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Pulmonary Tuberculosis: A Comprehensive Approach*

Bienvenido Alora, M.D.,** Angeles Tan-Alora, M.D.,** Sandra Victorio, M.D.,*** Melchor Chan, M.D.,*** Bernardo Briones, M.D.*** and Marilyn Ong Mateo, M.D.***

(*Awarded 2nd Prize in the PSMID-United Laboratories Annual Research Contest, 1984; **Faculty of Medicine& Surgery, University of Santo Tomas ***Santo Tomas University Hospital) No Abstract Available [Phil J Microbiol Infect Dis 1984; 13(2):88-100] Key Words: Pulmonary tuberculosis, M. tuberculosis

INTRODUCTION For generations, man, the tubercle bacillus, and the practicing physician were all intermeshed. 1 Among Filipinos, tuberculosis is accepted as an inevitable companion and it is a common presumption that every Filipino has a "touch of TB." With the constantly changing patterns of pulmonary tuberculosis, coupled with its overwhelming prevalence among Filipinos, the management of the disease tends to become a matter of style rather than science. If indeed tuberculosis is to return to the mainstream of medicine, it must be placed back into perspective, based on an in-depth analysis of its clinical manifestations, diagnosis and transmission. There are several ways of approaching the disease. For the clinician, the diagnosis of PTB necessarily incl des chest x-rays and sputum examinations for acid-fast bacilli, aside from u the clinical history and physical examination findings. Many times, bacteriologic negativity does not prevent the initiation of specific chemotherapy. For the epidemiologist, there is an accepted parallelism between AFB positivity and transmission of the disease, except in previously treated eases.2-5 It would therefore be useful from this viewpoint to attempt to identify other features that may distinguish a potential AFB "transmitter" from a "non-transmitter." The staggering costs of anti-TB medications, the pressing problem of non-compliance, the large numbers of patients suffering from chronic destructive PTB and the apparent difficulty in epidemiologic control, necessitates a careful review of these approaches to the disease so that proper guidelines may be set for initiation of therapy. This prevents the indiscriminate use of drugs and concentrates resources towards those who would most benefit from it. In addition to the clinical, roentgenologic and bacteriologic aspects of the disease, this investigation ventured to include the bronchoscopic patterns of pulmonary tuberculosis, since bronchial involvement not only impairs pulmonary function to a considerable degree in chronic PTB, but may also become a source of infection dissemination. 6 In order to reconcile organized medicine with the individual clinician, this comprehensive approach to study of the disease was undertaken. It is the objective of the study to provide new insights into an old problem. We studied the clinical, roentgenologic, bronchoscopic and bacteriologic features of the disease and attempted to identify conglomerate patterns by which pulmonary tuberculosis may present. Specifically, the objectives are: l) To describe the clinical features of Filipino patients with pulmonary tuberculosis; 2) To demonstrate the roentgenologic patterns of PTB and attempt to identify significant associations between these patterns and certain clinical features, 3) To describe the endobronchial patterns in these patients and attempts to associate specific patterns with the clinical and roentgenologic features, 4) To identify clinical, roentgenologic, or bronchoscopic patterns that may distinguish an "AFB positive" from an "AFB negative" patient.

MATERIALS AND METHODS Patient recruitment and selection From June 1982 to May 1984, a total of 118 patients from the ward and outpatient service who were suspected to have pulmonary tuberculosis by chest x -ray or mere clinical suspicion were screened for possible inclusion. The patients were included in the study if at least one of the following criteria was met: 1) positive mycobacterium culture of bronchial specimens;* 2) caseating granuloma on bronchial biopsy; 3) positive AFB staining on smears taken from any of the bronchial specimens; (*Editor's Note: A (+) AFB smear may indicate the presence of micro-organisms other

than M. tuberculosis, such as Nocardia spp. and other mycobacterial spp. e.g. M. avium and M. bovis. A definite bacteriologic diagnosis of tuberculosis still requires cultural demonstration of Mycobacterium tuberculosis.) 4) a

