Tubercalosis Flashcards
Risk of reactivation TB is significantly……… (6- to 50-fold) in chronic kidney disease (CKD) due to impairments in cell-mediated immunity (CMI),
increased
Younger patients with active pulmonary TB frequently have…………
In contrast, older patients such as this one often have nonspecific symptoms such as weeks or months of…………… . Mild, productive cough may occur, particularly in the mornings (overnight pooling of secretions).
Lymphadenopathy, particularly hilar (seen on this patient’s x-ray) and cervical (………), is common.
fever and cough. , fatigue, anorexia, muscle wasting, and weight loss ,
reflecting lymphatic spread increased
hypergammaglobulinemia (eg, elevated total protein in this patient): reflecting the
heterogeneous antibody response against M tuberculosis
hypoalbuminemia (late finding, particularly in the elderly): possibly due to………………… ; in addition, malnutrition often coexists with TB,
compounding hypoalbuminemia.
inflammatory cytokines stimulating production of acute phase reactants at the expense of albumin
……………are classic, although older individuals frequently have multifocal radiographic infiltrates.
Upper lobe cavitation and hilar lymphadenopathy ,
Pulmonary tuberculosis is common in older individuals with comorbidities (eg, renal failure) due to………… .
waning cell-mediated immunity
Diagnostic tests for pulmonary tuberculosis
AFB smear microscopy
Nucleic acid amplification
Sputum culture
Cannot differentiate TB from non-TB mycobacteria
AFB smear
microscopy
Low sensitivity because high burden (>10,000/ml) of organisms required in sample
AFB smear
microscopy
Low cost & rapid (minutes to hours)
AFB smear
microscopy
Can differentiate TB from non-TB mycobacteria
NAAT
Gold standard, quantitative & allows for drug sensitivity testing but Slow: takes 3-8 weeks
Sputum culture
chronic cough, fever, weight loss, cavitary upper lobe lesion, lymphadenopathy, and employment history (prison setting) raise strong suspicion for …………
active pulmonary tuberculosis (TB).
culture results are often unavailable for ……… weeks due to the slow replication rate of the organism.
> 4
sensitivity of a single sample is low (-50%).
acid-fast bacillus (AFB) stain
TB cannot be ruled out with one negative AFB sputum stain. However, sensitivity is increased to - 85% by …………
taking 3 samples 8-24 hours apart
results take 24-48 hours.
NAAT
Tuberculin skin testing (TST) is used to
identify asymptomatic patients with prior exposure to Mycobacterium tuberculosis and latent tuberculosis ( TB) infection.
Isonized INH-induced peripheral neuropathy is caused by
pyridoxine (vitamin B6) deficiency
Which patient mostly susceptible to have pyridoxine deficiency
malnourishment, pregnancy,
or certain comorbid illnesses (eg, diabetes mellitus
Those at high risk for pyridoxine deficiency (such as this patient with diabetes mellitus) should be given
prophylactic pyridoxine supplementation
while on INH.
Patients with HIV have a much………… risk of reactivation tuberculosis than the general population.
higher
Approximately 10°/o-20% of patients on isoniazid will develop…………… within first few weeks of treatment. This hepatic injury is typically self-limited and will resolve without inteN ention.
mild aminotransferase elevation
Which patients have PPO/TST induration >=5 mm
• HIV-positive patients
• Recent contacts of known TB case
• Nodular or fibrotic changes on chest x-ray consistent with previously healed TB
• Organ transplant recipients & other immunosuppressed patients
Which patients have PPO/TST induration >=10 mm
• Recent immigrants ( <5 years) from TB-endemic areas
• Injection drug users
• Residents & employees of high-risk settings ( eg, prisons, nursing homes, hospitals, homeless shelters)
• Mycobacteriology laboratory personnel
• Higher risk for TB reactivation (eg, diabetes, leukemia, end-stage renal disease, chronic malabsorption
syndromes)
• Children age <4, or those exposed to adults in high-risk categories
