum on days 0 and 14, and then challenged with inhaled OVA on days 28, 29 and 30. In test groups, the agonistic anti-4-1 BB mAb was administered at the time of initial systemic sensitization with OVA. On day 31, mice were challenged with inhaled methacholine, and enhanced pause was measured as an index of airway hyper-responsiveness (AHR). Levels of OVA-specific IgE in serum, and levels of various cytokines in bronchoalveolar lavage (BAL) fluids were measured. The severity of airway inflammation was determined by differential cell counts in BAL fluids and histopathologic lung analysis. To evaluate local immunity, we cultured lymphocytes from draining perihilar lymph nodes and evaluated the proliferative response to OVA and the levels of IL-5 in the culture supernatant. In addition, the functional mechanism of 4-1 BB stimulation was evaluated in splenocytes obtained at day 7 after systemic OVA sensitization.

RESULTS

We found that treatment with the anti-4-1 BB mAb significantly decreased AHR and the production of allergen-specific IgE. Bronchial inflammation, however, had only partially improved and the levels of IL-4 and IL-5 in BAL fluids showed only a small degree of reduction compared with the control Ig-treated mice. Thoracic lymphocytes from anti-4-1 BB-treated mice showed significant suppression of OVA-induced proliferation and IL-5 production. In anti-4-1 BB-treated mice, splenocytes exhibited poor proliferation and marked apoptosis 7 days after systemic OVA challenge.

CONCLUSION

These results suggest that stimulation of the 4-1 BB pathway effectively suppresses some features of allergic asthma, including allergen-specific IgE production and AHR, through deletion of allergen-specific Th2 cells. However, we found that bronchial allergic inflammation was not strictly mediated by suppression of the Th2 immune response in this murine model of asthma. Despite these somewhat contradictory effects, intervention in the 4-1 BB pathway might provide a potential novel immunotherapeutic approach for treatment of allergic asthma.

Comparison of two commercial interferon- assays for diagnosing Mycobacterium tuberculosis infection

The clinical usefulness of ex vivo interferon-gamma assays may largely depend on the assay format and epidemiological status of tuberculosis (TB) in the region studied. From July 2004 to June 2005 a prospective comparison study was undertaken at a tertiary referral hospital in South Korea. The results of tuberculin skin tests (TST) and the commercially available QuantiFERON-TB Gold (QFT-G) and T SPOT-TB (SPOT) assays were compared in an intermediate TB-burden country. Of the 224 participants studied, results from all three tests (TST, QFT-G, and SPOT) were available in 218; 87 with active TB and 131 at a low risk for TB. Using 10 mm as a cut-off for TST, SPOT sensitivity (96.6%) was significantly higher than that seen for TST (66.7%) and QFT-G (70.1%). QFT-G showed superior specificity over TST (91.6 versus 78.6%). Although the specificity of QFT-G was higher than that of SPOT (91.6 versus 84.7%), the difference was not statistically significant. Whilst some differences were found in the performance of the two commercialised interferon-gamma assays, they seemed to be superior in their detection of Mycobacterium tuberculosis infection compared with tuberculin skin tests. The most appropriate choice of interferon-gamma assay to use may depend on the clinical setting.