tuberculosis tuberculosis --clinical clinical forms forms

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Tuberculosis Tuberculosis -- clinical clinical formsforms

Dr. Dr. A.TorossianA.Torossian, M.D., Ph. D., M.D., Ph. D.Department of Respiratory Department of Respiratory

DiseasesDiseases

TB DISEASETB DISEASE

nnPrimaryPrimarynnPostPost--primary (Secondary)primary (Secondary)

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Primary tuberculosisPrimary tuberculosis

nnMost common in children, Most common in children, adolescents and young adultsadolescents and young adults

(According to the World Health Organization, children with TB represent 10 % to 20 % of all TB cases.)

nn The patient is sick from TB for the The patient is sick from TB for the first time in lifefirst time in life


nn Frequently involves regional lymph nodesFrequently involves regional lymph nodesif located in the lung parenchyma (it may if located in the lung parenchyma (it may

involve involve onlyonly intrathoracicintrathoracic lymph nodes or lymph nodes or other group of lymph nodes) other group of lymph nodes)

nn Hypersensitivity reactions (Para specific Hypersensitivity reactions (Para specific symptoms)symptoms)

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ErythemaErythema nodosumnodosum in TBin TB


nn Usually Usually paucibacillarypaucibacillary -- difficult for difficult for microbiology diagnosismicrobiology diagnosis

nn Difficult to obtain samples for microbiology Difficult to obtain samples for microbiology -- gastric washing for AFB staining and gastric washing for AFB staining and culture, PCR (DNA amplification testing)culture, PCR (DNA amplification testing)

nn Non infectious in most of the casesNon infectious in most of the casesnn Usually positive TST (IGRA)Usually positive TST (IGRA)

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nn Heals often with calcificationsHeals often with calcificationsnn Dormant MT in calcified lymph nodes or Dormant MT in calcified lymph nodes or

parenchyma parenchyma -- a risk for reactivation and a risk for reactivation and postprimarypostprimary forms of TB later in lifeforms of TB later in life

nn Usually good prognosis Usually good prognosis nn HematogenousHematogenous and lymphatic spreadand lymphatic spread


nn In In immunocompromisedimmunocompromised host host ––dissemination and complicationsdissemination and complications--progressive primary tuberculosisprogressive primary tuberculosis

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Pulmonary TB in children can range from an asymptomatic primary infection to a progressive primary TB.

Primary TB is very often characterized by the absence of signs on clinical evaluation. Asymptomatic presentations are more common among school-age children (80-90 %) than in infants less than one year old (40-50 %)

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Common primary formsCommon primary forms

nnPrimary complexPrimary complexnn Tuberculosis of the Tuberculosis of the intrathoracicintrathoracic

lymph nodes (lymphadenitislymph nodes (lymphadenitis))

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Standard 6 (ISTC)In all children suspected of having intrathoracic (i.e.,

pulmonary, pleural, and mediastinal or hilar lymph node) tuberculosis, bacteriological confirmation should be sought through examination of sputum (by expectoration, gastric washings, or induced sputum) for smear microscopy and culture.

In the event of negative bacteriological results, a diagnosis of tuberculosis should be based on the presence of abnormalities consistent with tuberculosis on chest radiography, a history of exposure to an infectious case,evidence of tuberculosis infection (positive tuberculin skin test or interferon - gamma release assay), and clinical findings suggestive of tuberculosis.

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Disseminated tuberculosis

n a form of the disease that affects many sites in the body simultaneously and is not limited to the lungs

n It can be a result of one-time dissemination (miliary tuberculosis) or the heamatogenous spread may occur more than once

n Disseminated (miliary) tuberculosis and tuberculous meningitis are acute, severeforms of tuberculosis caused by the haematogenous spread of the bacilli, oftenoccurring soon after primary infection.

n They occur most often in children andyoung adults. Unlike pulmonary tuberculosis, these acute forms are highly fatal.

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Characteristic chest radiograph

A “miliary” pattern may be seen on a goodquality anterior radiograph: extensive, tiny

(1-2 mm) nodules resembling milletseeds, all the same size and spread

symmetrically over both lungs

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Smear microscopy of sputum from cases with disseminated (miliary)tuberculosis is usually negative, as the disease is paucibacillary

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nn TST is usually negative!!!TST is usually negative!!!nn IGRAsIGRAs are preferredare preferrednn Chest XChest X--ray may be normal at the ray may be normal at the

beginning (repeat after 8beginning (repeat after 8--10 days)10 days)

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When disseminated forms of TB are suspected, treatment should be commenced immediately without waiting for bacteriological proof of diagnosis

Postprimary TB(secondary TB)(secondary TB)

n there is specific immune response developed already

n two ways of occurring: by inhalation of new bacilli or by reactivation of a dormant endogenous infection (reinfectionreinfection and and reactivation)eactivation)

