How do you approach biologic initiation in patients with inflammatory arthritis and repeatedly indeterminate Quantiferon?  

This is an unusual but anxiety-inducing situation. Remember that an "indeterminate" Quantiferon is not an "intermediate" Quantiferon. It's not half-positive, it's uninterpretable. The result provides absolutely no reason to be more or less concerned that the patient has lTB, latent or otherwise. I...

Indeterminate Quantiferon Gold testing can result from corticosteroid exposure in the time preceding the blood draw. There is good reason to check the steroid exposure history and ensure a steroid-free period of at least a month before making a decision about tuberculosis exposure. Alternatively, a ...

The T-spot test, similar to the in tube quantiferon assays, are all interferon-g release assays. They are able to utilize specific antigens such as ESAT-6 and CF-10 that are not represented in BCG, giving it that advantage in terms of specificity. But immunosuppressants such as glucocorticoids or an...

Also, don't forget if the patient is on HCQ that can affect the assay and hence results as another confounder.

Generally tend to treat, depending on specific immunosuppressive regimen, epidemiological likelihood of TB exposure, and tolerance of TB regimen (more likely to treat if regimen clinically and chemically well tolerated).