chest x-ray interpreted as pulmonary tuberculosis plus clinical and radiographic improvement with anti-tuberculosis medications, with the response noted in not less than 4 weeks. This was to diminish radiological bias in favor of PTB, as well as to exclude other bacterial pulmonary lesions which may also respond to the anti-TB drugs. Excluded from further analysis were those who failed to meet any of the criteria as well as those who were diagnosed to have concomitant pulmonary malignancy with tuberculosis, since in the latter group, it would be difficult to distinguish characteristic lesions that will differentiate malignancy from tuberculosis. Gathering of data Clinical histories and physical findings of each patient were recorded on a standard protocol. Standard posteroanterior chest radiographs were obtained on all patients. The flexible fiber bronchoscope was utilized for a two-fold purpose: (1) to visualize the proximal airways, and (2) to obtain bronchial specimens for histopathological and bacteriological studies. Using the Machida FBS 6T-11 flexible fiber bronchoscope, bronchoscopy was performed via the transnasal approach by one of the investigators with the patient lying supine and using the standard method acceptable to bronchoscopists.7 This was done under local anesthesia with 10% lidocaine spray. Atropine SO 4 1 mg and either diazepam or chlorazepate 10 mg were administered intramuscularly 30 minutes to 1 hour prior to the procedure. Anesthesia of the vocal cords, trachea, and bronchi was accomplished by direct instillation of 10-20 cc of 1% lidocaine. The visual assessment started from the larynx, the trachea, the main stem bronchi down to the subsegmental branches. Direct smears for acid-fast bacilli (AFB) staining using Ziehl-Neelsen technique, and cytology were obtained from bronchial brushings, washings and aspirates. Intra-bronchial biopsies were obtained whenever possible. Mycobacterium cultures were performed by one of the investigators using the coconut water-egg-malachite green (CEM) medium17 and interpreted after a 6-8 week incubation period. The patients were followed up clinically every 2 to 4 weeks, and repeat chest x-rays were done when warranted. Triple therapy consisting of any 3 of the following drags, i.e., isoniazid, rifampicin, streptomycin, pyrazinamide or ethambutol, were instituted in those diagnosed or suspected to have pulmonary tuberculosis. Classification of data and terminology I. Clinical data - Among the several clinical data that were recorded, the following were the most consistently answered and were least prone to subject/examiner variability: smoking history more than 15 pack-years, personal history of diabetes mellitus symptoms noted either within one week

prior to admission or consultation or at any time during confinement; productive cough hemoptysis, pleuritic pain, fever. II. Chest x-ray findings - The chest x-rays (posteroanterior view) were appraised by a radiologist and classified according to: A. Location - The delineation, between upper and lower lung fields was an imaginary line traced across the hilum on a standard posteroanterior film14 - upper lung field involvement only; upper and lower lung field involvement; lower lung field involvement only; others: hilar involvement only, pleural involvement only B. Interpretation - This is based on the usual classification of pulmonary tuberculosis according to extent and presence of cavitation16 minima l PTB; moderate PTB; far-advanced PTB; others (equivocal or not PTB): segmental pneumonia (mid-or lower lung fields), hilar adenopathy, nodule(s), and pleural effusion. III. Bronchoscopic findings - The details of the bronchoscopic description were arbitrarily grouped into the following, based on the classification of Lukomsky and Orlov6,8 pertaining to non-specific bronchitis as well as those noted among their tuberculous patients: (0) Normal (1) Grade 1 inflammatory changes that include hyperemia, swelling, with or without secretions. (2) Grade 2 inflammatory changes that include: granulations, erosions, or ulcerations, with or without changes in (1) (3) Grade 3 inflammatory changes which include carinal blunting, mural, cicatricial stenosis with or without changes in (1) or (2) (4) Evidence of mucosal thinning or atrophy with or without changes as in (1), (2) or (3). IV. AFB positivity and previous treatment with anti-TIB drugs AFB positive - if the patient had a positive AFB smear on any of the bronchia l specimens AFB negative - if the patient had no positive smear on all of the bronchial specimens Previous treatment - if the patient had at least 2 weeks of treatment with any 2 or 3 antiTB medications prior to bronchoscopy. No previous treatment - if the patient had not taken any previous anti-TB medications, or took his medications irregularly, i.e. less frequently than twice a week, or discontinued them at least one year prior to bronchoscopy. Statistical analysis Data were statistically analyzed using the z-test, chi-square test, and analysis of variance for statistical significance. The level of significance was placed at 0.05. RESULTS Among the total 118 patients who underwent bronchoscopy, 56 (47.46%) met the criteria for pulmonary tuberculosis. Excluded were 10 patients (8.47%) who had concomitant pulmonary tuberculosis and malignancy, and those who had pulmonary malignancy alone (20.34%). Among those who were diagnosed to have pulmonary tuberculosis on chest x-ray but had negative AFB smears (30.51%), 11 (9.32%) were lost to follow-up whereas 8 (6.78%) did not show convincing evidence of improvement with anti-TB medications, or improved remarkably in less than 2 weeks of therapy; these were excluded from the study. Among the 56 selected patie nts, there were 25 females (44.64%), and 31 males (55.35%) with a male to female ratio of 1:1.2. Ages ranged from 17 to 72 years old with a mean age of 46.9 ± 14.6 years old (± S.D.). Thirty-nine (69.64%) were AFB positive and 17 (30.36%) were AFB negative.

