Pneumonia, cheesy A16.2

In 1882 Robert Koch discovered the tuberculosis bacterium. The species name M. tuberculosis was introduced in 1896 by Lehmann and Neumann. In 1908 A. Calmette and C. Guérin succeeded in breeding a strain of M. bovis by passages in culture media.

In the context of post-primary tuberculosis, central (cheesy) necrosis of the granuloma centres occurs - particularly in the apical (S1) and posterior (S2) upper lobe segment and also in the upper segment of the lower lobe of the lung (S6) (apex upper lobe TBc). This necrosis can liquefy as the disease progresses, leading to the formation of a cavern. If several segments or lobes are affected, these foci fuse and lead to a so-called cheesy pneumonia.

Tuberculosis bacteria (tuberculosis complex) are non-pigmented mycobacteria. In contrast to the ubiquitous mycobacteria, some of which are capable of producing very intensive pigments, Mycobacterium tuberculosis has approximately eggshell-coloured colonies, while Mycobacterium bovis has almost translucent to grey-white colonies. Taxonomically, the genus "Myobacterium" contains about 95 different species: M. tuberculosis, M. bovis, M. africanum, M. microti, M. canetti; furthermore M. leprae and ubiquitous mycobacteria.

About one third of the world population is infected with the tubercle bacillus. However, tuberculosis bacteria (TB, Mycobacterium tuberculosis complex) as the pathogen of pneumonia are rather rare. After an initial infection with the mycobacterium tuberculosis, post-primary tuberculosis occurs in approx. 5% in the following 2 years and also in 5% in the course of further life. Tuberculosis is the seventh most frequent cause of death worldwide, pneumonia (independent of the pathogen) is the third most frequent cause of death.

Outbreak of post-primary tuberculosis after initial infection with mycobacterium tuberculosis (in industrialised countries often affects elderly people and immunocompromised persons) can lead to cheesy pneumonia in the further course of the disease.

Symptoms:

• recurrent fever attacks, sometimes only subfebrile temperatures (50%)
• Night sweat (50%)
• productive cough (up to 65%)
• Hoarseness
• general weakness with a pronounced feeling of illness
• Weight loss
• Dyspnea
• Hemoptoe (25%)

Tuberculous pneumonia usually manifests itself as a fulminant pneumonia (segmental or lobar pneumonia) and cannot be clinically distinguished from pneumonia caused by other bacteria. For this reason, every change in the tip of the lung (S1, S2, S6) indicates a tuberculous etiology until the opposite is proven. Similarly, in patients with therapy-resistant pneumonia, tuberculosis can be ruled out as the cause. Since co-infections with tuberculosis and HIV/AIDS have increased in recent years, testing for a possible HIV infection should be carried out at the same time.

X-ray: Typical picture is an upper lobe infiltrate with cavern formation. However, since normal findings also occur, it is always advisable to have a computer tomography performed in case of doubt.

The laboratory findings are often inconspicuous. CRP and procalcitonin increase only slightly in relation to normal bacterial pneumonia. In the further course of the disease, normochromic, normocytic anaemia, hypalbuminaemia, leucocytosis and hypergammaglobulinaemia may occur.

Granulomatous inflammation with central, partly confluent (cheesy) necrosis.

The diagnosis is confirmed only by the detection of Mycobacterium tuberculosis. For this purpose, the following are suitable for both the smear and the establishment of a mycobacterial culture

• Morning sputum (possibly as provoked sputum after inhalation of 10% saline solution)
• bronchial secretion obtained by bronchoscopy
• Bronchial lavage (BALF)
• Fasting gastric juice

Three consecutive samples should always be examined, since light microscopic detection is only possible at germ counts of >10,000 per ml, which corresponds to a sensitivity of 40% - 60%. Since mycobacteria grow only slowly, it takes about 4 - 6 weeks before growth is visible in the culture. In modern laboratories, molecular biological detection methods are therefore preferred nowadays, by which bacteriological detection is already available after 2-3 weeks.

Note: Due to their ability to not release certain dyes even by acid and alcohol treatment, tuberculosis bacteria are also called acid-resistant rods or acid-resistant bacteria.

Caution: Do not preserve the tissue material intended for culture in formalin.

pneumonia of other genesis, bronchial carcinoma, mycosis of the lung

If tuberculous etiology is detected, there is an indication for antituberculosis therapy.

If a pleural effusion exists, an initial pleural drainage is recommended to prevent the formation of a rind.

The drug treatment of tuberculous pneumonia corresponds to the treatment of pulmonary tuberculosis and is always carried out with a combination of drugs. For this purpose, there are 4 main substances available as 1st choice agents: isoniazid, rifampicin, pyrazinamide and ethambutol. 2nd choice agent is recently - according to the WHO - streptomycin, as it cannot be administered orally and is no longer used in several countries for the treatment of uncomplicated tuberculosis.

The following dosage is recommended for daily administration:

• Isoniazid (INH) 5 mg/kg KW, max. 300 mg
• Rifampicin (RMP) 10 mg/kg KW, max 600 mg
• Pyrazinamide (PZA) 25 mg/kg KW, max 2500 mg
• Ethambutol (EMB)15 mg/kg KW, max. 1600 mg

A standard short therapy for adults is a 6-month chemotherapy. In the first 2 months, the so-called initial phase, a combination of INH, RMP, PZA and EMB is treated.

In the following 4-month stabilization phase, treatment is continued with a combination of INH and RMP.

The drugs should be administered orally 1 x / d as a single dose. .

In some countries, intermittent drug administration with 3 x weekly intake is practised during the stabilisation phase. This procedure is not recommended in Germany, as the maximum therapeutic safety is only given if the drugs are taken daily.

If there are any doubts about the regular intake of the drugs, the intake must be constantly monitored.

The success of the therapy should be checked regularly once a month, including the organs that are at risk from taking the medication. These include:

• Liver function with INH, RMP, PZA (additive effect!)
• ophthalmological controls in case of EMB
• Renal function with aminoglycosides
• Check audiogram for aminoglycosides
• Blood glucose monitoring with additional administration of cortisone (see above)

The patient's body weight should also be checked regularly.

Negative cultures are to be expected in more than 80% of patients after 2 months of combination therapy.

The course of the cheesy pneumonia depends on the course of the tuberculosis (s.d.) Prophylaxis: An active BCG vaccine from an attenuated M. Bovis strain has been available since 1921. However, the RKI no longer recommends this vaccine since 1998:

• low incidence of Tbc in Germany
• not safely effective (according to studies effectiveness between 80% and completely ineffective).
• AAW

With immunocompetent and sufficient therapy, healing occurs with pronounced scarring and intrapulmonary distortion.

If the immune system is poorly defended, transition to a sepsis acutissima tuberculosa (Landouzy sepsis) is possible. Letality very high.

According to the IfSG §6 and §7 there is a reporting obligation for tuberculous pneumonia.

• Doctor's obligation to notify: Both the illness and death from tuberculosis requiring treatment must be notified by name, even if bacteriological proof is not available. In addition, there is an obligation to notify if treatment of tuberculosis requiring treatment is refused or discontinued.
• Obligation to report to the laboratory: The detection of acid-proof rods in sputum is subject to reporting, followed by direct pathogen detection and the result of resistance determination.

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