The Effects Of Inactive Pulmonary Tuberculosis On Clinical Features Of The Patients With Combined Pulmonary Fibrosis And Emphysema

ObjectiveCombined pulmonary fibrosis and emphysema (CPFE) is defined as coexisting lower lobe predominant pulmonary fibrosis and upper lobe predominant emphysema on the radiological examination from the same body. Its pulmonary function test shows preserved lung volumes but a severely decreased diffusing capacity of the lung for carbon monoxide. High resolution computer tomography (HRCT) scan is the gold standard of non-invasion diagnosis. With the widely application of HRCT, the clinical recognition rate of CPFE has enhanced. Simultaneously, the detection rate of inactive pulmonary tuberculosis has risen, and the phenomenon of coincidence of CPFE and inactive pulmonary tuberculosis is not uncommon. The inactive pulmonary tuberculosis lesions are usually left after mycobacterium tuberculosis infection and any active pulmonary tuberculosis images can’t be found on the HRCT scan at the same time. Although tuberculosis lesions remain inactive, reports about pulmonary function impairment of pulmonary tuberculosis patients after microbial cure and latent infection aren’t rare. Our study is to investigate the effects of inactive pulmonary tuberculosis on the clinical features of the patients with CPFE and help to understand this disease deeply and make reasonable treatment plan.MethodsHRCT were adopted to screen the patients. Patients with CPFE and inactive tuberculosis were brought into observation group, the other patients only with CPFE were assigned into control group.Visual semi-quantitative scoring system was employed to quantify emphysema, fibrosis and inactive tuberculosis lesions respectively. According to inactive tuberculosis scores, the observation group was further divided into two subgroups:≥10 points group and<10 points group. Indices of the general information (including sex, age, years of smoking, smoking index, symptoms and signs), arterial blood gas analysis, HRCT images and scores and pulmonary function test among the four groups were compared respectively. The correlations of inactive tuberculosis scores and indices of blood gas analysis and pulmonary function test were also analysed.ResultsGeneral information:Ninety persons were up to standard, the count of patients of observation group was forty-eight (≥10 points group had twenty patients and<10 points group had twenty-eight patients), and the count of patients of control group was forty-two. Most of patients of two groups were the elder male with a history of long-term smoking.The differences of general information of groups were not statistically significant.HRCT images:There were several characters of CPFE on the HRCT images of all the patients. The main styles of the fibrosis lesions and emphysema were reticular abnormality and paraseptal emphysema respectively. The differences of scores of fibrosis and emphysema of groups were not statistically significant. The main image character of inactive tuberculosis was scar, the total scores of each inactive tuberculosis were relatively far away from the max predicted value.Indices of arterial blood gas analysis:The differences of arterial oxygen pressure, carbon dioxide pressure and hemoglobin emphysema between the observation group and control group were not statistical significant. Compared with the control group and<10 points group,≥10 points group had higher incidence of hyoxemia and hyperhemoglobinemia, P＜0.05. Compared with the control group, there was not any significant differences in all the indices of arterial blood gas analysis of<10 points group.Pulmonary function indices:Mixed ventilation disorder was the main impairment pattern in pulmonary function of all the patients. The diffusing capacity of the lung for carbon monoxide (DLco) had impairment in different degrees. Compared with the control group, the observation group had higher incidence of airflow obstruction (32/48) and lower maximal expiratory flow at 75% of the vital capacity (MEF25) and maximal middle expiratory flow (MMEF), P<0.05. Moreover,≥10 points group had lower peak expiratory flow(PEF),maximal expiratory flow at 25% of the vital capacity (MEF75) and maximal expiratory flow at 50% of the vital capacity (MEF50), P＜0.05. Compared with the<10 points group,≥ 10 points group had higher incidence of airflow obstruction (18/20) and obstruction ventilation disorder (8/20) and lower PEF, MEF50, MEF75 and MMEF,P<0.05.The test of correlation of tuberculosis scores and blood gas analysis: tuberculosis scores negatively correlated with FVC, FEV1, MMEF, MEF50, and MEF75 and positively correlated with hyperhemoglobinemia concentration, RV and RV/TLC.Conclusions1、CPFE is most often seen in male smokers, whose pulmonary volume could preserve and DLco decrease significantly.2、The incidence of coexisting of CPFE and inactive tuberculosis is not uncommon. Although the general information of CPFE accompanying inactive tuberculosis had no significantly difference from the patients only with CPFE, patients with CPFE and inactive tuberculosis had severer airflow obstruction which aggravated anoxia.3、The extent of inactive tuberculosis lesions is related to the degree of pulmonary function impairment. Microbial cure may be not the end point of tuberculosis treatment, the later follow-up with pulmonary function test and radiologic check is also important.