Sung Youn Kwon

Nutritional deficit as a negative prognostic factor in patients with miliary tuberculosis

The effects of malnutrition on outcomes in miliary tuberculosis (MTB) are not well described. The aim of the present study was to find predictors for the development of acute respiratory failure (ARF) and survival in MTB patients, focusing on parameters reflecting nutritional condition. Out of the patients from three hospitals who had microbiologically or histopathologically confirmed tuberculosis, 56 patients presenting with typical disseminated pulmonary nodules on radiographs were retrospectively enrolled. A four-point nutritional risk score (NRS) was defined according to the presence of four nutritional factors: low body mass index (BMI; <18.5 kg·m−2), hypoalbuminaemia (<30.0 g·L−1), hypocholesterolaemia (<2.33 mmol·L−1) and severe lymphocytopenia (<7×105 cells·L−1). The male to female ratio was 1:3. ARF developed in 25% of patients (14 out of 56), with a 50% fatality rate. A high NRS (≥3 points) was an independent risk factor for the development of ARF and fatality. In 90-day survival analysis, ARF, severe lymphocytopenia, hypocholesterolaemia, low BMI and higher NRS were risk factors for poor outcome. In multivariate analysis, only high NRS was an independent risk factor for 90-day survival rate in patients with MTB. A high nutritional risk score was a good predictor of poor outcome in miliary tuberculosis patients. Additional approaches to recover the nutritional deficits may become a focus in future management of miliary tuberculosis.

Impact of Toxocariasis in Patients with Unexplained Patchy Pulmonary Infiltrate in Korea

Toxocariasis is one of the causes of pulmonary eosinophilic infiltrate that is increasing in Korea. This study was designed to identify the prevalence of toxocara seropositivity in patients with unexplained pulmonary patchy infiltrate and to evaluate associated factors. We evaluated 102 patients with unexplained pulmonary patchy infiltrate on chest computed tomography (CT) scan. As a control set, 116 subjects with normal chest CT were also evaluated. History of allergic disease, drug use, parasitic disease and raw cow liver intake were taken. Blood eosinophil count and total IgE level were measured. Specific serum IgG antibody to Toxocara canis larval antigen and specific IgG antibodies to 4 other parasites were measured by enzyme-linked immunosorbent assay (ELISA). In the infiltrate group, 66.7% subjects were toxocara seropositive whereas 22.4% of the control group were seropositive (p<0.001). In the infiltrate group, patients with a history of eating raw cow liver (odds ratio [OR], 7.8) and patients with eosinophilia (OR, 5.2) had a higher incidence of toxocara seropositivity. Thirty-five percent of toxocara seropositive patients with infiltrate exhibited migrating infiltrate and 48% had decreased infiltrate on the follow-up CT. We recommend that toxocara ELISA should be performed in patients with unexplained pulmonary patchy infiltrate, and that the eating of raw cow liver should be actively discouraged.

Nested PCR in lung tissue for diagnosis of pulmonary tuberculosis.

Diagnosis of pulmonary tuberculosis (TB) is difficult in cases with an unusual presentation and often requires a lung biopsy. The goal of this study was to determine the clinical usefulness of nested PCR on lung tissue for the diagnosis of pulmonary TB. Clinical and laboratory data were reviewed from patients who underwent diagnostic lung biopsies, followed by nested TB PCR on formalin-fixed paraffin-embedded lung tissue specimens. The diagnostic yield and clinical impact of nested PCR were investigated. Of the 223 patients studied, 142 were diagnosed with TB. Microbiologically confirmed TB was identified in 71 patients. Compared to culture results, the sensitivity, specificity, positive predictive value and negative predictive value of nested PCR were 85%, 99%, 98% and 88%, respectively. Nested PCR was more sensitive than acid-fast bacilli smear of respiratory specimens and histopathological findings. The PCR results provided an early diagnosis and initiation of treatment for TB. However, negative PCR results did not lead to discontinuation of unnecessary TB treatment in patients on medication. In conclusion, nested PCR on lung tissue specimens is a useful diagnostic test for pulmonary TB in patients with an unusual presentation.

Thoracic nodal staging in non-small cell lung cancer by FDG-PET

Background : Current non-invasive methods for evaluating the mediastinum by computed tomographic (CT) scan have limited sensitivity and specificity. The recently introduced PET was reported to be a more sensitive and specific method for the mediastinal staging of NSCLC (sensitivity : 76-100 %, specificity : 81-100%) than CT or MRI. We assessed the usefulness of PET in the mediastinal staging of NSCLC. Methods : We reviewed the medical records of NSCLC patients that had undertaken staging work-up by both CT and PET before thoracotomy between January 1997 and December 1998. A total of 23 patients were enrolled in the study (14 males and 7 females) with a mean age of 619 years. By comparing the clinical(CT and PET) and pathologic stagings, we evaluated the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of PET in thoracic nodal staging. Results : Sensitivity, specificity, positive predicted value and negative predicted value were 38%, 40%, 25% and 50% respectively for computed tomography, and 50%, 60%, 30% and 69% for PET. The accuracy of FDG-PET in our study was lower than that reported by previous other studies. Conclusion : The addition of FDG-PET to CT scanning has limited benefit for the thoracic nodal staging of NSCLC, but its value in our study was lower than that observed by others.

The Usefulness of Serologic Diagnosis for Tuberculosis with Two Rapid Immunochromatographic Assay Devices

Background: Many diagnostic tests have developed to diagnose tuberculosis and other mycobacterial diseases but the diagnosis of tuberculosis relies largely on radiological findings and acid-fast staining of sputum and/or culture. Recently, new serologic diagnostic methods, which are safe and easy to use have been introduced into Korea. In this study, the usefulness of serologic diagnosis for tuberculosis and the disease pattern induced variation of the test were evaluated. Methods: Serological assay was performed upon 108 patients with two test kits, the ICT tuberculosis and the BioSignTB, which are based upon a rapid immunochromatographic assay technique, capable of being interpreted within 15 minutes. The case groups consisted of 61 patients with active pulmonary tuberculosis(36 patients), extrapulmonary tuberculosis(3 patients), or both(22 patients). Control groups consisted of 47 patients with inactive old pulmonary tuberculosis(17 patients), nontuberculous pulmonary disease(16 patients) and nonpulmonary cardiac disease(14 patients). Results : The diagnostic sensitivity, specificity, positive predictive value(PPV) and negative predictive value(NPV) of the ICT tuberculosis were 64.3%, 91.5%, 90.0% and 68.3% respectively. The diagnostic sensitivity, specificity, PPV and NPV of the BioSignTB were 76.5%, 95.3%, 94.1 % and 78.8% respectively. Differences in sensitivity were not significant between patients with previous history of tuberculosis or patients without prior history of tuberculosis. The ICT tuberculosis test showed higher sensitivity in pulmonary tuberculosis patients(76.5%) than extrapulmonary tuberculosis patients(33.3%). There was no difference in sensitivity between patients with or without cavitary lesion by chest X-ray. Conclusion: Considering high specificity and PPV, serologic diagnosis using a rapid immunochromatographic assay device is another helpful diagnostic method in the diagnosis of tuberculosis, when combined with previous diagnostic methods such as chest X-ray, microbiologic study but it has limitation in terms of confirming the diagnosis for tuberculosis as the only diagnostic method because of relatively low sensitivity and NPV.