daily q/a - happy_studying

[ArchivalUser]

1.A 63 year old man undergoes annual screening for tuberculosis . the patient is a physician and this screening is required for maintaining his hospital appointment.his medical hx is significant for bladder cancer that was treated with bacillus calmitte-guerie. there is no current evidence of active bladder cancer on f/u cystoscopy and he has no respiratoy or systemic symptoms.on p/e vitals signs are normal and remaining physical examination including cardiopulmonary exam are normal.
which of the following is the most appropriate next step in management ?
a.chest xray
b.interferon gamma release assay
c.tuberculin skin test
d.two step tuberculin skin testing

[ArchivalUser]

B) IF gamma release assay..not sure...I thought may be he il be false positive for Tuberculin test as he took BCG before...Thank you for your daily questions...

[ArchivalUser]

I also found this just now on Uptodate.com..

Because IGRAs are not affected by Bacille Calmette-Guérin (BCG) vaccination status, IGRAs are useful for evaluation of Latent TB infection in BCG-vaccinated individuals, particularly in settings where BCG vaccination is administered after infancy or multiple (booster) BCG vaccinations are given. In contrast, the specificity of tuberculin skin test (TST) varies depending on timing of BCG and whether repeated (booster) vaccinations are given.

IGRAs cannot distinguish between latent infection and active tuberculosis (TB) disease and should not be used for diagnosis of active TB, which is a microbiological diagnosis. A positive IGRA result may not necessarily indicate active TB, and a negative IGRA result may not rule out active TB .

So guessing B to be correct...Thank you

[ArchivalUser]

Ans is C- Tuberculin skin test.
If pt had BCG vaccine before, tuberculin test can comeback + (or may be a FP) in this case you do A- CXR.


Thank you!

[ArchivalUser]

Thanks guys for taking the time to reply!!
@snoopy - u are correct (:
Ans: In this physician who has a h/o bladder cancer treated with BCG, tuberculosis screening using interferon-gamma-release assay (IGRA) is preferred.
Either an IGRA or tuberculin skin test (TST) can be used to diagnose tb, although neither can distinguish between latent and active disease!!
However, an IGRA is preferred for two groups of patients:
-those who have received BGC as a vaccine or as a cancer therapy
-those who are unlikely to return for interpretation of the TST.
Conversely, TST is preferred for testing children who are younger than 5 years of age!!

Take home message--- the interferon-gamma-release assay is preferred over tuberculin skin test for tb screening when patients have received BCG either as a vaccine or as cancer therapy!!
Source:MKSAP 16

Thank you guys!!

[ArchivalUser]

hey Happy studying i was waiting for your answer.:-)..Thank you..

[ArchivalUser]

I Got it. GJ

Thank you guys!