Relationship between computed tomography findings and nutritional status in elderly patients with pulmonary tuberculosis

Radiological significance of high-resolution computed tomography for elderly pulmonary tuberculosis patients - an analysis with culture test

Purpose

Pulmonary tuberculosis (PTB) is one of the major health problems in the elderly population, causing significant morbidity and mortality. The aim of this study is to evaluate the significance of the high-resolution computed tomography (HRCT) modality for the diagnosis of PTB, in comparison to culture test.

Material and methods

Thoracic HRCT images of the study population, comprising 124 patients clinically suspected for PTB with smear and culture reports, were analysed for sensitivity and specificity of the HRCT test. Features of active PTB were centrilobular nodules, ‘tree-in-bud’ pattern densities, macro-nodules, consolidations, cavitary lesions, ground-glass opacities, and miliary nodules.

Results

Among the study population, 108 cases presented HRCT features of active PTB and the remaining cases were negative but had presented a few features mimicking PTB. As inferred from positive culture test results, 106 cases had active PTB, the remaining cases were culture negative for PTB. False-positive (FP) or ‘type I error’ cases, and false-negative (FN) or ‘type II error’ cases were ascertained by Bayes’ theorem. Sensitivity (true positive rate) and specificity (true negative rate) of HRCT test were 0.8125 and 0.8571, respectively.

Conclusions

For proper diagnosis the predictive capability, as two values of ‘a posteriori probability’, was computed; the mean value of ‘a posteriori probability’ for HRCT was 0.6358. When its culture test was positive, the HRCT test was 69.56-92.85% efficient in ascertaining positive results with a sample; on the other hand, when its culture test was negative it was 66.66-100% efficient for a negative result. Thus, the HRCT test is considerably dependable.

A high-resolution computed tomography-based scoring system to differentiate the most infectious active pulmonary tuberculosis from community-acquired pneumonia in elderly and non-elderly patients

OBJECTIVE

The objective of this study was to use high-resolution computed tomography (HRCT) imaging to predict the presence of smear-positive active pulmonary tuberculosis (PTB) in elderly (at least 65 years of age) and non-elderly patients (18-65 years of age).

METHODS

Patients with active pulmonary infections seen from November 2010 through December 2011 received HRCT chest imaging, sputum smears for acid-fast bacilli and sputum cultures for Mycobacterium tuberculosis. Smear-positive PTB was defined as at least one positive sputum smear and a positive culture for M. tuberculosis. Multivariate logistic regression analyses were performed to determine the HRCT predictors of smear-positive active PTB, and a prediction score was developed on the basis of receiver operating characteristic curve analysis.

RESULTS

Of 1,255 patients included, 139 were diagnosed with smear-positive active PTB. According to ROC curve analysis, the sensitivity, specificity, positive predictive value, negative predictive value, false positive rates and false negative rates were 98.6 %, 95.8 %, 78.5 %, 99.8 %, 4.2 % and 1.4 %, respectively, for diagnosing smear-positive active PTB in elderly patients, and 100.0 %, 96.9 %, 76.5 %, 100.0 %, 3.1 % and 0.0 %, respectively, for non-elderly patients.

CONCLUSIONS

HRCT can assist in the early diagnosis of the most infectious active PTB, thereby preventing transmission and minimizing unnecessary immediate respiratory isolation.

KEY POINTS

• HRCT can assist in the early diagnosis of the infectious active PTB • HRCT imaging is useful to predict the presence of smear-positive active PTB • Predictions from the HRCT imaging are valid even before sputum smear or culture results.

Hypoalbuminemia and lymphocytopenia are predictive risk factors for in-hospital mortality in patients with tuberculosis

OBJECTIVE

The aim of this study was to clarify the association between nutritional state on admission and in-hospital death in tuberculosis (TB) patients, including a high proportion of elderly patients.

METHODS

A retrospective cohort study of 246 TB patients was conducted. The serum albumin concentrations and peripheral blood lymphocyte counts were measured on admission, and the primary outcome of interest was in-hospital death. Patient mortality was categorized into two groups: TB death and non-TB death. A multivariate analysis was performed to evaluate the relationship between nutritional state on admission and in-hospital mortality in TB patients.

RESULTS

The median [interquartile range] patient age was 79 [69-83] years, and the in-hospital death rate was 20.73% (TB death: 26 patients; non-TB death: 25 patients). The multivariate analysis revealed that the serum albumin concentrations (OR: 0.21, 95% CI: 0.10-0.41; p<0.0001) and peripheral blood total lymphocyte counts (Category 2 [627.2-1,106.7/mm(3)] vs. 1 [<627.2/mm(3)]. OR: 0.28, 95% CI: 0.11-0.73; p=0.009, Category 3 [>1,106.7/mm(3)] vs. 1. OR: 0.24, 95% CI: 0.08-0.76, p=0.015) on admission were significantly associated with all in-hospital deaths in the TB patients. The serum albumin concentrations and peripheral blood total lymphocyte counts were also found to be associated with in-hospital deaths directly caused by TB.

CONCLUSION

Hypoalbuminemia and lymphocytopenia on admission are predictive risk factors for in-hospital mortality in TB patients. Nutritional defects should thus receive special attention in order to reduce TB patient mortality, particularly among elderly patients.

Nutritional assessment in patients with pulmonary nontuberculous mycobacteriosis

OBJECTIVE

To determine the nutritional factors that influence disease spread in patients with pulmonary Mycobacterium avium complex (MAC) infection.

METHODS

A prospective observational study.

PATIENTS

Patients with pulmonary MAC infection were enrolled in this study. Chest computed tomography (CT), abdominal CT, and physical, clinical, and nutritional laboratory data were collected after obtaining informed consent.

RESULTS

Seventy-eight patients (16 males and 62 females) were consecutively enrolled. While the mean body mass index (BMI) was low (19.6 ± 2.7 kg/m(2)), the mean serum albumin concentration was within normal range (4.2 ± 0.2 g/dL). We evaluated the number of affected lung segments to define the degree of disease spread, and examined the relationships between various parameters and disease spread. Multivariate analysis identified the duration of the disease (+1.6 segment/100 months, p=0.03), BMI (-0.5 segment/BMI, p=0.003), and white blood cell count (+0.7 segment/1,000 WBC, p=0.03) as factors contributing to disease spread.

CONCLUSION

BMI is an excellent marker for nutritional assessment and for predicting disease spread in patients with pulmonary MAC infection.