These were further subdivided into those with and those without previous treatment. There were no statistically significant differences between those with previous treatment. There was no statistically significant difference between those with previous t eatment and those r without (p >0.10); hence the distinction between these two groups was not considered in subsequent analyses. The mycobacterium culture performed on 33 of the bronchial specimens showed a low positivity yield of 21.21% (7/33). Likewise, only 8 of the 18 bronchial biopsies showed caseating granuloma (44.44%) while the rest showed either acute or chronic inflammation. Majority presented with productive cough (78.57%) followed by fever (37.50%), pleuritic pain (30.36%) and hemoptysis (26.78%). These symptoms occurred either alone or in combination. Notably, 17.86% were asymptomatic. Thirty nine percent had a smoking history of at least 15 pack years and 19.69%were diabetics. (Figure 1)

Figure 1. Percentage distribution by clinical data among 56 patients with pulmonary tuberculosis

The radiographic findings based on location of the lesion and on interpretation are summarized in Tables 1 and 2 respectively, Notably, 16% of the patients had pure lower lung field tuberculosis. Eighteen (32.14%) of the initial chest x-rays were interpreted as equivocally PTB or non-tuberculous lesions; in these patients, the diagnosis of PTB was based on positive AFB smears, and/or bronchial biopsies showing caseating granuloma.

Table 1. Number and percentage distribution by radiographical location of the lesions among 56 patients with pulmonary tuberculosis Radiographical location of the lesions Upper lung field(s) only Lower lung field(s) only Upper and lower lung fields Others: Hilar involvement only Pleura] involvement only Total No. 28 9 11 7 1 56 Percentage 50.00 16.08 19.64 12.50 1.78 100.00

The bronchoscopic findings as shown in Table 3 demonstrates that 20 cases (35.71%) had Grade I inflammatory changes, 6 (10.71%) had Grade 2 changes, 21 (37.50%) had Grade 3 while 5 (8.93%) presented with Grade 4 changes. When smoking history, diabetes mellitus, productive cough, and hemoptysis were tested individually for association with AFB positivity, no significant differences were found that distinguished an "AFB positive" from an AFB negative" patient (Table 4). Notably, 20.51% of those who were AFB positive were asymptomatic.

