An-Shen Lin

A cluster of patients with severe acute respiratory syndrome in a chest ward in southern Taiwan

ObjectiveSevere acute respiratory syndrome (SARS) is an emerging and easily clustering infectious disease. We describe an outbreak of SARS in a chest ward of a medical center in southern Taiwan and seek to identify the risk factors of those SARS patients who required mechanical ventilation. We focus on previous health patients.DesignThis retrospective case series was collected during the SARS outbreak. Degrees of severity were established, based on whether intubation and mechanical ventilation was necessary.SettingA 2500-bed medical center in southern Taiwan.PatientsForty-four patients exhibited symptoms that met the modified World Health Organization (WHO) definition of SARS. These included of three subgroups: health-care workers (n=16), relatives (n=14), and patients already admitted for other ailments (n=14). Of these, 20 eventually required mechanical ventilation.Measurements and resultsLaboratory analyses showed statistically significant differences between intubated and nonintubated patients in white blood cell count, neutrophil percentage, and C-reactive protein level as well as in age and underlying malignancy. Risk factors for SARS patients who had been healthy prior to their illness included old age, high peak fever grade, increased neutrophil count, increased neutrophil percentage, and close or prolonged contact with a SARS patient.ConclusionsOld age, high white blood cell counts, high peak grade fever, and close or prolonged contact with a SARS patient increase the risk of intubation in previous healthy SARS patients.

Aberrant Toll-like receptor 2 promoter methylation in blood cells from patients with pulmonary tuberculosis

OBJECTIVES Toll-like receptor 2 (TLR2) is a major mediator of innate immunity against tuberculosis (TB). This study aimed to determine if TLR2 promoter DNA methylation is associated with pulmonary TB. METHODS The DNA methylation levels of 20 CpG sites over the TLR2 promoter region and TLR2 gene/protein expressions of immune cells of the blood were examined in 99 sputum culture-positive pulmonary TB patients and 77 healthy subjects (HS). RESULTS TB patients had higher methylation levels over five CpG sites (3, 7, 9, 13, and 18), lower TLR2 gene expression, lower TLR2 expression on monocyte, higher TLR2 expression on NK cell, and higher serum TNF-α/IFN-γ levels than HS after adjusting for confounding factors. Patients with a high bacillary load had lower methylation levels at CpG-15, -17, and -20. Patients with drug-resistant TB had higher CpG-18 methylation levels and lower TLR2 expression on NK cell. Patients with far advanced lesion on chest radiograph had higher serum TNF-α level and higher TLR2 expression on NK cell. Patients with a high TLR2 expression on NK cell had lower one-year survival. CpG-18 methylation level, TLR2 expressions on monocyte/NK cell, and TNF-α/IFN-γ levels were all reversed to normal after 6-month anti-TB treatment. CONCLUSIONS Aberrant methylation of certain CpG sites over TLR2 promoter region is associated with active pulmonary TB or its phenotypes, probably through the down-regulation of TLR2 expression.

Risk factors of multidrug-resistant Acinetobacter baumannii recurrence after successful eradication in ventilated patients

Background Clinically, multidrug-resistant Acinetobacter baumannii (MDR-AB) recurrence is found in some patients although identified as successfully eradicated. We aim to discover the characteristics of patients with MDR-AB recurrence in the respiratory tract. Methods We retrospectively collected 106 chronic respiratory failure patients with MDR-AB harvest in pulmonary secretion culture. Results MDR-AB was successfully eradicated in 69 patients. Diabetes mellitus (p = 0.030, odds ratio [OR]: 2.7, 95% confidence interval [CI]: 1.1–6.4) and acute respiratory distress syndrome (p = 0.001, OR = 4.8, 95% CI: 1.8–12.7) reduce the MDR-AB eradication rate. Besides, a classification of colonization or infection was made beyond the 69 MDR-AB eradicated patients. In the colonization group, diabetes mellitus (p = 0.009; OR = 5.1, 95% CI: 1.5–17.6) is the only independent factor to increase the recurrence rate. Glycated hemoglobin level is also analyzed for each group to investigate diabetes control effect, but no significant difference found. Conclusions Diabetes mellitus is a risk factor of MDR-AB recurrence among MDR-AB-colonized patients; the impact of localized pneumonia patch in MDR-AB-infected patients requires further study to be clarified.