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PostprimaryPostprimary formsforms

nn Most common in adultsMost common in adultsnn The most frequent site of the infection The most frequent site of the infection --

the upper lobes of the lungs the upper lobes of the lungs nn Lymph nodes Lymph nodes -- less involvedless involvednn Para specific symptoms Para specific symptoms -- less likelyless likely


nn Frequent cavitationsFrequent cavitationsnn BronchogenicBronchogenic spreadspreadnn Highly infectious when with cavitations Highly infectious when with cavitations

and sputumand sputumnn Usually verified with microbiological testsUsually verified with microbiological testsnn TSTTST-- not so informative (not so informative (IGRAsIGRAs have to be have to be

used)used)

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nn Bad prognosis if not treated properlyBad prognosis if not treated properlynn Chronic forms and relapses in some Chronic forms and relapses in some

patientspatientsnn Resistant cases more oftenResistant cases more oftennn CoCo--morbidities commonmorbidities common


nn Side effects from the treatment Side effects from the treatment -- more more likelylikely

nn Complications Complications -- quite common quite common ((haemoptoehaemoptoe, , pneumothoraxpneumothorax, , empyemaempyema, , fungus, respiratory failure, fungus, respiratory failure, corcor pulmonalepulmonalechronicumchronicum, heart failure, , heart failure, amiloidosisamiloidosis, etc.), etc.)

nn Residual fibrosis and Residual fibrosis and pneumosclerosispneumosclerosisafter healing after healing -- affect lung function, may affect lung function, may be precancerousbe precancerous

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Natural evolution in Natural evolution in immunocompetentimmunocompetent hostshosts

If, after interview and clinical examination, there is no evidence of another cardio-pulmonary condition in a patient who presents with cough lasting for more than 3 weeks, pulmonary tuberculosis should be suspected. Bacteriologicalexaminations must then be performed, starting with smear microscopy for acidfast bacilli.

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• Pulmonary tuberculosis cannot be diagnosed with certainty by radiographyalone.

• If a radiograph is suggestive of tuberculosis, bacteriological examinationsmust be requested.

• If a radiograph shows cavities but bacteriological examination is negative,the diagnosis of a condition other than active tuberculosis needs to be considered.

Certain radiographic abnormalities are consistent with tuberculosis:

Nodules - round shadows (or “densities”) with clearly defined borders; their size varies from a micronodule (less than 3 mm in diameter), to a nodule (more than 3 mm and less than 1 cm in diameter), to a round shadow (more than 1 cm in diameter)

Patchy shadows, or infiltrations, have irregular borders that are not as clearly defined. They are of varying size, sometimes extending to large parts of the lungs.

Cavities are the most characteristic sign of tuberculosis. A cavity is an area of lucency with a fairly thick wall (more than 1mm). Cavities sometimes contain liquid at the base (liquefied caseous material), evident as an “air fluid level”.

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Lesions due to tuberculosis can be unilateral or bilateral.

They are most frequently observed in the upper zones of the radiograph.

The extent of the abnormalities may vary from a minimal lesion (an area less than the size of a single intercostal space), to far advanced lesions, with extensive involvement of both lungs.

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Chronic forms of TBChronic forms of TB

When tuberculosis has progressed over several months, the destruction of the lung parenchyma and gradual fibrosis lead to retraction of the neighbouring structures: the trachea may be displaced, the hilum may become elevated, thediaphragm may be pulled upward and the cardiac silhouette may change shape and place.The cavities develop thick walls (chronic cavities) and cannot be cured (sometimes surgery may be helpful)

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Differential diagnosisDifferential diagnosis

nn PneumoniaPneumoniann Lung cancerLung cancernn PneumoconiosisPneumoconiosisnn ColagenosisColagenosisnn SarcoidosisSarcoidosisnn PneumomycosisPneumomycosisnn othersothers

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ComplicationsComplications

nn HaemoptysisHaemoptysis ((HaemoptoeHaemoptoe))nn PneumothoraxPneumothorax, , pyopneumothoraxpyopneumothoraxnn Pleural effusion, Pleural effusion, empyemaempyemann BronchiectasisBronchiectasisnn Additional infections Additional infections -- bacteria, fungi bacteria, fungi

((AsspergilusAsspergilus fulmigatusfulmigatus))nn Respiratory failureRespiratory failure

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Chest X-ray showing fibrotic infiltrate and cavity with a fungus ball in the upperleft lobe.

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Drug resistance!Drug resistance!

MDR/XDR MDR/XDR -- TBTB

Chronic forms Chronic forms -- summerysummery

nn Complications and bad prognosisComplications and bad prognosisnn Highly infectiousHighly infectiousnn Drug resistance is commonDrug resistance is commonnn ComorbiditiesComorbidities are common and influence are common and influence

the course of the diseasethe course of the diseasenn Difficult for managingDifficult for managing

tuberculosis tuberculosis --clinical clinical forms forms

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