Table 2. Number and percentage distribution by radiographical interpretation among 56 patients with pulmonary tuberculosis Radiographical interpretation Minimal PTB Moderately advanced PTB Far-advanced PTB Others: Segmental pneumonia Nodule Adenopathy Pleura1effusion Total No. 5 30 3 6 4 7 1 56 Percentage 8.92 53.69 5.36 10.71 7.14 12.50 1.78 100.00

Table 3. Number and percentage distribution by bronchoscopic findings among 56 patients with pulmonary tuberculosis Grade 0 1 2 3 4 Total Bronchoscopic findings Normal Mucosal swelling and/or hyperemia Erosions/granulations + changes in 1 Luminal narrowing/stenosis+ changes in 1 or 2 Mucosal atrophy + changes in 1, 2, or 3 No. 4 20 6 21 5 56 Percentage 7.15 35.71 10.71 37.50 8.95 100.00

Table 4. Number and percentage distribution by clinical data and AFB positivity among 56 patients with pulmonary tuberculosis AFB negative Clinical data Productive cough Hemoptysis Pleuritic pain Fever Asymptomatic Smoking history Diabetes mellitus Alpha = 0.05 NS = not significant No. 31 10 9 16 8 18 9 % 79.49 25.64 23.08 41.02 20.51 46.15 23.08 No. 13 5 8 5 2 4 2 AFB positive % 76.47 29.41 47.06 29.41 11.76 23.53 11.76 p value NS NS NS NS NS NS NS

There was likewise no significant association between the chest x -ray location of the lesion and smoking history, presence of pulmonary symptoms or AFB positivity (x2 = 5.74, 3.46, and 5.85 respectively; p > 0.1). Compared to non-diabetics, however, a significant proportion of diabetics presented with pure lower lung field tuberculosis (x2 = 4.17; p < 0.05) (Table 5). The chest x-ray classification groupings of minimal, moderate and far-advanced did not appear significantly distinct from each other in terms of associated presence or absence of pulmonary symptoms (x2 = 3.66; p > 0.5), or AFB positivity (x2 = 5.01; p > 0.05) (Table 6).

Table 5. Number and percentage distribution by occurrence of lower lung field lesions and diabetes mellitus among 56 patients with pulmonary tuberculosis Diabetics No. 4 7 11 Non-diabetics No. % 5 11.11 40 88.89 45 100.00

Radiographical location of the lesions Lower lung field(s) only Other radiographical locations Total x2= 4.17 p < 0.05

% 36.36 63.64 100.00

Total 9 47 56

Table 6. Number and percentage distribution by radiographic interpretation, presence of pulmonary symptoms and AFB positivity among 38 patients with pulmonary tuberculosis With pulmonary symptoms N= 32 No. % 4 12.50 25 78.12 3 9.38 32 100.00 NS AFB positive N=25 No. % 2 8.00 21 84.00 2 8.00 25 100.00 NS

Radiographic interpretation Minimal PTB Moderately advanced PTB Far-advanced PTB Total alpha = 0.05 NS = not significant

As shown in Table 7, those with Grades 1 and 3 inflammatory changes on bronchoscopy, i.e., hyperemia and swelling (z = 2; p = 0.05) and intraluminal narrowing (z = 2; p = 0.05), tend to be associated with the presence of pulmonary symptoms of cough and hemoptysis. Interestingly, those with normal bronchoscopic findings were also asymptomatic (x2 = 19.84; p <0.001).

Table 7. Number and percentage distribution by bronchoscopic findings and presence of pulmonary symptoms* among patients with pulmonary tuberculosis With symptoms Grade Bronchoscopic findings No. % 0 Normal 0 0.0 1 Mucosal swelling and/or hyperemia 19 4.30 2 Erosions/granulations ± changes in 1 5 10.87 3 20 43.48 Luminal narrowing/stenosis ± changes in 1 or 2 4 2 4.35 Mucosal atrophy ± changes in1, 2, or 3 Total 46 100.00 * pulmonary symptoms include only productive cough and hemoptysis Without symptoms No. % 4 40.00 1 10.00 1 10.00 1 10.00 3 30.00 10 100.00