Exercise Capacity and Pulmonary Function in Hospital Workers Recovered from Severe Acute Respiratory Syndrome

Background: Persistent impaired pulmonary function and functional capacity are common among survivors of severe acute respiratory syndrome (SARS). Whether the impairment was caused by SARS or pre-existing physical condition remains unclear. Objective: This study investigated the influence of SARS on exercise capacity and pulmonary function of previously healthy medical staff.Methods: Pulmonary function tests, including spirometry and carbon monoxide diffusing capacity (DLCO), as well as symptom-limited cardiopulmonary exercise testing (CPET) with an incremental protocol using an electronically braked cycle ergometer, were performed by 13 previously healthy hospital workers 14 months after SARS recovery. Other 14 age- and sex-matched healthy medical workers completed CPET simultaneously, and exercise capacities of these two groups were compared. Results: Most values of spirometry performed were within normal range. Only one showed mildly restrictive abnormality with decreased forced expiratory volume in 1 s (72.2% predicted) and forced vital capacity (68.1% predicted). Eight subjects had decreased DLCO levels (mean 79.37 ± 7.73%), and low exercise capacity was noted in 9 subjects. Discordance in impairment of the measured DLCO and exercise capacity was revealed by comparison. Besides, there was no significant difference in results of CPET between subjects recovered from SARS and those never infected. Conclusions: Minor pulmonary function defects as well as decreased exercise capacity were detected in previously healthy medical staff after recovering from SARS. No significant correlation between exercise capacity and pulmonary function was found.

Risk Factors and Outcomes of Patients with Prolonged Mechanical Ventilation after Successful Weaning

Prolonged mechanical ventilation (PMV) places a large burden on patients, families, and healthcare resources. Some of these patients are successfully weaned and discharged, but some experience recurrent respiratory failure and undergo reinstitution of mechanical ventilation (MV). The purpose of this paper is to identify the risk factors that lead to reinstitution of MV in patients who have undergone successful weaning, and to evaluate their outcome. From January 2006 to December 2007, 314 patients were successfully weaned in the respiratory care center (RCC) of Chang Gang Memorial Hospital. Patients with reinstitution of MV were compared to patients without reinstitution of MV to identify the risk factors that lead to reinstitution. The observation period was from the day of RCC admission to the day of discharge from the hospital. Of the 314 patients, 133 (42.4%) underwent reinstitution of MV due to recurrent respiratory failure, and 181 (57.6%) were discharged without reinstitution. Patients without tracheostomy (p＜0.005) had an increased incidence of reinstitution. Seventeen percent of PMV patients expired during RCC admission and 78 (58.7%) of the 133 patients that received reinstitution of MV expired during hospitalization. The incidence of MV reinstitution after successful weaning is increased in patients without tracheostomy and in those with congestive heart failure as the cause of acute respiratory failure. The prognosis of patients with MV reinstitution is poor.

Pulmonary Granulomatous Inflammation and Unexplained Repeated Infections-A Case of Chronic Granulomatous Disease

Chronic granulomatous disease (CGD) is a rare inherited disorder caused by a failure of intracellular superoxide production by phagocytes. It is usually identified in early childhood with severe recurrent bacterial and fungal infections. We present a case of CGD in a young male adult in whom the disease initially presented with left middle lung consolidation with cavitation. The patient had a history of unexplained repeated infection (including liver abscess and submandibular cellulitis at the age of 17 and 19 years). A specimen of cutting biopsy of the lung showed granulomatous inflammation. Pulmonary granuloma is a common manifestation of tuberculosis in Taiwan, but no acid-fast bacilli were identified by Ziehl-Neelsen staining in a specimen of sputum and cutting biopsy. In addition, no autoimmune disease was detected. The patient had negative respiratory burst activity in the polymorphonuclear leukocyte function test, a low response in the chemiluminescence test, and a normal finding in the chemotaxis assay, so the diagnosis of CGD was finally established. CGD rarely starts presenting in adulthood, either because it is not well-recognized in non-pediatric chest wards or because of the administration of potent antimicrobials that unintentionally treat many CGD-associated infections, postponing the diagnosis until more severe infections occur. Therefore, any adolescent or adult with unexplained and repeated infections that are accompanied by granuloma formation should be checked for phagocyte function defects. Early diagnosis of CGD is important because of the benefits of timely treatment and infection prophylaxis.

Pulmonary Function and Exercise Capacity of a Physician Who Recovered From Severe Acute Respiratory Syndrome

Severe acute respiratory syndrome (SARS) is a new infectious disease with its initial worldwide outbreak in 2003. At that time (29 April to 26 May), there were 44 identified SARS patients, including 16 healthy hospital workers, in a nosocomial outbreak in a 2,500-bed medical center (Kaohsiung Chang Gung Memorial Hospital) in southern Taiwan Two medical workers developed acute respiratory distress syndrome (ARDS) and required intubation. Only 1 survived and later recovered. We followed up this patient with pulmonary function tests (PFTs), including spirometry and diffusing capacity, and high resolution computed tomography (HRCT) at 1 and 14 months after hospital discharge. A cardiopulmonary exercise test was performed at 14 months. Diffusing lung capacity for carbon monoxide (DLCO) was mildly impaired at the 1-month follow-up (77.33%), but returned normal at the 12-month follow-up (82.60%). FEV1 and FEV1/FVC were within normal range, although minimal fibrosis was detected on the HRCT. Exercise capacity was normal, including the patients recovery of physical fitness.