p value p <0.001 p = 0.05 NS p = 0.05 NS

The bronchoscopic patterns did not significantly predict AFB positivity (p > 0.l). Neither were there significant associations between the grade of inflammation, by bronchoscopy and the presence of a history of smoking or diabetes mellitus (p > 0.01). By analysis of variance, no significant differences existed among the chest x-ray interpretations of minimal, moderate and far-advanced, by the grade of inflammation on bronchoscopy (F = 0.84, p > 0.05). By multivariate discriminant analysis, group 3 bronchoscopic lesions, i.e., with intraluminal narrowing or carinal blunting was significantly associated with hilar adenopathy on chest x-ray (x2 = 9.16; p < 0.02). Chest x-ray findings of pneumonia, nodule or pleural effusion showed no specific association with bronchoscopic findings (p > 0.70). DISCUSSION Radiographic Patterns The roentgenologic picture of pulmonary tuberculosis has undergone some changes for the past decades especially with the advent ofchemotherapy. 9,10 The incidence of lower lung field tuberculosis defined as "tuberculous disease found below an imaginary line traced across the hilum on a standard postero-anterior film,11 has recently garnered some interest. Sixteen percent of our cases, in comparison to the 2-7% incidence in other studies,12 presented with purely lower lung field tuberculosis. These masqueraded initially as pneumonia, pleural effusion or a suspicious nodule, and the correct diagnosis was determined only after fiber bronchoscopy with retrieval of bronchial specimens, which yielded positive AFB smears. In common practice, tuberculosis is considered only when such patients do not respond to the usual antibiotics.

A significant proportion of diabetics in the present study had lower lung field tuberculosis as compared to the non-diabetics. There is, however, no satisfactory explanation for this association. Moreover, it does not appear that patients with lower lung field tuberculosis have especially lowered resistance to tuberculosis. 13 Inspite of the high incidence of endobronchial involvement reported in lower lung field tuberculosis,12,13 our bronchoscopic findings showed mostly nonspecific inflammation and a normal bronchus in one patient. Since disease of the lower lobes usually arises from bronchogenic spread from an upper lobe cavity o disease, our bronchoscopic patterns do not r preclude the possibility that lower lung field tuberculosis may be primary rather than secondary. In such cases, the tuberculin test may have some credence among adult Filipinos in the future. The significance of the usual roentgenologic classification as minimal, moderate or faradvanced pulmonary tuberculosis is unclear, and has recently been labeled by the American Thoracic Society14 as merely of historical interest. In the present study, the poor association of this roentgen classification with distinctive clinical and bronchoscopic features as well as AFB positivity merits a reassessment of the significance of classifying pulmonary tuberculosis in this manner. Endobronchial patterns A diagnosis of endobronchial disease in tuberculosis is made when bronchoscopic evidence of stenosis or severe endobronchitis is detected with or without roentgenographic evidence of atelectasis or tension cavities.11 The finding of intraluminal narrowing with mural or cicatricial stenosis and/or carinal blunting in a considerable number of our cases is a relevant one since such findings may sometimes be mistaken to represent indirect signs of lung cancer inoperability. 7 A bronchial biopsy would be diagnostic in such cases. The findings of mural stenosis in a patient with pulmonary tuberculosis with resultant intraluminal narrowing would suggest external compression by intrathoracic lymph nodes. The association of this finding with hilar adenopathy on chest x-ray further alludes to this fact. The occurrence, anatomy, and roentgen appearance of such tuberculous mediastinal lymphadenopathy in the adult was sufficiently discussed by Kittredge et al. 15 Lukomsky et al6 thoroughly describes the endobronchial lesions in tuberculosis and explains its pathophysiology by means of extension of the intrathoracic lymph nodes into the bronchial lumen first to create a bronchoglandular fistula, subsequently followed by scarring of the walls and hence compromising bronchial patency. Lymph node calcification and its erosion into the bronchus leads to broncholithiasis. The end-result of these processes is obstruction subsequently leading to bronchiectasis, obstructive pneumonitis, atelectasis and chronic nonspecific infection superimposed on the tuberculous process. This explanation however was applied to cases of primary tuberculosis, which predominated in this setting. This is probably the reason why we did not detect any bronchoglandular fistula nor broncholiths in the present cases. Moreover, the occurrence of tubercles or mucosal granulations (grade 2 lesions), which were more specific for tuberculosis, was much less than the nonspecific inflammatory changes. The element of bronchial obstruction, however, including its consequences, appears plausible even among our cases of secondary pulmonary tuberculosis. The implications on functional impairment, too, are similar. Interestingly, the presence of pulmonary symptoms among our cases, was significantly associated with the presence of inflammatory changes on bronchoscopy, whether such changes are specific for tuberculosis or not. Conversely, the absence of pulmonary symptoms was associated with normal bronchoscopic findings. Such findings may provide the rational basis for the use of supportive measures in symptomatic patients with pulmonary tuberculosis.

Endobronchial tuberculosis can be present with a normal chest x -ray but is usually associated with extensive cavitary pulmonary disease. Classically, laryngeal, and inferentially endobronchial, tuberculosis has been considered extremely infectious. In contrast, the present study showed no difference among the bronchoscopic findings when each category was tested for association with various chest x-ray patterns or AFB positivity. A recent report however, suggests that it is not the laryngeal/endobronchial disease per se but the often-associated extensive pulmonary disease that is responsible for the contagiousness.16 Bacteriologic (AFB) positivity The bacteriologic diagnosis of tuberculosis involves the use of Ziehl-Neelsen staining and culture of the organism. The coconut water-egg-malachite green medium (CEM) used in the present study, was developed by the Bureau of Research and Laboratories in 1976. 17 One acceptable explanation for the low positivity yield among our culture specimens was the anesthetic used during fiber-bronchoscopy. 18,22 Nevertheless, the long incubation period and the expense deem it unnecessary and impractical to perform such cultures routinely. Since acidfastness is not a property exclusive to Mycobacterium tuberculosis, attention has been called to the problem of falsely positive and falsely negative AFB smears.2 However, within our local setting, where the disease is highly prevalent, the diagnosis of tuberculosis is a reasonable certainty if the AFB smear is positive.13 Hence, acid-fast staining remains a valuable technique for rapidly establishing a presumptive diagnosis of tuberculosis.23,24 Moreover, the dose correlation between positivity of sputum AFB smears and infectiousness5 make this technique a valuable adjunct in the general management and contact investigation of tuberculous cases, as well as the need for isolation in those without previous therapy. 2 The implication of AFB positivity among previously treated patients differs from those who have had no previous therapy. This may be explained by (1) non-compliance, (2) resistance, and (3) shedding of dead bacilli. 5 Among those with previous therapy, infectivity is significantly decreased even in the presence of an AFB positive sputum. Since our study disclosed no significant group difference between those with and those without previous therapy, such variables have been eliminated, and a parallelism drawn between AFB positivity and infectiousness. The present study further reiterates certain disturbing facts about tuberculosis. A considerable percentage of AFB positive patients are without symptoms. Other studies even claim a higher incidence of up to 70%,25 even with elimination of the variables of previous therapy which has been shown by itself to affect infectiousness. Also, contrary to common knowledge, the extent of lesions either by x -ray or bronchoscopy does not reliably predict infectiousness so that those with apparently milder involvement by x -ray may be excreting more AFB bacilli in their sputum. Such individuals constitute the "walking time bombs" of the disease. Epidemiologically, the implications of this are obvious. In a Hong Kong study of the characteristics and course of sputum smear-negative PTB,26 large radiographic lesions and a history of hemoptysis were likely to be associated with the disease, inspite of negative AFB smears. In such patients, therefore, these factors may invariably influence, the decision to start therapy. In an extensive survey by Rouillon et al on the transmission of tuberculosis,5 they have shown that patients in whom tubercle bacilli can be detected by direct examination of the sputum smears are the main source of transmission. Moreover, the individuals infected by them break down more often with the disease. Indeed the study of transmission cannot be separated from that of the natural history of the disease, since transmission occurs if the new host becomes himself not only a patient but is also infectious to others in which case human suffering and the bacillary

species are both perpetuated. Efforts, therefore, to perform AFB staining among tuberculous patients cannot be overemphasized. CONCLUSIONS No definite generalizations can be derived from a sample of 56 patients, even if t e h criteria for inclusion were stringent enough to exclude other variables, which may prejudice the results. The present investigation, however, serves as a model for a comprehensive approach to pulmonary tuberculosis as a disease. The patterns that were observed, whether they are in conformity with previous concepts or not, deserve emphasis if we are to deal with the disease in a more rational manner. 1) The presence of pulmonary symptoms of productive cough and hemoptysis is associated with bronchoscopic findings of mucosal swelling and hyperemia with or without intraluminal narrowing, whereas the absence of pulmonary symptoms is associated with normal bronchoscopic findings, 2) There is no definite association between the presence of pulmonary symptoms, history of smoking or diabetes with the radiographical location of the lesion or AFB positivity. AFB smears were positive even in the absence of symptoms. 3) Lower lung field tuberculosis was noted in 16 percent of the cases, and had a higher incidence among diabetics than in non-diabetics. 4) Those who presented with hilar adenopathy on chest x-ray were likely to have some degree of intraluminal narrowing on bronchoscopic examination. 5) When the PTB lesions were radiographically classified as minimal, moderate, or faradvanced, these categories were not significantly distinct from each other in terms of associated presence of pulmonary symptoms, bronchoscopic findings or AFB positivity. 6) Fiber bronchoscopy was found useful in cases of pulmonary tuberculosis which presented atypically, or when other diagnostic possibilities were to be ruled out. Recommendations The ultimate control of pulmonary tuberculosis will necessarily cover epidemiological dimensions. We recognize, however, that the practicing clin ician is still the key towards achieving such a goal. We therefore direct our recommendations to prepare him for this responsibility. Based on the latest classification of tuberculosis conceived by the American Thoracic 27 Society, and the observations derived from the present study, we recommend that the clinician label the host-parasite interaction as it is and evaluate it every time he sees his patient, doing away with such safe words as "reactor", "primary lesion", "inactive", or "minimal." Arbitrarily, a description of the disease would include (based on Category III of the ATS classification, i.e. infected, with disease): A. Location of the disease, i.e. pulmonary, pleural, lymph node etc. B. Bacteriologic status, i.e. AFB positive, culture negative etc. C. Roentgenogram findings, i.e. location, extent, characteristics. D. Chemotherapy status, i.e., medications, date, regimen E. Other data: bronchoscopic findings, histopathology report etc. "PTB, moderately advanced, probably active" now becomes: "Pulmonary tuberculosis, AFB negative, UL (upper lung field) cavitations, on INH, RFN, SZN." The initiation of the therapy, therefore, will not depend solely on the chest x-ray, but on the entire clinical picture of the individual patient. For instance, if an asymptomatic patient presents with fibrotic upper lobe infiltrates on chest x -ray, the decision to initiate therapy will

depend on: is he AFB positive? is there a concomitant illness? is the patient immunocompromised, i.e., on steroids? can the patient be followed up regularly? This extensive description of the disease status of the individual necessitates a team approach. The clinician will now be more particular with the proper collection of sputum for AFB smears, the radiologist will be more cautious not to under, or overdiagnose pulmonary tuberculosis, and the clinical pathologist will be more persistent in trying to detect acid fast bacilli on smears. When pulmonary tuberculosis presents in an atypical manner, e.g. lower lobe pneumonia, fiber bronchoscopy is most useful in providing visual confirmation of the absence of other disease such as malignancy, or in the proper collection of samples for bacteriologic studies. Indeed, if tuberculosis is to be treated like other diseases it must be consistently "S-O-APed" (Subjective, Objective, Assessment, Plans) just like any other real problem. REFERENCES

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